Water Treatment Process for the Oil Industry

8/15/2019 Water Treatment Process for the Oil Industry

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Oil & Gas Industry

Basically there are 3 types of water in the Oil & Gas Industry.

Frac Water: consists of water, sand (or another “proppant”) and a small quantity of chemicals (anti-

scalants, friction reducers and biocides), injected under high pressure. Rock is fractured at 1,500 to

6,000 meters depth.

Produced Water: is water from the reservoir that flows to the surface with gas during the life of the

well.

Flowback Water: is Frac water that returns during fracking (5-20%). Contains dissolved solids from

the reservoir and chemicals used in fracing.

Produced Water Constituents

This water has high levels of TDS and leaches out minerals from the shale including barium, calcium,

iron and magnesium. It also contains dissolved hydrocarbons along with naturally occurring radioactive

materials (NORM) such as radium isotopes.

Contains both organic and inorganic constituents.

Organic constituents:

Heavy hydrocarbon and high molecular weight organic acids, both free phase and emulsified

Dissolved light gases

Additives and treating chemicals

Anti-scaling agents

Various organic phosphonates (proprietary chemical)

Polyacrylates (propreitary chemical)

Phosphinopolycarboxylates (proprietary chemical)

Hydrate inhibitors

MEG

Inorganic constituents:

Salt in high concentrations (can be up to 250,000 mg/L)

Fine particles

Dissolved acid gases (H2S and CO2)

Hardness from dissolved calcium and magnesium ionsAlkalinity from dissolved bicarbonate and carbonate ions

Trace elements, typically barium, lithium, potassium and strontium

Heavy metals

Naturally occurring radioactive materials (NORM)

Radium

Thorium

Uranium


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NuGlobal and the Oil & Gas Industry

3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497

www.NuGlobalWater.com

Other Constituents:

Corrosion Inhibitors, Antiscalants, BiocidesTypical Composition of Produced Water

pH: 6.5 to 8

Oil & Grease: 2,000 to 9,500 mg/L

TSS: 1,000 to 10,000

TDS: 5% - 10%

COD: 10,000 to 30,000 mg/L

Flowback Water Constituents

Contains some of the constituents of frac water

The fluid contains clays, chemical additives, dissolved metal ions and total dissolved solids (TDS). The

water has a murky appearance from high levels of suspended particles

pH: 4.5 to 6.5

TDS: 70,000 to 300,000 ppm

Chlorides: 50,000 to 120,000 ppm

Sulfates: 25 to 35 ppm

Sodium: 25,000 to 50,000 ppm

TSS: 500 to 1200 ppm

Strontium: 1,100 to 4,000 ppm

Barium: 20 to 200 ppm

Calcium: 5,000 to 50,000 ppm

Frac Water Constituents

Some of the constituents of frac water are:

Hydrochloric Acid

Glutaraldehyde

Quaternary Ammonium Chloride

Tetrakis Hydroxymethyl-Phosphonium Sulfate

Ammonium PersulfateMagnesium Peroxide

Magnesium Oxide

Calcium Chloride

Choline Chloride

Tetramethyl ammonium chloride

Sodium Chloride

Methanol

Formic Acid

Acetaldehyde

Potassium Metaborate

Triethanolamine Zirconate

Sodium TetraborateBoric Acid

Zirconium

Borate Salts

Polyacrylamide

Hydrotreated Light Petroleum Distillate

Methanol


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


Guar Gum

Polysaccharide BlendCitric Acid

Acetic Acid

Thioglycolic Acid

Sodium Erythorbate

Lauryl Sulfate

Isopropanol

Ethylene Glycol

Sodium Hydroxide

Potassium Hydroxide

Acetic Acid

Sodium Carbonate

Potassium CarbonateCopolymer of Acrylamide and Sodium Acrylate

Sodium Polycarboxylate

Phosphonic Acid Salt

Lauryl Sulfate

Ethanol

Naphthalene

Methanol

Isopropyl Alcohol

2-Butoxyethanol

Water


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


Neutralization

Filtration

Homogenization

Electrocoagulation

Electroflocculation

Electroflotation

Dissolved Air

Flotation

Filtration

Ultrafiltration

Nanofiltration

NF 2nd pass

Reverse Osmosis

Evaporation

Advanced Oxidation

Ozone

Sludge Treatment

Granular Activated

Carbon Fluidized Bed

Reactor (GAC-FBR)

SkimmerOVERALLPROCESS

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6

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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


Brief description of the system:

1. First of All we use the skimmer to recover the oil and avoid contamination in the following

processes.

