The application of prestack geostatistical inversion in the prediction of shale sweet spots and thin interbeds:a case study of Block W in Western Canada Basin

被引：0

作者：

Guo T. ^{[1
]}

Jiang M. ^{[2
]}

Ji Y. ^{[2
]}

Wang H. ^{[1
]}

Ma W. ^{[3
]}

Kong X. ^{[1
]}

机构：

[1] Research Institute of Petroleum Exploration and Development, PetroChina, Beijing

[2] CNODC, CNPC, Beijing

[3] School of Electronics Engineering and Computer Science, Peking University, Beijing

来源：

Guo, Tongcui (guotongcui@cnpcint.com) | 1600年 / Science Press卷 / 55期

关键词：

Fracture prediction; Geostatistical inversion; Rock physics; Shale gas; Sweet spots;

D O I：

10.13810/j.cnki.issn.1000-7210.2020.01.020

中图分类号：

学科分类号：

摘要：

Shale gas is a kind of unconventional natural gas.The prediction of shale "sweet spots" with high TOC, high brittleness and developed fractures between wells is always an important step in shale gas exploration and development in the regions with few wells.The target shale formation in Block W in Western Canada Basin is relatively thin (the maximal seismic reflection time is 20ms), and contains multiple thin limestone interlayers (0.5~3m).There are overlapping intervals between the P-wave impedances of brittle shales and ductile mudstones.It is difficult to predict shale sweet spots and thin limestone interbeds using seismic data.In this paper, a rock physics template for evaluating shale "sweet spots" was established based on the analysis on the rock-physical elastic parameters, and the elastic characteristics of shale "sweet spots" and interbeds were clarified.The 3D lithology-constrained pre-stack geostatistical inversion technique was used to predict the shale with high TOC and high brittleness, as well as limestone interbeds.Firstly, the rock physics parameters of the shale reservoir were analyzed.The prospective shale objectives have low Poisson's ratio, median Young's modulus, high TOC and high brittleness, while the limestone interbeds have high Poisson's ratio, high Young's modulus, low TOC and high density.Secondly, 1D constrained geostatistical inversion was applied to predict and test the parameters of prospective shale area and interbeds.Thirdly, 3D constrained prestack geostatistical inversion was applied to predict prospective shale area and interbeds.The results showed that the overlapping areas of high-TOC and high-brittleness shale and developed fractures are the target shale "sweet spots".The developed shale "sweet spots" area with thin limestone interbeds are chosen as the prospecting well location area, in order to ensure a high probability that horizontal well drills to high-quality reservoirs with high gas production. © 2020, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.

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页码：167 / 175

页数：8

共 17 条

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