准噶尔盆地乌夏地区侏罗系储集层成岩作用与孔隙演化

乌夏地区侏罗系储集层主要是冲积扇、扇三角洲及辫状河沉积环境下形成的岩屑砂岩及长石岩屑砂岩。对储集层成岩作用过程的研究结果表明,储集层的孔隙演化与成岩作用有密切关系。压实作用及早期胶结作用是促使原生孔隙遭受破坏的主要原因;碎屑颗粒、粘土矿物及碳酸盐的溶解是形成次生孔隙的主要因素;后期(含)铁方解石等胶结物使次生孔隙被充填。孔隙演化经历了原生孔隙破坏、次生孔隙形成、次生孔隙破坏3个阶段。

Diagenesis and Porosity Evolution of Jurassic Reservoir in Wu-Xia Area, Junggar Basin

The Jurassi reservoir in Wu-Xia area is dominated by lithic sandstone and feldspathic litharenite under alluvial fan, fan delta and braided river sedimentary environments. The diagenesis study shows that the porosity evolution of reservoir is closely related with the diagenesis types. Compaction and early cementation are the main reasons for destroying primary pores. The dissolution of detrital grain, clay mineral and calcite is the main factor for forming secondary pores. And the cement like ferrocalcite is responsible for the destruction of the secondary pores. The porosity evolution experienced three steps, including the destroying of primary pores, formation of secondary pores and destruction of secondary pores.