Productivity Evaluation of Fractured Wells in Shale Gas Reservoirs

doi:10.11885/j.issn.1674-5086.2019.11.17.01

Abstract

Abstract: Shale reservoir has nano-pores structure with self-generation and self-storage, so fracturing has become an important technology for shale gas exploitation. Based on the multi-scale non Darcy flow model, a multi-scale flow model is established to simulate various flow states including continuous flow, transition flow, slippage flow and free molecular flow. The steady-state production equation of fractured well with finite conductivity fracture is obtained. In this model, the influence of pore size on Knudsen coefficient is fully considered. The IPR curve of fractured well is obtained, and the effects of fracture half length, Knudsen diffusion coefficient, shale permeability, slippage factor, fracture penetration ratio and fracture conductivity on the production of fractured well are explored. The results show that the permeability correction coefficient has a great influence on productivity, and the productivity of fracturing well determined by multi-scale seepage model is very consistent with the actual production data. When the flow pressure in the bottom hole is less than 15 MPa, the slippage effect on production begins to increase in the fracturing well, and with the increase of slippage factor, the fracturing well production increases. The lower the permeability of shale gas reservoir, the greater Knudsen diffusion coefficient D_K and slippage effect on production.

Key words: shale gas, multi-scale flow, Knudsen diffusion coefficient, permeability correction coefficient, fracturing well

CLC Number:

TE312

HU Degao, GUO Xiao, ZHENG Aiwei, SHU Zhiguo, ZHANG Baiqiao. Productivity Evaluation of Fractured Wells in Shale Gas Reservoirs[J]. 西南石油大学学报(自然科学版), 2019, 41(6): 132-138.

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http://journal15.magtechjournal.com/Jwk_xnzk/EN/Y2019/V41/I6/132

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