sept05-baker.qxp 8/22/2005 4:42 pm page 66 special design ...oilproduction.net/files/hpht - drilling...

Bernardo Maldonado, Baker Oil Tools

THE COMPLETION OF high-pres-sure/high-temperature (HPHT) wellsinvolves high-risk and high-cost opera-tions with exposure levels among thehighest in the completion sector.

The task ahead is to teach the old dogsome new tricks needed to completesuper HPHT wells through new methodsfor product testing, development andmanufacturing.

As a completion service company, BakerOil Tools is working closely with opera-tors to fill the technology gaps.

To help identify HPHT operating environ-ments, safe operating envelopes andtechnology gaps, a new terminology isdeveloping.

The terminology segments HPHT opera-tions into three tiers. Tier I refers towells with reservoir pressures up to15,000 psi (1034 bar) and temperaturesup to 350º F (177º C).

Most HPHT operations to date havetaken place under Tier I conditions. TierII are the “ultra” HPHT wells which arecharacterized by reservoir pressures ofup to 20,000 psi (1379 bar) and/or tem-peratures of up to 400º F (204º C).

Many upcoming HPHT deepwater gas/oilwells, particularly in the Gulf of Mexico,fall into the Tier II category. The Tier IIIencompasses “extreme” HPHT wells,

with reservoir pressures of up to 30,000psi (2068 bar) and/or temperatures of upto 500º F (260º C).

Tier III is the HPHT segment with themost significant technology gaps. Sever-al deep gas reservoirs on North Ameri-can land and the Gulf of Mexico shelf fallinto this category.

R I S K S D I C T A T E A P P R O A C H

The risks and demanding performancerequirements for HPHT completions dic-tate special considerations and invest-ments. Most completions are designedbased on the casing and tubing program

selected for the well. For most Tier II andTier III HPHT completions, however, thecompletion design is identified first (suchas the OD/IDs of the SCSSV), which willdictate casing and tubing design.

Other considerations include a strategyto address the potentially damagingeffects of HPHT conditions on downholecomponents. High temperatures cancause:

• Significant pipe movement or highcompressional loads at the packer, par-ticularly when the high temperatures arecombined with high operating pressures;

• Increased mechanical and fluid fric-tion as well depth increases and/or devi-ates from vertical;

• Thermal cycling and resulting tubing

stresses requiring careful considerationof the use of tubing to packer connec-tions (floating seals vs. static or no sealsat all);

• Shorter elastomer performance lifeand derated yield strength of metalsused in packers and seals.

High pressure regimes require:

• Much thicker cross-sections in alltubulars and downhole equipment;

• High-yield-strength materials to han-dle excessive burst and collapse pres-sures;

• Corrosion-resistant alloys (CRAs)where needed to protect from wellborefluids that can corrode high-yield steel.

C R I T I C A L S U C C E S S F A C T O R S

To ensure that completion equipmentwill perform safely and productively inspecific HPHT environments, it is impor-tant to:

• Accurately define a set of operationalparameters and performance ratingrequirements for any new equipment;

• Set approved design specifications “instone” as soon as possible;

• Ensure that engineering feasibilitywork is accurate so equipment can bedelivered as designed;

• Ensure adequate testing facilities(there is a technical gap for Tier IIIHPHT equipment).

Completion engineering and well testdesign should begin during initial wellplanning. The overall completion philos-ophy will have significant impact on sub-sequent equipment selection.

Detailed contingency planning is crucialfor situations that require lead times foralternate equipment or services.

P R O J E C T M A N A G E M E N T

No process has proven to be more criticalto successful HPHT completions thanQuality Assurance and Quality Control(QA/QC). Equally important, the successof the QA/QC process depends on exten-

66 D R I L L I N G C O N T R A C T O R September/October 2005

Special design strategies vital as HPHTcompletions edge toward 500° F, 30,000 psi

HPHT Regimes

HPHTTier I

Ultra HPHTTier II

Extreme HPHTTier III

350°F

400°F

500°F

30 ksi

20 ksi

15 ksi

Pressure Temp

HPHT operations are segmented into tiers that are defined by reservoir temperatures and pressures.

COMPLETIONS

Sept05-Baker.qxp 8/22/2005 4:42 PM Page 66

sive operator involvement and clear,ongoing, accurate communicationbetween the operator, completionprovider and among project team mem-bers.

Both the operator and service providermust establish a project managementstructure that is customized to meet thespecific product challenges.

Extensive operator involvement in equip-ment design and manufacture is not typ-ical for standard wells, but it is crucial tosuccessful HPHT completions.

Operator involvement in equipmentdesign reviews ensures that the opera-tional requirements are addressedbefore the design is released for proto-type manufacture.

Similarly, the operator’s participation inidentifying safety-critical elements andcomponents is vital to subsequentprocesses such as engineering, qualifica-tion testing, manufacturing, assembly,subassembly make-up, testing, andinstallation.

Safeguards and processes from earlierstages of the project are wasted if theHPHT equipment is not deployed flaw-lessly at the wellsite.

To assure that knowledge and informa-

tion are transferred and the equipment isproperly installed, the operator and com-pletion company project managementteam members should continue theirinvolvement through the drilling andcompletion phases.

Service center personnel and field serv-ice technicians should be members of theteam that plans the completion proce-dure.

Detailed knowledge of how the equipmentwas designed, tested and assembled canprevent installation mishaps.

Some operators also conduct a completerun-through of the completion proce-dures with the entire team of servicetechnicians.

