| Author's Name: ZHANG Hongjie1, YANG Guang1, WU Hao1, SUN Long1, LIU Zhijun1, GAO Wei2,
QIAO Chuanxiang2, ZENG Yongjian3 |
| Institution: 1. Institute of Geophysical Exploration, PetroChina Jilin Oilfield Company； 2. The Exploration Department, PetroChina Jilin Oilfield Company；3. Beijing Precise Energy Technology Co., Ltd |
| Abstract: |
| Reasonable prediction of fracture parameters and brittleness index plays an indicative role in the hydraulic
fracturing process in the exploration and development of shale oil reservoirs and lays the foundation for the
comprehensive evaluation of sweet spots in a study area. Starting from the anisotropy theory, based on the linear sliding
theory, scattering theory and Born approximation theory, this paper derives the anisotropic reflection coefficient equation
of HTI media containing the brittleness index of Young's modulus to Poisson's ratio, Poisson's ratio, density, quasifracture normal weakness and quasi-fracture tangential weakness. And under the Bayesian framework, the expectation
maximization algorithm introduces the conditional expectation value of the implicit variable into the random simulation of
the model parameters at each iteration to solve the problem that the likelihood function can not take extreme values when
the posterior distribution function of the model parameters is implicit or nonlinear. Compared with the traditional method
of obtaining the maximum a posteriori probability solution, the introduction of the expectation maximization algorithm
can obtain more stable model parameter inversion results, and finally realize the direct prestack seismic inversion of the
brittleness index and fracture parameters of shale oil reservoirs. Model testing and actual data application verify the
accuracy and applicability of the inversion method proposed in this paper. |
| Keywords: shale oil reservoir; fracture parameters; brittleness index; Bayesian theory; direct inversion |
|
投稿时间：
2025-05-06 |
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