致密砂岩气藏气井产水来源综合识别方法——以苏里格气田西区为例  

Comprehensive identification method of waterproduction sources of gas wells in tight sandstone gas reservoirs

作　　者：谢泱 汪春浦 唐华佳 XIE Yang;WANG Chunpu;TANG Huajia(Geological Exploration&Development Research Institute of Chuanqing Drilling Engineering Co.,Ltd.,PetroChina,Chengdu 610051,Sichuan,China)

机构地区：[1]中国石油川庆钻探工程有限公司地质勘探开发研究院,四川成都610051

出　　处：《石油地质与工程》2024年第4期95-100,共6页Petroleum Geology and Engineering

摘　　要：针对在缺少单井产水计量的情况下,苏里格西区致密砂岩气藏气井产水来源识别困难的问题,通过引入水化学图示并结合矿化度分析、生产动态与核磁共振,创新性地建立了苏里格西区致密砂岩气藏气井产水来源综合识别方法。利用该方法对凝析水、工作液与地层水进行了识别。结果表明:气井凝析水与工作液的Stiff图版均被辅助线切割成两部分,而地层水的Stiff图版位于辅助线一侧,且不同时间的Stiff图版可判断气井是否发生水侵。工作液的矿化度大于20000 mg/L,而凝析水的矿化度小于20000 mg/L。对于地层水,层内水在井筒积液前油套压稳定,且压差小于2 MPa,而层间水油套压波动幅度大,且压差高于2 MPa。当含水饱和度小于驱替压力0.51 MPa的核磁饱和度时,地层水为束缚水;当含水饱和度大于驱替压力0.51 MPa的核磁饱和度或小于驱替压力0.032 MPa的核磁饱和度时,地层水为毛细管水;当含水饱和度大于驱替压力0.032 MPa的核磁饱和度时,地层水为自由水。In view of the difficulty in identifying the sources of water production of gas wells in tight sandstone gas reservoirs in Suligexi area without single well water production measurement,a comprehensive identification method was established by introducing hydro-chemical diagrams and combining mineralization analysis,production performance,and nuclear magnetic resonance.This method was used to identify condensate water,working fluid,and formation water.The results show that the Stiff chart of condensate water and working fluid in the gas well is cut into two parts by the auxiliary line,while the Stiff chart of formation water is located on one side of the auxiliary line,and the Stiff chart at different times can determine whether water invasion has occurred in the gas well.The working fluid has a salinity greater than 20000 mg/L,while the condensate water has a salinity less than 20000 mg/L.For formation water,the oil casing pressure inside the formation is stable and the pressure difference is less than 2 MPa before liquid accumulation in the wellbore,while the interlayer water oil casing pressure fluctuates greatly and the pressure difference is higher than 2 MPa.When the water saturation is less than the nuclear magnetic saturation of the displacement pressure of 0.51 MPa,the formation water is bound water.As for the nuclear magnetic saturation,when the water saturation is greater than that of at the displacement pressure of 0.51 MPa or less than 0.032 MPa,the formation water is capillary water;when the water saturation is greater than that of at a displacement pressure of 0.032 MPa,the formation water is free water.

关 键 词：苏里格西区 致密砂岩 水源综合识别 Stiff图版法 核磁共振 

分 类 号：TE135[石油与天然气工程—油气勘探]