2. The homogenization step is just to take control of the flow and if it’s necessary an adjustment of

pH level

3. Electrocoagulation for A: kill bacteria, B: break emulsions, C: coagulate and flocculate

contaminants and D: Reacting heavy metals (oxidized) and then remove them. We can improve the

process injecting ozone at this point.

4. Then we need DAF due to the amount of sludge produced in the Electrocoagulation. Because we

use the Electrocoagulation process the amount of sludge is 15 to 30 percent of generated by only

chemical treatment.

5. Then you must make a microfiltration or ultrafiltration (as bag filters, Tekleen or membranes),

this type of filter depends on the quality of EC and the efficiency of DAF.

6. Then, activated carbon filters are required for removal of organic compounds and adsorption of

oxidized compounds

7. Ozone. We kill bacteria at this point and an oxidation polish.

8. After that, Nanofiltration removes remaining heavy metals, hardness, alkalinity and salt as well

as sulfates and other large molecules (high molecular weight) in this process generally have a salt

rejection of 40% to 60% (some compounds are removed by 99% and others as chlorides are removed

between 15 and 20%)

9. Then you can polish the water with a Reverse Osmosis, with which we can reduce the total salts

left over from the previous step as much as 99%, some compounds of very low molecular weight assodium or chlorides are only rejected by 85 - 95%.

In general we can say that if we have a water with 50,000 ppm TDS we can reach water of 1,000

ppm or less.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


EQUIPMENT COST

The treatment has a small footprint, which can be located into a 53’ trailer.

The cost of the complete system varies depending on the amount of barrels of water to be

treated:

Barrels per

Day (Bbl/day)Cost (USD)

500 $ 290,000

1,000 $ 450,000

5,000 $ 800,000

10,000 $ 1,400,000

This system consider:

The cost of principal process equipment such as Electrocoagulation, DAF, Filters, etc.

The cost of an electric generator based on Diesel is also contemplated.

Also consider the cost of labor in the electrical and hydraulic installation, wiring and arrangement

of equipment.

It also includes the cost of installation and materials for hoses, pipes, cable, cabinets.

Includes all necessary sensors and equipment for automatic operation of the system.

Also included is the cost of the 53’ trailer.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


OPERATING COST

The operating cost is as shown below:

Barrels per

Day (Bbl/day)

Cost

(Cents/bbl)

500 95

1,000 87

5,000 55

10,000 46

This cost covers:

Power Consumption

Labour (semi-automatic system)

Chemicals necessary for the operation

Consumables

Sludge management

BENEFITS

With this system you can have basically 3 different sources of benefits:

Skimming the water: remove oils from Flowback and Produce Water

Cleaning the water: Reduce contaminants to a safe limit for Agriculture use or safe disposal.

Making Brine: Remove bacteria and polymers, maintaining a certain density of water, brine is

prepared at a density of 10 ppb by adding salts of sodium or calcium chloride

Skimming:

10,000 bbl / day of water containing 5-7% oil

500 bbl / day of recovery oil

The operating costs are the containers and transporting them. Besides the consumption of electric

energy.Sale price per barrel of oil: depends on oil quality and humidity the same, but the price is around 20

and 60 USD

Using oil skimming technology, the company can recover oil, with profits from the skimmed oil

comprising approximately 40 percent of its overall revenue.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


Cleaning the water:

10,000 bbl / day of water

Treatment cost 55 cents including labor

Cost of treatment per day $ 5.500

Sales Price 2.98 USD clean water

500 bbl / day of water


Cost of treatment per day 450 USDPrice 2.98 USD clean water

Making Brine

500 bbl / day of water


Cost of treatment per day 450 USD

Cost per barrel for brine preparation: 3.80 to 5.00

Total daily cost: 2,350 to 2,950

Price of Brine 10 to 11 USD


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


SKIMMER

A BRIEF STATE OF THE ART

Drum and Disc Type Skimm ers

Drum and disc type skimmers are fairly simple in execution:

The lower edge of a revolving drum or a disc submerges and collects oil on thesurface, carried up to a scraper, where the oil is then scraped off into a trough ortank.

Drawbacks

The disc or drum must contact the surface. This means that either the waterlevel must be rigidly controlled or the whole machine put on a raft.

Floating the machine often interferes with the other equipment in the reservoirand runs the risk of sinking due to solids building up, or an accident.

