吐哈盆地十三间房地区煤系烃源岩生烃评价及排烃特征

Evaluation of the hydrocarbon generation and hydrocarbon expulsion characteristics of coal-measure source rock in Shisanjianfang area,Tuha Basin

利用钻井、地震数据及三维地质建模技术对十三间房地区煤系烃源岩厚度及分布特征进行了预测,根据地球化学测试数据对十三间房地区水西沟群烃源岩的有机质类型、有机质丰度、有机质成熟度进行了评价,利用生烃潜力法建立了研究区烃源岩的排烃模式,明确了研究区的排烃特征。研究结果表明,研究区西北部烃源岩厚度较大,在350~600 m之间,平均值为480 m。烃源岩有机质丰度较高,处于成熟—高成熟热演化阶段,有机质类型主要为Ⅱ、Ⅲ类,具有一定的生烃潜力。研究区水西沟群煤岩排烃门限深度为2 000 m,最大排烃率为530 mg/g,在2 500 m处迅速达到排烃高峰,最大排烃速率为150 mg/(g·hm);煤系泥岩排烃门限深度为2 200 m,在2 800 m处迅速达到排烃高峰,最大排烃率为320 mg/g,表明研究区具有一定的开采潜力。本次研究对相似地质条件地区生烃和排烃研究具有一定的借鉴意义。

The organic matter type,abundance of organic matter and maturity of organic matter of hydrocarbon of Shuixigou formation in Shisanjianfang area had been evaluated through the geochemical test data. A hydrocarbon expulsion mode of the study area has been established by hydrocarbon-generated potential method,and the hydrocarbon expulsion characteristics has been determined. The result show that,the northwest of the study area with the thick source rock,the thickness between 350-600 m,the average is 480 m. Higher abundance of organic matter and the thermal evolution stage is between maturation to high maturation,the organic matter types mainly for class Ⅱ and Ⅲ,has a certain hydrocarbon-generating potential. The expulsion threshold depth of coal petrography in the Shuixigou Ground of the study area is 2 000 m,and the biggest hydrocarbon expulsion rate is 530 mg/g. In the 2 500 m,quickly reaching the peak of hydrocarbon expulsion,and the biggest hydrocarbon expulsion rate is 150mg/( g·hm). The expulsion threshold depth of coaly mudstones in the Shuixigou Ground of the study area is 2 200 m,and the biggest hydrocarbon expulsion rate is 320 mg/g. In the 2 800 m,quickly reaching the peak of hydrocarbon expulsion,indicating that the study area has certain exploration potential. These research results have certain reference significance of the hydrocarbon expulsion study for the area which has the similar geological conditions.