The Liwan 3–1 gas field, situates in block 29/26 with an average water depth of 1,300m, represents the first major deepwater discovery in the South China Sea. The development scenario of Liwan 3–1 indicates potentially an efficient way for those gas fields around the continental slope of South China Sea. Before the first appraisal well being drilled, CNOOC Research Institute was commissioned to carry out Liwan 3–1 feasibility study on December 27, 2007. This paper provides an overview of several development scenarios based on the limited data of Liwan 3–1 such as wells information and assumed data such as reservoir profile and pressure. In view of those potential discoveries near Liwan field, regional development strategy is also taken into consideration. As a result, the suggested development scenario is subsea wells tieback to Boosting and Processing Center (BPC). Through BPC, the natural gas is processed and boosted via shallow water pipeline to onshore terminal plant. BPC is actually not only a feasible scenario to speed up Liwan 3–1 development, but also a regional solution for potential fields near Liwan 3–1.
The Liwan 3–1 gas field is the first discovery in the deepwater of South China Sea and shared by CNOOC and Husky. Liwan 3–1 locates at a water depth of nearly 1500m and about 65km from PY30-1–1. The discovery of Liwan 3–1–1 well in 2006 showed that the gas production rate almost reaching 5 billion m3/a. Two appraised wells named Liwan 3–1–2 and Liwan 3–1–3 were also completed in the end of 2008 and in the middle of 2009 by West Hercules semisubmersible drilling platform respectively followed by another appraised well later.
In this paper, several development scenarios of Liwan 3–1 gas field are demonstrated firstly. Then the scenarios of BPC (Boosting and Processing Center) are also studied based on a regional development view of potential fields near Liwan 3–1 and the scenario of one APP (accommodation and power platform) plus two PCPs (processing and compressing platform) is recommended. In view of minimizing investment and adopting regional development scenario, subsea wells tieback to BPC is suggested for the development of Liwan 3–1.
