Introduction to Hydrocarbons IndustryThe Oil Chain

Hydrocarbons life -cycleRepresent all those activities regarding petroleum compound (both liquid and gaseous) from their exploration to their distribution and use.It can be divided into two different stages:

Petroleum definitionIt is a complex MIXTURE OF HYDROCARBONS with small amounts of other chemical compounds; its elementary composition is:

C and H elements (97%)

S, N, O elements (less than 3%)

C: carbon; H: hydrogen; S: sulfur; N: nitrogen; O: oxygen

Hydrogen Carbon

Hydrocarbons Structures

Hydrocarbon

Hydrocarbons origin Carbon Cycle

Carbon is the basis of all organic substances, from fossil fuels to human cells. On Earth, carbon is continually on the move cycling through living things, the land, ocean, atmosphere. Out of this cycle dead organic material buried and under increasing conditions of temperature and pressure may turn into fossil fuelsWhen humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide.

Hydrocarbons origin

Hydrocarbons MigrationPrimary migration: expulsion from a source rock towads more permeable rocksSecondary migration: the movement of hydrocarbons inside a permeable rocks

Hydrocarbon accoumulation: Reservoir

A Reservoir is a formation that contains hydrocarbons. Reservoir has a distinctive shape, or configuration, that prevents the escape of hydrocarbons that migrate into it

Reservoir Rock

A pore is a small open space

Connected pores give a rock permeability

This subsurface body of rock has sufficient porosity and permeability to store and transmit fluids

Hydrocarbons life -cycleRepresent all those activities regarding petroleum compound (both liquid and gaseous) from their exploration to their distribution and use.It can be divided into two different stages:

ExplorationLand and offshore seismic survey works on the principle of the time it takes for reflected sound waves to travel through matter (rock) of varying densities

Well Drilling Land Drilling RigThe well is created by drilling a hole into the earth with a drilling rig which rotates a drill string with a bit attached

After the hole is drilled, sections of steel tubing known as casing is placed in the hole to provide structural integrity

A circulation system pumps drilling mud (mixture of water, clay, weighting material and chemicals) to lift rock cuttings from the drill bit to the surface

Well Drilling Offshore Drilling RigsPermanent rigs: built once large deposits of hydrocarbons have been found.Moveable rigs: can be moved from place to place, allowing for drilling in multiple locations. Often used for exploratory purposes.

A Fixed Rig

B Jack up

C Semisubmersible

D Drilling Ship

Offshore Fixed Rig

Expensive, for economically viable reservoirs

For not excessively water depht

Multiple well heads and adjustable parts to extract oil from the surrounding area

Jack up Suitable for shallow waters

Towed onto location with its legs up and the barge section floating on the water

Upon arrival at the drilling location, the legs are jacked down onto the seafloor

Raised above the water to a predetermined height so that wave, tidal and current loading acts only on the legs

Semisubmersible Advantage of submerging most of the area of components in contact with the sea and minimizing loading from waves and wind

Can operate in a wide range of water depths, including deep water

Usually anchored

Drilling Ship Susceptible to sea motions

Capable of operating in deep water (over 2000 meters)

Usually anchored

Well LoggingWell logging is the practice of making a detailed record (log) of physical parameters of the rock formations drilled by the well (resistivity, density, hydrogen index, natural radioactivity, temperature, acoustic features, etc.).

It is widely used in all the phases of the Hydrocarbons Exploration and Production process:

while drilling; at the end of the drilling phase; during the productive phases of the wells.

Production linerIntermediate casingSurface casingCellarGround levelWell-headConsists of a series of metal tubes installed in the freshly drilled hole in order to: - strengthen the sides of the well hole. - ensure that no oil or natural gas seeps out of the well hole as it is brought to the surface. - keep other fluids or gases from seeping into the formation through the wellWell Casing

Completing a Well

Is the process of making a well ready for production

Consists of a number of steps:

Completion

Installing the wellhead

Installing lifting equipment or treating the well

CompletionThe goal of these operations is to optimize the flow of the reservoir fluids into the well bore, up through the producing string, and into the surface collection system.

WellheadThe primary role of the wellhead is to hold the casing and the production tubing.

On top of the wellhead lies the tubing hanger, from which the production tubing is run.

The christmas tree sits on top of the tubing hanger.

Christmas TreeThe set of valves, spools and fittings connected to the top of a well to direct and control the flow of formation fluids from the well

Oil and Gas ProcessingTreatments carried out are conducted on well area, in order to allow the delivering to the treatment plant and on treatment plants, whose function is to further separate and treat oil & gas.

Pretreatments Water/oil/gas separation Gas heating or inhibition to avoid hydrate formation

Final treatments Gas dehydration, sweetening and compression Oil desalting, dehydration, desulphurisation and fractionation

Oil and Gas Plants Utilities Electric energy production

Fuel gas treatment

Instruments air treatments

Steam production

Waters treatment for industrial and civil usage

Fire-fighting network

Flares system

Water disposal

Cathodic protection

ChemicalsFirefightingSystemWell AreaGatheRing Gas Plant Production Facilities Block DiagramPlant InletTreatmentMeasureDeliverCompressionEffluent

ChemicalsHydrate InhibitionCorrosion PreventionFirefighting SystemWater, Foam, Powder,CO2 ExtinguishersWell AreaWell HeadsHeatersTest SeparatorPlatformsGathering SystemFlow-linesPipe-linesSea-linesGas Pretreatments and Gathering System

Gas Plant TreatmentsPlant InletSlug-CatcherPig TrapsTreatmentSeparationDehydrationSweeteningMeasureDeliver

Block diagram of a typical oil-producing facility

Oil Centre Block Diagram

Hydrocarbons life -cycleRepresent all those activities regarding petroleum compound (both liquid and gaseous) from their exploration to their distribution and use.It can be divided into two different stages:

Oil and gas transportationOIL TANKERSPIPELINE

Downstream Activities: RefiningA refinery breaks down crude oil into various components which then are selectively changed into new products.

Four basic kind of process:Separation Structure rearrangementCrackingTreatments

Refining Typical ProcessesSeparation processesDesaltingAtmospheric DistillationVacuum DistillationSolvent Deasphalting

Structure rearrangement processesCatalytic ReformingIsomerizationAlkylation

Refining Typical ProcessesTreatmentHydrotreatment/ Hydrofinishing

Cracking processesVisbreaking/ Thermal crackingCokingCatalytic cracking (FCC/RCC)Hydrocracking- Distillate hydrocracking- Residue Hydrocracking

Atmospheric DistillationOil is piped through hot furnaces. The resulting liquids and vapors are discharged into distillation tower.

Inside the tower, the liquids and vapors separate into components or fractions according to weight and boiling point.

Products from Crude oilPetroleum gas: used for heating, cooking, making plastics. Commonly known by the names methane, ethane, propane, butane; boiling range less than 40 C. Often liquefied under pressure to create LPG (liquefied petroleum gas).Naphtha: intermediate that will be further processed to make chemicals or gasoline; boiling range 60 to 100 C. Gasoline: motor fuel; boiling range 40 to 205 C. Kerosene: fuel for jet engines and tractors; starting material for making other products; boiling range 175 to 325 C. Gasoil or Diesel distillate: used for diesel fuel and heating oil; starting material for making other products; boiling range 250 to 350 C. Lubricating oil: used for motor oil, grease, other lubricants; boiling range 350to 550 C. Heavy gasoil or Fuel oil: used for industrial fuel; starting material for making other products; boiling range 350 to 600 C. Residuals: coke, asphalt, tar, waxes; starting material for making other products; boiling range greater than 600 C.

Products Distribution in Crude Oil

Product distribution in crude oil does not match with product demand distribution

Refined Products Demand

Hydroskimming and Conversion RefineriesHydroskimming Refinery:A refinery which uses only limited processes to produce basic fuels (gas, LPG, motor gasoline, distillates) No upgrading of heavy residual oils to lighter products.Usually processing of higher cost light crude feeds to limit the production of heavy fuel oils

Conversion Refinery:A refinery which has more complex processes to convert heavy oil fractions to more valuable lighter productsLight product upgrading processes to increase quality of produced gasolineProduct treatment facilities to remove sulphurand other contaminantsUsually processing of heavy, lower quality crudes or crude blends.