These machines cannot elevate the skimmed oil very high so pumping is oftennecessary. The heavy, gritty oil skimmed sometimes requires the addition ofwater so that it can be pumped, requiring secondary decanting.

http://www.skimoil.com/oil_skimmers.htm

Float on the surface, sealed flotation makes it unsinkable. The drums are

motor driven (by air or hydraulics) and turn slowly attracting the oil to itssurface and rotating around to the wiper blade which scrapes the floating

oil off and it runs into the sump area, where it is picked up by pump suction

and transferred to storage.

http://www.skimoil.com/oil_skimmers.htmhttp://www.skimoil.com/oil_skimmers.htmhttp://www.skimoil.com/oil_skimmers.htm


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


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These drum skimmers are the most efficient and the most selective floating

skimmers available anywhere, due to the large surface area that is exposed tothe floating oil. Easy to install and operate. Drum skimmers need only 3" of waterto float in. Great for heavy industrial or spill work and is the tool of choice forseveral spill contractors and facility owners since it is so fast and does not giveyou much water to deal with. Readily skims light or heavy floating oils, even worksin ice — any weather.

Model No. Recovery

Rate Width Length Height Weight Construction

FDS20RS 20 GPM 28" 42" 14" 45 lbs polypro

FDS34RS 34 GPM 34" 48" 18" 80 lbs anodized alum

FDS68RS 68 GPM 37" 92" 18" 100 lbs anodized alum

Sizes from 2- 200 GPM floating oil recovery.

Belt Skimmers

Belt type skimmers look like belt conveyors standing on end with the idler pulleyunder water and the drive pulley above the skimmed oil storage tank. Floating oilclings to the belt surface and is conveyed to a scraper, where the oil is scraped offinto a trough and flows to the storage tank.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


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However, in order to compensate for level fluctuation, belts are used to reach the

low levels. When the liquid level is above this low level, the bottom of the belt hangsdown into the solution. Thus the oil that had previously settled on the surface is nowpicked up and carried into the liquid, defeating the entire skimming process andexacerbating typical oil in water problems: clogged lines and filters, less efficientcleaning, etc.

Drawbacks

Only offer a small strip to the surface to which the oil can adhere and createno movement to draw the oil.

Support or bridging needed to mount.

Require a bottom pulley to keep tension on the belt, trapping debris and oiland throwing the skimmer off track.

Oil and debris can also create problems with a belt skimmer’s drivemechanism and wiper blades, requiring constant adjustment and/or correctivemaintenance.

Tube Skimm ers

Tube skimmers are designed to ensure consistent, even operation, regardless of theapplication. And when it comes to performance, tube skimmers consistently

outperform any other types of skimmers.

Tube skimmers run on a simple concept: continuously remove oil from the surfaceof the water using a closed-loop tube that attracts the floating oil or grease.Oil adheres to the outside of the closed looped tube, which is continuously drivenacross the separator’s surface and through a set of scrapers that remove the oil,which is then drained into a collection tank.

Tube skimmers can efficiently remove all petroleum-based oil, fats, greases and oilywastes as well as animal and vegetable oils that float on the surface of water. Andunlike other skimmers, which can get clogged by floating debris, tube skimmers have

the ability to snake over, under and through debris to constantly pick up oil. Tubeskimmers are a practical solution, with benefits that include:

Availability in a variety of configurations. Skimmers are capable of removing oils,great and floating sludge from a variety of containment systems, including in-planopen or closed tanks and vats.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


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Flexibility and versatility. When equipped with a balanced boom system TubeSkimmers can extend as far as 16 feet and, can move around as desired formaximum portability, eliminating the need for expensive bridging or foundations.In addition, the free floating collector tube floats up and down with the liquid level,keeping the machinery up and out of danger.

Easy to install. Tube Skimmers are operationally efficient. Tube skimmers providepre-fabricated mounting systems that provide easy, economical installation.

Low maintenance. Due to simplicity of design, tube skimmers are not susceptibleto clogging and parts maintenance problems of other types of systems.

Less costly to use. Tube Skimmers can be unattended and left to run 24 hours aday, seven days a week. No operators or additional manpower is required to attendto a tube skimmer.

Drawback

Apparently it only can reach 100 Gallons per Hour.

http://www.oilskim.com/

http://www.oilskim.com/http://www.oilskim.com/http://www.oilskim.com/http://www.oilskim.com/


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497


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Model 6V Hanging Mount Oil Skimmers

Oil Skimming Station

Designed for virtually maintenance-free operation and very “user friendly”.


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3699 FM 2657

Kempner, TX 76539

Tel: +1 (254) 238 5497

Ideally suited for outdoor applications such as ponds.

Winterization option to ensure efficient oil recovery in temperatures as low as -20F (-29C).

Model 6V Brill oil-recovery system from Oil Skimmers Inc. to recover up to 25 barrels of oila day from its saltwater disposal pit. According to

President Hoss Smith, sales of the skimmed oil comprise 40% of the company’s revenues

from recovered oil.

Water Treatment Process for the Oil Industry

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