High Pressure Gas Lift Optimization Using Nodal Analysis

Abstract

This study seeks to explore the potential benefits of high pressure gas lift (HPGL) optimization. We will compare HPGL optimization with constant injection rates evaluating the potential uplift in oil production and profitability across diverse well and reservoir conditions. The methodology integrates nodal analysis simulation with economic analysis to optimize HPGL rates in tubing and annular flow. Initially, the study employs Prosper to create a baseline model representing average well and reservoir conditions in the Permian Basin. Subsequently, it simulates diverse well conditions (e.g., production rates, tubular configurations) and reservoir characteristics (e.g., pressure, productivity index), aiming to identify the most profitable gas injection rate considering varying oil prices and gas injection costs. Extensive sensitivity analyses further explore how all these various factors influence HPGL optimization, ensuring a comprehensive understanding of its efficiency and profitability. This comprehensive study has shown significant results and insights. The implementation of HPGL rates significantly enhanced oil production and profitability compared to traditional constant gas injection rates. The study revealed that the gas injection rate that optimizes oil production does not always align with the gas injection rate that maximizes profits. The most economically efficient gas injection rate was identified by addressing the additional revenue from the incremental oil output against the costs associated with gas injection. Sensitivity analysis further highlighted the significant influence of various well and reservoir conditions on the efficiency of HPGL. This underlines the complexity of HPGL optimization, which demands a balance between technical feasibility and economic practicality. Additionally, the research uncovered that specific tubular configuration led to higher oil production and profitability when employing HPGL in unconventional wells and producing oil through the annulus, compared to the conventional method of producing oil through the tubing. This study suggests great potential for innovative approaches in HPGL strategies, offering promising avenues for enhancing oil recovery and financial returns in the petroleum industry. This study intends to serve as a roadmap for HPGL operators to evaluate the incremental oil production and profits achievable in various well and reservoir conditions. Additionally, it introduces a direct method for single-point HPGL operators to estimate bottom hole pressure from measured surface injection pressure, surpassing the accuracy of traditional multiphase fluid correlations, which often rely on uncertain well tests and flow parameters, thus offering a more reliable approach for HPGL operations.