BlowoutPrevention

ROTARY DRILLING

Fourth EditionUNIT III • LESSON 3

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

rotary drilling series

Unit i: the rig and its Maintenance

Lesson1: TheRotaryRigandItsComponentsLesson2: TheBitLesson3: DrillStringandDrillCollarsLesson4: Rotary,Kelly,Swivel,Tongs,andTopDriveLesson5: TheBlocksandDrillingLineLesson6: TheDrawworksandtheCompoundLesson7: DrillingFluids,MudPumps,andConditioningEquipmentLesson8: DieselEnginesandElectricPowerLesson9: TheAuxiliariesLesson10: SafetyontheRig

Unit ii: normal drilling operations

Lesson1: MakingHoleLesson2: DrillingFluidsLesson3: DrillingaStraightHoleLesson4: CasingandCementingLesson5: TestingandCompleting

Unit iii: nonroutine operations

Lesson1: ControlledDirectionalDrillingLesson2: Open-HoleFishingLesson3: BlowoutPrevention

Unit iV: Man Management and rig Management

Unit V: offshore technology

Lesson1: Wind,Waves,andWeatherLesson2: SpreadMooringSystemsLesson3: Buoyancy,Stability,andTrimLesson4: JackingSystemsandRigMovingProceduresLesson5: DivingandEquipmentLesson6: VesselInspectionandMaintenanceLesson7: HelicopterSafetyLesson8: OrientationforOffshoreCraneOperationsLesson9: LifeOffshoreLesson10: MarineRiserSystemsandSubseaBlowoutPreventers

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

iii

Contents

Figures vi

Tables viii

Acknowledgments ix

About the Authors x

Units of Measurement xiv

Overview 1To summarize 4

Formation Pressure 5 Formation Pressure Gradients 7Normal and Abnormal Pressures 9Hydrostatic Pressure versus Formation Pressure 11 Circulating Pressure 14Pressure Surges and Swabbing 15Hole Filling 17Formation Fracture and Lost Circulation 20To summarize 24

Abnormal-Pressure Formations 25Shale Compaction 25Detection of Abnormal Pressure 28 Drilling Rate Changes 28 Sloughing Shale 30 Shale Density 30 Gas-Cut Mud 31 Chloride Increases 31 Mud Temperature Increase 32 Electric Log Data 32To summarize 34

Kick Detection 37Pit Gain 39Mud Flow from the Well 41Increase in Flow While Circulating 42Drilling Break 42Decrease in Circulation Pressure 43Shows of Gas, Oil, or Salt Water 44Gas Behavior and Gas-Cut Mud 45To summarize 48

Killing a Well Kick Onshore 49Steps to Control an Onshore Well Kick if on Bottom

While Drilling 50

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

iv

Controlling a Well Kick While Making a Trip 51Drill Pipe as a Bottomhole Pressure Gauge 51Slow Pump Rate 54Driller’s Method 55Wait-and-Weight Method (Engineer’s Method) 62Concurrent Method 67Bullhead Kill Method 67Dynamic Kill Method 68Momentum Kill Method 69Kicks with Drill Pipe off Bottom 70 Top Kill (Volumetric) 70 Reverse Circulation 71Mistakes in Well Control 72 Pulling into the Casing 72 Constant Pit-Level Method 72 Excessive Mud Weight 73 Constant Choke-Pressure Method 73To summarize 74

Kick Control in Offshore Operations 77Diverter BOP Systems 78Procedure to Control the Well with a Diverter System 79Controlling Kick from a Floating Rig with Competent Casing Set 79To summarize 80

Special Problems in Kick Control 81Shallow Gas Formations 81Kicks with the Drill Pipe Out of the Hole 82Stripping into the Hole 86 Surface Pressure Conditions 86 Preliminary Procedures for Stripping In 86 Stripping In with the Annular Preventer 87 Stripping with Ram Preventers (Ram-to-Ram Stripping) 91 Volumetric Displacement Correction for Casing Pressure 92Stripping Out of the Hole 94 Hole in the Drill Pipe 94 Plugged Pipe or Bit 94Snubbing Operations 96 Lost Circulation 98To summarize 100

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

v

Preventer Equipment 103Pressure Ratings 106Flanges and Fittings 106Casing and Wellheads 110Annular Preventers 115Pipe Ram Preventers 117Drilling Spools/Flow Cross 122Mud Riser and Fill-up Connections 125Rotating Heads 127Operating Equipment 128Flow and Choke Fittings 134Kill Lines 136Mud-Handling Equipment 137Auxiliaries 140 Kelly Cock 140 Inside Blowout Preventer 142Accessories 144 Degasser 144 Trip Tank 145 Pit-level Indicator and Pit-volume Recorder 146 Pump Stroke Counter 148 Mud-Flow Indicator 149To summarize 150

Preventer Tests and Drills 153Testing Procedures 154Testing on Casing 154Testing with a Hanger Plug 156Cup or Packer Tests 157Blowout Preventer Drills 158To summarize 160

Appendix 161

Glossary 167

Review Questions 189

Index 195

Answers 205

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

x

About the Authors

TIM BELL Tim Bell is a Senior Well Control Engineer for Cudd Well Control. Tim has over eight years experience in the oil and gas industry.

