1. Brittleness index calculation based on amplitude-variation-with-offset inversion for coal-bed methane reservoir: A case study of the Qinshui Basin, China
- Author
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Cheng Yan, Huang Yaping, Dong Shou-hua, Zhang Ping-song, and Wu Haibo
- Subjects
Index (economics) ,010504 meteorology & atmospheric sciences ,business.industry ,Petrophysics ,Inversion (geology) ,Geology ,Soil science ,Structural basin ,010502 geochemistry & geophysics ,01 natural sciences ,Methane ,chemistry.chemical_compound ,Geophysics ,Brittleness ,chemistry ,Coal ,business ,Amplitude versus offset ,0105 earth and related environmental sciences - Abstract
The brittleness index (BI) is an important parameter for coal-bed methane (CBM) reservoir fracturing characterization. Most published studies have relied on petrophysical and well-log data to estimate the geomechanical properties of reservoir rocks. The major drawback of such methods is the lack of control away from well locations. Therefore, we have developed a method of combining BI calculation from well logs with that inverted from 3D seismic data to overcome the limitation. A real example is given here to indicate the workflow. A traditional amplitude-variation-with-offset (AVO) inversion was conducted first. BI for the CBM reservoir was then calculated from the Lamé constants inverted from prestack seismic data through a traditional AVO inversion method. We build an initial low-frequency model based on the well-log data. Comparison of the seismic inverted BI at the target reservoir and BI extracted from the well-log data showed satisfactory results. This method has been proved to be efficient and effective enough at identifying BI sweet spots in CBM reservoirs.
- Published
- 2020