启动压力和动边界对致密气藏不稳定试井解释的影响研究
|
摘要
致密气藏的气水渗流会出现非线性特征,主要原因是受启动压力的影响。目前致密气藏的常规试井解释通常不考虑启动压力的影响,存在较大误差。针对此问题建立考虑启动压力和动边界影响的直井不稳定试井模型并求解,研究各因素对直井不稳定试井曲线特征的影响。结果表明,压力降落曲线晚期上翘段的斜率受到启动压力梯度大小的影响,启动压力越大,曲线上翘程度越大;动边界的影响主要在井筒储存阶段后,启动压力越大时,动边界向外扩展的速度越慢,出现边界反应的时间越晚;无量纲半径只影响动边界扩展到封闭外边界后的井底压力动态,无量纲半径越大,出现边界反应的时间越晚,稳定的井底流压越低。实际应用表明,气井的压力恢复曲线拟合效果良好,该模型适用于低渗透气田的试井解释,解释结果合理可靠。
Due to the influence of threshold pressure,gas and water seepage are featured with nonlinear characteristics,and conventional well test interpretation usually does not consider this influence,which results in some errors.Therefore,a transient well test model for vertical wells was established with the consideration of the influence of threshold pressure and moving boundary,and analyzed the various factors influencing the transient well test curves.Results showed that the threshold pressure has an impact on the slope of upward curve when pressure drops at the late period,the larger the threshold pressure,the greater the degree of curve upwards;After gas is filled in wellbore,the influence of moving boundary will appear,and the higher the threshold pressure,the slower the extension of moving boundary outwards,and the boundary reflection appears later;the dimensionless radius only affect the bottom hole pressure response when the moving boundary has extended to the sealed outer boundary,the longer the dimensionless radius,the later the boundary reflection appears,and the stable bottomhole flowing pressure is lower.Practical application showed that the pressure recovery curve was fitted very well,the model is suitable for well test interpretation in low permeability gas field,and the result is reasonable and reliable.
Due to the influence of threshold pressure,gas and water seepage are featured with nonlinear characteristics,and conventional well test interpretation usually does not consider this influence,which results in some errors.Therefore,a transient well test model for vertical wells was established with the consideration of the influence of threshold pressure and moving boundary,and analyzed the various factors influencing the transient well test curves.Results showed that the threshold pressure has an impact on the slope of upward curve when pressure drops at the late period,the larger the threshold pressure,the greater the degree of curve upwards;After gas is filled in wellbore,the influence of moving boundary will appear,and the higher the threshold pressure,the slower the extension of moving boundary outwards,and the boundary reflection appears later;the dimensionless radius only affect the bottom hole pressure response when the moving boundary has extended to the sealed outer boundary,the longer the dimensionless radius,the later the boundary reflection appears,and the stable bottomhole flowing pressure is lower.Practical application showed that the pressure recovery curve was fitted very well,the model is suitable for well test interpretation in low permeability gas field,and the result is reasonable and reliable.
引文
[1]程时清,徐论勋,张德超.低速非达西渗流试井典型曲线拟合法[J].石油勘探与开发,1996,23(4):50-53.
[2]程林松,任胜利,廉培庆.动边界双重介质油藏低速非达西渗流试井模型[J].计算力学学报,2011,28(6):879-883.
[3]任东,刘启国,汤勇,等.基于启动压力梯度的火山岩气藏多重介质试井模型[J].天然气工业,2011,31(10):50-53.
[4]刘春枚.徐深气田压力恢复试井资料解释技术及认识[J].石油地质与工程,2014,28(1):103-105.
[5]田婉玲,齐二坡,吴茂富,等.气井试井产能分析新方法与新模型应用[J].天然气与石油,2012,30(4):46-49.
[6]方甲中,程林松,任胜利,等.动边界复合油藏低速非达西渗流试井分析[J].西南石油大学学报(自然科学版),2011,33(5):104-108.
[7]成绥民,成珍,杨勤涛,等.气水两相渗流稳定与不稳定试井分析[J].油气井测试,2006,15(3):4-8.
[8]Blasingame T A.The characteristic flow behavior of lowpermeability reservoir systems[C].SPE Unconventional Reservoirs Conference,Keystone,Colorado,USA.SPE114168,2008.
[9]Warren G M.Numerical solution for pressure transient analysis[C].SPE Gas Technology Symposium,Calgary,Alberta,Canada.SPE 26177,1993.
[10]罗金丽,靳正平.川西致密砂岩气藏试井曲线特征分析[J].矿物岩石,2001,21(4):65-70.
[11]吴凡,孙黎娟,乔国安,等.气体渗流特征及启动压力规律的研究[J].天然气工业,2001,21(1):82-84.
[12]孙致学,汪绍卫,董时正.致密低渗透气田的试井特征分析——以新场气田为例[J].油气井测试,2005,14(1):26-30.
[13]葛宏选,党海龙,解伟,等.变形介质油藏非线性不稳定渗流特征研究[J].非常规油气,2015,2(3):50-57.
[14]张瀛,王兴明,冯金义,等.马西凝析气藏试井解释方法研究[J].非常规油气,2015,2(2):38-43.
[2]程林松,任胜利,廉培庆.动边界双重介质油藏低速非达西渗流试井模型[J].计算力学学报,2011,28(6):879-883.
[3]任东,刘启国,汤勇,等.基于启动压力梯度的火山岩气藏多重介质试井模型[J].天然气工业,2011,31(10):50-53.
[4]刘春枚.徐深气田压力恢复试井资料解释技术及认识[J].石油地质与工程,2014,28(1):103-105.
[5]田婉玲,齐二坡,吴茂富,等.气井试井产能分析新方法与新模型应用[J].天然气与石油,2012,30(4):46-49.
[6]方甲中,程林松,任胜利,等.动边界复合油藏低速非达西渗流试井分析[J].西南石油大学学报(自然科学版),2011,33(5):104-108.
[7]成绥民,成珍,杨勤涛,等.气水两相渗流稳定与不稳定试井分析[J].油气井测试,2006,15(3):4-8.
[8]Blasingame T A.The characteristic flow behavior of lowpermeability reservoir systems[C].SPE Unconventional Reservoirs Conference,Keystone,Colorado,USA.SPE114168,2008.
[9]Warren G M.Numerical solution for pressure transient analysis[C].SPE Gas Technology Symposium,Calgary,Alberta,Canada.SPE 26177,1993.
[10]罗金丽,靳正平.川西致密砂岩气藏试井曲线特征分析[J].矿物岩石,2001,21(4):65-70.
[11]吴凡,孙黎娟,乔国安,等.气体渗流特征及启动压力规律的研究[J].天然气工业,2001,21(1):82-84.
[12]孙致学,汪绍卫,董时正.致密低渗透气田的试井特征分析——以新场气田为例[J].油气井测试,2005,14(1):26-30.
[13]葛宏选,党海龙,解伟,等.变形介质油藏非线性不稳定渗流特征研究[J].非常规油气,2015,2(3):50-57.
[14]张瀛,王兴明,冯金义,等.马西凝析气藏试井解释方法研究[J].非常规油气,2015,2(2):38-43.