Pompano Through-Flowline (TFL) System

Abstract

Abstract The Pompano ten-well diverless subsea oil production template system, located 4–1/2 miles from the host platform. incorporates proven, 3-inch through flowline (TFL) equipment. The system was placed into production during May, 1995. The TFL equipment is used to enhance the well start-up operations and to provide a means for low well maintenance costs. This paper describes the TFL system and an iso-thermal, single-phase, steady-state hydraulic analysis model that was used to aid efficient design of the TFL system and its operation. Also, future development requirements that are needed to allow extending this technology for use in larger subsea wellbore sizes and for greater offset distances from a host facility are discussed. Summary The Pompano Field development was done in two phases. The first phase consisted of installing a deep water platform, topsides and export pipelines in 1994. The second phase consisted of installing a 10-well subsea oil production template in 1995 and tying it back to the host platform. The subsea template system, which incorporates through-flowline (TFL) well servicing capability, is discussed in this paper. The subsea system, with emphasis on the TFL aspects is described and costs are provided. A single-phase, steady-state, iso-thermal circulation model is described. This model was used during pre-design to aid simulation of the wide range of TFL system operating conditions that are expected during field life. Actual field experience that has been gained since start-up of the subsea system in 1995 demonstrates the value of doing this type of hydraulic modeling. Further TIlL-related development work is needed to extend TFL capabilities beyond those applied at Pompano, and these development needs are discussed. Conclusions are provided at the end of the paper. Introduction The Pompano field development. Figures 1 and 2, was implemented in two phases by BPX and its minority partner, Kerr-McGee. The first phase involved application of a drilling and producing platform in 1290 fsw and the second phase involved application of a 10-well, subsea well template that is located about 4–1/2 miles from the platform in 1850 fsw. Pliocene reserves are all located within directional drilling reach of the platform, and some of the offset Miocene reserves can also be reached from the platform using extended reach drilling. Miocene reserves that can't be efficiently drilled from the platform are being developed using the subsea well template. Thus, the overall project includes conventional platform wells, extended reach wells and subsea wells. The field development, while presenting many challenges, has either met or exceeded expectations. Drilling from both the platform and subsea template sites provides on-going opportunity for developing the reservoirs with efficiency and flexibility. One of the keys to getting this Project sanctioned(approved) was to demonstrate that essentially all of the platform and subsea well equipment designs and procedures could be done quickly and cost-efficiently. This was accomplished by identifying a balanced field development solution, or one that considered front-end capital costs, schedule, over-life operating costs, and risk containment. Risk containment was achieved by applying proven technology wherever possible. For example, the Pompano platform was based on the cost-efficient platform design that had been applied for the MC 109 (Amberjack) project also, Pompano topsides and export pipelines were designed to handle production from both the initial Phase 1 wells and the subsequent, Phase 2 subsea wells. This eliminated the need for any time-consuming and costly retro-fit activities. The focus of this paper is on the Phase 2, subsea well TFL-equipped system. An iso-thermal, steady-state hydraulic modeling technique that was used during pre-design is described. It's purpose was to help clarify various system features, aid with the system design, and ultimately, to provide field operations with a useful tool. P. 219^