Geological, Geophysical and Petrophysical Characterization of Hydrocarbon Reservoirs in South China Sea Deep Water Block 29/26

摘要

In 2004, Block 29/26 Production Sharing Contract (PSC) was signed between Husky Energy Inc. and China National Offshore OilCorporation (CNOOC). The block is located about 300 km offshore Hong Kong (Figure 1), on the north east slope of the gas-proneBaiyun (White Cloud) Sub Sag of the Zhu-Ⅱ sub-basin in the larger Pearl River Mouth Basin (PRMB). The water depth on theblock is from 650 m to 1500 m.A total of 27 deep water exploration and appraisal wells were drilled in the period between 2006 and 2011. Three commercial gasfields, Liwan 3-1-1, LH34-2 and LH29-1, were discovered in April 2006, September 2009 and December 2009, respectively.Several sub-economic gas accumulations were also discovered in the same period. Reservoir and hydrocarbon detection and trapdelineation, were the key challenges faced by the exploration team. An integrated subsurface approach, including extensive 3Dseismic surveying and high quality processing, seismic inversion, accurate structural/stratigraphic mapping, accurate depthconversion and seismic-based geomorphology, played a key role in making these discoveries. At the time of writing this paper,Block 29/26 is the only deep water block in South China Sea (SCS) with commercial discoveries, and boasts the most extensivedeep water database in the region, including large amounts of seismic, conventional and side-wall cores, wireline logs, pressure andfluid samples as well as subsequent lab analyses data. Full investigation of the available information can be expected to provide thenecessary guidance for future exploration and development activities in this region.There are several types of reservoirs encountered in Block 29/26. Each type of reservoir has distinctively different logcharacteristics and seismic responses. This paper provides a systematic review on the applicability of AVA technology to theseismic data on the block and focuses on the challenges that need to be addressed in the future.