Simple Refinery

Conversion Refinery

Refined Products Distribution

LPG (Liquified Petroleum Gas)

Highly volatile hydrocarbon liquid stored under pressureMainly constituted by propane and butanes coming from primary distillation and from light ends of conversion processesIts main uses are in the heating and automotive fields.Main specs (from EN 589): motor octane number, MON 89 minimum sulphur content, 50 ppm maximum RVP at 40C, 1550 kPa maximum

Gasoline Blending and SpecsMain gasoline quality specs from EN228

Jet Fuel

Used in aviation both for civil and military applicationQuality must be homogeneous on an international basis due to long distance application Jet A-1 (JP-8) is the main productMain spec for Jet A1 fixed by IATA (International Aviation Transport Association)

Main Jet A1 Def Stan 91-91/3 and ASTM D1655-99

Gasoil or Diesel specs and blending

Main gasoil quality specs from EN590

Separation Processes

DesaltingThe main function of the Desalter is to remove salt and water form the crude oil before it reaches any of the major unit operations. The Desalter removes contaminants from crude oil by first emulsifying the crude oil with chemicals and wash water to promote thorough contact of the water and oil. After the oil has been washed and mixed as an emulsion of oil and water, demulsifying chemicals are then added and electrostatic field sare used to break the emulsion.

DistillationThe ADU (Atmospheric Distillation Unit) separates most of the lighter end products such as gases, gasoline, naphtha, kerosene, and gasoil from the crude oil.

The VDU (Vacuum Distillation Unit) takes the residuum from the ADU (Atmospheric Distillation Unit) and separates the heavier end products such as light vacuum gas oil, heavy vacuum distillate, slop wax and residue.

Solvent DeasphaltingSeparation process in which residue is separated by molecular weight (density), instead of by boiling pointSolvent Deasphalting process produces a low-contaminant deasphalted oil (DAO) rich in paraffinic type molecules. These fractions can then be further processed in conventional conversion units such as an FCC unit or hydrocracking unit.The pitch product contains the majority of the residues contaminants (metals, asphaltenes, Conradson carbon) and is rich in aromatic compounds and asphaltenes.

Treatment Processes

HydrotreatingThe products from the Crude Units and the feeds to other units contain some natural impurities, such as sulfur and nitrogen and other contaminants. Using the Hydrotreating process these impurities can be removed to reduce pollution when finished fuels (gasoline, diesel, fuel oils) are used. Hydrofinishing is used to modify also other properties (i.e. aromatic content) Heavier oils, high in sulfur and nitrogen, have also to be treated before downstream catalytic conversion processes. Hydrotreating (Hydrodesulphurization & Hydrodenitrogenation) are catalytic processes using H2 to perform a very mild hydrogenation of S and N2 in hydrocarbons. S and N2 are converted to H2S and NH3.

Structure Rearrangement Processes

Catalytic ReformingOctane rating is a key measurement of how well a gasoline performs in an automobile engine. Much of the gasoline that comes from the Crude Units or from the Cracking Units does not have enough octane to burn well in cars. The gasoline process streams in the refinery that have a fairly low octane rating are sent to a Reforming Unit where their octane levels are boosted. Catalytic reformate furnishes approximately 40% of the blending components to produce gasoline. Cat reforming is a primary source for benzene, toluene and xylenes(BTX).

C5/C6 IsomerizationIn chemistry isomerisation is the process by which one molecule is transformation into another molecule which has exactly the same atoms, but wherein these atoms are rearranged e.g. A-B-C B-A-C (these related molecules are known as isomers)

Isomerization converts straight-chain paraffins n-pentane and n-hexane into their respective branched-chain isoparaffins having of substantially higher octane number. n-pentane (RON 62) iso-pentane (RON 92)n-hexanes (RON 25) iso-hexanes (RON 75)

AlkilationIn chemistry isomerisation is the process by which one molecule is transformation into another molecule which has exactly the same atoms, but wherein these atoms are rearranged e.g. A-B-C B-A-C (these related molecules are known as isomers)

Isomerization converts straight-chain paraffins n-pentane and n-hexane into their respective branched-chain isoparaffins having of substantially higher octane number. n-pentane (RON 62) iso-pentane (RON 92)n-hexanes (RON 25) iso-hexanes (RON 75)

Cracking Processes

Types of CrackingThermal Crackingyou heat large hydrocarbons at high temperatures (sometimes high pressures as well) until they break apart. Steam: high temperature steam (816C) is used to break ethane, butane and naphtha into ethylene and benzene which are used to manufacture chemicals.Visbreaking: residual from the distillation tower is heated (482 C), cooled with gas oil and rapidly burned (flashed) in a distillation tower. This process reduces the viscosity of heavy weight oils and produces tar.Coking: residual from the distillation tower is heated to temperatures above 482C until it cracks into heavy oil, gasoline and naphtha. When the process is done, a heavy, almost pure carbon residue is left (coke). The coke is cleaned from the cokers and sold.

Types of Cracking

Catalytic Crackinguses a catalyst to speed up the cracking reaction. Catalysts include zeolite, aluminium hydrosilicate, bauxite and silica-alumina.Fluid catalytic cracking: a hot, fluid catalyst cracks heavy gas oil into diesel oils and gasoline. Hydrocracking: similar to fluid catalytic cracking, but uses a different catalyst, lower temperatures, higher pressure, and hydrogen gas. It takes heavy oil and cracks it into gasoline and kerosene (jet fuel). After the hydrocarbons are cracked into smaller hydrocarbons, the products go through another fractional distillation column to separate them.

Residue Hydrocracking The residue is the crude oil fraction that doesnt distille under vacuum conditionsThe residues can be classified in:Atmospheric residue (B.P. 350/370+ or 410+C)Vacuum residue (B.P. 500-550+)

The crude oil can contain 10-50% (even more) of vacuum residue

Residue Hydrocracking:Converts the residue heavy MW molecules into distillateIncreases the H/C of the productRemoves heteroatoms (in particulars: S, N and metals)

Maintenance

Maintenance DefinitionMaintenance is a combination of technical and administrative actions, including supervisory actions, whose purpose is to maintain and/or restore an item to enable it to work properly

Basic Function of MaintenanceThe function of the maintenance system is:

to guarantee the running of the production plant

to minimize maintenance costs

Preventive Maintenance

Corrective Maintenance

Extraordinary Maintenance

Reliability centred maintenance

Minor Improvements

Plant Maintenance Typologies

Energy Industry Scenarios

Operating Cycle In Energy Industry (Eni Example)

The main oil companies in the world (2004) Classification criteria SUPERMAJORIt includes three companies (Exxon-Mobil, BP, Shell) with reserves higher than 15 Billions of boe and a production that is greater than 3 billions of boe/dayMAJOR INTEGRATEDIt includes five companies (Chevron-Texaco, Total, Conoco-Phillips, Eni, Repsol-YPF) With reserves between 3 15 billions of boe and production ranging from 1 to 3 millions of boe/g.LARGE INDIPENDENTIt includes 4 companies (Anadarko, Occidental, Burlington, Unocal) with reserves between 1,8 3 billions of boe and production ranging from 0,4 e 1 million of boe/g; Their activity is .concentrated in the North American

The main oil companies in the world Oil reserves The Middle East has 66% of the word oil reserves. The first 12 international oil companies (Exxon-Mobil, BP Shell, Chevron Texaco, Total, Conoco-Philips, Eni, Repsol-YPF, Anadarko, Occidental, Burlington, Unocal) hold reserves of around 6% of the world total. If we compare these data, we can understand the strategic importance of the Middle East.