He is involved in all phases of well-control engineering, includ-ing blowout contingency planning, dynamic well-kill design and execution, underground blowout control, rig equipment inspec-tions, engineering, and field operations.

Tim has experience in the majority of petroleum producing states in the United States. He also has experience with interna-tional blowouts, firefighting operations, on- and offshore events, inland barge blowouts, H2S wells, oil-based mud kicks, and high-pressure and geothermal wells. Tim has been involved with special service projects including ROV assisted subsea hot tapping, freeze jobs and post-event consulting. Tim has held several positions in well control, drilling, completions, production and workovers as an operations engineer and wellsite supervisor. In addition to blowouts and well-control jobs, Tim’s past projects have included horizontal wells, coalbed methane exploration and development, deep gas wells, and unconventional tight gas reservoirs.

Tim graduated from Texas Tech University with a Bachelor’s degree in Petroleum Engineering. Upon graduation, he was hired by Devon Energy as an operations engineer. In the fall of 2004, Tim left Devon to become Vice President of Operations for Quest Resources. Tim made the move to Cudd Well Control in January of 2007 and currently holds the position of Senior Well Control Engineer. Tim is involved in all aspects of well-control engineering, blowout interven-tion and firefighting operations and recovery. Tim is a member of the Society of Petroleum Engineers and is IADC WellCAP certified.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

xi

Dan Eby is the Vice President of Operations and Engineering Manager for Cudd Well Control. Dan has 29 years of experi-

ence in the petroleum industry with several major oil companies and well-control service providers. As Vice President of Opera-tions, Dan is in charge of the daily operation of Cudd Well Control, including all technical field work and business decision making.

As Engineering Manager, he is involved in all phases of well-control engineering including blowout contingency planning, relief well planning, dynamic kill design and execution, and field operations.

Dan has worked in over 30 different countries with diverse assignments in well control, drilling, completions, and workover. He has acted as both project engineer and well site supervisor. In addition to blowouts, the projects include deepwater exploration, HPHT sour gas wells, horizontal wells, subsea completions, coalbed methane exploration, and hazardous waste disposal wells.

In addition to work on well-control jobs and blowouts, Dan’s experience includes well-control instruction, development of well-control technical manuals, development of recommended practices for unconventional well-control problems, acting as MMS liaison, and the design and supervision of high-pressure snubbing jobs, both onshore and offshore.

Dan graduated from Texas A&M University with a B.S. in Building Construction in 1977, followed by a B.S. in Civil Engineer-ing in 1979. Dan is a licensed professional engineer in the state of Texas and a member of the Society of Petroleum Engineers, National Society of Professional Engineers, Texas Society of Professional Engineers, and the International Association of Drilling Contrac-tors Well Control Committee.

DANIEL EBY

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

xii

Jace Larrison is a Senior Well Control Engineer for Cudd Well Con-trol. Upon graduation, Jace began work for Cudd Pressure Control,

now Cudd Energy Services (CES), as a field engineer for snubbing and coiled tubing. Jace has an extensive background in snubbing operations that includes operational soundness with 170K hydraulic rig-assist units as well as all sizes of CES Stand-Alone (HWO) units. Special Service experience includes hot tapping, cryogenic freezing, conventional dry-ice freezing, and valve drilling operations. Jace has well-control operational experience on projects including onshore, inland water, and offshore critical pressure control situations, onshore blowouts, geothermal blowouts, inland water blowouts, high volume H2S blowouts and numerous other special projects related to well control. Jace has worked in most oil and gas producing areas of the United States as well as many international locations such as Australia, Saudi Arabia, Qatar, Turkmenistan, Kazakhstan, Libya, and Egypt.

Jace is involved in all aspects of well-control engineering, including Blowout Contingency Planning (BCP), well-control equipment inspections, recommendations for special well-control problems, kill design and execution, kick resolution and model-ing, and all aspects of field operations. Jace has also taught several industry classes related to well-control subject matter and has been involved in giving numerous presentations at industry-related events such as case histories and well-control topic discussions.

Jace is a graduate of Texas Tech University with a B.S. in Petro-leum Engineering. In 2002, he received the Texas Tech SPE outstanding member of the year award and was a TTU SPE officer for the 2002–2003 academic year. Jace is a member of the American Association of Drill-ing Engineers and the Society of Petroleum Engineers.

JACE LARRISON

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

xiii

Bhavesh Ranka is a Well Control Engineer with Cudd Well Control. He graduated from Mumbai University in India with

a degree in Chemical Engineering. He received his M.S. in Natural Gas Engineering from Texas A&M University, Kingsville.

He has been involved in all aspects of well-control engineer-ing including blowout contingency plans, well-control equipment inspection, drilling plan reviews, gas dispersion modeling, and kick simulation. His work in field operations includes blowouts, rig fires, and well-control operations.

Bhavesh has worked offshore and at onshore locations in Texas, Louisiana, Oklahoma, Colorado, New Mexico, Montana, and Wyoming. He has also been involved in well-control training. His special services experiences include hot-tap, valve drilling, and freeze operations.

BHAVESH RANKA

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

xiv

Throughout the world, two systems of measurement dominate: the English system and the metric system. Today, the United

States is one of only a few countries that employ the English system.The English system uses the pound as the unit of weight, the

foot as the unit of length, and the gallon as the unit of capacity. In the English system, for example, 1 foot equals 12 inches, 1 yard equals 36 inches, and 1 mile equals 5,280 feet or 1,760 yards.

