1. Historical Review of Dual and Multiple CompletionsBy
Joe Dunn Clegg
2004 Gas-Lift Workshop
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
2004 Gas-Lift Workshop
Joe Dunn Clegg

3. 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.
2004 Gas-Lift Workshop
Joe Dunn Clegg

4. 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 ….…D depths < 10%; D gradients < 10%
Review potential operating problems/costs
Key often a long flowing life
Dual artificial lift & workovers usually a problem $
2004 Gas-Lift Workshop
Joe Dunn Clegg

5. Annulus- Tubing Dual for flowing wells Packer Leakage Tests?
2004 Gas-Lift Workshop
Joe Dunn Clegg

6. Annulus- Tubing Dual with Cross-Over Flow Coupling Cross-over Packer
Landing Nipple
Blast Joint
Polished Nipple
No-Go Nipple
Perforations
Annulus-
Tubing
Dual with
Cross-Over
2004 Gas-Lift Workshop
Joe Dunn Clegg

7. Fad in the 1960’s Work-Overs? Secondary Recovery? Unitization?
Courtesy
Otis
Fad in the 1960’s
Work-Overs?
Secondary Recovery?
Unitization?
Little Operating
Cost Data Available
2004 Gas-Lift Workshop
Joe Dunn Clegg

8. Exxon Special Multiple “Tubingless” Completion 2004 Gas-Lift Workshop
Joe Dunn Clegg

9. Concentric Dual Completion Tubing Upper Zone OK for Flowing Zones i.e.
Gas Wells
Lower
Zones
2004 Gas-Lift Workshop
Joe Dunn Clegg

10. Dual Parallel Gas-Lift Survived the test of time 11
2004 Gas-Lift Workshop
Joe Dunn Clegg 11

11. Dual Parallel Gas-Lift w/concentric tbg. string Upper Zone Production
Normal gas injection
Lower Zone
Production x
Lift Gas o 12
2004 Gas-Lift Workshop
Joe Dunn Clegg

12. Proposed Dual Parallel Gas-Lift x X X 9 5/8”Csg 3 1/2” OD Tbg w/ W/Gas
Injection
String
&
1.9” OD Tbg
Special
Crossover
(Hydraulic)
(Permanent)
2004 Gas-Lift Workshop
Joe Dunn Clegg 13

13. Three Tubing String Dual Gas-Lift Casing Size? Rigid <90’
(Hydraulic)
Rigid
<90’
(Hydraulic)
(Permanent)
2004 Gas-Lift Workshop
Joe Dunn Clegg
Outz & Osmus

14. Dual Rod Pumping: One Beam Unit
Schematic
Sucker-rod string
Upper Zone Production
Upper Zone Gas
Lower Zone Production
Liquid & Gas
Upper Zone
Lower Zone
Circulating Sleeve
Upper Pump
Seal
Lower Pump o
2004 Gas-Lift Workshop
Joe Dunn Clegg

15. Head to Head
Dual Beam
Rod Pumps
2004 Gas-Lift Workshop
Joe Dunn Clegg

16. Triple Beam Rod Pumps
2004 Gas-Lift Workshop
Joe Dunn Clegg

17. Head to Head Dual For Triple Units Single Dual Head
2004 Gas-Lift Workshop
Joe Dunn Clegg

18. Dual Hydraulic Commingled Production Lower Zone All Production +
Power Fluid
All Production +
Power Fluid
9 5/8” Csg
Upper Zone
Power Fluid
Commingled
Production
Upper Zone
2004 Gas-Lift Workshop
Lower Zone
Joe Dunn Clegg

19. Dual Hydraulic Pumping: No vents Production lower pump +
all power fluid
Production upper zone
Power fluid for upper pump UP
Power fluid for lower pump LP
Dual Hydraulic
Pumping: No vents
2004 Gas-Lift Workshop
Joe Dunn Clegg

20. Hypothetical Dual ESP Installation Upper Zone Pump Perforations
Packer
Lower Zone Pump
Feasible
but not
Practical
Upper
Zone o o
Lower Zone
2004 Gas-Lift Workshop
Joe Dunn Clegg

21. Multilateral Dual Upper Zone Lateral Lower Zone Opposed Multilateral
2004 Gas-Lift Workshop
Joe Dunn Clegg

22. Multiple Completion: Commingled Zones One Tubing String
2004 Gas-Lift Workshop
Joe Dunn Clegg

23. 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
2004 Gas-Lift Workshop
Joe Dunn Clegg

24. The Winner Duals Singles Multiples Flowing Wells Special Cases
2004 Gas-Lift Workshop
Joe Dunn Clegg