Reservoir Evaluation and Development ›› 2018, Vol. 8 ›› Issue (1): 64-70.

• Non-conventional Reservoir • Previous Articles     Next Articles

Evaluation and research of brittleness on simulated reservoir volume in coal

Lu Yanjun1,Yang Zhaozhong2,Shelepov V V1,Han Jinxuan1,Li Xiaogang2,Han Wei3   

  1. 1. Department of Geology, Moscow Lomonosov State University, Moscow 119991, Russian Federation
    2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
    3. Shaanxi Haili Petroleum Machinery Co., Ltd., Weinan, Shaanxi 715106, China
  • Received:2017-02-23 Online:2018-02-26 Published:2018-12-05


The hydraulic fracturing is a major means of the coalbed methane(CBM) exploitation, and the effective channels of the methane seepage can be formed in the coal seams by this means. The stimulated reservoir volume(SRV) can not only help the coal seams form the seepage channels, but also increase the desorption-diffusion areas of the methane and improve the production of the single well by formed the complicated fractures. The brittleness index is one of the key parameters for evaluating the SRV implement, therefore, based on the stress-strain curves of the coal and shale, it is analyzed with the help of the strain-energy density. The higher the brittleness index of the shale is, the lower the strain-energy density will be. Based on the calculation method of the brittleness index of the shale, the calculation method of the coal brittleness index that combines with the strain-energy density and minimum energy principle is put forward, and the modified brittleness index of the coal is obtained, which can be used for the characterization of the coal brittle failure and evaluation of the fracture formation after fracturing. Finally, the analysis of the calculation results and data of 6 fracturing wells, indicates that the strong correlation between the coal brittleness index and stimulated volume, which means that the higher the brittleness index is, the larger the stimulated volume of unit fracturing fluid in the coal seams will be. This method can be applied to design the SRV of the coal seams and guide the exploitation of CBM.

Key words: stimulated reservoir volume(SRV), mechanical property of coal, strain energy density, brittleness index, multifractures

CLC Number: 

  • TE357