Effect Evaluation of Drainage Gas Recovery by Velocity String in Sulige Gas Field

Abstract

The universal features of the gas wells in Sulige gas field are low pressure, low production rate, and the liquid-carrying capabilities of the wells that are poor. Accompanied with the gas well entering the process of middle and late life span, the pressure of the well bottom gets low and the liquid-carrying capability of the well becomes poorer. Liquid-carrying capability of gas well could be effectively improved by using velocity string. However, the former effect evaluations of drainage gas recovery by velocity string are confined to individual well. On the basis of all the gas wells which use the technology of velocity string in Sulige gas field, classification evaluations are made in this paper according to the pretest gas production rate. The technological principle of drainage gas recovery by velocity string is analyzed, and the model of critical liquid-carrying which fits for Sulige gas field is derived. Then, coiled tubing of φ38.1 mm is optimally selected which serves as velocity string according to this model. Finally, the scope of applications of drainage gas recovery by velocity string in Sulige gas field is obtained and the new application fields of this technology are proposed.

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.