桂中坳陷现今水文地质地球化学与油气保存  

Present hydrogeological-hydrogeochemical charactersand hydrocarbon preservation conditions of Guizhong depression

作　　者：金爱民[1] 尚长健[2] 李梅[1] 朱蓉[1] 楼章华[1] 

机构地区：[1]浙江大学海洋科学与工程学系,浙江杭州310058 [2]浙江大学地球科学系,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2011年第4期775-781,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家重点实验室开放基金资助项目(PLC201002);全国油气资源战略选区调查与评价项目(XQ-2007-01);国家自然基金联合化工重点资助项目(40839902);国家"973"重点基础研究发展规划资助项目(2005CB422107)

摘　　要：从水文地质地球化学角度,对桂中坳陷及周缘岩溶地质、温泉水成因和分布以及温泉水循环深度、地层水化学特征等进行分析,探讨桂中坳陷及周缘地区油气保存条件及勘探潜力.研究结果表明:桂中坳陷内现今埋深小于800m的浅部地层岩溶发育,受大气水下渗作用强烈,水文交替频繁,地层水普遍为低矿化度水,属自由交替带,油气保存条件普遍差;埋深大于800m的地层,大气水下渗作用逐渐减弱,进入交替阻滞带,油气保存条件逐渐变好,交替停止带可能分布在2 000m以下地层.坳陷外围尤其是坳陷东部和东南部,发育中高温温泉,大气水下渗深度在1 000m以上,不利于油气保存.桂中坳陷中西部大气水下渗作用对油气保存条件的破坏影响相对较弱.The karst geology, spring water＇s distribution, origin and the circle depth, formation water＇s chemistry characteristics of Guizhong depression and its margin were analyzed from the hydrogeological and hydrogeochemieal point of view. The hydrocarbon preservation conditions and exploration potential of Guizhong depression and its margin were deeply discussed. Results showed that the shallow formation with depth less than 800 meters, i.e. free exchanging zone, was of karst landform, strong meteoric water infiltration influence, frequent hydrological alternation, and low salinity of formation water in Guizhong depression. The hydrocarbon preservation conditions herein were generally poor. The strata of depth greater than 800 m was named as exchanging-retarded zone, the meteoric water infiltration influence were gradually weakened, and its oil and gas preservation condition became better. Exchanging-stagnant zone may be located in the formation deeper than 2 000 m. The margin of Guizhong depression, especially the east and southeast, with mid-high temperature springs developing and meteoric water infiltration depth above 1 000 m, was not favorable to oil and gas preservation. However, the damage of meteoric water infiltration to hydrocarbon preservation conditions in the central and western Guizhong depression was relatively weak.

关 键 词：桂中坳陷 水文地质地球化学 大气水下渗 油气保存 

分 类 号：TE144[石油与天然气工程—油气勘探]