DETERMINATION OF FLOWING BOTTOM-HOLE PRESSURE FROM WELL-HEAD DATA

ABSTRACT

Production well optimization and modelling are very important in the efficient management of oil and gas production from a well. A major factor contributing to this process is the accurate estimations of the flowing bottom-hole pressure at the formation as it helps in various petroleum production engineering analysis. Some of these analyses include studies on Vertical Lift Performance (VLP) and Inflow Performance. The effective determination of bottom-hole pressure has been a major concern in the industry due to several reasons as it can either be measured or estimated. In the case of measurement, a pressure gauge is needed down-hole, this is very accurate but expensive and time consuming. For this reason, this project will focus on flowing bottom-hole pressure estimation from wellhead pressure and data as it is generally cost effective and it can be easily determined within a short period of time. This will be achieved through the modification of Sukkar and Cornell’s model for dry gas. A method which uses a single flow model to simulate multiphase fluid flow system and the mixing rule that correspond to the fluid flow pattern is presented. The result of this work obtained with the use of MATLAB when applied to simulation of two-phase flow in vertical oil wells and low Gas-Oil ratio wells are relatively accurate. However, high Gas-Oil ratio wells fall short of the model estimation of pressure.