塔里木盆地塔中低凸起地层水与油气关系

RELATIONSHIP OF FORMATION FLUID AND HYDROCARBON IN TAZHONG LOW UPLIFT OF THE TARIM BASIN

薛会 张金川 王毅 卞昌荣 王敏

Xue Hui Zhang Jinchuan Wang Yi Bian Changrong Wang Min

中国石油化工股份有限公司 石油勘探开发研究院, 北京 100083 2. 中国地质大学, 北京 100083

Research Institute of Petroleum Exploration and Production, SINOPEC, Beijing 100083, China 2. China University of Geosciences, Beijing 100083, China

通过对塔中地区地层水矿化度、水型及水化学指数分析认为,塔中地区封闭保存条件良好。除志留系外,石炭系和奥陶系高矿化度中心和正、负向地层水化学指数中心与油气分布匹配良好。石炭系,塔中东南部保存条件较好;奥陶系,塔中北坡Ⅰ号断裂带保存条件较好。石炭系和奥陶系油气运移与水动力有关,分别受重力流和压实流影响。前者由北西向南东运移,后者由北东向南西运移。地层水总矿化度和水化学指数变化与含油气性关系密切,就塔中地区而言,有利于油气保存的地层水化学指标分别为:地层水矿化度大于35g/L,变质系数大于0,钙镁系数大于1,钠氯系数小于0.9,脱硫系数小于3,碳酸盐平衡系数小于0.2。

The Tazhong low uplift is considered to be in good preservation condition through analyses of salinity,water types and geochemistry exponents of formation water.The centers of high salinity,positive and negative geochemistry exponents match with hydrocarbon distribution very well in Carboniferous and Ordovician layers except Silurian.Carboniferous layer in the southeastern Tazhong and Ordovician layer in structural belt I in the northern slope of Tazhong are both favorable for preservation.Hydrocarbon migratory directions in both formations are related to hydrodynamic force.The former is from northwest to southeast affected by gravity flow while the latter is from northeast to southwest due to compaction flow.The relationship between salinity,geochemistry exponents and hydrocarbon accumulation is tight for the Tazhong low uplift.Beneficial geochemistry exponents of formation water inClude:1) salinity(35 g/L);2) rCl-/rMg2+-rNa+/rMg2+(0);3) rCa2+/rMg2+(1);4) rNa+/rCl-(0.9);5) rSO2-4×100/(rCl-+SO2-4)(3);6)(rHCO-3+rCO2-3)/rCa2+(0.2).

国家重点基础研究发展计划(973计划)项目(2005CB422104)

https://doi.org/10.11781/sysydz200706593