Analysis of elastic properties and anisotropic rock physics modeling of Qianjiang Formation shale
Rock physics modeling is an important method to quantitatively describe the elastic properties of shale oil and gas reservoirs.However,there are differences in the elastic response of oil and gas reservoirs with different geological genesis and hydrocarbon phases.Therefore,a combination of rock physics experiments and geological characterizations are required to clarify and then develop theoretical modeling.The study area is the inter-salt shale oil reservoir of Qianjiang Formation in Jianghan Basin.Through digital core microstructure characterization and core experiment analysis,an anisotropic rock physics modeling process is proposed based on the geological background,lithological,pore structure,and elastic anisotropy law of the study area rock.The rock physics model and the interpretation template are validated by core and logging data,respectively.Further,we propose an anisotropic parameter inversion strategy based on this anisotropic rock physics model and the Metropolis-thermal bath algorithm.The application results in the lower Eq4 in well B of the Qianjiang Depression show that the average relative errors of the predicted P-wave and S-wave velocities are-1.32％and-2.39％,respectively.The results show that the anisotropy of the Qianjiang Formation shale is influenced by the stratification of multiple minerals,the directional arrangement of clays,and the horizontal fractures.The rock physics model established by combining anisotropic SCA,Backus average,and T-matrix theory can accurately describe the elastic properties of the Qianjiang Formation shale.In addition,the inversion based on the anisotropic rock physics model can obtain multiple pore contents,fracture aspect ratios and anisotropy.These results can provide the foundation for shale reservoir mechanical property evaluation,accurate velocity modeling,and engineering geological parameter analysis.
Qianjiang Formation shaleSalt lake shale reservoirAnisotropyRock physical templateMetropolis-thermal bath algorithm
万方数据
维普
