底水对松南火山岩气藏采收率影响研究  

Study on impact of bottom water on recovery of Songnan volcanic gas reservoir

作　　者：康晓凤 KANG Xiaofeng(Northeast Oil&Gas Branch,SINOPEC,Changchun 130062,China)

机构地区：[1]中国石化东北油气分公司,长春130062

出　　处：《非常规油气》2023年第6期82-87,共6页Unconventional Oil & Gas

基　　金：中国石化东北油气分公司局控项目“松南气田火山岩气藏开发中后期稳产技术研究”(2021-KF-11)。

摘　　要：为了研究底水对气藏采收率的影响,针对松南火山岩气藏高压、高温、高含CO_(2)以及高产水的特点,对7种常用产能预测方法的精度进行了评价,优选出适用该气藏的产能预测方法;结合气井流压梯度测试结果,对大斜度井临界携液流量计算模型进行了修正;在此基础上,分析了回压和水气比对废弃地层压力和采收率的影响。结果表明:1)以二项式为基础,采用实测静压、流压和实际产气量、产水量对松南地区底水和酸性火山岩气藏进行产能预测,相对误差小于10%。2)综合考虑深度、井斜角、油管内径、CO_(2)含量及水气比等因素的影响,建立了适用于松南气藏大斜度井的临界携液流量计算模型,符合率98.2%。3)降低回压和控制水气比可有效提高气藏采收率。回压每下降1MPa,采收率可提高2.6个百分点;水气比降低1m^(3)/10^(4)m^(3),采收率可提高0.58个百分点。以上成果认识,对制定底水气藏提高采收率对策具有一定指导意义。In order to study the influence of bottom water on gas reservoir recovery,the accuracy of seven common productivity prediction methods was evaluated according to the characteristics of high pressure,high temperature,high COz content and high water production rate in Songnan volcanic gas reservoir,and the productivity prediction method suitable for the gas reservoir was selected.Combined with accurate pressure gradient test results of gas wells,the calculation model of critical liquid carrying capacity of the highly deviated well was modified.On the basis of this,the influence of back pressure and the water gas ratio on abandoned formation pressure and recovery was an-alyzed.The results show that:1)Based on binomial data,this paper applies the measured static pressure,flow pres-sure and actual gas and water production to forecast the productivity of bottom water and acid volcanic gas reservoirs in Songnan,whose relative error is less than 10%.2)Considering the influence of depth,deviation angle,tubing in-side diameter,CO_(2) content and water gas ratio,the calculation model of critical liquid carrying capacity suitable for highly deviated well in Songnan gas reservoir was established,with a coincidence rate of 98.2%.3)Reducing back pressure and controlling water gas ratio can effectively improve gas reservoir recovery.When the back pressure de-creases by 1 MPa,the recovery could increase by 2.6 percentage.When the water-gas ratio decreased by 1m^(3)/10^(4)m^(3),the recovery could increase by 0.58 percentage.The above understanding has certain guiding significance for formulating strategies to improve the bottom water gas reservoir recovery.

关 键 词：火山岩气藏 采收率 动态分析 临界携液流量 废弃地层压力 

分 类 号：TE377[石油与天然气工程—油气田开发工程]