The metric system uses the gram as the unit of weight, the metre as the unit of length, and the litre as the unit of capacity. In the metric system, 1 metre equals 10 decimetres, 100 centimetres, or 1,000 millimetres. A kilometre equals 1,000 metres. The metric system, unlike the English system, uses a base of 10; thus, it is easy to convert from one unit to another. To convert from one unit to another in the English system, you must memorize or look up the values.

In the late 1970s, the Eleventh General Conference on Weights and Measures described and adopted the Systeme International (SI) d’Unites. Conference participants based the SI system on the metric system and designed it as an international standard of measurement.

The Rotary Drilling Series gives both English and SI units. And because the SI system employs the British spelling of many of the terms, the book follows those spelling rules as well. The unit of length, for example, is metre, not meter. (Note, however, that the unit of weight is gram, not gramme.)

To aid U.S. readers in making and understanding the conver-sion system, we include the table on the next page.

Units of Measurement

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

Quantity Multiply To Obtain or Property English Units English Units By These SI Units

Length, inches (in.) 25.4 millimetres (mm) depth, 2.54 centimetres (cm) or height feet (ft) 0.3048 metres (m) yards (yd) 0.9144 metres (m) miles (mi) 1609.344 metres (m) 1.61 kilometres (km) Hole and pipe di ame ters, bit size inches (in.) 25.4 millimetres (mm) Drilling rate feet per hour (ft/h) 0.3048 metres per hour (m/h) Weight on bit pounds (lb) 0.445 decanewtons (dN) Nozzle size 32nds of an inch 0.8 millimetres (mm) barrels (bbl) 0.159 cubic metres (m3) 159 litres (L) gallons per stroke (gal/stroke) 0.00379 cubic metres per stroke (m3/stroke) ounces (oz) 29.57 millilitres (mL) Volume cubic inches (in.3) 16.387 cubic centimetres (cm3) cubic feet (ft3) 28.3169 litres (L) 0.0283 cubic metres (m3) quarts (qt) 0.9464 litres (L) gallons (gal) 3.7854 litres (L) gallons (gal) 0.00379 cubic metres (m3) pounds per barrel (lb/bbl) 2.895 kilograms per cubic metre (kg/m3) barrels per ton (bbl/tn) 0.175 cubic metres per tonne (m3/t) gallons per minute (gpm) 0.00379 cubic metres per minute (m3/min) Pump output gallons per hour (gph) 0.00379 cubic metres per hour (m3/h) and flow rate barrels per stroke (bbl/stroke) 0.159 cubic metres per stroke (m3/stroke) barrels per minute (bbl/min) 0.159 cubic metres per minute (m3/min) Pressure pounds per square inch (psi) 6.895 kilopascals (kPa) 0.006895 megapascals (MPa)

Temperature degrees Fahrenheit (°F) degrees Celsius (°C)

Thermal gradient 1°F per 60 feet –– 1°C per 33 metres ounces (oz) 28.35 grams (g) Mass (weight) pounds (lb) 453.59 grams (g) 0.4536 kilograms (kg) tons (tn) 0.9072 tonnes (t) pounds per foot (lb/ft) 1.488 kilograms per metre (kg/m) Mud weight pounds per gallon (ppg) 119.82 kilograms per cubic me tre (kg/m3) pounds per cubic foot (lb/ft3) 16.0 kilograms per cubic me tre (kg/m3) Pressure gradient pounds per square inch per foot (psi/ft) 22.621 kilopascals per metre (kPa/m) Funnel viscosity seconds per quart (s/qt) 1.057 seconds per litre (s/L) Yield point pounds per 100 square feet (lb/100 ft2) 0.48 pascals (Pa) Gel strength pounds per 100 square feet (lb/100 ft2) 0.48 pascals (Pa) Filter cake thickness 32nds of an inch 0.8 millimetres (mm) Power horsepower (hp) 0.75 kilowatts (kW) square inches (in.2) 6.45 square centimetres (cm2) square feet (ft2) 0.0929 square metres (m2) Area square yards (yd2) 0.8361 square metres (m2) square miles (mi2) 2.59 square kilometres (km2) acre (ac) 0.40 hectare (ha) Drilling line wear ton-miles (tn•mi) 14.317 megajoules (MJ) 1.459 tonne-kilometres (t•km) Torque foot-pounds (ft•lb) 1.3558 newton metres (N•m)

°F - 32 1.8

English-Units-to-SI-Units Conversion Factors

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

1

Overview

In this chapter:

• ThehistoryoftheLucaswellatSpindletop

• TheprobablecausesoftheblowoutattheLucaswell

• Thesignsofanimminentwellkickthatcanleadtoablowout

Figure 1. Anthony Lucas, chief engineer at Spindletop

OnJanuary10,1901,theblowout oftheLucaswellatSpindletopnearBeaumont,Texas,wasspectacularandwidelypublicized.

Beforethedevelopmentofblowout preventers (BOP),blowoutswerecommon.Theywerecalledgushersiftheyproducedoil.

TheHamillbrothershadstarteddrillingtheLucaswellthreemonthsearlierusinganewtoolcalledarotary drill.Becauseoftheirexperienceusingtherotarydrill,theHamillshadbeenhiredbyAn-thonyF.LucasandhispartnerstocometoBeaumonttotrydrillingthroughthesandandrockatSpindletop(fig.1).

