Performance Evaluation of Trilateral Wells: Field Examples
- D.T. Vo (Unocal Corp.) | M.V. Madden (Unocal Corp.)
- Document ID
- Society of Petroleum Engineers
- SPE Reservoir Engineering
- Publication Date
- February 1995
- Document Type
- Journal Paper
- 22 - 28
- 1995. Society of Petroleum Engineers
- 1 in the last 30 days
- 253 since 2007
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Recent advances in horizontal drilling and completion technology have led tothe successful completion of multi- lateral horizontal wells. These wells havetwo or more laterals penetrating separate zones which produce through a singlewellbore to the surface. Evaluating these commingled horizontal wells posesunique problems which have led to the development of a practical procedure forthat purpose.
This paper demonstrates a practical procedure used in evaluating theperformance of three lateral (trilateral) horizontal wells. The procedure,coupling the analysis of pressure buildup and rate-time data, involves the useof a consistent mathematical model to generate pressure and rate responses forpressure test interpretation and performance prediction. The procedure isdemonstrated for several new trilateral wells drilled in the Dos Cuadras Field,offshore California.
Results from field tests indicate the procedure is efficient in evaluatingthe performance of these trilateral wells. From pressure test interpretation,reservoir and well parameters are obtained, and the contribution of alllaterals is confirmed. The computed model parameters are then used in a ratehistory match and accurate long-term performance predictions are made.Deconvolution is shown to improve the history match process. In addition, theperformance evaluation of these trilateral wells is compared with previouslydrilled single lateral horizontal wells in the same field. The comparisonconfirms that the new trilateral horizontal well technology is economicallyviable, allowing reserves to be developed for approximately two thirds the costof three single lateral horizontal wells.
One of the major advances in horizontal well drilling technology in the lastfew years involves the drilling and completion of wells with multiple laterals.These wells have more than one lateral entering separate zones with theproduction commingled through a single wellbore extended to the surface. Whilethe completion of these wells has successfully lowered reserve developmentcosts, evaluation of their performance is difficult.
The objectives of this paper are to present a practical procedure forevaluating multilateral horizontal wells and to demonstrate its use with fieldexamples. The suggested procedure involves the use of pressure transienttesting to establish a reservoir-well model, which is enhanced and confirmed byhistory matching available well production data. The reservoir-well model isthen used to make long-term rate predictions. Because both pressure transientand rate data are analyzed, the procedure involves the use of a consistentmathematical model for handling either the boundary condition of rate orpressure constraints. Also, because both rate and pressure data vary during theproduction period, a deconvolution scheme was used to facilitate the historymatch process involved in the analysis.
|File Size||533 KB||Number of Pages||7|