Paper: The Use of Well Flow Analysis In Well Completion Decisions

Well flow analysis is the examination of well performance based on fundamental mathematical models of flow in well tubulars and flow through porous media. It is used to assign the pressure drop to each part of the flow path existing between the well drainage boundary and the wellhead pressure. Many types of computer software are available to perform the calculations and plot the results in an easy to read chart of well head pressure versus flow rate. Multiple curves can be generated so that actual performance can be compared to predicted performance for different wellbore conditions. Such curves will be used in this presentation to evaluate performance of different wells. One case study will demonstrate the use of well flow analysis to define the wellbore condition after perforating a gas well in South Texas. Well bore condition is defined by the perforation geometry and near perforation permeability. A pressure build-up test will be analyzed to provide a skin factor. This skin factor will be further evaluated using a simple, steady state, radial flow model for perforations to determine the near wellbore permeability.