Hydrocarbon production (thousand boe/day)2001SUPERMAJORMAJOR INTEGRATED

2001SUPERMAJORMAJOR INTEGRATEDProved hydrocarbon reserves (billion boe)MAJOR INTEGRATED

Hydrocarbons production growthCAGR objectiveExxonMobil0,3%Shell-4,3%BP10,8%ChevronTexaco-6,1%Total2,1%ConocoPhillips-0,6%Eni5% 2004-20083% 2004-20103,5-3,8 Mboe/d 2005-20063 Mboe/d al 20084% 2004-20105% 2004-2006>5% 2004-20084,0%2004Carried out

GlossaryAliphatic: See alkane.Alkane: Any hydrocarbon molecule with the maximum ratio of hydrogen to carbon. The general formula for alkanes is CnH2n+2, where n is 1, 2, 3, etc.Alkanes: Hydrocarbon molecules with the maximum ratio of hydrogen to carbon. The general formula for alkanes is CnH2n+2, where n is 1, 2, 3, etc.Alkylation: Processes that combine small molecules in pairs to make a larger molecule; butane alkylation uses strong acid catalysts (sulfuric or hydrofluoric acid) to combine isobutene with isobutane, producing isooctane.Alumina: Aluminum Oxide, Al2O3. Exists in a variety of forms, many with high surface areas. Aluminas are very important catalyst supports and catalyst components

GlossaryAromatic: A large family of hydrocarbon compounds based on the benzene structure. Chemists link the name aromatic to the exceptional stability that derives from the benzene structure; see Benzene.Asphaltenes: A class of organic materials defined by their insolubility in pentane or heptane. Asphaltenes are generally polar molecules, rich in S, N, O, and organically bound Ni and V. The vast majority of asphaltenes distill at temperatures above about 1000 F (540 C). They are an important component of asphalt.Boiling Point Range: A convenient way of describing a petroleum fraction is to measure the lowest and highest temperature at which some of the molecules in the fraction will distill. See Carbon Number.Cap Rock: Impervious layer which overlies a reservoir rock preventing hydrocarbons escaping.

GlossaryCarbon Dioxide (CO2): Colourless, odourless, and slightly acid-tasting gas, sometimes-called carbonic acid gas, molecule of which consists of one atom of carbon joined to two atoms of oxygen.Carbon Number: A way of describing the size of hydrocarbons in terms of the total number of carbons in the molecule. Boiling points of hydrocarbons generally increase with carbon number.Casing: Steel lining used to exclude unwanted fluids; control well pressures; support sides of well bore.Catalyst: Any substance that changes the rate of a reaction without itself being changed in the reaction; catalysts can be solids, liquids or gases, and they may be individual molecules that are dissolved in a liquid containing the reacting molecules. The most common industrial catalysts are solids used in treating feeds that are liquids or gases.Coke: In catalysis, refers to a carbon-rich deposit that can form on the surface, often blocking access to active sites.

GlossaryContinuous Regeneration System: Any process step that treats catalyst removed from a reactor to restore its activity (regeneration) and return it to the reactor.Cracking: A general term covering any of a variety of reactions and processes that convert high boiling fractions to more valuable lower boiling fractions. Desulfurization: Any process or process step that results in removal of sulfur from organic molecules.Drill Bit: Located at end of drill-string cutting head is generally designed with three cone-shaped wheels tipped with hardenedteeth.Drilling Mud/Fluid: Mixture of base substance and additives usedto lubricate drill bit and to counter act natural pressure information. Drilling mud provides circulation, flushing rock cuttingsfrom bottom of well bore to surface.

GlossaryEndothermic: Reactions that proceed with absorption of enthalpy (heat energy) are termed endothermic; see exothermic.Exothermic: Reactions that proceed with release of enthalpy (heat energy) are termed exothermic; see endothermic.FCC: Fluid catalytic cracking. A process for converting high boiling gas oils to lighter liquids, primarily gasoline range naphtha and diesel range gas oils. The most widely practiced refinery conversion process.Fixed-Bed Catalyst: Any catalyst used in a reactor where the catalyst fills the reactor and remains motionless (fixed) and the gas and/or liquid feed mixtures flows past. The fluid flows through the void spaces between catalyst particles.

GlossaryFluid-Bed Catalyst: Any catalyst used in a fluidized bed. When gas is allowed to flow upward through container filled with fine powder at a sufficient velocity, the gas-solid mix exhibits the properties of a boiling liquid. Catalysis under these conditions can be very efficient because of the thorough mixing. At higher gas velocities, the solids may be carried out of the bed and upward through the container. Such systems are called transport or riser reactors.Gas Oil: General term describing any distillable refinery stream boiling above about 350 F. Diesel, turbine, and jet fuels are blended from gas oils. Higher boiling gas oils are called heavy.HDN: See Hydrodenitrogenation.HDS: See Hydrodesulfurization.Hydrocarbons: Family of organic compounds, composed entirely of carbon and hydrogen (for example, coal, petroleum and natural gas).

GlossaryHydrocracking: Process, or family of processes, combining hydrogenation of olefins and aromatics with catalytic cracking. Hydrodenitrogenation: Hydrotreating processes that remove nitrogen from feeds; these are usually also effective for hydrodesulfurization. See Hydrotreating.Hydrodesulfurization: Hydrotreating processes that remove sulfur from feeds; these are usually not also effective for hydrodesulfurization. See Hydrotreating.Hydrotreating Catalysts: Catalysts that operate in an hydrogen environment and function to remove heteroatoms (S, N, O, Ni, V, etc.) and add hydrogen to olefins and aromatics.Isomer: When two molecules have the same elemental composition but different structures, they are said to be isomers.

GlossaryIsomerization: The process of changing a molecule into one or more of its isomeric forms. See Isomer.LCO: Light cycle oil. A fraction of FCC product liquid distilling between about 400 F and about 700 F.Liquefied Petroleum Gas: Generally, any light hydrocarbon fuel that must be compressed to keep it from boiling away. (LPG) Commercial LPG usually contains mixtures of propane (C3H8) and butane (C4H10).Molecular Sieves: Any of a variety of high surface area solids having pores roughly the size of individual molecules and thus able to adsorb smaller molecules while excluding larger ones.MTBE: Methyl-t-butyl ether, an oxygen containing fuel component used in reformulated gasoline. Commonly made from methanol (methyl alcohol) and isobutene.

GlossaryNaphtha: Any low boiling refinery stream. Gasoline is made by blending several virgin and treated naphthas. Natural Gas: A naturally occurring mixture of hydrocarbon gases often found in association with oil. Methane [CH4] is the chief constituent of most natural gas (constituting as much as 85% of some natural gases).Octane Number: Measurement of the resistance of gasoline to explosive preignition, also known as knocking. Reference is to 2,2,4-trimethylpentane (isooctane) mixtures with n-heptane, with pure isooctane defined as 100.Olefins: Hydrocarbon molecules containing carbon-carbon double bonds. The name olefin comes from roots the imply oil former. The general formula for olefins is CnH2n, where n is 1, 2, 3, etc. Olefins are not found in crude oil, but are formed during cracking reactions in many refinery processes.

GlossaryOrganic: In chemistry, refers to carbon-containing molecules. At one time, chemists believed incorrectly that such molecules could only be made by living plants and animals or by doing reactions with such molecules. Paraffins: Synonym for alkanes. The name paraffin often refers specifically to alkane molecules (isomers) having long straight chains. These are the constituents of common candle wax.Petroleum: A thick, flammable, yellow-to-black mixture of gaseous, liquid, and solid hydrocarbons that occurs naturally beneath the earth's surface.Platinum Reforming: Process for increasing the aromatic content of naphtha by passing the naphtha and hydrogen over a catalyst containing platinum supported on alumina. See Naphtha, Aromatic..

GlossaryPoison (Catalyst): Any molecule or material that tends to collect on a catalyst surface, blocking access to active sites or destroying their activitiesPromoter: Any component added to a catalyst to increase activity or selectivity. Examples are tin added to platinum reforming catalysts to improve selectivity to coke formation and chloride added to isomerization catalysts to increase activity.PSA: Pressure swing adsorption. Technique for separating gases from a mixture using adsorbents that discriminate by molecular size.Reactor: Any of a variety of containers for carrying out refining, chemical, or other similar processes. Often reactors are little more than large tanks, but they can be very sophisticated, with methods for mixing reactants and controlling temperature.Reformate: Highly aromatic naphtha made by platinum reforming. See Aromatic, Platinum Reforming.