A6-inch(15.24centimetres)diametercasingwassetat880feet(268metres),whereitwasexpectedthatoilwouldbefound.Whennooilwasstruck,thewellwasdeepenedto1,020feet(310.9metres).Thefinal140feet(42.67metres)ofdrillingproceededquickly—muchfasterthanhadbeendrilledbefore.Thecrewwaspreparinganewbitwith700feet(213.4metres)ofdrill pipeintheholewhenthewellstartedtounload;thatis,drillingmudstartedflowingfromthecasing.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

5

FormationPressure

In this chapter:

• Rockformationsthatcantrapoil

• Thedifferencebetweenandcausesofformationpressureandhydrostaticpressure

• Thecausesofformationpressuregradients

• Howtocalculatehydrostaticpressure

• Thedifferencesamongnormal,abnormal,andsubnormalhydrostaticpressures

• Theinterdependenceofformationandhydrostaticpressureinwellcontrol

• Themeasurementandcontrolofcirculatingpressurescausedbydrillingfluidandequipment

Toclassifylayersofrock,geologistsuseabasicsubdivisioncalledaformation.Aformationisarockunitthatisdistinctiveandconsists

ofacertainnumberofrockstratawithcomparableorsimilarproper-ties.Therefore,thecharacteristicsofformationsresultindifferencesinthewayfluidsaretrapped(fig.4).

Formation pressureistheforceexertedbyfluidsinanundergroundrockformation.Indrillingoperations,formationpressureismeasuredandrecordedusingadrilledholeatthedepthoftheformationwiththewell’ssurfacevalvescompletelyclosedorshut-in.Itissometimesreferredtoasreservoirpressure.Formationpressuremustbecare-fullymonitoredandcontrolledduringdrillingoperations.Thisisanimportantfactorinblowoutprevention.Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

25

Abnormal-PressureFormations

ShaleCompaction

In this chapter:

• Shalecompactionasacauseofabnormalformationpressure

• Commonsignsanddetectionmethodsusedtolocateabnor-malformationpressures

A bnormalformationpressureandlostcirculationinunconsolidated formationsarerelatedproblems.Higherthannormalformation

pressuregradientsareencounteredatvaryingdepthsinmanyloca-tions.Theseareasrequireextracaretobeproductiveandincurad-ditionaldrillingexpense.Costlyblowoutscanoccurwhenabnormalpressurezonesareunexpectedlypenetrated.

Arockwithpores oropenspacesiscalledporous. Hydrocarbonscanoccuronlyinporousreservoirrocks.Aporousrockhasameasur-ablequalitycalledporosity.Porositycanbeverylow,almostzeroor, in theory, itcanbeashighas55%forextremely well-sorted(samediameter) rockgrains.Becausemostrockshavegrainsofvaryingsizes,thepracticallimitofporosityisusuallyaround30%forsandstone.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

37

KickDetection

In this chapter:

• Preliminaryeventsthatindicateakickhasbeentaken

• Well-controlequipmentusedtoassessanddetectakick

• Somecorrectivemeasuresusedtostopakick

Drillingabnormally-pressuredformationsisknowntobehazard-ous, butmanywell-control problems also happen in normal

formationpressures.Someproblemsoccurwhilepipeisbeingmovedinoroutoftheborehole(fig.22).

Whenthefirststandsofpipearepulledortrippedout,therecanbeareductioninbottomholepressure.Thismaybecausedbythecessationofcirculation,andperhapsbecauseofswabbing.Ifthereisanyindicationofflow,thewellshouldbeshut-inandcirculatedbyfollowingstandardwell-controlpracticestoremoveanyinfluxandfillthewellwithcleandrillingfluid.Ifnecessary,themudweightshouldbeincreasedbeforesubsequentattemptstotripthepipe.

Sometimes, the preliminary indications of a kick are almostunmistakable.These“positive”indicatorsinclude:

• Unexplainedmud-pitgain• Mudflowwiththepumpsoff• Increaseinflowwhilecirculating

Inothercases,theindicationsofapossiblekickareambiguous.These“possible”indicatorsinclude:

• Adrillingbreak,asuddenincreaseinROP(rateofpenetration)• Decreaseincirculatingpressure• Showsofgas,oil,orsaltwater

Strong indicators of a kick include:• Unexplained mud-pit gain• Mud flow with the pumps

off• Increase in flow while

circulating

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

49

KillingaWellKickOnshore

In this chapter:

• Stepstocontrolanonshorewellkick

• Stepstocontrolawellkickwhilemakingatrip

• Variousmethods,proceduresandcalculationsusedtokillakick

• Killingawellkickwiththepipeoffthebottomoftheborehole

• Commonmistakesmadeinkillingawellkick

Bytakingimmediateaction,thedrillercanminimizethesizeofakick.Minimizingthesizeofthekickandcangreatlyenhancethe

abilityofadrillingcrewtohandlethekickproperly.Quickactioncanpreventthesituationfromescalatingintoablowout.

