摘要
煤层气井的产出水蕴含着重要的地质与产能信息,揭示产出水的地球化学特征与主控因素,阐明产出水的演化路径及其与产能的内在关系,有助于理解产能的非均质性并为开发方案优化提供依据。近年来,黔西地区织金区块煤层气的勘探开发取得重要突破,这为中国南方多层、薄层状煤层条件下煤层气的开发提供了技术示范,但仍然存在产出水质变化大、产能不确定性高、控产因素不明等问题。通过采集黔西地区织金区块上二叠统长兴组—龙潭组煤层气井的产出水样并开展水文地球化学测试,探讨了水化学特征、演化路径及其产量判识意义。产出水质包括Na-HCO_(3)型与Na-Cl型,前者的总固溶体(TDS)含量为944~2681 mg/L,后者的TDS含量为3603~8800 mg/L。以TDS含量为刻度,水样的5个聚类(聚类①—聚类⑤)代表地下水的滞留程度依次增高。脱硫酸作用、阳离子交换吸附作用、浓缩作用是控制产出水化学特征与演化的主要因素。产出水的水质变化先后经历了氧化条件下补给作用主导的低TDS含量(<200 mg/L)Ca-SO_(4)型水质、还原条件下脱硫酸作用与阳离子交换吸附作用主导的中等TDS含量(900~3000 mg/L)Na-HCO_(3)型水质、高度滞留条件下浓缩作用主导的高TDS含量(3500~9000 mg/L)Na-Cl型水质。产出水的演化可分为还原阶段和封闭阶段,处于封闭阶段的产出水(TDS>3000 mg/L)对应高产井。提取煤层气产量判识的关键水化学指标及其临界值,通过分析TDS含量和Cl^(-)、Na^(+)、Sr^(2+)等特征离子浓度可更有效地判识高产井;借助脱硫系数可更有效地判识低产井。黔西地区织金区块煤层气井的选址应避开地下水径流强烈地带,布设在具有高TDS含量、高Cl^(-)含量、低SO_(4)^(2-)含量的滞留区,珠藏次向斜轴部为布设煤层气井的有利区。水动力干扰及其诱发的低效降压仍是制约直井/定向井多层合采产能效率的�
The water produced from coalbed methane(CBM)wells contains rich information on geology and productivity,which can reveal the geochemical characteristics and main controlling factors of produced water and make clear the evolution path of produced water and its inherent link with production capacity,thus helping understand the heterogeneity of production capacity and provide a basis for the optimization of development programs.In recent years,significant breakthroughs have been made in the CBM exploration and development in Zhijin block of western Guizhou Province,providing a technical demonstration for the CBM development multiple thin coal seams in South China.However,there are still a number of problems,including great variability in produced water quality,high uncertainty in production capacity,and unclear control factors for gas production.In this study,hydrogeochemical tests were performed on the water produced from CBM in Zhijin block of western Guizhou Province,which aims to explore the hydrochemical characteristics,evolution path and its significance in judging productivity.The quality of the produced water can be divided into Na-HCO_(3)and Na-Cl types;the total dissolved solid(TDS)of the former ranges from 944 mg/L to 2681 mg/L,and that of the latter ranges from 3603 mg/L to 8800 mg/L.According to the scale of TDS,the five clusters of samples show the successively increasing degree of groundwater retention.Desulphidation,cation exchange adsorption,and concentrating action are the main factors controlling the hydrochemical characteristics and evolution of produced water.The produced water is of Ca-SO_(4)type with low TDS(<200 mg/L)under oxidation conditions,Na-HCO_(3) type with medium TDS(900-3000 mg/L)dominated by desulphidation and cation exchange adsorption under reduction conditions,and Na-Cl type with high TDS(3500-9000 mg/L)dominated by concentrating action under high retention rate.The evolution process of produced water can be divided into reduction stage and retention stage,and the produced water(
作者
郭晨
李瑞腾
秦勇
卢玲玲
易同生
陈贞龙
袁航
高为
程曦
Guo Chen;Li Ruiteng;Qin Yong;Lu Lingling;Yi Tongsheng;Chen Zhenlong;Yuan Hang;Gao Wei;Cheng Xi(College of Geology and Environment,Xi'an University of Science and Technology,Shaanxi Xi'an 710054,China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation,Shaanxi Xi'an 710054,China;Geological Research Institute for Coal Green Mining,Xi'an University of Science and Technology,Shaanxi Xi'an 710054,China;Key Laboratory of CBM Resources and Reservoir Formation Process,Ministry of Education,China University of Mining and Technology,Jiangsu Xuzhou 221116,China;Department of Geology,Northwest University,Shaanxi Xi'an 710069,China;Aerophoto Grammetry and Remote Sensing Bureau,China National Administration of Coal Geology,Shaanxi Xi'an 710199,China;Guizhou Bureau of Coal Geological Exploration,Guizhou Guiyang 550008,China;Sinopec East China Oil&Gas Company,Jiangsu Nanjing 210011,China;Guizhou Provincial Engineering and Technology Research Center of Coalbed Methane and Shale Gas,Guizhou Guiyang 550008,China)
出处
《石油学报》
EI
CAS
CSCD
北大核心
2024年第3期517-530,共14页
Acta Petrolei Sinica
基金
国家自然科学基金项目(No.42002195,No.42130802)
贵州省科技计划项目(黔科合战略找矿[2022]ZD001-1)
贵州省科技计划项目(黔科合平台人才CXTD[2022]016)
陕西省重点研发计划项目(2022GD-TSLD-64)资助。
关键词
产出水
水化学演化
黔西地区
煤层气合采
流体干扰
produced water
water chemical evolution
western Guizhou
coalbed methane co-production
fluid interference
