多层疏松砂岩气藏开发中后期气井出水判断方法  

A Method to Identify Produced Water Type in Multilayered Loose Sandstone Gas Reservoirs in Middle and Late Production Stages

作　　者：陈汾君 刘世铎 柴小颖 邓成刚 庞进[3] 涂加沙 CHEN Fenjun;LIU Shiduo;CHAI Xiaoying;DENG Chengang;PANG Jin;TU Jiasha(PetroChina Qinghai Oilfield Company,Research Institute of Exploration and Development,Dunhuang,Gansu 736202,China;PetroChina Qinghai Oilfield Company,Research Institute of Drilling and Production Technology,Dunhuang,Gansu 736202,China;School of Oil and Gas Engineering,Chongqing University of Science and Technology,Chongqing 401331,China)

机构地区：[1]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [2]中国石油青海油田分公司钻采工艺研究院,甘肃敦煌736202 [3]重庆科技学院石油与天然气工程学院,重庆401331

出　　处：《新疆石油地质》2020年第4期491-498,共8页Xinjiang Petroleum Geology

基　　金：国家科技重大专项(2016E-D1D6GF)。

摘　　要：气井出水现象始终伴随着多层疏松砂岩气藏的开发过程。进入气藏开发中后期,由于边水侵入、层内束缚水变为可动水、层间水窜等,导致气井同时存在多种水源,出水特征变得更为复杂。根据地层沉积环境和气藏形成机理,分析各种水源在地层中的存在状态,重点研究凝析水、边水、层内原生可动水、层内次生可动水和层间水的产出条件和特征。利用凝析水水气比经验公式计算气藏开发中后期不同地层压力下的凝析水水气比,得出凝析水量;利用井位信息和水气比判断是否产边水,通过水气比与见水时间幂指数关系得出边水水量;开展岩心气驱水实验,测定不同泥质含量岩心束缚水饱和度,根据测井含水饱和度计算可动水饱和度,确定层内原生可动水水气比和不同地层压力下的层内次生可动水水气比,得出层内水量;开展泥岩隔层水突破实验,测定不同泥质含量泥岩层的地层水突破压差,利用达西公式计算不同泥质含量和厚度的隔层突破压力,结合测井解释结果和其他水源判断结果,判断气井是否产出层间水。综合5种水源判断结果,建立多层疏松砂岩气藏开发中后期出水判断模式,计算气井各种产水量组成。该研究结果对于多层疏松砂岩气藏开发中后期排水、堵水、阻水和控水对策的制定具有重要的意义。Water breakthrough in gas wells is a common problem during the whole development process of multilayered loose sandstone gas reservoirs.In the middle and late production stages of gas reservoirs,the formation water become more complex due to the existence of multiple water such as invaded edge water,movable water transformed from irreducible water and channeling water.Based on the studies of sedimentary environment and gas reservoir forming mechanism,the paper analyzes the states of each type of water and studies the occurrences and characteristics of the produced water including condensate water,edge water,primary water,secondary water and interlayer water.The empirical condensate WGR formula is used to calculate the condensate WGR under different formation pressures in the middle and late production stages of gas reservoirs,and then the output of the produced condensate water can be calculated.Whether edge water is produced or not can be determined by using the well location and produced WGR and the edge water output can be obtained from the power correlation between WGR and water breakthrough time.An experiment of water displacement by gas is carried out and the irreducible water saturation of the cores with different mud contents are measured,movable water saturation is calculated from the water saturation of well logging,then the primary water/gas ratio and secondary water/gas ratio under different formation pressures can be determined and water yield within the layer is obtained.A water breakthrough experiment for mud interlayer is carried out to measure pressure differential for formation water breakthrough,then the critical formation water breakthrough pressures can be calculated for the interlayers with different shale contents and thicknesses by using Darcy’s formula,finally whether interlayer water is produced from a gas well can be judged by combining logging interpretation results and other water type determination data.Based on the identification results of the 5 produced water types,a model for p

关 键 词：涩北二号气田 多层疏松砂岩气藏 开发中后期 气井出水类型 产水量 水源判别 

分 类 号：TE332[石油与天然气工程—油气田开发工程]