鄂尔多斯盆地姬塬地区延长组长8地层水化学特征及其地质意义  

The chemical characteristics and geological significance of formation water of Chang 8 Subsection in Jiyuan area of Ordos Basin

作　　者：马海勇[1,2] 周立发[1] 邓秀芹[2] 李继宏[2] 杨丽萍 

机构地区：[1]西北大学地质学系,陕西西安710069 [2]长庆油田公司勘探开发研究院/低渗透油气田勘探开发国家工程实验室,陕西西安710018 [3]长庆油田公司培训中心,陕西西安710018

出　　处：《西北大学学报（自然科学版）》2013年第2期253-257,共5页Journal of Northwest University（Natural Science Edition）

基　　金：国家科技重大专项基金资助项目(2011ZX05044;2011ZX05001-004)

摘　　要：目的研究鄂尔多斯盆地姬塬地区长8地层水化学性质、油气运移及保存条件,揭示长8地层水与油藏圈闭演化特征的关系。方法利用长8地层水化学分析方法,分析地层水矿化度、离子组合系数的平面分布规律,结合区域构造演化特征对地层水化学性质、油藏保存条件进行综合研究。结果长8地层水水型为CaCl2型,靠近伊陕斜坡、浅水三角洲砂体发育区矿化度高,钠氯系数、脱硫系数低,为较强的还原环境;天环拗陷轴部断层发育区具有矿化度低,钠氯系数、脱硫系数高的特点。结论研究区长8地层水分布特征受燕山期构造运动的影响较强,不同区域地层水的化学性质明显不同,高矿化度区钠氯系数、脱硫系数低,反映较强的还原环境;封闭性好,油藏保存较好。Aim The chemical characteristics of formation water was used to study the condition about the oil and gas migration and preservation of Chang 8 Subsection in Jiyuan area of Ordos Basin. Methods Based on the characteristics of tectonics evolution, the flat distribution regulation of the formation water salinity, water type, ratio of Na ＋ and Cl^-, coefficient of desulphuration were analyzed. Results It is found that the formation water type is CaC12, the formation water salinity is high, the ratio of Na ＋ and Cl^ - and coefficient of desulphuration is low where the shallow-water deltas has been developed in Chang 8 sandstones and close to Yishan Slope. The formation water salinity is low, the ratio of Na ＋ and Cl^- and coefficient of desulphuration is high near Tianhuan depression or faults. Conclusion The formation water distribution of Chang 8 Subsection was influenced by Yanshan movements, different regions have different chemical characteristics of formation water, the closed geological environment is good for oil to be preserved where the formation water salinity is high, the ratio of Na ＋ and Cl^- and coefficient of desul- phuration is low.

关 键 词：鄂尔多斯盆地 姬塬地区 长8 地层水矿化度 

分 类 号：TE122.1[石油与天然气工程—油气勘探]