【摘要】 利用钻井、地震和分析测试资料,对徐深气田盖层发育及分布、封气能力的有效性和封气时间的有效性进行了研究,得到徐深气田天然气盖层主要为登二段发育的泥岩和营一段顶部发育的火山岩,前者整个断陷分布,是断陷南部营四段火山角砾岩和断陷北部营三段火山岩储集天然气的盖层,后者仅分布在断陷南部,是营一段火山岩储集天然气的盖层。徐深气田中12个气藏盖层排替压力均大于储层排替压力和气藏剩余压力之和,封气能力的有效性好,有利于天然气聚集与保存。登二段和营一段顶部盖层封气性形成时期主要分别为泉一、二段沉积时期和登四段沉积时期,均早于沙河子组煤系源岩的大量排气期(青山口组沉积时期),封气时间的有效性好,也有利于天然气的大规模富集成藏。更多还原

【Abstract】 Through drilling and seismic data,development and distribution of caprock of Xushen gas field was studied.It was considered that caprock of Xushen gas field is mainly mudstone caprock of K1d2 and volcanic caprock on top of K1yc1,and the former which distributes in the whole of depression is caprock of gas reserved in K1yc4 volcanic breccia in the south of depression and caprock of gas reserved in K1yc3 volcanic in the north of depression,the later which distributes in the south of depression is caprock of gas reserved in volcanic.Through test and logging data,displacement pressure of caprock and reservoir and excessive pressure of gas reservoirs were studied.It was considered that displacement pressure of caprock in 12 gas reservoirs is larger than the sum of displacement pressure of gas reservoirs.Their seal gas ability effectiveness is good,and it is favorable for gas to accumulate and preserve.Through the study of evolution of seal gas ability of caprock and relation between formation period of seal gas ability and massive expulsion gas period of seal source rock,it was considered that formation period of seal gas of K1d2 caprock and K1yc1 caprock are sedimentary period of K1q1,2 and K1d4 and they are earlier than massive expulsion gas period of gas source rock(Sedimentary period of K1sh).Their seal gas time effectiveness is good.It is favorable for large-scaled gas accumulation.更多还原