Whenakickisdetected,followingthepropersequenceofstepsiscriticaltosuccessfulemergencycontrol.Dependingonthecause,differingmethodsandproceduresmaybeusedtokillawellkick.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

77

In this chapter:

• Proceduresincontrollingakickoffshorefromafloatingrig

• DiverterBOPsystems

• Proceduresforwellcontrolwithadivertersystem

KickControlinOffshoreOperations

Theproceduresforcontrollingkicksinoffshoredrillingfromafloatingrigaresimilartothoseforonshoreasdiscussedinthe

previouschapter.Off-shore mayrefertoanybodyofwater,includ-inginlandlakes,seas,and rivers. There areadditional steps andadditional equipmentwithwhichcrewmem-bersmust be familiar(fig.36).

Figure 36. A subsea ram-type blowout preventer C

ourtesyofCuddWellControl

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

81

In this chapter:

• Thedangersofshallowgasformations

• Proceduresandcalculationsrequiredtocontrolkickswiththedrillpipeoutofthehole

• Well-control problems encountered when stripping intothehole

• Well-controlproblemsencounteredwhenstrippingoutofthehole

• Theproceduresandequipmentusedinsnubbingoperations

• Theproceduresusedtocontrollostcirculation

SpecialProblemsinKickControl

ShallowGasFormationsShallowgasformationspresentadangerbecause:

• Thegaspocketisgenerallyatadepththatallowsapotentialkicktorapidlyunloadthemudfromthewellbore,and

• Shuttinginthewellmightcausetheformationtofractureandthewellborefluidstobroachallthewaytothemudline.

Eitherofthesepossibilitiescanresultinaseriouswell-controlproblem.Ifashallowgaskickoccursbeforeenoughcasingisset,thedivertersystemwilldiverttheflowawayfromtherig.Forakickinashallowgasformation,theoffshorecrewshouldtakethesamestepsasthoselistedfordivertingthewellinthepreviouschapter.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

103

In this chapter:

• Themain pieces of equipment used inwell control andblowoutprevention

• Thepurposeandfunctionofeachpieceofequipment

• Auxiliaryandaccessoryrigequipmentthatcontributestowellcontrol

PreventerEquipment

Thehydrostaticpressureofthedrillingfluidcolumnontheforma-tionistheprimarybarrierinpreventingawellfromblowingout.

Whenformationpressureisgreaterthanthehydrostaticpressureofthemudcolumn,BOPsandrelatedequipmentshutinawellatthesurfaceandserveasasecondbarrier.

InadditiontoBOPs,otherequipmentisusedtoassistinthecon-trolofwellpressure.Chokesandchokemanifoldsallowacontrolledremovaloftheintrudedformationfluidsfromthewellbore.Mud-gasseparatorshelpconservedrillingfluidswhileremovingthegasfromthedrillingfluidsanddischargingthegastotheatmosphere.Rotating headspermitdrillingtocontinueatanincreasedROPinformationswithhigh-pressure/low-volumegasflow.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

153

PreventerTestsandDrills

In this chapter:

• ThereasonsforBOPpressuretesting

• ThemethodsfortestingvariousBOPcomponents

Blowoutpreventersareemergencyequipment.TheBOPsareonlyeffectiveifthey:• Canhandlethepressureinvolved• Areingoodoperatingcondition,and• Areusedcorrectly

ThedecisiontoprovideadequateBOPsinvolvestheoperatingcompany,thedrillingcontractorandthedrillingcrews.Thedrillersontherigarekeyintheresponsibility,buteverycrewmembershouldknowhowtooperatethepreventerequipmentandbealerttothesignsofawellkick.Functiontestingofthepreventersandcarefulpressuretesting ensures that everything is in good operating condition andreadyforuse.

TestingoftheBOPstotheirratedpressure(ifequaltoorbelowtheratingofthewellhead)shouldbeconductedtoconfirmthattheequip-mentwillholdunderthegiventestpressure.Allpreventersandvalves,includingthechokemanifold,shouldbetestedwithpressurefromtheupstreamside.Therefore,testpressureisappliedtothepreventerorvalvefromthesidenormallyoriginatingthepressureinakillsituation.

Frequentoperationalchecksandregularpressuretestsensurethatvalvesandothercomponentsareingoodworkingorder.Lubri-cation,asnecessary,ensureseasyoperationoftheequipmentinanemergency.Regularmaintenanceislessexpensivethanreplacementofanitemorthepossiblydrasticconsequencesincurredwhenequip-mentdoesnotfunctionproperly.

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

195

Index

abnormalformations,42abnormalpressure,28abnormal-pressureformationsdetectionof,28–35shalecompaction,25–27

accumulators,128,132,133acoustictraveltime,32adapterspools,108adjustablechokes,89,135AmericanNationalStandardsInstitute(ANSI),109

AmericanPetroleumInstitute(API),106,109.See alsoAPIRP53(AmericanPetroleumInstitutestandards)

annularblowoutpreventers,50,87–90,115–117

annularspace,13annulus,14ANSI(AmericanNationalStandardsInstitute),109

APIRP53(AmericanPetroleumInstitutestandards)accumulatorpressurelevelinblowoutpreventercontrolunit,133blowoutpreventerworkingpressuretestschedule,154closingsystemsspeed,128forflangesandgaskets,109foroperatingequipment,128pressureratings,109recommendationsandratingsforblowoutpreventers,106forwellheadequipment,109workingpressures,136

assembliesblowoutpreventers(BOPs),104,111,112,113,128,150,154chokemanifold,145connectionto,106highpressure,108skid-mounted,130testing,154valve,87workingpressureof,106,110–111

associatedgas,73A-suction,114auxiliariesdegassers,144insideblowoutpreventers,142–143kellycock,140–141mud-flowindicators/sensors,149pit-levelindicatorsandpit-volumerecorders,146–147pumpstrokecounter,148triptanks,145

back-pressure,18back-pressurevalves,140balledupbits,14barite,7bellnipples,125–126bits,1,14,94–95blanketsands,10blindflange,106blindrams,89,121,122

