Simulation of Gas Generation from the Paleogene Enping Formation in the Baiyun Sag in the Deepwater Area of the Pearl River Mouth Basin, the South China Sea

Abstract

The deepwater area of the Baiyun Sag is the primary region of deepwater oil and gas exploration in China. Since the breakthrough made in natural gas exploration in the structure of the LW3-1 gas field, explorers have given significant attention to the conditions and process of gas generation and to the accumulation and preservation of natural gas. The Paleogene Enping Formation provides one of the two sets of major source rocks in the Baiyun Sag. We selected three samples of source rocks from the Enping Formation, performed a thermocompression simulation experiment, calculated the hydrocarbon generation kinetic parameters, and simulated single-well gas generation to explore the process of gas generation in the gas-generating center of the Enping Formation in the Baiyun Sag. The major conclusions included the following: (1) The lacustrine dark mudstone and the carbonaceous mudstone from the Enping Formation in well HZ08-1-1 have hydrocarbon yields of 383.7 versus 307.3 kg/t of total organic carbon (TOC) and gas yields of 370.1 versus 302.9 kg/t of TOC. (2) The thermal evolution of the Enping Formation in the Baiyun Sag can be divided into three evolutionary stages. (3) Finally, the source rocks of the Enping Formation have a gas generation peak from approximately 17.5 to 8 Ma.