【摘要】 鄂尔多斯盆地南缘中生界长8储层是进行油气开发的重点层位。针对长8储层砂泥岩交互,低孔低渗的特点,对其岩心样品开展了模拟地层下的岩石力学实验;利用测井资料,计算出了动态岩石力学参数并结合实验结果进行了动静态参数拟合;在岩石力学参数剖面的基础上,对岩石力学参数空间分布的影响因素进行分析。实验结果表明:三轴条件下,岩心样品均随着围压的增大,破坏强度变大,即弹性极限显著增加;随着围压的增大,岩石的抗压强度显著增加;随着围压的增大,岩石的变形显著增大。在进行自然伽马加权的情况下拟合情况较好,因此构建了较可靠的岩石力学参数剖面。影响泊松比、杨氏模量和抗压强度空间分布的主要因素为岩性、泥质含量和深度。研究成果对鄂南地区长8储层的压裂优化设计提供了重要的依据。更多还原

【Abstract】 The Mesozoic Chang 8 is the key area for oil and gas development in the southern margin of the Ordos Basin. According to the characteristics of sandstone-mudstone interaction,low porosity and low permeability in Chang 8 reservoir,rock samples were subjected to experimental of rock mechanics under simulated strata. The failure strength of core samples were increased with the increase of confining pressure under triaxial condition,indicating that the elastic limit increased significantly. With the increase of confining pressure,the compressive strength of rock increases significantly and the deformation increased significantly. Using logging data,dynamic rock mechanics parameters were calculated and the static and dynamic parameters were fitted according to the experimental results. The results show that the fitted condition is better under the condition of weighted gamma value,so a more reliable rock mechanics parameter profile is obtained. Based on the reswlts,the factors affecting the spatial distribution of rock mechanical parameters are analyzed. Lithology,shale content and burial depth are the main factors affecting the spatial distribution of Poisson’s ratio,elastic modulus and compressive strength. The research results provide an important basis for fracturing optimization design of Chang 8 reservoir in southern Ordos.更多还原