Well Test Model and Analytical Method of Finite Conductivity Vertical Fracture Bilinear Flow of Low-Speed Non-darcy Flow

Abstract

For low-permeability reservoirs, non-Darcy flow is not considered in the current bilinear flow model of vertical fractures, and then, the effect of trigger pressure gradient on bottom pressure is also not considered, which makes difference between the test analysis result and the actual value. Therefore, a new bilinear flow model for finite conductivity vertical fractures with trigger pressure gradient is set up and the typical curve is drawn by studying the non-Darcy seepage law. Finally, the new solution of bottom pressure is obtained. And the influences of flow conductivity, the effect of wellbore storage, the skin effect, trigger pressure gradient, and the effect of boundary distance on typical curves have been analyzed. The researched results show that trigger pressure gradient has greater effect on the typical curve in the later stage. The higher the trigger pressure gradient is, the faster the boundary responses is and the more upward the curve of the later stage is, which even leads the radial fluid flow to disappear. The case study shows that the presented new model not only uses pressure data of a low-permeability reservoir efficiently and increases the accuracy of well test results, but also provides a reliable reference for the dynamic analysis of field fracture wells.

Copyright 2017, Shaanxi Petroleum Society.

This paper was prepared for presentation at the 2017 International Field Exploration and Development Conference in Chengdu, China, 21–22 September 2017.

This paper was selected for presentation by the IFEDC&IPPTC Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the IFEDC&IPPTC Committee and are subject to correction by the author(s). The material does not necessarily reflect any position of the IFEDC&IPPTC Committee, its members. Papers presented at the Conference are subject to publication review by Professional Committee of Petroleum Engineering of Shaanxi Petroleum Society. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of Shaanxi Petroleum Society is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of IFEDC&IPPTC. Contact email: paper@ifedc.org or paper@ipptc.org.