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

196

BLOWOUTPREVENTION

blowoutassemblieshighpressure,108workingpressureof,110–111blowoutpreventers(BOPs).See alsounderpreventersannular,50,87–90,115–117auxiliaries,142–143CameronTypeU,118–119capabilitiesof,104closureof,41componentsof,105controlunit,133darttype,142–143droptype,142–143historyof,1hydraulicfluidsforoperationof,129Hydril-TypeGK,116Hydril-TypeV,119–120inside(IBOPs),142–143NLShaffertype,119–120piperam,91–92,115,117–122stack,89

blowouts,1,3borehole,7bottomholepressure(BHP),3,12,84Boyle,Robert,45Boyle’slaw,45bullheadkillmethod(bullheading),67–68,82bullplug,106

CameronTypeUrampreventers,118–119caprock,42casingandwellheads,110–114casingpressure,46casings,1casingseats,22casingshoes,20,110–111cellar,114

cementing,20,110cementingunit,89,94cementplugs,148centrifugaldegassers,138,144centrifugalpumps,18chlorideincreases,31chokeadjustments,62chokelines,106choke-manifoldfriction,66chokes.See alsoconstantchoke-pressuremethodadjustable,89,135adjustments,62fittings,134–135manifoldassemblies,55,134,145

circulate-and-weightmethod,67circulatingpressure,14–15circulationpressure,94closedinwell,50closedreservoirs,10closingsystems,128closingtime,128closingunitpumps,87concurrentmethod,67conductivity,32conductorpipe,44,78,113,117conductorpipeoutlet,125connectiongas,31constantchoke-pressuremethod,73constantpit-levelmethod,72controllingawellkickwhilemakingatrip,51controllingkickfromafloatingrigwithcompetentcasingset,79

cross-flow,98cuppackers,157–158cuptesters,157–158cuttings,71Petr

oleum

Extens

ion-The

Univ

ersity

of Tex

as at

Austin

197

INDEX

darttypeinsideblowoutpreventers,142–143decreaseincirculatingpressure,43–44degassers,138,144delaytiming,58density(unitweight),7,8derrickhand,3detectionofabnormalpressure,28–35chlorideincreases,31drillingratechanges,28–29electriclogdata,32–33gas-cutmud,31mudtemperatureincrease,32shaledensity,30sloughingshale,30

detectionofhighformationpressures,28d-exponentfactor,29differentialpressure,28displacementmonitoring,89ditches,125diverterbopsystems,78drillcollars,19drilledshowgas,31,44drilledshows,44driller’smethod,55–61drillingbreak,3,28,42drillingfluiddensity,12drillingfluids,7drillingratechanges,28–29drillingspools/flowcross,114,122–124drillpipe.See alsoblowoutpreventers(BOPs);circulationpressure;full-openingsafetyvalves(FOSVs);lostcirculation;shut-indrillpipepressure(SIDPP);tripsasabottomholepressuregauge,51–53,83displacement,19,92fishingoperations,121hydrostaticpressure,13,44outofthehole,82

piperampreventers,117pressures,134pulling/pulled,44,145–146shearing,118atSpindletop,Texas,1–3

drillpipepressure,12,44drillpipepressuregauge,62drillpiperubbers,91drill-stem(full-openingsafety)valves(FOSVs),143

drillstems,121drillstring,14,51–53droptypeinsideblowoutpreventers,142–143

dynamickillmethod,68

electriclog,28electriclogdata,32–33,35detectionofabnormalpressure,32–33engineer’smethod,62–67entrainedgas,54equivalentcirculatingdensity(ECD),78excessivemudweight,73

fill-uplineconnections,126finalcirculatingpressure(FCP),62fishingoperations,121flangesandfittings,106–109floatindrillstring,51–53flowandchokefittings,134–135flowcheck,16flowchecks,41flowline,44flow-linetemperatures,32fluidpressure,7formationfluids,2formationfracture,67formationfractureandlostcirculation,20–24

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

198

BLOWOUTPREVENTION

formationintegrity.Seeformationfractureandlostcirculation

formationpressureabout,5–6formationfractureandlostcirculation,20–24formationpressuregradients,7–8holefilling,17–19vs.hydrostaticpressure,11–15hydrostaticpressurevs.,11–15monitoring,6normalandabnormalpressures,9–10pressuresurgesandswabbing,15–16

formationpressuregradients,7–8formations,5formationtypesandmudloss,23fracturepressure,20freewater,27full-openingsafetyvalves(FOSVs),51,70,105,143

gasbehaviorandgas-cutmud,45–47gascharge,133gas-cutmud,31,45–47gaskets,109gasmigration,61,82,86gelstrength,14–15glycol,129gradients,51–53gravity-flowtriptanks,145guideshoes,110–111gushers,1

