A NEW APPROACH OF CONSTANT RATE IN GAS WELL DELIVERABILITY ANALYSIS USING ANSAHS METHOD

• Main Author: Sebastian Loana, Johan
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40063
• Institution: Institut Teknologi Bandung

Industrial practice of gas field development requires a structured analysis for each of its gas well. Several methods are available in this analysis, including the production rate-time analysis that has been used worldwide. However, the currently available method is developed under the constant bottom hole pressure in its production time, which different from the practice in production operation of a gas field. Application using constant bottom hole approach will required a simulator to acquire the plateau rate profile of each gas well. Thus, this study presents a well deliverability analysis using constant gas rate approach, in order to reduce the time required for the analysis to obtain the rate profile under the constant gas rate production constraint. This paper presents the new approach of the previous work of Joseph Ansah “Semi-Analytical (p/z) Rate-Time Relation for Analysis and Prediction of Gas Well Performance” (1996). The fundamental theory of stabilized rate equation in gas well and material balance is used as the basis of the equation derivation. Modeling process of gas well behavior is using the analysis of PVT properties of viscosity-compressibility during the pressure depletion. Current available approach in gas well deliverability analysis is within the constant bottom hole constraint. Thus it creates limitation of current previous work, which unable to model the actual production practices, where bottom hole pressure is lowered steadily over the productive life of the well. In order to compensate for the changes of bottom hole pressure during well life, a new approach of constant gas rate deliverability analysis is developed in this study. The study also provides a comprehensive PVT analysis to develop analytic solution for the equation to be used in gas well deliverability analysis. The study result is then validated using simulation model from CMGTM. Validation of this proposed approach is shown as the simulation model from CMGTM has matched the equation result, with the average relative error of 1.81%. Coupling with currently available equation, new approach proposed could model the entire gas well behavior. The application of this equation will also reduce the analysis time required and numerical error significantly.