东濮凹陷文东地区沙三段地层水特征及成岩响应

Characteristics and diagenetic response of Es₃ formation water of Wendong Area,
Dongpu Depression

佟昕¹ 马鹏杰¹ 张世奇¹ 周瑶琪¹ 慕小水² 徐田武²

中国石油大学（华东）地球科学与技术学院，山东 青岛 266580 中国石化中原油田分公司勘探开发研究院，河南 濮阳 457001

School of Geosciences, China University of Petroleum, Qingdao 266580, China Research Institute of Exploration and Development, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China

以地层水统计分析为基础，利用氘和氧同位素、铸体薄片及扫描电镜等测试手段，对东濮凹陷文东地区沙三段地层水化学特征、成因及其在成岩作用中的响应进行了研究。结果表明：文东地区沙三段地层水型以CaCl₂为主，盐岩的溶解控制了地层水矿化度。地层水参数指示沙三段地层封闭性强，水岩作用强烈。相对于Cl^-，Na⁺+K⁺的缺失与阳离子交替吸附作用、斜长石钠长石化及自生伊利石的发育有关；阳离子交替吸附作用、斜长石钠长石化、膏盐岩的溶解、硬石膏胶结物蚀等作用使地层水富Ca²⁺，白云石化及绿泥石化造成了Mg²⁺的缺失；膏岩溶解及有机质的成熟使得地层水富含SO₄^2-，HCO₃^-，CaSO₄与CaCO₃过饱和的流体环境，碳酸盐与硬石膏胶结物十分发育。

Based on the analysis of formation water, applying various measurements such as analysis of Deuterium and Oxygen isotopes, cast thin section and scanning electron microscope, the characteristics and origin of formation water and its diagenetic response were studied. The result shows that this formation water is mainly of CaCl₂ type, and disassociation of rock salt controls the salinity. Formation parameters reflect a good sealing of Es₃ with strong water-rock reaction. The missing of Na⁺+K⁺, compared with Cl^-, is caused by cation alternative adhesive action, albitization of plagioclase and authigenic illite. Cation alternative adhesive action, albitization of plagioclase and disassociation of evaporite rock and anhydrite cements provide more Ca²⁺, dolomitization and chloritization result in a lack of Mg²⁺. Disassociation of gypsum rock and maturation of organic make the formation water rich in SO₄^2-and HCO3^-. Supersaturated CaCO₃ and CaSO₄ lead to good development of carbonate and anhydrite cements.

10.6056/dkyqt201505011