A Novel Technique Applied in Early-Time Pressure Transient Analysis for Fractured Wells with Unpropped Segments

Luo, Le (China University of Petroleum Beijing) | Cheng, Shiqing (China University of Petroleum Beijing) | Dai, Li (China University of Petroleum Beijing) | Wang, Yang (China University of Petroleum Beijing) | Zhang, Jiaosheng (Research Institute of Exploration and Development, Changqing Oilfield Company, CNPC) | Ma, Changlin (Research Institute of Exploration and Development, Changqing Oilfield Company, CNPC) | Yu, Haiyang (China University of Petroleum Beijing)



Propping agents inside hydraulic fractures perform significant role in constructing high-speed flow channel to deliver fluids into wellbore. However, proppant transport in fracture is always influenced by many factors, resulting unpropped fracture. Under such situation, this paper proposes a novel pressure-transient analysis method to better interpreted created fracture properties. The application of signal amplification technology is conducted on pressure transient analysis to deal with non-uniqueness problems. Aiming at transient linear flow, trilinear flow model in fractured wells is further modified and upgraded to characterize unpropped segments. Based on the solutions, this study applied signal amplification technology to extract weak-signals to assist early-time pressure transient analysis. The new type curves regarding with pressure response in partially unpropped fracture is then generated to capture the characteristics of this phenomenon. Subsequently, sensitivity analyses make clear the effects of key parameters on pressure response, which shows the superiorities of the new type curves in pressure transient analysis. The approaches proposed by this paper undoubtly will help solve inverse problems of wells exhibiting long-period linear flow in tight reservoirs.