GlossaryReforming: See Platinum Reforming, Steam Reforming.Regeneration: A general term applying to any process or step that treats are used catalyst to restore fresh activity. In an FCC Unit, specifically refers to the step where coke is removed by burning in air.Reid Vapor Pressure: A specific test measuring the presser of light molecules that evaporates from gasoline under carefully defined conditions. Gasolines are blended to have Reid Vapor Pressure (RVP) in the range 7 to 10 pounds per square inch, with variations with season and elevation to allow easy starting without excess air pollution.Residuum: General term for any refinery fraction that is left behind in a distillation. Atmospheric residuum, sometimes called long resid or atmospheric tower bottoms (ATB), is the undistilled fraction in an atmospheric pressure distillation of crude oil. Likewise, vacuum resid, short resid, or vacuum tower bottoms (VTB), is the undistilled fraction in a vacuum distillation.

GlossaryReservoir :Subsurface, porous, permeable rock formation in which hydrocarbons are present.Rig: a structure housing equipment used to extract oil from underground oil reservoirs.Riser Reactor: The cracking portion of the FCC process, essentially a hundred foot tall vertical pipe. Oil, hot catalyst, and steam are injected continuously into the bottom of the riser, and the reaction occurs as the mixture rises to the top. Residence times in risers are typically one to two seconds. Risers are one of a general class of transport reactors, where reactions occur in dilute phase as the feed mixtures pass through a pipe. See Fluid Bed Reactor.RON: Research octane number. One of two ASTM tests for octane measures RON, predicting behavior under acceleration at low speed. RON is generally higher than MON. See Octane Number.RVP: See Reid Vapor Pressure.

GlossarySaturated Hydrocarbon: A molecule containing only hydrogenand carbon and having all olefinic and aromatic double bondsremoved by addition of hydrogen.Sedimentary rock: Formed by consolidation of deposits formed bysettlement of sand, silt, and other materials.Selectivity: Many reactions can potentially occur in any real catalyst systems. Selectivity is the measure of the ability of the catalyst to promote desired reactions without affecting those that are not desired.Source rocks: Rocks containing sufficient organic substances to generate hydrocarbons.Steam Reforming: Catalytic process for converting a mixture of steam and hydrocarbon to synthesis gas, a mixture of hydrogen and carbon monoxide.

GlossaryStructural traps: Formed by Earth movements that fold rocks into suitable shapes or juxtapose reservoir and sealing rocks along faults. Traps may also form when rocks are domed over rising salt masses.Trap: Geological structure in which hydrocarbons build up to froman oil or gas field.Tubing: Piping installed in wells for production of oil and gas.Unsaturated Hydrocarbon: Any hydrocarbon containing olefinic or aromatic structures. See Olefin, Aromatic.Well: A hole bored or drilled into Earth for purpose of obtaining water, oil or gas, or other natural resources.Well bore: Hole in rock made by drill bit.Well completion: Process by which a finished well is either sealedoff or prepared for production.

GlossaryWellhead: Control equipment fitted to top of a well casing,incorporating outlets, valves, etc.Zeolite: Any of a large family of crystalline metal oxide materials characterized by the presence of extensive regular interconnected pore systems. Most are based on mixtures of aluminum and silicon oxides, while others have phosphorous and other elements as well. See Molecular Sieve.

The hydrocarbon life cycle, considered as all those activities regarding both liquid and gaseous compound from their exploration to their distribution and use, can be divided into two distinct stages: the first preceding the entire process and called Upstream, which includes exploration for new fields, their drilling and production and a second stage called downstream which include the transport (which, truth be told, some call midstream), refining, petrochemicals and distribution of the product to the end use*Each petroleum variety has a unique mix of molecules, which define its physical and chemical properties, like color and viscosity. It is usually black or dark brown (although it may be yellowish or even greenish). In the reservoir it is usually found in association with natural gas, which, being made of lighter hydrocarbons, forms a gas cap over the petroleum, and saline water, which being heavier generally floats underneath it. *In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. The classifications for hydrocarbons are as follows:Saturated hydrocarbons (alkanes) are the most simple of the hydrocarbon species and are composed entirely of single bonds and are saturated with hydrogen; they are the basis of petroleum fuels and are either found as linear or branched species of unlimited number. The general formula for saturated hydrocarbons is CnH2n+2 (assuming non-cyclic structures). Methane [1C] and ethane [2C] are gaseous at ambient temperatures and cannot be readily liquified by pressure alone. Propane [3C] is however easily liquified, and exists in 'propane bottles' mostly as a liquid. Butane [4C] is so easily liquified that it safely provides a safe, volatile fuel for small pocket lighters. Pentane [5C] is a clear liquid at room temperatureUnsaturated hydrocarbons have one or more double or triple bonds between carbon atoms. Those with one double bond are called alkenes, with the formula CnH2n (assuming non-cyclic structures). Those containing triple bonds are called alkynes, with general formula CnH2n-2. Cycloalkanes are hydrocarbons containing one or more carbon rings to which hydrogen atoms are attached. The general formula for a saturated hydrocarbon containing one ring is CnH2n Aromatic hydrocarbons, also known as arenes, are hydrocarbons that have at least one aromatic ring. Hydrocarbons can be gases (e.g. methane and propane), liquids (e.g. hexane and benzene), waxes or low melting solids (e.g. paraffin wax and naphtalene) or polymers (e.g. polyethylene, polypropylene and polystyrene).

The hydrocarbons in crude oil are mostly alkanes, cycloalcanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium.

*All living things are made of carbon. Carbon is also a part of the ocean, air, and even rocks. Because the Earth is a dynamic place, carbon does not stay still. In the atmosphere, carbon is attached to some oxygen in a gas called carbon dioxide, CO2. Plants absorb CO2 from the atmosphere during photosynthesis to make their own food and grow, and release CO2 back into the atmosphere during respiration. Another major exchange of CO2 occurs between the oceans and the atmosphere: the dissolved CO2 in the oceans is used by marine biota in photosynthesis. Dead organisms of plant and animals are microbiologically or chemically oxidized to CO2. Out of this cycle, about 0.1% of the carbon is withdrawn and buried with the sediments: Dead organic material buried and in conditions of increasing temperature and pressure may turn into fossil fuels made of carbon like coal and oil over millions of years. When humans burn fossil fuels, most of the carbon quickly enters the atmosphere as carbon dioxide (CO2). *Imagine standing on the shore of an ancient sea, millions of years ago. A look below the surface reveals that life and death occur constantly in the blue depths of the sea. Countless millions of tiny microscopic organisms eat, are eaten and die. As they die, their small remains fall as a constant rain of organic matter that accumulates in enormous quantities on the sea floor. There, the remains are mixed in with the sand that form the ocean bottom.As the countless millennia march inexorably by, layer upon layer of sediments build up. Those buried the deepest undergo a transition; they are transformed into rock. Also, another transition occurs: changed by heat, by the tremendous weight and pressure of the overlying sediments, the organic material in the rock becomes petroleum and gas.*While petroleum was being formed, cataclysmic events were occurring elsewhere. Great earthquakes opened huge cracks, or faults, in the earths crust. Layers of rock were folded upward and downward. Molten rock thrust its way upward, displacing surrounding solid beds into a variety of shapes. Vast blocks of earth were shoved upward, dropped downward or moved laterally. Earths very shape had been changed.Meanwhile, the newly born hydrocarbons lay cradled in their source rocks. But as the great weight of the overlying rocks and sediments pushed downward, the petroleum was forced out of its birthplace. It began to migrate. Seeping through cracks and fissures, oozing through minute connections between the rock grains, petroleum began a journey upward. Indeed, some of it eventually reached the surface where it collected in large pools. However, some petroleum did not reach the surface. Instead, its upward migration was stopped by an impervious or impermeable layer of rock. It lay trapped far beneath the surface*Many people believe that oil and natural gas are found in big underground caves. This is not the case. Rather, these hydrocarbons are in permeable and porous rocks such as sandstone. These rocks contain microscopic spaces, called pores, which fill with fluids. The fluids may be water, oil, or natural gas. An oil or natural-gas reservoir is more like a sponge than a bottle. Once an oil or natural-gas field has been productive for a period of time, a good portion of the hydrocarbons has been removed. The porous and permeable rock layer that contains these fluids is covered by an impermeable cap rockoften salt or shalethat does not let them pass through. Normally, oil and natural gas will tend to migrate upward through permeable rock because they are lighter than the water that is also found in such rock formations. The cap rock traps them.

