四川盆地南川地区及邻区页岩气保存差异的流体响应特征  

Fluid response characteristics of shale gas preservation differences in Nanchuan and its adjacent blocks in Sichuan Basin

作　　者：楼章华[1] 张欣柯 吴宇辰 高玉巧[2] 张培先[2] 金爱民[1] 朱蓉[1] LOU Zhanghua;ZHANG Xinke;WU Yuchen;GAO Yuqiao;ZHANG Peixian;JIN Aimin;ZHU Rong(Ocean College,Zhejiang University,Zhoushan,Zhejiang 316021,China;Research Institute of Exploration&Development,Sinopec East China Oil and Gas Company,Nanjing,Jiangsu 210011,China)

机构地区：[1]浙江大学海洋学院,浙江舟山316021 [2]中国石化华东油气分公司勘探开发研究院,江苏南京210011

出　　处：《油气藏评价与开发》2023年第4期451-458,共8页Petroleum Reservoir Evaluation and Development

基　　金：国家科技重大专项“彭水地区常压页岩气勘探开发示范工程”(2016ZX05061);中国石化科技项目“渝东南盆缘转换带页岩气富集主控因素研究”(P18057-2);中国石化科技项目“南川复杂构造带页岩气勘探开发关键技术”(P19017-3)。

摘　　要：四川盆地南川地区及邻区上奥陶统五峰组—下志留统龙马溪组页岩气勘探开发已取得丰硕成果,但如何利用流体特征综合分析各区块页岩气保存差异值得关注。研究表明:①随着开采时间延长,产出水矿化度逐渐升高,且明显不同于压裂液,表明页岩层内存在可动地层水,其矿化度超过50 g/L,CaCl_(2)水型;②富集高产井低产水,矿化度低,NaHCO_(3)水型,具有凝析水特征;③不同保存条件下,产出水氘、氧同位素特征随时间而有不同变化,盆内高压稳定区块,逐步偏离大气降水线,盆外常(低)压复杂区块,一直靠近大气降水线;④从盆内到盆外,由深至浅,页岩裂缝充填方解石脉流体包裹体的均一温度逐渐降低(从240℃至90℃),包裹体盐水的变质系数也逐渐变大,反映了页岩气保存条件的差异破坏程度。The exploration and development of shale gas in Upper Ordovician Wufeng Formation to Lower Silurian Longmaxi Formation in Nanchuan and its adjacent blocks have yielded fruitful results.However,it is crucial to pay closer attention to the comprehensive use of fluid characteristics for analyzing the differences in shale gas preservation conditions in each block.Research findings reveal the following key points:①With the prolongation of recovery time,the mineralization degree of the produced water gradually increases,exhibiting notable differences from fracturing fluid.This suggests the presence of the presence of movable CaCl_(2)-rich formation water in shale layer,characterized by a mineralization degree exceeding 50 g/L;②Enriched and high-yield wells exhibit low water production,low mineralization and rich in NaHCO_(3),which are indicative of condensate water;③Under different preservation conditions,the deuterium oxygen isotopes of the produced water vary with time.The high pressure stable block in the basin gradually deviates from the atmospheric precipitation line,while the normal(low)pressure complex block outside the basin remains close to the atmospheric precipitation line;④From the inside to the outside of the basin and from deep to shallow,the homogenization temperature of fluid inclusions in shale fracture filled calcite veins gradually decreases(from 240℃to 90℃).Simultaneously,the metamorphism coefficient of the inclusions also gradually increases,reflecting the degree of differential damage of shale gas preservation conditions.

关 键 词：页岩气 保存条件 水化学特征 同位素 南川 

分 类 号：TE37[石油与天然气工程—油气田开发工程]