hangerplugs,156hangers,112hardshut-in,79hardshut-inwell,50highformationpressuredetection,28highpressureblowoutassemblies,108

holeinthedrillpipe,94hookload,3hydraulicaccumulators,132hydraulically-operatedvalves,108hydraulichigh-pressurechokemanifold,134hydraulicrigassistsnubbingunits,96hydraulicworkover(HWO)unit,96–97Hydril-TypeGKblowoutpreventers,116Hydril-TypeVrampreventers,119–120hydrostatichead,14hydrostaticpressure,2,7,8circulatingpressure,14–15vs.formationpressure,11–15

hydrostatic-pressuregradient,8

idealgas,45increaseinflowwhilecirculating,42inducedkicks,83initialcirculatingpressure(ICP),62insideblowoutpreventers(IBOPs)darttype,142–143droptype,142–143

internalblowoutpreventers.Seeinsideblowoutpreventers(IBOPs)

internaldiameter(ID),13InternationalAssociationofDrillingContractors(IADC),60

jetnozzles,14joints.Seetooljoints

kelly,41kellycocks,140–141testsub,155

kickcausesof,15defined,2signsof,4Petr

oleum

Extens

ion-The

Univ

ersity

of Tex

as at

Austin

199

INDEX

kickcontrol,offshoreoperationsabout,77controllingkickfromafloatingrigwithcompetentcasingset,79diverterbopsystems,78proceduretocontrolthewellwithadivertersystem,79

kickcontrol,specialproblems,81–101kickswiththedrillpipeoutofthehole,82–86shallowgasformations,81insnubbingoperations,96–99strippingintothehole,86–93strippingoutofthehole,94–95

kickdetection,37–48decreaseincirculatingpressure,43–44drillingbreak,42gasbehaviorandgas-cutmud,45–47increaseinflowwhilecirculating,42mudflowfromthewell,41pitgain,39–40showsofgas,oil,orsaltwater,44

kickindicators,37–38kickswithdrillpipeoffbottom,70–71reversecirculation,71topkill(volumetric),70–71

kickswiththedrillpipeoutofthehole,82–86killingawellkickabout,49bullheadkillmethod,67–68concurrentmethod,67controllingawellkickwhilemakingatrip,51driller’smethod,55–61driller’smethodfor,55drillpipeasabottomholepressuregauge,51–53dynamickillmethod,68engineer’smethod,62–67kickswithdrillpipeoffbottom,70–71

mistakesinwellcontrol,72–73momentumkillmethod,69slowpumprate,54stepstocontrolanonshorewellkickifonbottomwhiledrilling,50wait-and-weightmethod,62–67

killlines,106,136killsheet,62kill-weightmud,55–56,66

leak-offtest,20liners,18logs,28,32–33,35losszone,23lostcirculation,20,23,98–99lost-circulationmaterial,99lostreturns,20lowerkellycock,140–141lube-and-bleedmethod,70,82LucasAnthonyF.,1

makehole,3managedpressuredrilling(MPD),127Marine Riser System and Subsea Blowout

Preventers(PETEX),78mastercontrolpanels,128mistakesinwellcontrolconstantchoke-pressuremethod,73constantpit-levelmethod,72excessivemudweight,73pullingintothecasing,72

momentumkillmethod,69mud,7,13–24,28–29,32–34,37–47,51–59,61–62,65–67

mudflow,41mud-flowindicators/sensors,149mud-gasseparator,54mud-handlingequipment,137–139mudlogs,28,31mudlossandformationtypes,23

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

200

BLOWOUTPREVENTION

mudpits,18mudreturnflowrate,42mudreturnline,38mudriserandfill-upconnections,125–127mudrisers,125mudtemperatureincrease,32mud-weightcalculationsof,74–75concurrentmethod,67differentialpressure,25equivalent,20excessive,73fluiddensity,8,24formationpressurecontrol,22,53fracturepressure,23,31kickand,37killingawellkick,50,70,82–83lossof,47maximum,23mudtemperatureincrease,32normalizedpenetrationrate,29pressuresurging,15strippinginprocedure,90,93wait-and-weightmethod,62–67

naturally-fracturedformation,98nippled-upconnection,114nitrogen,133NLShafferrampreventers,119–120nomagraphs,90normalizedpenetrationrate(d-exponent),29normal-ratetrend,28nozzles,14

offshore,77openhole,83operatingequipment,128–133operatingpressurecontrol,56operatingpressuresource,128

operatingpressurestandards,133outerdiameter(OD)drillcollars,13“out-runningthewell”kills,69overbalance,9overburden,10overburdenpressure,10overkill,73overpressurizedformations,28,42oxygen,133

packers,117permeability,26permeablerocks,26piperamblowoutpreventers,117–122piperams,117pitgain,3,39–40pitlevel,40pit-levelchange,17pit-levelindicators,40pit-levelindicatorsandpit-volumerecorders,146–147

pit-volumeincrease,65pluggedpipeorbit,94–95plugs,94,106,148,156pores,26–27porosity,25porousrocks,25positive-displacementmeters,18poundspergallon(ppg),8poundspersquareinch(psi),47poundspersquareinchperfoot(psi/ft),8powerrigs,128preliminaryproceduresforstrippingin,86pressure,2pressurechanges,15pressuregradient,7pressureloss,13pressureoverbalance,9