*Hydrocarbons - petroleum and natural gas - are found in certain layers of rock that are usually buried deep beneath the surface of the earth.In order for a rock layer to qualify as a good source of hydrocarbons, it must meet several criteria: Good reservoir rocks have Porosity. Porosity is a measure of the openings in a rock, openings in which petroleum can exist. Even though a reservoir rock looks solid to the naked eye, a microscopic examination reveals the existence of tiny openings in the rock. These openings are called pores. Another characteristic of reservoir rock is that it must be Permeable. That is, the pores of the rock must be connected together so that hydrocarbons can move from one pore to another. Unless hydrocarbons can move and flow from pore to pore, the hydrocarbons remain locked in place and cannot flow into a well. This slide have to be used to recall the up stream activities in The hydrocarbon life cycle with specific reference to their exploration*Reservoirs are located (although nothing is certain until they are drilled and extraction starts) and analyzed by geologists using a variety of tools. Their task is to find the right conditions for an oil trap -- the right source rock, reservoir rock and entrapment. Many years ago, geologists interpreted surface features, surface rock and soil types, and perhaps some small core samples obtained by shallow drilling. Modern oil geologists also examine surface rocks and terrain, with the additional help of satellite images. However, they also use a variety of other methods to find oil. They can use sensitive gravity meters to measure tiny changes in the Earth's gravitational field that could indicate flowing oil, as well as sensitive magnetometers to measure tiny changes in the Earth's magnetic field caused by flowing oil. They can detect the smell of hydrocarbons using sensitive electronic noses called sniffers. Finally, and most commonly, they use seismology, creating shock waves that pass through hidden rock layers and interpreting the waves that are reflected back to the surface.When a prospect has been identified and evaluated and passes the oil company's selection criteria, an exploration well is drilled in an attempt to conclusively determine the presence or absence of oil or gas.The major systems of a land oil rig:Power system large diesel engines - burn diesel-fuel oil to provide the main source of power electrical generators - powered by the diesel engines to provide electrical power Mechanical system - driven by electric motors hoisting system - used for lifting heavy loadsturntable - part of the drilling apparatus Rotating equipment - used for rotary drilling swivel - large handle that holds the weight of the drill string; allows the string to rotate and makes a pressure-tight seal on the hole kelly - four- or six-sided pipe that transfers rotary motion to the drill string turntable or rotary table - drives the rotating motion using power from electric motors drill string - consists of drill pipe (connected sections of about 30 ft / 10 m) and drill collars (larger diameter, heavier pipe that fits around the drill pipe and places weight on the drill bit) drill bit(s) - end of the drill that actually cuts up the rock; comes in many shapes and materials (tungsten carbide steel, diamond) that are specialized for various drilling tasks and rock formations Casing - large-diameter concrete pipe that lines the drill hole, prevents the hole from collapsing, and allows drilling mud to circulate Circulation system - pumps drilling mud (mixture of water, clay, weighting material and chemicals, used to lift rock cuttings from the drill bit to the surface) under pressure through the kelly, rotary table, drill pipes and drill collars

With these zones safely isolated and the formation protected by the casing, the well can be drilled deeper (into potentially more-unstable and violent formations) with a smaller bit, and also cased with a smaller size casing. Modern wells often have 2-5 sets of subsequently smaller hole sizes drilled inside one another, each cemented with casing.

*There are two basic types of offshore drilling rigs: those that can be moved from place to place, allowing for drilling in multiple locations, and those rigs that are permanently placed. Moveable rigs are often used for exploratory purposes because they are much cheaper to use than permanent platforms. Once large deposits of hydrocarbons have been found, a permanent platform is built to allow their extraction.*Moveable rigs are commonly used to drill exploratory wells. In some instances, when exploratory wells find commercially viable natural gas or petroleum deposits, it is economical to build a permanent platform from which well completion, extraction, and production can occur. These large, permanent platforms are extremely expensive, however, and generally require large expected hydrocarbon deposits to be economical to construct. There are a number of different types of permanent offshore platforms, each useful for a particular depth range.

*A jack-up rig is a type of offshore oil and gas drilling platform that may stand still on the sea floor resting on a number of supporting columns. One of the most popular designs uses 3 columns.The supporting columns may be moved up and down by a hydraulic or electrical system. The whole rig can also be jacked up when the supporting columns are touching the sea floor. During transit, the platform floats on its hull and is typically towed to a new location by offshore tugs. Jackup rigs provide a platform that is more stable than a semi-submersible platform but can only be placed in relatively shallow waters.towed to the drilling site, three or four 'legs' are lowered until they rest on the sea bottom. This allows the working platform to rest above the surface of the water. Suitable for shallow waters, as extending these legs down too deeply would be impractical. These rigs are typically safer to operate, as their working platform is elevated above the water level.

*Semisubmersible rig: a particular type of floating vessel that is supported primarily on large pontoon-like structures submerged below the sea surface. The operating decks are elevated perhaps 100 or more feet above the pontoons on large steel columns. This design has the advantage of submerging most of the area of components in contact with the sea and minimizing loading from waves and wind. Semisubmersibles can operate in a wide range of water depths, including deep water. They are usually anchored with six to twelve anchors tethered by strong chains and wire cables, which are computer controlled to maintain stationkeeping. Semisubmersibles (called semisubs or simply semis) can be used for drilling, workover operations, and production platforms, depending on the equipment with which they are equipped. When fitted with a drilling package, they may be called semisubmersible drilling rigs*Drilling Ship: A maritime vessel modified to include a drilling rig and special station-keeping equipment. The vessel is typically capable of operating in deep water. A drillship must stay relatively stationary on location in the water for extended periods of time. This positioning may be accomplished with multiple anchors, dynamic propulsion or a combination of these. **The measurement versus depth or time, or both, of one or more physical quantities in or around a well. The term comes from the word "log" used in the sense of a record or a note. Wireline logs are taken downhole, transmitted through a wireline to surface and recorded there. Measurments-while-drilling (MWD) and logging-while-drilling (LWD) logs are also taken downhole. They are either transmitted to surface by mud pulses, or else recorded downhole and retrieved later when the instrument is brought to surface. Mud logs that describe samples of drilled cuttings are taken and recorded on surface. *Installing well casing is an important part of the drilling and completion process. Well casing consists of a series of metal tubes installed in the freshly drilled hole. Casing serves to strengthen the sides of the well hole, ensure that no oil or natural gas seeps out of the well hole as it is brought to the surface, and to keep other fluids or gases from seeping into the formation through the well. A good deal of planning is necessary to ensure that the proper casing for each well is installed. Types of casing used depend on the subsurface characteristics of the well, including the diameter of the well (which is dependent on the size of the drill bit used) and the pressures and temperatures experienced throughout the well. In most wells, the diameter of the well hole decreases the deeper it is drilled, leading to a type of conical shape that must be taken into account when installing casing. Once a well has been drilled, cased and logged, a decision must be made whether to complete the well or plug it.If it has been verified that commercially viable quantities of hydrocarbons are present for extraction, the well must be 'completed' to allow for the flow of petroleum or natural gas out of the formation and up to the surface. This process includes the evaluation of the pressure and temperature of the formation, and then installing the proper equipment to ensure an efficient flow of natural gas out of the well. .**In a cased-hole completion, small holes called perforations are made in the portion of the casing which passed through the production zone, to provide a path for the oil to flow from the surrounding rock into the production tubing. After a flow path is made, acids and fracturing fluids are pumped into the well to fracture or otherwise prepare and stimulate the reservoir rock to optimally produce hydrocarbons into the wellbore. Finally, the area above the reservoir section of the well is packed off inside the casing, and connected to the surface via a smaller diameter pipe called tubing. This arrangement provides a redundant barrier to leaks of hydrocarbons as well as allowing damaged sections to be replaced. Also, the smaller diameter of the tubing produces hydrocarbons at an increased velocity in order to overcome the hydrostatic effects of heavy fluids such as water.In many wells, the natural pressure of the subsurface reservoir is high enough for the oil or gas to flow to the surface. However, this is not always the case, especially in depleted fields where the pressures have been lowered by other producing wells, or in low permeability oil reservoirs. Installing a smaller diameter tubing may be enough to help the production, but artificial lift methods may also be needed. Common solutions include downhole pumps, gas lift, or surface pump jacks.

