华池油田华152区长3油层组砂岩的成岩作用与孔隙演化

华池油田华152区长3油层组储层以粉细粒长石砂岩、岩屑长石砂岩为主，发育多种孔隙类型，主要有粒间溶孔、粒内溶孔、剩余粒间孔、晶间微孔隙和构造缝，其中粒间溶孔是长3油层组储层的主要孔隙类型。主要成岩矿物为伊利石、绿泥石、伊／蒙混层、高岭石、方解石、白云石、石英等。根据成岩作用的矿物岩石学标志，将研究区成岩阶段界定为中成岩A期。压实和胶结作用破坏了砂岩的原生孔隙结构，而溶蚀作用形成次生孔隙，有效地改善了砂岩的孔隙结构。

Diagenesis of the Chang-3 sandstone reservoirs from the Hua-152 block in the Huachi Oil Field

The Chang-3 sandstone reservoirs from the Hua-152 block in the Huachi Oil Field mostly consist of finegrained feldspar sandstone and lithic sandstone in which various pore types are developed, including intergranular solution openings, intragranular solution openings, residual intergranular pores, intercrystal micropores and structural fissures. The intergranular solution openings occur as main pore types in the study area. The major diagenetic minerals include illite, chlorite, mixed illite-smectite, gaolinite, calcite, dolomite and quartz overgrowths. According to mineral indicators for diagenesis, the Chang-3 sandstone reservoirs in the study area are interpreted to be in the stage A of middle diagenesis. The compaction and cementation are responsible for the destruction of the primary pore structures of the sandstones, whereas the dissolution of feldspar and lithic fragments resulted in the development of secondary pores and improvement of the pore structures of the sandstones.