THERMO-COMPRESSION CHARACTERISTICS OF HYDROCARBON GENERATION FOR THE SOURCE ROCKS IN THE FUNINGFORMATION OF SOUTH YELLOW SEA BASIN

The kinetics data of hydrocarbon generation is very important to hydrocarbon resource evaluation. The source rock samples taken from the 4th Member of the Funing Formation in the Naner Sag of the South Yellow Sea Basin are used in this paper for thermo-compression simulation and fitting experiment of kinetic parameters for hydrocarbon generation. The results suggest that the generation of hydrocarbon in the 4th Member of the Funing Formation can be subdivided into three stages. In the first stage, hydrocarbon production dominated by oil increased rapidly with the rise of temperature. In the second stage, with the increase in temperature, hydrocarbon production including both oil and gas increased slowly. In the third stage, hydrocarbon production, dominated by gas, increased rapidly with the rise of temperature. The experimental results show that the activation energy for oil generation and gas generation is 228 kJ/mol and 280 kJ/mol, Respectively. Compared with the results from conventional experiment under open system and the gold tube autoclave test for the source rock samples of the Funing Formation, a lag phenomenon is noticed. The source rock samples still have high liquid hydrocarbon production in the highly matured stage. The activation energy value of the 4th Member of Funing Formation derived from this experiment is higher than that in the other two cases of experiment. It is believed that the evolution of organic matter is protected by the high pressure porewater and influenced by the hydrocarbon generation space, which caused the delay of the thermal evolution process of the source rock. Based on the comprehensive analysis of this experiment and previous experimental results, the experiment environment of the thermo-compression simulation for hydrocarbon generation in finite space is concluded, which is closer to the geological conditions for hydrocarbon generation, and results of this experiment are useful to oil and gas resource evaluation and exploration in the South Yellow Sea Basin