Geochemical Characteristics And Hydrocarbon-generating Strength For The Source Rock In Baxian Depression

Baxian Depression is an oil-enriched sag in the east of Jizhong Depression where the source rocks are in good quality.In order to accurately grasp the oil and gas distribution in the delicate phase of exploration,we must find out the favorable area of source rock,calculate its hydrocarbon-generating intensity and lay the foundation for the discovery of new oil and gas reservoirs.The article discusses the organic geochemical characteristics and hydrocarbon-generating intensity of Baxian Depression using the data from well logging,seismology and geochemistry.Based on the evaluation from abundance,type and maturity of organic matter in Baxian Depression,the development position of primary source rocks is identified,i.e.Es4,the middle sub-section of Es3,the lower sub-section of Es3 and the lower sub-section of Es1.The abundance of organic matter in those four sections is relatively higher than other positions,and most of them are kerogen type II which have reached the threshold of source rocks.Combined with?logR and seismic methods,the article depicts the geochemical characteristics of source rocks in different layer sections from the perspective of single well,tied well and plane,identifies the regularities of distribution for high and medium quality of source rocks,builds a hydrocarbon generation model for quantitative assessment of source rock using the thermal simulation experiment,and finally discusses the center of oil generation and distribution pattern of hydrocarbon-generating intensity for different types of source rocks.The article draws a conclusion that oil and gas resources in Baxian Depression are mainly derived from the oil contribution of Es3 in the middle and lower sub-section of the source rock,followed by the Es4 segment of source rock,and Es1 in the lower sub-section of the source rock is the least contribution among those three layers.