东胜气田独贵气区高含水致密砂岩气藏气井合理工作制度  

A rational working system for gas wells in tight sandstone reservoirs with rich water,Dugui gas province,Dongsheng gasfield,Ordos Basin

作　　者：李阳[1] 成双华 LI Yang;and CHENG Shuanghua(No.2 Gas Production Plant,Sinopec North China Oil&Gas Company,Xianyang,Shanxi 712000,China)

机构地区：[1]中国石化华北油气分公司采气二厂,陕西咸阳712000

出　　处：《天然气技术与经济》2024年第5期16-22,28,共8页Natural Gas Technology and Economy

基　　金：中国石油化工股份有限公司油田勘探开发事业部先导项目“东胜气田独贵气区控水稳气开发对策研究”(编号:YTBXD-04)。

摘　　要：为了有效支撑高含水致密砂岩气藏高效开发,以鄂尔多斯盆地东胜气田独贵气区为研究对象,在研究高含水致密砂岩气井不同水气比条件下产出特征的基础上,分析了应力敏感及生产压差对气井产出的影响,评价了不同配产工作制度下气井的产出效果,提出了气井差异化配产方案及压降速率控制标准。研究结果表明:①研究区气藏储层孔喉组合以微孔细喉为主,具有低孔隙度—特低孔隙度、致密低渗透及强非均质性的特征;②高含水致密砂岩气藏气井开发效果受产水量影响较大,气井水气比越高,产气量递减越大、压降速率越快、弹性产率越低;③随着生产压差不断扩大,造成部分毛细管水和束缚水膜变成可动水,气井产水量增加,弹性产率变低,累计产气量减小,稳产难度增大,开发效果变差。结论认为:①对于衰竭式开发的高含水致密砂岩气藏,控制气井的配产和压降速率是延长气井稳产期、提高天然气采收率的重要手段;②所建立的高含水致密砂岩气藏气井差异化配产方案和气井压降速率控制图版在生产实践中证明符合率达到87.5%,可推广应用于同类型气藏的开发开采,更好地指导气井效益开发。Taken Dugui gas province as an example,the production traits were discussed for tight sandstone gas wells rich in water at various water/gas ratio to hold up the efficient development in such gas reservoirs.On this basis,the effect of stress sensitivity and pressure difference on the production was also analyzed.Moreover,production outcome was accessed for gas wells with different proration working systems,and differentiated proration plans and standards were proposed to condition the pressure-drop rate.Results show that(i)with the unique pore-throat assemblage dominated by micropore and fine throat,the reservoirs in the study area feature low to ultra-low porosity,low permeability and strong heterogeneity;(ii)the development in these wells is seriously affected by water production.The higher the water/gas ratio,the larger the production decline and pressure-drop rate,and the lower the elastic yield;and(iii)with the increasing division in production pressure,part of capillary water and bound-water membrane may turn into movable water.As a result,water production increases,both elastic yield and cumulative production decrease,creating further complication in stabilizing production to deteriorate the development.In conclusion,for this kind of tight sandstone reservoirs rich in water in the mode of depletion development,controlling the proration and pressure-drop rate is an important means for gas wells to prolong their stable period and improve recovery.What's more,after the proposed differentiated proration plan and pressure-drop rate control chart have been in practice,the coincidence rate achieves up to 87.5%.So,these plan and chart may be popularized to the development in similar reservoirs and provide better guidance for the efficient development.

关 键 词：鄂尔多斯盆地 东胜气田 二叠系下石盒子组 高含水致密砂岩气藏 产出特征 影响因素 工作制度 

分 类 号：TE37[石油与天然气工程—油气田开发工程]