**An assembly of valves, spools, pressure gauges and chokes fitted to the wellhead of a completed well to control production. Christmas trees are available in a wide range of sizes and configurations, such as low- or high-pressure capacity and single- or multiple-completion capacity.*Production is the process of extracting oil and gas from the underground reservoir and bringing it to the surface to be separated into gases and fluids that can be sold. Production begins with a high level of production and decreases through time until the well is ultimately plugged and abandoned. This decrease in production is a natural result of the inevitable decline in original pressure within the reservoir.

*On Well area, the first gas treatments are temporary. Their aim is to prevent the hydrates formation on gas phase and theyre classified as follows:separation of free water and liquid hydrocabons from gas phase; increase in the temperature of gas above that of hydrate formation;inhibitors injection on gas to prevent hydrate formation.

**After the temporary treatments, gas is delivered to the treatment plant and then to users according to the requested specifications.The final treatment will eliminate the harmful elements from natural gas it consists in: reducing water (dehydration); reducing the content of superior hydrocarbons (adsorption); reducing the content of hydrogen sulphide and carbon dioxide (sweetening).The above-mentioned treatments are carried out by appropriate types of plants according to the composition of natural gas. Moreover, the plants are managed so as to meet the users specifications.From the wellhead, the separated gas and crude are sent, through a gathering network, to the oil and gas centre where it has the necessary processing.Gas Processing:The treatment eliminates the harmful elements from natural gas it consists in: reducing water (dehydration);reducing the content of superior hydrocarbons (adsorption);reducing the content of hydrogen sulphide and carbon dioxide (sweetening).The above-mentioned treatments are carried out by appropriate types of plants according to the composition of natural gas. Moreover, the plants are managed so as to meet the users specifications.

The crude processing in the oil/gas centre (or gathering centre), consists in separating the oil from gas and other foreign substances in order to deliver to the utilization centres (refinery, sea terminal, etc.) a product that is in accordance with the quality and safety rules.To sum up, it is necessary to further separate the oil from gas, water and then free it from any possible salts, sulphur, sand and other solid substances which are in suspension in the crude.The water effluent from the separators is conveyed to a treatment plant in which any traces of oil are removed before discharging or reinjection

The oil and gas centre includes all the equipments fit for treating, stocking and measuring the oil, gas and produced water

*The function of the plant is to separate and treat oil & gas coming from the wells.The gas is sent into the Gas Network and, therefore, it must be sweetened, removing H2S and CO2, and conditioned, controlling its hydrocarbon dew-point.The removed H2S is treated and transformed into liquid sulphur using the Claus process.Oil, after the stabilisation process in which light hydrocarbons and water are removed, is pumped to Refinery via a pipeline.*This slide have to be used to recall the downstream activities in The hydrocarbon life cycle with specific reference to their refining.

A refinery is a factory which takes a raw material (crude oil) and transforms it into fuels and other products.A refinery breaks down crude oil into various components which then are selectively changed into new products.

Crude distillation units (atmospheric and vacuum distillation) and following treatment/conversion units (isomerization, reforming, FCC, alkilation, desulphurisation, hydrocracking, visbreaking) give origin to different streams that properly blended constitute finished products.

*Crude distillation units (atmospheric and vacuum distillation) and following treatment/conversion units (isomerization, reforming, FCC, alkilation, desulphurisation, hydrocracking, visbreaking) give origin to different streams that properly blended constitute finished products.

*Crude oil, as it comes from the earth, is a mixture of hydrocarbons - compounds of hydrogen and carbon. The basic purpose of a refinery is to separate and transform these various hydrocarbon groups so that they may be used, combined or further treated to create the thousands of products made from petroleum. One of the fundamental processing units is the fractionating tower (shown at right in the drawing). Because hydrocarbons vaporize at different temperatures, the crude oil is heated and the mixture of hot vapors and liquid goes into the tower. The liquid or residual oil is drawn off at the bottom to be used as asphalt or heavy fuel. As the vapors rise, they cool, condense and are drawn off at various levels in the tower; the most volatile are drawn off as gases at the top. These "streams" are piped to other areas of the refinery, such as the catalytic cracker, reformer and alkylation unit, to be formed by various combinations of heat, pressure and chemistry into the products desired.*The petroleum industry generally classifies crude oil by the geographic location it is produced in, its API gravity (an oil industry measure of density), and by its sulfur content. Crude oil may be considered light if it has low density or heavy if it has high density; and it may be referred to as sweet if it contains relatively little sulfur or sour if it contains substantial amounts of sulfur.84% by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including gasoline, diesel, jet, heating, and other fuel oils, and liquefied petroleum gas.

Petroleum is used mostly, by volume, for producing fuel oil, diesel and gasoline (petrol), both important "primary energy" sources.

The hydroskimming (topping/refining) refinery consists of an atmospheric distillation unit for separating the crude oil and a catalytic reformer to transform the low-octane naphtha into high-octane gasoline.The most versatile refinery configuration today is known as the conversion refinery (see figure). A conversion refinery incorporates all the basic building blocks found in the hydroskimming refineries, but it also features gas oil conversion plants such as catalytic cracking and hydrocracking units, olefin conversion plants such as alkylation or polymerization units, and, frequently, coking units for sharply reducing or eliminating the production of residual fuels. Modern conversion refineries may produce two-thirds of their output as unleaded gasoline, with the balance distributed between high-quality jet fuel, LPG, low-sulfur diesel fuel, and a small quantity of petroleum coke. Many such refineries also incorporate solvent extraction processes for manufacturing lubricants and petrochemical units with which to recover high-purity propylene, benzene, toluene, and xylenes for further processing into polymers*Hydroskimming is the simplest type of refinery used in the petroleum industry A hydroskimming refinery is defined as a refinery equipped with Atmospheric Distillation, naphtha reforming and necessary treating processes. However a Hydroskimming refinery produces a surplus of fuel oil with a relatively unattractive price and demand.Most refineries therefore add vacuum distillation and catalytic cracking, which adds one more level of complexity by reducing fuel oil by conversion to light distillates and middle distillatesModern conversion refineries may produce two-thirds of their output as unleaded gasoline, with the balance distributed between high-quality jet fuel, LPG, low-sulfur diesel fuel, and a small quantity of petroleum coke. *Liquefied petroleum gas (also called LPG, GPL, LP Gas, or autogas) is a mixture of hydrocarbon gases used as a fuel in heating appliances and vehicles, and increasingly replacing chlorofluorocarbons as an aerosol propellant and a refrigerant to reduce damage to the ozone layer.

Varieties of LPG bought and sold include mixes that are primarily propane, mixes that are primarily butane, and the more common, mixes including both propane (60%) and butane (40%), depending on the seasonin winter more propane, in summer more butane. Propylene and butylenes are usually also present in small concentration. A powerful odorant, ethanethiol, is added so that leaks can be detected easily. The international standard is EN 589.

LPG is manufactured during the refining of crude oil, or extracted from oil or gas streams as they emerge from the ground.

At normal temperatures and pressures, LPG will evaporate. Because of this, LPG is supplied in pressurised steel bottles. In order to allow for thermal expansion of the contained liquid, these bottles are not filled completely; typically, they are filled to between 80% and 85% of their capacity. The ratio between the volumes of the vaporised gas and the liquefied gas varies depending on composition, pressure and temperature, but is typically around 250:1. The pressure at which LPG becomes liquid, called its vapor pressure, likewise varies depending on composition and temperature; for example, it is approximately 220 kilopascals (2.2 bar) for pure butane at 20 C (68 F), and approximately 2.2 megapascals (22 bar) for pure propane at 55 C (131 F). LPG is heavier than air, and thus will flow along floors and tend to settle in low spots, such as basements. This can cause ignition or suffocation hazards if not dealt with.

