ANALYSIS OF TEMPERATURE AND PRESSURE SURGE DISTRIBUTION FOR SINGLE PHASE GAS FLOW DURING WELLBORE SHUT-IN AND START-UP

Abstract

Analysis of temperature and pressure surge distribution for single phase gas flow during wellbore start-up and shut-in is a complex phenomenon for gas producing industries.  Its occurrence forced the flowing gas to stop abruptly creating a pressure surge and high temperature within the wellbore system.  This situation has to be studied for proper characterization, and protection of the producing wells from damage and premature closure.  Many authors studies this phenomena in order to have a permanent solution but yet the problem still remain due to differences in environment. In this work, a one-dimensional transient governing equation based on depth and time dependent for start-up and shut-in has been developed.  It is solved by finite difference scheme of Steger Warming Flux Vector Splitting Method (FSM).  The method is fully transient and unconditionally stable.  Surge pressure were analysed and wellbore temperature is predicted using the unsteady state heat transfer model.   The results shows that if shut-in time is short, the sound wave propagation speed is faster than that of its longer time period.  The result of this work provides a technical reliance to gas producing industries and can serve as guidance in field operations to avoid gas leakages or wellbore damage.