China Petroleum Exploration ›› 2018, Vol. 23 ›› Issue (2): 104-116.DOI: 10.3969/j.issn.1672-7703.2018.02.013

• PETROLEUM ENGINEERING • Previous Articles    

Post hydraulic fracturing evaluation and productivity prediction method of fractured tight sandstone gas reservoirs supported by geology-engineering integration

Yang Xiangtong1, Teng Qi1, Zhang Yang1, Yu Yinhua2, Li Wei1, Feng Jueyong1, Zheng Zijun2, Wang Zhenlan2, Gao Xinxin2, Dong Jianyi2   

  1. 1 PetroChina Tarim Oilfield Company;
    2 ENTI(Xi'an) Oil & Gas Technology Co., Ltd
  • Received:2017-10-30 Revised:2018-02-08 Online:2018-03-15 Published:2018-03-16
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Abstract: Aiming at two core technologies (fracturing pressure analysis and numerical simulation) for post-fracturing evaluation, the technical process and potential of production increase of hydraulic fracturing were evaluated. After hydraulic fracturing operation, fracture parameters such as length, width and conductivity can be obtained by fitting net fracturing pressure; 3D fracture pattern can be described in details by 3D software simulation; and effective fracture length and fracture conductivity etc. can be obtained by numerical simulation of production history to further evaluate fracturing quality and effectiveness in a scientific and reasonable way, and therefore evaluate the technical process of hydraulic fracturing. The potential of production increase can be evaluated by production performance analysis after hydraulic fracturing. As the fluids in fractured tight sandstone reside in two interconnected systems (the matrix provides main reservoir space, and the fractures provide major flowing channels), based on the studies of geology-engineering integration, and using imaging logging data to characterize fractures, the method for calculating fracture porosity, facture permeability and shape factor of natural fracture systems is proposed; and by integrating matrix, natural fractures, artificial fractures, fluid/rock properties and production history, a dual-medium model is established which can simulate real production history after reasonable adjustment of some uncertain parameters in the model, so as to evaluate hydraulic fracturing effectiveness. This method is useful for fracturing evaluation, post-fracturing production prediction and optimization of fracturing stimulation plan. It can provide strong support for design and implementation of fracturing stimulation in exploration areas, new wells or new production zones.

 

Key words: fractured tight sandstone, post-fracturing evaluation, history fitting, production prediction, fracture system, geology-engineering integration

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