川西新场地区须家河组泥岩欠压实与油气层关系

新场地区须家河组气藏属于致密碎屑岩气藏,具有超深、超压、超致密、低孔渗等特点。通过研究新场地区深层油气藏泥岩欠压实特征及其与储层、盖层、油气运移聚集和分布的关系,认为:新场地区须家河组地层存在明显的泥岩欠压实段,油气层多分布于欠压实段内;由于欠压实砂岩中的颗粒表面被烃类润湿后,抑制了降低孔隙度的成岩作用,其异常地层压力在一定程度上阻碍了砂岩的进一步压实,储层的物性相对变好,新场地区须家河组地层在整体致密-超致密背景上发育了部分储集性能较好的储层;由于欠压实高压泥岩的压力封闭作用,须三段、须五段成为有效盖层;欠压实泥岩内由烃类产生的剩余孔隙流体压力及构造作用形成的裂缝有利于油气向欠压实段内的砂岩运移和聚集。

THE RELATIONSHIP OF UNDER-COMPACTION OF MUD ROCK AND OIL AND GAS RESERVOIR IN XUJIAHE FORMATION IN XINCHANG AREA,ESTERN SICHUAN

The xujiahe gas reservoir in Xinchang Area is a tight clastic rock gas reservoir,the characters of which are super deep,over-pressured,excessively tight,low porosity.By researching the characters of under-compaction of mud rock in the deep oil and gas reservoir in Xinchang Area and their relativity with reservoir,cap formation,migratory aggregation and distribution,the thesis proposes the following views.Firstly,obvioursly,there is under-compaction of mud rock division in xujiahe formation in Xinchang Area,...