摘要
大庆油田长垣地区A开发区为中浅层砂岩储层,经过长期注水开发,地层压力发生明显变化,导致地应力场和岩石力学参数发生改变,而地层地应力场的状态和岩石的力学性质决定了压裂的裂缝延伸方向、形态和方位,影响着压裂的增产效果。通过开展不同围压下岩样三轴压缩测试及测井数据计算转换,构建适用于A开发区的三向地应力计算模型。使用该模型计算该区30口井初始岩石力学参数、地应力,计算结果与通用方法符合率分别为83.9%~99.5%、80.4%~99.2%。现场应用结果表明,储层段的垂向主应力最小,压裂形成的裂缝为水平缝;在实际生产过程中,随着地层压力的不断下降,储层段的有效垂向应力增大,杨氏模量有所增加,泊松比先增大后减小;计算得到的水平应力差范围,为压裂方案优化设计提供了依据。
Development Zone A is a shallow sandstone reservoir.After long-term water injection development,the formation pressure has greatly changed,resulting in changes in the geostress field and rock mechanical parameters.The state of the geostress field and the rock mechanical properties determine the extension direction,shape and orientation of fracturing fractures,which affects the stimulation effect of fracturing.Through triaxial compression test of rock samples under different confining pressures and calculation and conversion of logging data,a three-dimensional geostress calculation model suitable for Development Zone A is constructed.The model is applied to calculate the initial rock mechanical parameters and geostress of 30 wells in this area,and the coincidence rates of the calculation results with the general method are 83.9%~99.5%and 80.4%~99.2%respectively.The application results show that the vertical principal stress of the reservoir interval is the smallest,and the fractures formed by fracturing are horizontal fractures.In the actual production process,with the constant change of formation pressure,the effective vertical stress of reservoir interval increases,Young’s modulus increases,and Poisson’s ratio first increases and then decreases.The calculated range of horizontal stress difference provides a basis for the optimal design of fracturing scheme.
作者
韩松
李丽丽
胡智凡
孙丽静
赵辉
HAN Song;LI Lili;HU Zhifan;SUN Lijing;ZHAO Hui(Research Institute of Oil Production Engineering of Daqing Oilfield Co.,Ltd.,PetroChina,Daqing 163453,Heilongjiang,China;State Key Laboratory of Continental Shale Oil,Daqing 163453,Heilongjiang,China;Heilongjiang Provincial Key Laboratory of Oil and Gas Reservoir Stimulation,Daqing 163453,Heilongjiang,China;No.4 Oil Production Plant of Daqing Oilfield Co.,Ltd.,PetroChina,Daqing 163453,Heilongjiang,China)
出处
《石油地质与工程》
2025年第3期85-91,共7页
Petroleum Geology and Engineering
基金
中国石油天然气股份有限公司专项课题“老区直井/定向井提高重复压裂增产效果技术研究与现场试验”(2022KT1704)资助。
关键词
中浅层砂岩储层
岩石力学参数
地应力
水平裂缝
middle-shallow sandstone reservoir
rock mechanics parameters
geostress
horizontal fractures
