Historical Review of Dual and Multiple Completions

2004 Gas-Lift Workshop

Joe Dunn Clegg 1

Historical Review of Dual and Multiple Completions

By

Joe Dunn Clegg


Joe Dunn Clegg 2

History Early Days (1859 to 1900) Spindletop & East Texas: RRC & Proration After WW II: Commingling & Dual Approval The 1950’s & 60’s: Hard times : Duals + The 1960’s: Computers and Offshore The Good Years: 1970 to 1984 Reality and Profitability Using the Best Technology


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Multiple Zones

One zone: Only single possible Two or more zones: Development Plan

Needed--How best to produce reserves. Aggie approach: Singles & Plug-Back Well for each zone (expensive) Mix of singles, duals, multiples and

…..recompletions.


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Multiple Zones Objective: to make more production with less initial

costs & less operating expenditures .…make more money

Applicable for only limited rates in certain environments….. 2”x 2” for < 1000 bpd x 1000 bpd

Avoid large mismatches in depth and pressure ….… depths < 10%; gradients < 10%

Review potential operating problems/costs Key often a long flowing life Dual artificial lift & workovers usually a problem

$


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Annulus-TubingDualforflowing wells

PackerLeakageTests?


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Flow CouplingCross-over

Packer

Tubing

Flow CouplingLanding Nipple

Blast JointPolished Nipple

Packer

No-Go Nipple

Perforations

Annulus-TubingDual withCross-Over


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Fad in the 1960’s

Work-Overs?

Secondary Recovery?

Unitization?

Little OperatingCost Data Available

CourtesyOtis


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Multiple“Tubingless”Completion

Exxon Special


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ConcentricDualCompletionTubing

UpperZone

LowerZones

OK forFlowingZonesi.e. Gas Wells


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DualParallelGas-Lift

Survivedthe testof time

11


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DualParallelGas-Liftw/concentrictbg. string

x Lift Gas

Lower ZoneProduction

o

Upper Zone ProductionNormal gas injection

12


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W/GasInjection

String&

SpecialCrossover

9 5/8”Csg

3 1/2” OD Tbg w/

1.9” OD Tbg

(Hydraulic)

(Permanent)

x

X XProposed DualParallelGas-Lift

13


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ThreeTubing StringDual Gas-Lift

Rigid<90’

(Hydraulic)

(Hydraulic)

(Permanent)

Outz & Osmus

Casing Size?


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Circulating SleeveUpper PumpSealLower Pump

Sucker-rod string

Upper Zone ProductionUpper Zone GasLower Zone Production

Liquid & Gas

Upper Zone

Lower Zone

Dual Rod Pumping: One Beam Unit

o

Schematic


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Head to HeadDual BeamRod Pumps


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Triple Beam Rod Pumps


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Head to Head Dual For Triple Units Single Dual Head


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9 5/8” Csg

Lower Zone Power Fluid

All Production +Power Fluid

Upper ZonePower Fluid

Dual Hydraulic

Lower Zone

Upper Zone

CommingledProduction


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Dual Hydraulic Pumping: No vents

Production lower pump +all power fluid

Production upper zone

Power fluid for upper pump

Power fluid for lower pump

LP

UP


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oo

Upper ZonePump

Perforations

Packer

Lower Zone PumpLower Zone

HypotheticalDual ESPInstallation

UpperZone

Feasible but notPractical


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Multilateral Dual

Upper Zone Lateral

Lower Zone OpposedMultilateral


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MultipleCompletion:

CommingledZones OneTubing String


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My Conclusions Singles or Commingling Preferred Duals are profitable for selected cases Multiples (>2) are seldom justified over well life

except for flowing wells Most successful high rate (> 200 BPD) artificial

lift: ...Gas Lift Savings on drilling costs are often lost due to

higher operating costs, higher workover costs and lost reserves

Multiple completions increase stress


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Duals Singles Multiples

The Winner

Special Cases Flowing Wells

Historical Review of Dual and Multiple Completions

Documents

zone expensive mix of

higher operating costs

head dual

gas liftsavings

dual approvalthe

drilling costs

initial costs

historical review of