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在库车坳陷克拉苏构造带大北地区地质研究的基础上,利用显微镜观测、激光共聚焦显微扫描、高压压汞分析及孔渗测试等方法,研究了致密砂岩气储层物性特征。结果表明,库车坳陷的致密砂岩气储层孔隙类型以槽型孔、溶蚀孔为主;致密砂岩气储层排驱压力一般在5 MPa以上,孔隙分选性差,孔喉半径较小;致密砂岩气储层孔隙度小于5%时,孔隙度与渗透率之间的相关性较差,表现为孔隙度低而渗透率高,推断是微裂缝的发育提高了砂岩的渗透率;致密砂岩气储层岩石类型以长石岩屑质石英砂岩为主,胶结作用以方解石胶结为主,裂缝改造作用明显。
Based on the geological research of the Dabei area in the Kelassu tectonic belt of the Kuqa Depression, physical properties of tight sandstone gas reservoirs were studied by means of microscope observation, confocal laser scanning microscopy, high pressure mercury intrusion analysis and pore permeability test. The results show that the pore types of tight sandstone gas reservoirs in the Kuqa Depression are mainly trough-shaped pores and dissolved pores. The drainage pressure of tight sandstone gas reservoirs is generally above 5 MPa with poor pore separation and small pore throat radius. When the porosity of tight sandstone gas reservoir is less than 5%, the correlation between porosity and permeability is poor, which is characterized by low porosity and high permeability. It is inferred that the development of micro-fractures increases the permeability of sandstone; the tight sandstone The rock types of gas reservoirs are mainly feldspar-bearing quartzites, cementation is dominated by calcite cementation, and the effect of fracture alteration is obvious.