Record-Breaking on Wireline Data Acquisition: Leveraging Large Dimension of Wireline Formation Tester in Slim Hole and High Deviation Well – Pushing the Boundaries of Wellbore Clearance Issue

Abstract

Abstract The gas-fields in the north Malay Basin and Gulf of Thailand region are well-known with the presence of high CO2 and H2S concentration in the reservoirs. Sophisticated and robust tools are needed to measure important data in order to support further development and reservoir management of the field. Thus, reservoir data such as pressure and fluid type become crucial in achieving the production target and reservoir management of this field. Fields are located in the North Malay Basin, a few hundred kilometres from the onshore border of Malaysia and Thailand. This paper describes deploying large dimension of wireline formation tester in slim hole and high deviation well which the tool option is limited in the current market. The well design with slim hole 6-1/8" high deviation in the pay zone interval brings with them operational challenges for deploying wireline logging a critical direct measurement of downhole fluid analysis (DFA) and obtain low contamination sample which unable to provide accurate measurement under slim hole. As the Wireline formation testing (WFT) which equipped with pump out capability in the market is limited. The existing slim – WFT which can provide only a limited pumping volume leads the operator to find alternative methods due to the limitation of direct measurement to require downhole data. Hence, a more popular WFT with larger pump volume is required. A combination using a large volume WFT equipped with rollers and articulated hole finder (AHF) are appropriate to acquire downhole fluid information. The ability of fluid characterization using a pump out formation tester coupled with downhole fluid identification has been introduced to aim an accurate decision and provide real-time data. Capability to pump-out formation fluid and acquire sample that met the expectation of contamination levels. As a result, successful determination of fluid contact, formation pressure, fluid type, reservoir mobility, and CO2 content which are the main driver to production optimization and field development. In addition, wireline data acquisition is accessible in slim hole 6-1/8" high deviation, bring more options the tool availability in the current market as only few contractors are able to provide those technologies. Using this structured approach to wireline conveyance, the operations were successfully accomplished and met the well objectives by performing pressure tests and sampling with adequate stationary time resulting in significant savings for the operator. Deploying large dimensions of WFT in slim hole 6-1/8" high deviation wells are often a source concern for subsurface, drilling and service company personnel. However, this is the first ever implementation in the region and worldwide which pushing the limitation of the tool deployment and alternative options for operators with the well design alike.