*Gasoline is produced in oil refineries. Material that is separated from crude oil via distillation, called virgin or straight-run gasoline, does not meet the required specifications for modern engines (in particular octane rating), but will form part of the blend.

The bulk of a typical gasoline consists of hydrocarbons with between 5 and 12 carbon atoms per molecule.

The various refinery streams blended together to make gasoline all have different characteristics. Some important streams are:

Reformate, produced in a catalytic reformer with a high octane rating and high aromatic content, and very low olefins (alkenes). Cat Cracked Gasoline or Cat Cracked Naphtha, produced from a catalytic cracker, with a moderate octane rating, high olefins (alkene) content, and moderate aromatics level. Here, "cat" is short for "catalytic". Hydrocrackate (Heavy, Mid, and Light), produced from a hydrocracker, with medium to low octane rating and moderate aromatic levels. Virgin or Straight-run Naphtha directly from crude oil with low octane rating, low aromatics (depending on the crude oil), some naphthenes (cycloalkanes) and no olefins (alkenes). Alkylate, produced in an alkylation unit, with a high octane rating and which is pure paraffin (alkane), mainly branched chains. Isomerate (various names) which is obtained by isomerising the pentane and hexane in light virgin naphthas to yield their higher octane isomers

Gasoline is a mixture of hydrocarbons, although some may contain significant quantities of ethanol and some may contain small quantities of additives such as methyl tert-butyl ether as anti-knock agents to increase the octane rating. The hydrocarbons consist of a mixture of n-paraffins, naphthenes, olefins and aromatics. Naphthenes, olefins and aromatics increase the octane rating of the gasoline whereas the n-paraffins have the opposite effect

VolatilityGasoline is more volatile than diesel oil, Jet-A or kerosene, not only because of the base constituents, but because of the additives that are put into it. The final control of volatility is often achieved by blending with butane. The Reid Vapor Pressure test is used to measure the volatility of gasoline. The desired volatility depends on the ambient temperature: in hotter climates, gasoline components of higher molecular weight and thus lower volatility are used. In cold climates, too little volatility results in cars failing to start. In hot climates, excessive volatility results in what is known as "vapour lock" where combustion fails to occur, because the liquid fuel has changed to a gaseous fuel in the fuel lines, rendering the fuel pump ineffective and starving the engine of fuel

Octane RatingAn important characteristic of gasoline is its octane rating, which is a measure of how resistant gasoline is to the abnormal combustion phenomenon known as detonation (also known as knocking, pinging, spark knock, and other names). Deflagration is the normal type of combustion. Octane rating is measured relative to a mixture of 2,2,4-trimethylpentane (an isomer of octane) and n-heptane*Jet fuel is a type of aviation fuel designed for use in aircraft powered by gas-turbine engines..

Jet fuel is clear to straw colored. The most common fuel is an unleaded/paraffin (kerosene) oil-based fuel classified as Jet A-1 (otherwise known as AVTUR), which is produced to an internationally standardized set of specifications. (see below).

The only other jet fuel that is commonly used in civilian turbine engine-powered aviation is called Jet B, a fuel in the naphtha-kerosene region that is used for its enhanced cold-weather performance. However, Jet B's lighter composition makes it more dangerous to handle, and it is thus restricted only to areas where its cold-weather characteristics are absolutely necessary.

Jet fuel is a mixture of a large number of different hydrocarbons, possibly as many as a thousand or more. The range of their sizes (molecular weights or carbon numbers) is restricted by the requirements for the product, for example, freezing point or smoke point. Kerosene-type jet fuel (including Jet A and Jet A-1) has a carbon number distribution between about 8 and 16 carbon numbers; wide-cut or naphtha-type jet fuel (including Jet B), between about 5 and 15 carbon numbers

*Petroleum diesel is produced from petroleum and is a hydrocarbon mixture, obtained in the fractional distillation of crude oil between 200 C and 350 C at atmospheric pressure.The density of petroleum diesel is about 0.85 kg/l (7.09 lbs/gallon) whereas petrol (gasoline) has a density of about 0.72 kg/l (6.01 lbs/gallon), about 15% less. When burnt, diesel typically releases about 38.6 MJ/l,whereas gasoline releases 34.9 MJ/l about 11% less. Diesel is generally simpler to refine from petroleum than gasoline. The price of diesel traditionally rises during colder months as demand for heating oil rises, which is refined in much the same way. Due to its higher level of pollutants, diesel must undergo additional treatments which contributes to a sometimes higher costUltra-low sulfur diesel (ULSD) is a term used to describe a standard for defining diesel fuel with substantially lowered sulfur contents.

*Desalting and dewatering of crude oil upstream of the crude distillation unit is a process operation for the removal of undesirable components from crude oil before it reaches any of the major unit operations. The main function of the Desalter is to remove salt and water form the crude oil.Other contaminants such as clay, silt, rust, and other debris also need to be removed. These can cause corrosion and fouling of downstream equipment when deposited on heat transfer surfaces. Also, there are metals that can deactivate catalysts used in the process of refining.The Desalter removes contaminants from crude oil by first emulsifying the crude oil with chemicals and wash water to promote thorough contact of the water and oil. The salts containing some of the metals that can poison catalysts are dissolved in the water phase. After the oil has been washed and mixed as an emulsion of oil and water, demulsifying chemicals are then added and electrostatic field sare used to break the emulsion.

*The various components of crude oil have different sizes, weights and boiling temperatures; so, the first step is to separate these components. Because they have different boiling temperatures, they can be separated easily by a process called fractional distillation. Fractional distillation is useful for separating a mixture of substances with narrow differences in boiling points and is the most important step in the refining process. The ADU (Atmospheric Distillation Unit) separates most of the lighter end products such as gases, gasoline, naphtha, kerosene, and gasoil from the crude oil. The bottoms of the ADU is then sent to the VDU (Vacuum Distillation Unit).

Crude oil is preheated by the bottoms feed exchanger. It is further preheated and partially vaporized in the feed furnace and passed to the atmospheric tower where it is separated into componentsA tower may contain 20 or more fractionation trays and be equipped with a top pump-around, an overhead reflux system and three side strippers (for naphtha, kerosene, and gas oil products).The VDU (Vacuum Distillation Unit) takes the residuum from the ADU (Atmospheric Distillation Unit) and separates the heavier end products such as light vacuum gas oil, heavy vacuum distillate, slop wax and residue.

Heavy crude oil is preheated by the bottoms feed exchanger, it is further preheated and partially vaporized in the feed furnaceand passes to the vacuum tower where it is separated into slop oil, vacuum gas oil, vacuum distillate, slop wax and bottoms residue.A vacuum tower may contain a combination of fractionation trays and beds. It may have side draw-offs and pump around sections for vacuum gas oil, vacuum distillate and slop wax products.

