Analytical model for production performance analysis of multi-fractured horizontal well in tight oil reservoirs

作者：Ji, Jinghao; Yao, Yuedong^*; Huang, Shan; Ma, Xiongqiang; Zhang, Shuang; Zhang, Fengzhu

来源：Journal of Petroleum Science and Engineering, 2017, 158: 380-397.

DOI：10.1016/j.petrol.2017.08.037

• Tight oil reservoirs
• Multi-fractured horizontal well
• Production performance analysis
• Non-Darcy flow
• Stress sensitivity

The combination of horizontal well drilling and reservoir stimulating via multiple fracturing has been proved to be an effective technology to exploit low permeability unconventional tight oil reservoirs. Through multiple fracturing, the very-complex fracture network called the stimulated reservoir volume (SRV) around primary fractures can be generated, which is expected to affect well performance significantly. The pores in tight oil reservoirs with multi-fractured horizontal wells (MFHWs) can be roughly divided into three major types: matrix, natural fractures and hydraulic fractures, which lead to multi-scaled flow during the development of tight oil reservoirs. Furthermore, non-Darcy flow and stress sensitivity make the fluid flow in such reservoirs become more complicated. So it is very difficult to accurately determine the productivity of MFHWs in these reservoirs. Various analytical models have been established to analyze the transient performance of MFHW fast and accurately. However, the typical seepage characteristics in tight oil reservoirs are seldom considered in these models, such as non-Darcy flow and stress sensitivity.
This paper presents a new analytical model for MFHW in tight oil reservoirs, where the reservoir is subdivided into five continuous flow regions: the unstimulated reservoir volume (USRV) regions 1 and 2, the stimulated reservoir volume (SRV) regions 3 and 4, and the hydraulic fracture (HF) region 5. The effects of non-Darcy flow and stress sensitivity are both considered. Laplace transformation, perturbation method and Stehfest numerical inversion are employed to solve the model comprehensively. The model solution is verified with analytical and numerical methods. The effects of related influential parameters on well production performance are investigated. Field example is conducted to show the applicability of the new model, history matching curve and results are obtained according to real production data. The research results summarized in this paper can provide some significance for production performance analysis of MFHW in tight oil reservoirs.

• 出版日期2017-9
• 单位中国石油大学（北京）