C L O S I N G T E C H N O L O G Y G A P S

High gas prices and the search for hydro-

September/October 2005 D R I L L I N G C O N T R A C T O R 67

Major HPHT BOT Projects & HPHT Potential Extreme/Ultra Reservoir Regimes

200

220

240

260

280

300

320

340

360

380

400

420

440

460

480

500

8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Reservoir Pressure (ksi)

Rese

rvoi

r Te

mpe

ratu

re (°

F)

DeepGas Deepwater BOT Projects

Shearwater

Mobile Bay

DeepAlex

W. Cameron

SableS. TimbalierE. CameronErskine

EgretHeronJadeHuldra

AsgardKristin

BruneiKvitebjorn

RhumDevenick

Atlantis

Ursa UrsaPompano

Thunderhorse

Most HPHT projects to date have been Tier I. Industry growth areas such as deepwater oil and gas and deepwater shelf gas, are in Tiers II and III.

Tier II and Tier III HPHT Technical Challenges

COMPLETIONS


carbons in deeper formations are keydrivers of the development of Tier IIIHPHT cased hole completion systems(CHCS).

At the same time, these systems mustsatisfy the need for reduced risk, rig timeand cost.

Meeting these needs depends on closingtechnology gaps in three key areas – test-ing facilities, seals and polymers, andmetallurgy.

“Extreme” HPHT testing facilities mustbe designed for ultimate safety in testing

equipment to severe combined loads andpressures to meet regulatory require-ments.

Test facilities must include high-pres-sure consoles, torque machines, nitrogenbooster pumps and tanks as well as sandflow loops.

Additionally, pumping large volumes ofnitrogen at extremely high pressurespresents health, safety and environmen-tal (HSE) issues that must be addressed.

The industry must develop polymers andseals that can withstand these “extreme”

HPHT well conditions up to 30,000 psi(2068 bar) and 500º F (260º C) whileretaining mechanical properties, chemi-cal performance and well fluid compati-bility.

Reliability prediction and HSE issuesmust be addressed. Extensive sealresearch must be conducted. In somecases, metal-to-metal seals may replaceelastomers.

Metallurgy, first and foremost, must beavailable. Sourcing metals such as nickelalloys, Hastelloy (C-276) or possibly tita-nium, will be a challenge.

Well fluid compatibility (sour vs sweetservice) is another key issue, as are tem-perature de-rating effects on minimumyield strength (MYS).

Careful planning must consider leadtimes and availability of these metallur-gies in the overall procurement/manufac-turing schedule of the equipment.

For example, materials needed to manu-facture HPHT equipment with lead timesof up to 3-4 months is not uncommon.

In addition, heat treated nickel alloys arenot NACE-approved above 450º F (232ºC), which may present regulatory chal-lenges.

There is no question that the E&P indus-try is developing “new tricks” to dealwith the exciting but challengingprospect of drilling “ultra” and“extreme” HPHT hydrocarbon reser-voirs.

Those “new tricks” will help this “old

Project Pressure Temperature Tier (psi) (F) Level

Atlantis 10,000 265 Tier IKvitebjorn 10,000 310 Tier IAsgard 10,000 330 Tier IHuldra 10,000 350 Tier IUrsa 1 11,000 250 Tier IRhum/Devenick 11,000 300 Tier IJade 11,000 350 Tier IEgret/Heron 12,000 350 Tier ISable Island 12,000 350 Tier IKristin 13,500 325 Tier IBrunei 13,800 310 Tier IErskine 14,500 350 Tier IUrsa 2 15,000 250 Tier IPompano 15,000 250 Tier IThunderhorse 15,000 265 Tier ISouth Timbalier 15,000 350 Tier IE. Cameron 15,000 350 Tier IShearwater 15,000 380 Tier IIDeepAlex 15,000 450 Tier IIIElgin/Franklin 16,000 400 Tier IIW. Cameron 20,000 350 Tier IIMobile Bay 20,000 420 Tier III

Baker Oil Tools Recent Experience


COMPLETIONS


dog” continue to meet the world’s grow-ing demand for energy for the foresee-able future.

H P H T Q U A L I F I C A T I O N , T E S T I N G

A key factor in the success of HPHT proj-ects is the physical qualification andtesting of the proposed equipment.

Testing facilities such as the Baker OilTools’ Navigation R&E Test Lab canrecreate downhole HPHT environmentswith pressures to 30,000 psi and temper-atures to 680º F. Each test cell has avideo monitoring and data acquisitionsystem.

The existing lab equipment is suitablefor testing HPHT systems designed forTier II conditions.

The industry will have to undertake sig-nificant investment in equipment andmaterials to generate the technologiesand qualify the equipment for “extreme”Tier III conditions. �

Printed with permission, Baker HughesinDepth Magazine


T-Series™ Safety Va lve

Extreme Sur -Set Landing Nipple

Extreme Sur -Set™ Landing Nipple

HPHT Packer

WEG

HPHT PackerTubing Anchor

Extreme Sur-Set™PunchCommunicationNipple

Packer Type(Static Seals)

Tiers 1, 2 & 3

The above illustration shows samples of Baker Oil Tools’ cased hole completion systems for Tier I, IIand III HPHT wells.


FB-3 RetainerProduction Packer

Flow Coupling


WEG


T-Series Safety Va lve

Packer Type(Floating Seals)

Tiers 1 & 2


Isolation Packer

Snap-in Shear -out Shear ReIease Anchor

WEG


Isolation Packer

Liner Hanger/Packer System


Liner top IsolationPacker (Static Seals)

Tiers 1, 2 & 3



ZX Liner Packer

Locator

WEG


Flex-Lock Liner Hanger


Liner Top(Floating Seals)

Tiers 1 & 2

COMPLETIONS


sept05-baker.qxp 8/22/2005 4:42 pm page 66 special design ...oilproduction.net/files/hpht - drilling...

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