【摘要】 综合应用电子显微镜、扫描电镜、阴极发光、X衍射、稳定同位素分析和流体包裹体分析测试等技术,通过半定量化研究深入探讨了莺歌海盆地XF13区块黄流组储层中富CO2和富烃类气两类气体充注对储层中碳酸盐胶结物形成的影响,结果表明:(1)靠近底辟的XF13A、XF13B井受到了晚期富CO2热流体充注影响,促进了溶蚀作用(次生孔隙比例为39.9%～58.4%),但由于处于幕式半开放的封闭成岩体系中,溶蚀过程中形成的大量Ca2+、Mg2+、Fe2+等离子没有及时排出,这些离子重新化合沉淀形成大量晚期碳酸盐胶结物,使得碳酸盐胶结物体积分数(4.5%～13.5%)和类型增多,进而破坏孔隙喉道,形成中孔低渗储层;(2)远离底辟的XF13E、XF13F等井黄流组储层主要是早期烃类气充注,溶蚀作用较弱(次生孔隙比例为7.2%～27.7%)且处于开放的酸性热液体系中,造成碳酸盐胶结物体积分数(1.0%～6.0%)和类型相对较少,形成中孔中渗储层。更多还原

【Abstract】 This paper studies the effects of CO2-rich and hydrocarbon-rich gas charging on the formation of carbonate cement from Huangliu Formation,XF13 block in Yinggehai Basin on the basis of synthetic analysis,including optical microscopy,scanning electron microscopy,cathode luminescence,X-ray diffraction,stable isotope analyses,and fluid inclusion determination.Results show that:(1) The late-stage chargingof CO2-rich thermal fluid occurred in the XF13 Aand XF13Bwells close to the diapir zone,and this region experienced strong dissolution(the secondary porosity contributes 39.9%-58.4%for the total plane porosity).Because the diagenetic system was relatively close with episodic semi-open system,massive ions,such as Ca2+,Mg2+,and Fe2+generated by dissolution are largely preserved in the system.These ions are combined to form various high-content carbonate cements(4.5%-13.5%)which filled the pore throats and reduced the permeability.Consequently middle porosity-low permeability reservoir was formed.(2)The XF13 Eand XF13Fwells far from the diapir zone were mainly charged by the early-stage hydrocarbon-rich fluid.This region experienced weak dissolution(the secondary porosity contributes 7.2%-27.7%for the total plane porosity).At the same time,the diagenetic system is relatively open with acid hydrothermal system,forming only some types of low-content carbonate cements(1.0%-6.0%).As a result,middle porosity-middle permeability reservoir was formed.更多还原