*A process used to produce asphalt is solvent deasphalting. In this extraction process, which uses propane (or hexane) as a solvent, heavy oil fractions are separated to produce heavy lubricating oil, catalytic cracking feedstock, and asphalt. *Hydrotreating technology is one of the most commonly used refinery processes, designed to remove contaminants such as sulfur, nitrogen, condensed ring aromatics, or metals. The feedstocks used in the process range from naphtha to vacuum resid, and the products in most applications are used as environmentally acceptable clean fuels. The catalytic reaction (Co and/or Ni-Mo catalysts) occurs from 370C to 415C; at higher T too much coke would form and catalyst life between regenerations would be too short.Naphtha, Jet fuel, Diesel, Gas oil, lube oil, fuel oil can be treated to remove deleterious / not valuable substances

Recent regulatory requirements to produce ultra-low-sulfur diesel (ULSD) and gasoline, have created a very dynamic market as refiners must build new or revamp their existing assets to produce the green fuels*In Reforming process hydrocarbon molecules in the feedstocks re-arranged or re-structured into high octane gasoline components. Catalyst. Noble metal (Pt and Re) on chlorinated silica or silica-alumina.Feedstock. Naphtha, typically straight-run, alternatively from thermal cracking, coking and hydrocracking, hydrotreated to remove sulfur, nitrogen, water and metal contaminants (noble metal catalyst poisons). Operating conditions. T=480-525C, P=5-35 atm depending on type or version of catalytic reforming and desired reaction severityThe composition of the feed (paraffin, olefin, naphthene and aromatic content PONA) affect yield and reformate quality.Higher is the Octane number of reformate lower is the yield and higher light ends production.The global result of reforming reactions is H2 production.The overall net H2 production ranges from 50 to 200 m3(at 0C and 1 atm) per m3 of liquid naphtha feed Some H2 is recycled to sustain reformer reactor pressure and to reduce coke formation Most of the hydrogen is used throughout the refinery in cracking (hydrocracking) and treating (hydrotreating) unitsSemi-rigenerative catalytic reformer (SRR): typically constituted of three reactors, each with a fixed bed of catalyst, and all of the catalyst is regenerated in situ during routine catalyst regeneration which occur approximately once each 6 to 24 months. Such a unit is referred to as a Continuous catalyst regeneration reformer (CRR): characterized by continuous in-situ regeneration of part of the catalyst in a special regenerator, and by continuous addition of the regenerated catalyst to the operating reactors. Coke deposits on the catalyst cause a decline in activity, with reduction of octane number and reformate yield. The catalyst is regenerated by admitting hot air to remove the carbon from the catalyst forming CO & CO2, followed by chlorination. The high T required for regeneration cause the catalysts pores to collapse. Consequently, every 2-3 years the entire reformer must be shut down for catalyst change out.

*Since isomers may differ greatly in physical and chemical properties, isomerisation offers the possibility of converting less desirable compounds into isomers with desirable properties, in particular to convert n-paraffins into iso-paraffins, thereby increasing the octane of the hydrocarbon stream. The main fields of application of isomerisation are: ISOMERISATION of normal butane into isobutane ISOMERISATION of pentanes and hexanes into higher- branched isomers

Since branched isomers have a higher antiknock quality than the corresponding linear paraffins, this form of isomerisation is important for the production of motor fuels.At present day interest isomerisation is specially focussed on the upgrading of fractions containing C5 Pentane and C6 Hexane for use as motor gasoline components. This application has been prompted by the world drive to remove the lead additives gradually from motor gasoline in order to reduce air pollution. The octane loss caused by the removal or reduction of lead antiknock additives can be compensated for by isomerisation of pentane/hexane paraffin fraction of the light gasoline fractions.

**Cracking is the process whereby complex organic molecules such as kerogens or heavy hydrocarbons are broken down into simpler molecules (e.g. light hydrocarbons) by the breaking of carbon-carbon bonds in the precursors. The rate of cracking and the end products are strongly dependent on the temperature and presence of any catalystsThermal cracking is currently used to "upgrade" very heavy fractions ("visbreaking), or to produce light fractions or distillates or coke.Two extremes of the thermal cracking in terms of product range are represented by the high-temperature process called "steam cracking" (ca. 750 to 900 C or more) which produces valuable ethylene and other feedstocks for the petrochemical industry, and the milder-temperature delayed coking (ca. 500 C) which can produce, under the right conditions, valuable needle coke, a highly crystalline petroleum coke used in the production of electrodes for the steel and aluminium industries.

The Visbreakingprocess is a relatively mild thermal cracking, mainly used to reduce the viscosities and pour point of the vacuum residues producing stable Fuel Oils. Visbreakingis also used to:-increase cat cracker and hydrocrackerfeedstocks-produce gasoline and atmospheric gasoil.

VisbreakingRefinery production of heavy F.O. can be reduced from 20-35% and cutter stocks requirements from 20-30% by visbreaking.Long paraffinic side chains attached to aromatic rings are the primary cause of high pour points and viscosities for the residues: VB is carried out at mild conditions to optimize the cracking because if the operation is to severe the resulting product becomes unstable during storage (sludge formation). The degree of conversion is a function of the nature of residua feedstock to the visbreaker. High asphaltenecontent in the feed reduces the conversion ratio (the thermal cracking reactions affects the resin-asphalteneratio), meanwhile aromatic cutter stock permit higher conversion levels before reaching fuel stability limitations.

*Fluid catalytic cracking is a commonly used process and a modern oil refinery will typically include a cat cracker, particularly at refineries with high demand for gasoline.The gasoline produced in the FCC unit has an elevated octane rating but is less chemically stable compared to other gasoline components due to its olefinic profile. Olefins in gasoline are responsible for the formation of polymeric deposits in storage tanks, fuel ducts and injectors. The FCC LPG is an important source of C3-C4 olefins and isobutane that are essential feeds for the alkylation process and the production of polymers such as polypropylene.

Hydrocracking is a catalytic cracking process assisted by the presence of an elevated partial pressure of hydrogen gas. Similar to the hydrotreater, the function of hydrogen is the purification of the carbon stream from sulfur and nitrogen hetero-atoms.The products of this process are saturated hydrocarbons; depending on the reaction conditions (temperature, pressure, catalyst activity) these products range from ethane, LPG to heavier hydrocarbons comprising mostly of isoparaffins. Hydrocracking is normally facilitated by a bi functional catalyst that is capable of rearranging and breaking hydrocarbon chains as well as adding hydrogen to aromatics and olefins to produce naphthenes and alkanes. Increased product yields can be obtained using titanium oxide in the fermentation process.Major products from hydrocracking are jet fuel, diesel, relatively high octane rating gasoline fractions and LPG. All these products have a very low content of sulfur and contaminants

FCCmain product: LPG + naphthahigh quality naphtha (octane)low quality dieselnaphtha needs further treatment (HDS)

Hydrocrackingmain product: jet fuel + dieselhigh quality jet fuel and diesellow quality naphthanaphtha to reforming

*The conversion of residue into distillate occur mainly via thermal reactionsThe main scope of catalyst is favor the H2up-take, prevent condensation reactions, remove S, N, metalsThe reactions occurs on a catalyst in presence of HydrogenCan be applied to Atmospheric Residue and Vacuum ResidueAre High Pressure Processes (150200 barg)High Hydrogen Consumption (1025 kg H2/ton of feed)High Investment Cost (65-100 k/ton/g; hydrogen manufacturing unit included)

Main products are :Good quality FCC feed (low S and N, hydrogenated)Low sulphur and metals Fuel OilUsually diesel and naphtha products require additional treating to match automotive fuels specification

**In its wider meaning, Maintenance is the Company Function with the objective of preserving the Company Assets at the highest value, in order to ensure optimum return of investment. More specifically, means to ensure availability of Plant equipment by: -maintaining the efficiency of a machine within a predefined standard-assuring the perfect functioning of all pieces of equipment -minimising failure risks-fixing of happened or forecasted failures, not altering the equipment project characteristics-improve equipment performances

*Maintenance is the activities aimed at giving a service to Operations, which can guarantee, in accordance with the strategies and production targets, plant availability.The development of the activities must be organized in order to supply the required services at the pre-determined times, with the expected quality and minimal cost.The maintenance system is integrated with the other company systems and has several and important interfaces with them.The maintenance system main functions are the management of the service (planning, improvement, formation), the management of the internal and external resources (planning and execution of the works) the control of the maintenance system function.To make it simple:Preventive maintenance is conducted to keep equipment working and/or extend the life of the equipment. Corrective maintenance, sometimes called "repair", is conducted to get equipment working again. The primary goal of maintenance is to avoid or mitigate the consequencs of failure of equipment. This may be by preventing the failure before it actually occurs which PM and condition based maintenance help to achieve. It is designed to preserve and restore equipment reliability by replacing worn components before they actually fail. Preventive maintenance activities include partial or complete overhauls at specified periods, oil changes, lubrication and so on. In addition, workers can record equipment deterioration so they know to replace or repair worn parts before they cause system failure. The ideal preventive maintenance program would prevent all equipment failure before it occurs

*An energy industry is an industry involved the production and sale of energy, including fuel extraction, manufacturing, refining and distribution. **