前梨园洼陷深盆气藏

前梨园洼陷受凹陷边界兰聊断裂控制,持续发育,为深盆气形成提供了必要的基础。洼陷内下第三系发育良好的烃源岩,演化程度高,气源充足,沙河街组三段三、四亚段发育低孔低渗的致密砂岩储层,为深盆气藏形成创造了条件。前梨园洼陷周缘已发现气藏具有“气水倒置”、异常高压、含气井段长且产量低、气藏不受构造控制等特征。东濮凹陷是陆相断陷盆地中“断洼型”深盆气的典型代表,环洼的斜坡带是下一步勘探的有利区。

DEEP BASIN GAS ACCUMULATION IN QIANLIYUAN DEPRESSION

Being controlled by Lanliao fault on the margin, Qianliyuan depression continues developing to provide the necessary foundation of the formation of deep basin gas accumulations. Well-developed hydrocarbon source rocks occur in Lower Tertiary in the depression, which has high evolution degree and abundant gas source.Tight sand reservoirs with low-porosity and low-permeability develop in the 3rd and 4th sub-members of the third members, Shahejie Formation,which are favorable for the formation of deep basin gas accumulations.Gas accumulations, characterized by “inverted gas and water”, anomalous high-pressure, long gas-bearing interval and low production,as well as unrelated with structure,etc.,have been discovered around Qianliyuan depression. Dongpu depression is a typical “fault-sag” type deep basin gas among the non-marine fault-depression basins, and the slope zone surrounding the depression will be favorable target for exploration in the future.