First Open Hole Horizontal Near HP/HT Critical Sour Gas Wells Completion in Indonesia: Lesson Learned from BD Field Development Project in Kujung Formation

Abstract

BD is a near high pressure-high temperature (HPHT) critical sour gas field located in offshore Madura Strait in water depth of 152 ft. An exploration and appraisal well were drilled in 1987 and 1992 respectively, targeting BD reef at depth of 10,676ft SSTVD. Both well test results confirmed the limestone formation has characteristic of 305°F and 8,105 psi, with 5,000 ppm of H2S and 5.5% of CO2 content. Four (4) development wells including three (3) horizontal and one (1) vertical well, were drilled to drain the reserves from BD field. The project was expected to deliver 120 MMSCFD of gas and 6,000 bpd of condensate for a period of 15 years production from BD field. Design, equipment and material to complete the well need to meet the target and be selected based on industry guidance and the environment to ensure the integrity of the well during the production time. Completion for BD wells adapts multiple tie-back concept to provide consistent large flow area and big bore advantages, providing flexibility for future well intervention. It consists of 3 (three) main assemblies and was designed based on series of load cases to predict the completion reliability to withstand the load during the life of the well. During the installation, the assemblies were run in different batches and fluid environment. Despite the challenges encountered during the preparation and installation, all wells were successfully completed and cleaned up safely without any incident. The completion could exceed the initial production target set by the reservoir engineering team. This paper will discuss about the completion process from the first near HPHT sour field development project in Indonesia. It describes the design process, preparation and installation of the BD completion especially in the horizontal well. Challenges, basis of design, material selection, lessons learned and optimization taken to safely deliver the completion are also covered in this paper.