【摘要】 岩石动、静态弹性参数之间存在差异,开展储层条件下岩石动、静态弹性参数实验,确定动、静态弹性参数转换关系,对储层压裂改造有重要的实际意义。利用NER公司的Auto Lab 1500对苏里格气田致密砂岩进行模拟储层条件(包括地层温度、压力)下的岩石力学性质测试。结果表明:(1)同一批岩样,相同测量条件下测量得到的动态杨氏模量大于静态杨氏模量,且动态杨氏模量与静态杨氏模量有较好的线性关系,动态泊松比大于静态泊松比,但无明显相关性。(2)同一块岩芯,纵、横波速度随围压增大而增大,随温度升高而减小;动、静态杨氏模量随压力的增大而增大,动态杨氏模量随温度增大而减小,静态杨氏模量随温度升高而增大;动态泊松比随围压增大而减小,随温度升高略微减小,静态泊松比随围压增大而增大,随温度升高减小明显。对产生这种现象的机制进行分析,并确定在不同温度、压力条件下动、静态弹性参数之间的转换关系,为苏里格地区致密砂岩储层地层条件下岩石力学性质的研究提供了基本参数,对制定油气层的压裂施工方案提供参考依据。更多还原

【Abstract】 Differences existed in dynamic and static elastic parameters. In order to obtain the transformation functions between dynamic and static elastic parameters,experiments were done under reservoir conditions,which had important practical significance for fracturing in reservoirs. Rock mechanical properties of tight sandstones under reservoir conditions(including formation temperature and pressure) in Sulige gas field were obtained using the Auto Lab 1500 machine made by the New England Research Company. The results demonstrated that dynamic Young’s modulus was greater than the static Young’s modulus,and there was a liner relationship between them in the same core samples under the same experimental conditions. The dynamic Poisson’s ratio was higher than the static Poisson’s ratio,but there was no obvious relationship between them. The compressional velocity and shear velocity would both increase when confining pressure increases or temperature decreases in one core sample. The dynamic Young’s modulus of one core sample would increase when confining pressure increases or temperature decreases. However,the static Young’s modulus of one core sample would increase when confining pressure increases or temperature increases. The dynamic Poisson’s ratio of one core sample would decrease but the static one would increase when confining pressure increases. The dynamic Poisson’s ratio of one core sample would decrease but the static one would decrease obviously when temperature increases. The mechanism for this phenomenon was analyzed,and the transformation functions between the dynamic and static elastic parameters under different temperature or pressure were obtained. Basic parameters were offered for rock mechanical property researches under reservoir conditions in tight sandstones in Sulige gas field,which provide foundation for the development of oil layer fracturing program.更多还原