ABSTRACT: Advanced and innovative applications of a wireline formation tester as an alternative to well testing
Pearson, Michael R1, Martin F.W. Baxter2, Ha Kwong Tak3, Sharon M Hurst4 (1) Schlumberger Overseas S.A, Bangkok, Thailand (2) Carigali-Triton Operating Company, Sdn. Bhd, Kuala Lumpur, Malaysia (3) Sarawak Shell Berhad, Miri, Malaysia (4) Phillips Petroleum Company, Bartlesville, OK
Drill Stem Testing (DST) has traditionally been used to evaluate reservoir productivity and obtain fluid samples in exploration and appraisal wells. However, DSTs can be costly and may be undesirable in some circumstances. This paper presents examples where a third-generation Wireline Formation Tester (WFT) has been used to reduce or avoid the need for DSTs.
One operator has been able to acquire reservoir fluid samples that are confirmed by on-site chromatography and calibrated by Drill Stem Tests to be fully representative of in-situ reservoir fluid compositions. This has been achieved through the use of a WFT with pump-out capability and a downhole fluid analyser.
Another example presents the use of a WFT in cased-hole as part of an appraisal program in a field comprising stacked, unconsolidated reservoirs. It was difficult to run WFTs in open hole because of collapsing formations, differential sticking and sand production. Using a WFT in cased-hole offered a significant cost saving by reducing the number of DSTs required to characterize these reservoirs. The results were comparable to those of a DST.
A third example demonstrates the use of the Wireline Formation Tester in a deep-water exploration well where the operator had concerns about the safety of conducting DSTs on what was expected to be a high-rate gas-condensate producer.
AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia