Flowback and early-time production modeling of unconventional gas wells using an improved semi-analytical method  

作　　者：Miao Zhang Kien Nguyen Zhi-Qiang Wang Luis F.Ayala 

机构地区：[1]College of Petroleum Engineering,China University of Petroleum,Beijing,102249,China [2]University of Tulsa,USA [3]The Pennsylvania State University,USA

出　　处：《Petroleum Science》2023年第6期3441-3449,共9页石油科学（英文版）

基　　金：support from National Natural Science Foundation of China(No.52174042);China University of Petroleum Beijing(No.2462021YXZZ011,No.PRP/indep-4-2113)for the completion of this study.

摘　　要：Multiple fractured horizontal wells (MFHWs) currently are the only possible means of commercial production from the low and ultra-low permeability unconventional gas reservoirs. In early production time, flowback fluid, which constitutes of hydraulic water and gas flow within fractures, is collected and analyzed. Flowback analysis has been shown to be a useful tool to estimate key properties of the hydraulic fracture such as conductivity and pore volume. Until date, most tools of flowback analysis rely on empirical and approximate methods. This study presents an improved Green-function-based semi-analytical solution for performance analysis of horizontal gas wells during flowback and early production periods. The proposed solution is derived based on coupling the solutions of two domains: a rigorously derived Green’s function-based integral solution for single-phase gas flow in matrix, and a finite-difference, multiphase solution for gas–water two-phase flow in the fracture. The validity of proposed semi-analytical solution is verified by finely gridded numerical models built in a commercial simulator for a series of synthetic cases considering a variety of fluid and reservoir property combinations, as well as various different production constraints. Comparisons against available empirical and approximate methods are also provided for these cases.

关 键 词：Hydraulic fractures FLOWBACK Unconventional gas wells 

分 类 号：TE32[石油与天然气工程—油气田开发工程]