鸡西盆地构造演化及煤层气资源量概率分布

鸡西盆地是松辽盆地外围东部勘探的重要目标区之一。早白垩世发育有多套煤系地层, 且分布面积广, 储量丰富, 是重要的烃源岩。本文在研究鸡西盆地地质构造特征的基础上, 恢复了鸡D1井区沉降史。沉降史曲线反映出该盆地经历了早期的快速断陷沉降, 但其间发生过三次短期抬升与剥蚀。从下白垩统上部猴石沟组沉积开始, 盆地进入了相对稳定沉降时期。海浪组沉积之后, 本地区发生了较长时间(约28 Ma) 的抬升与剥蚀, 而这一时期是鸡西盆地演化史上一次主要的构造变动期, 是盆地基本构造格局的形成期。根据早期的强烈快速断陷阶段形成的煤系相关参数并运用蒙特卡罗法计算的煤层气资源量在0.1、0.5、0.9的概率下分别为81.7 ×1011 m3、5.36 ×1011 m3、2.41 ×1011 m3。

Tectonic evolution and probability distribution of CBM resources in Jixi Basin

Jixi Basin is one of the important target areas for exploration among the external basins in the eastern part of Songliao Basin. Several sets of coal seams developed during Early Cretaceous with wide distribution and abundant reserves, and they are also important source rocks. On the basis of studying the characteristics of geological structure in Jixi Basin, the subsidence history of Well Ji-D1 was recovered. The curves of subsidence history reflect that the basin experienced the express faulting subsidence in early stage, but three times of short-term up lifts and erosions happened during this period. From the deposition of Houshigou Formation in the upper part of Lower Cretaceous, the basin began to enter a relatively stable period of settlement. After the deposition of Hailang Formation, long time ( about 28 Ma) up lift and erosion has taken place in the region, which was the main structural deformation period in the evolution history of J ixi Basin, and also was the formation period of basic structural pattern in the basin. According to the related parameters of coal seams formed by the express faulting subsidence in early stage and calculated the amount of coal-bed methane resources using Monte-Carlo method, the resources are 8.17 ×1011 m3 , 5.36 ×1011 m3 and 2.41 ×1011 m3 respectively at the probability of 0.1, 0.5 and 0.9.