准中莫西庄地区侏罗系地层水化学特征与油气分布关系  

Chemical characteristics of formation water and the relationship with hydrocarbon distribution in Moxizhuang area in the central of Junggar Basin

作　　者：赵一极 金爱民[1] 孙光远 刘惠民[2] 张学才[2] 任新成[2] 朱蓉[1] 楼章华[1] Zhao Yiji;Jin Aimin;Sun Guangyuan;Liu Huimin;Zhang Xuecai;Ren Xincheng;Zhu Rong;Lou Zhanghua(Ocean College,Zhejiang University,Zhoushan,Zhejiang 316021;Shengli Oilfield Branch Company,SINOPEC,Dongying,Shandong 257015)

机构地区：[1]浙江大学海洋学院,浙江舟山316021 [2]中国石化胜利油田分公司,山东东营257015

出　　处：《地质科学》2025年第2期511-525,共15页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石油化工股份有限公司科技攻关项目(编号:P22128);中国石化胜利油田分公司项目(编号:YKK2303,30203569-22-基金项目:ZC0613-0081)资助。

摘　　要：油田地下水与油气成藏关系密切,其成因及水化学特征反映了油气分布和富集规律。莫西庄地区侏罗系地层水总体为越流泄水浓缩高矿化特征,但部分测试产量较高单井的地层水反而呈现矿化度较低和钠氯系数、脱硫系数较高的情况,而矿化度异常高的单井无测试产量。论文通过地层水化学特征分析及碳氧同位素测试等进一步揭示地层水成因及与油气运聚分布的关系。莫西庄地区侏罗系地层水矿化度分布在0.71~78.62 g/L,平均值21.07 g/L,NaHCO3型为主。地层水特征及生产动态表明,凝析水导致部分测试产量较高井的地层水矿化度偏低。凝析水是含气的重要标志。碳酸盐胶结物δ^(13)C值分布在-20.13‰~2.40‰,δ^(18)O值分布在-26.11‰~-17.50‰。地化特征表明,深部流体上涌导致局部地区矿化度异常高,如庄2井最高达78.62 g/L,大量的胶结物充填导致储层致密,不利于油气富集。Formation water is closely related to the hydrocarbon accumulation,and its genesis and hydrochemical characteristics reflect the distribution and enrichment of hydrocarbon.The Moxizhuang area is located in the cross‑formation flow discharging area of Junggar Basin and the Jurassic formation water is generally characterized by concentration,but the formation water of some single wells with higher testing production shows low salinity and high sodium chloride coefficient and desulfurization coefficient,and other wells with abnormally high salinity have no test production.Through the analysis of the chemical characteristics of the formation water in Moxizhuang and the analysis of carbon and oxygen isotopes,the relationship between the genesis of the formation water and the distribution of hydrocarbon migration and accumulation is revealed.The salinity of Jurassic formation water in Moxizhuang area is 0.71~78.62 g/L,with an average of 21.07 g/L,and NaHCO3 is the main type.The characteristics of formation water and production performance show that condensate water leads to low salinity of formation water in some wells with high testing yield.Condensate water is an important symbol of the gas accumulation.Theδ^(13)C values of carbonate cements are distributed between-20.13‰and 2.40‰,and theδ^(18)O values are distributed between-26.11‰and-17.50‰.The geochemical characteristics show that the upwelling of deep fluid leads to high salinity.For example,the salinity of formation water in well Zhuang 2 can reach up to 78.62 g/L.A large amount of cement filling leads to tight reservoir,which is not conducive to oil and gas enrichment.

关 键 词：水化学特征 凝析水 碳氧同位素 油气分布 莫西庄地区 

分 类 号：TE122.1[石油与天然气工程—油气勘探]