Formation fluid type and composition are important and integral parameters in reservoir characterization and evaluation. Fluid type and composition can be obtained by capturing samples from limited depth across the producing zone. However, recent advances in downhole fluid analysis (DFA) enable the downhole fluid identification and composition measurement from depth where the fluid samples are either not collected or when PVT results are not readily available. A new wireline technology in insitu fluid analysis (IFA) was used to achieve this objective.

This work is based on field data from a newly drilled well in Malay Basin where the targeted reservoirs are comprised of clastic formation on the upper section of tested interval and of Central Luconia carbonate in the bottom section. The insitu fluid analysis technology has successfully guided the identification of oil and water in the clastic formation and gas in the carbonate. The detailed information on oil and gas composition, CO2 content, and fluid density was obtained in real time.

The presence of water in clastic formation identified by wireline formation tester triggered interest in more investigation. The water producing interval is located at about 100 m down dip from a nearby development well that is producing gas. Instead of initially planned full DST, decision was made to run the wireline formation testing dual packer module to perform interval pressure transient testing (IPTT) after the well had been cased. The IPTT and DFA confirmed the water section and saved significant cost on running unnecessary testing. The methodology, applications and suggested best practices are presented in this work.

You can access this article if you purchase or spend a download.