烃源岩排烃门限在生排油气作用中的应用

对于烃源岩的判别标准，目前仍广泛存在争议。主张以排烃门限的概念来确定有效排烃源岩、研究有效排烃源岩的生排烃量及其生排烃特征，以此来综合认识烃源岩的排烃历史和排烃过程。在研究过程中，首先根据烃源岩排烃品质评价图版判别排烃源岩，其次，根据排烃模型定量研究源岩的排烃特征。冀东探区高柳构造带古近系沙河街组三段（Es3）烃源岩的实例研究表明，其排烃门限深度对应的Ro 为0.78%。只有进入该排烃门限的烃源岩才能大量排烃，随热演化程度的增大，源岩排烃率和排烃效率逐渐增大。高柳构造带沙三段烃源岩的最大排烃强度超过450.00×104 t/km2，平均排烃强度为315.67×104 t/km2，排烃量总计9.47×108 t，排烃高峰时期是馆陶期，油气资源量可达到2.08×108 t。

Application of Hydrocarbon Expulsion Threshold in Studying the Hydrocarbon Generation and Expulsion

There has been disagreement about the judgment criterion of source rock for a long time.The concept of hydrocarbon expulsion threshold was used to identify the hydrocarbon expulsion source rock in our study on the hydrocarbon generation/expulsion quantity and the hydrocarbon generation/expulsion characteristics in this paper.Thus,the hydrocarbon expulsion history and hydrocarbon expulsion process can be acquired.The first step of the study is to judge the hydrocarbon expulsion source rock by using the source rock’s quality judgment plate;the second is to study the hydrocarbon expulsion characteristics by using the quantitative model.The studying on the Es3 source rock,Gaoliu Unit,Jidong Exploration Zone indicates that,the Ro corresponding to the hydrocarbon expulsion threshold is 0.78%.The largest hydrocarbon expulsion intensity is larger than 450.00×104 t/km2,and the average hydrocarbon expulsion intensity is 315.67×104 t/km2.The hydrocarbon expulsion peak period is Guantao period,and the total hydrocarbon expulsion quantity in the studying area is 2.08×108 t.