辽河盆地桃园构造东营组砂岩的储集空间类型及成岩作用

桃园构造位于辽河盆地东部凹陷，其产层老第三系东营组砂岩主要属河流相砂体。砂岩孔隙发育，渗透率大，属高孔、高渗储层。其储集空间类型主要有粒间原生孔、粒内溶孔、粒间溶蚀扩大孔及粒间胶结物溶孔。对砂岩有影响的成岩作用主要有压实作用、胶结作用及溶蚀作用。东营组泥岩中有机质为半成熟阶段，属早成岩阶段Ｂ期。引起砂岩中矿物溶蚀的有机酸主要来自下伏地层。而构造上发育的张性正断层成为深部地层中流体向上运移的通道。有机酸随流体上升，进入砂体产生溶蚀，改善了砂岩储集物性。尔后，天然气沿断裂向上运移进入砂岩，并沿砂体运移到有利圈闭处聚集成气藏。

RESERVOIR SPACE TYPE AND DIAGENESIS OF DONGYING GROUP SANDSTONE IN TAOYUAN STRUCTURE OF LIAOHE BASIN

Taoyuan structure is located in the eastern depression of Liaohe Basin and produces naturalgas. The gas-producing atratum belongs to Donsyins Group of Eogene Tertiary. The sedimentary faciesof the sandstone is mainly fluvial. The porosity and permeability of the sandstone are well developed,so the reservoir is of hisht porosity and permeability. The major pore types are original interparticlepore, intraparticle pore and interparticle cemented solution pore. The main fsctors influencing the sandStone are compaction, cementation and dissolution. The orsanic matter in Dongying mudstone wasburied at the early diasenetic stage. The organic acid dissolving unstable minerals in the sandstone camefrom the underlyins strata. The formal fault was the channel of f.luid from the deeper part upwards tothe Shallower part compared with the fluid. The organic acid entered in the standstone of DongyingGroup and made the reservoir sreatly changed. Natural gas moved in the reservoir alons the faults andaccumulated in the traps.