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

201

INDEX

pressureratings,106pressuresurgesandswabbing,15–16pressuresurging,15preventerequipment,103–152about,103–105annularblowoutpreventers,115–117auxiliaries,140–143casingandwellheads,110–114drillingspools/flowcross,122–124flangesandfittings,106–109flowandchokefittings,134–135killlines,136mud-handlingequipment,137–139mudriserandfill-upconnections,125–127operatingequipment,128–133piperamblowoutpreventers,117–122pressureratings,106rotatingheads,127–128

preventeroperatingpumps,130preventertestsanddrillsabout,153–154blowoutpreventerdrills,158–159cuporpackertests,157–158testingoncasing,154–155testingprocedures,154testingwithahangerplug,156

proceduretocontrolthewellwithadivertersystem,79

pullingintothecasing,72pumpstrokecount,17pumpstrokecounters,148

rams,87ram-to-ramstripping,91–92ram-typeblowoutpreventers,115rateofpenetration(ROP),28reciprocatingpumps,18

Recommended Practices for Blowout Prevention Equipment Systems for Drilling Wells(API).SeeAPIRP53(AmericanPetroleumInstitutestandards)

reducedcirculatingpressure,65regulatorvalves,87remotechokepanels,135remotecontrolpanels,131,135reservoirpressure,2resistivity,32reversecirculation,71ringgaskets,114ring-jointflanges,109rollerconebit,94rotary,41rotarydrills/drilling,1,2rotarytables,128rotatingheads,103,127–128

seismicdata,28settlingpit,139shale,10shalecharacteristics,32shalecompaction,25–27shaledensity,30shaleshakers,56shallowgasformations,81shearingofdrillpipe,118oftubing,118

shearrams,118shortway,71show,44showgas,31showofgas,oil,orsaltwater,44shut-in,50,79shut-incasingpressure(SICP),53,55,65shut-indrillpipepressure(SIDPP),51–53,65signsofblowouts,3,79siphons,139Petr

oleum

Extens

ion-The

Univ

ersity

of Tex

as at

Austin

202

BLOWOUTPREVENTION

skid-mountedassemblies,130slips,96,143sloughingshale,30slowpumprate,54snubbing,71,82snubbingoperations,96–99snubbingunits,89,96softshut-in,50,79softshut-inwell,50Spindletop,Texas,1squeezecementing,20stack,89stand-aloneunit,96,97standpipe,56standsofpipe,16starterheads,114stationaryslips,96stepstocontrolanonshorewellkickifonbottomwhiledrilling,50

strippingin,71strippingintotheholewithannularpreventer,87–90preliminaryproceduresforstrippingin,86ram-to-ramstripping,91–92strippingwithrampreventers,91–92surfacepressureconditions,86volumetricdisplacementcorrectionforcasingpressure,92–93

strippingout,94strippingoutoftheholeholeinthedrillpipe,94pluggedpipeorbit,94–95

strippingwithrampreventers,91–92strokesperminute(spm),54stuckpipe,61subseablowoutpreventers(BOPs),77–78subseawells,99suctionpit,62surfacecasing,110,117

surfacepressureconditions,86surgebottles,88surging,15swab,158swabbedshows,44swabbing,15swivel,140.See alsokelly

targets,106tees,106testpackers,157–158testsub,155TIWvalve,70tooljointsannularblowoutpreventers(BOPs),115piperams,118,121snubbingoperations,87,96strippingthejoint,87,91–92,100

topkill(volumetric),70–71totalfrictionlosses.Seecirculationpressuretour,54travelingslips,96tripgas,31triplexpumps,18tripmargin,16trips,16tripshows,44triptanks,17,145trueverticaldepth(TVD),7tubing,71shearingof,118

tubingheadfittings,71

unconsolidatedformation,25underbalanceddrilling(UBD),9,128underbalancedwells,9undergroundblowout,98upperkellycock,140U-tube,54

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

203

INDEX

vacuumdegassers,138,144variableborerams(VBRs),117ventlines,78–79,105,124,139,144viscosity,14volumetriccorrection,92volumetricdisplacementcorrectionforcasingpressure,92–93

volumetricmethod,16vugularformation,98

wait-and-weightmethod,62–67.See alsoengineer’smethoddisadvantagesof,66

warningsigns,79wellbores,2well-controlproblems,42wellheads,46,112–113wellpressure,2wireline,94workoverservice,39–40

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

To obtain additional training materials, contact:

PETEXThe University of Texas at Austin

Petroleum extension service10100 Burnet Road, Bldg. 2

Austin, TX 78758

Telephone: 512-471-5940or 800-687-4132

FAX: 512-471-9410or 800-687-7839

E-mail: petex@www.utexas.eduor visit our Web site: www.utexas.edu/ce/petex

To obtain information about training courses, contact:

PETEXlearning and assessment center

The University of Texas4702 N. Sam Houston Parkway West, Suite 800

Houston, TX 77086

Telephone: 281-397-2440or 800-687-7052

FAX: 281-397-2441E-mail: plach@www.utexas.edu

or visit our Web site: www.utexas.edu/ce/petex

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin

2.303400-88698-242-1

978-0-88698-242-3

Petrole

um Exte

nsion

-The U

nivers

ity of

Texas

at Aus

tin