Journal of Tropical Oceanography ›› 2017, Vol. 36 ›› Issue (1): 25-34.doi: 10.11978/2016047CSTR: 32234.14.2016047

• Orginal Article • Previous Articles     Next Articles

Thermal evolution of source rock and prediction of petroleum resources potential in Baiyun Depression, deep-water area of the northern South China Sea

Ke WANG(), Gongcheng ZHANG, Haizhang YANG, Zhigang TONG, Shuchun YANG   

  1. China National Offshore Oil Corporation Research Institute, Beijing 100028, China
  • Received:2016-05-06 Revised:2016-06-08 Online:2017-01-18 Published:2017-01-19
  • Supported by:
    National Science and Technology Major Projects “Key Techniques in the Deep Ocean Oil and Gas Exploration” (2008ZX05025、2011ZX05025)

Abstract:

Based on the data of drilling, logging, seismic, geology and basin modeling, we analyzed the characteristics of geothermal, source rock maturation, hydrocarbon expulsion, and accumulation coefficient by using the analogy and genetic methods. Then, prediction of petroleum resources potential in Baiyun depression is carried out. The results show that the Baiyun Depression presents high geothermal gradient, ranging from 34 to 67℃·km-1 and with an average of 40℃·km-1, which is favorable for organic matter maturation and hydrocarbon generation. Each source rock has been in the stage of mature or post mature, and the source rock maturation increases from the top formation of Zhuhai to the bottom formation of Wenchang; the area of post mature is 53.7% in the bottom formation of Wenchang. The strength of gas expulsion is bigger than the strength of oil expulsion, and the upper formation of Enping is the major formation of hydrocarbon expulsion. The hydrocarbon expulsion of three source rocks is 1143×108 m3, and prediction of petroleum resources potential in the Baiyun Depression is 25.2×108 m3 combining the accumulation coefficients of oil and gas.

Key words: Pearl River Mouth Basin, Baiyun Depression, source rock maturation and hydrocarbon expulsion, accumulation coefficient, resource potential