Transient Dynamic Model for Deviated Gas Lift Well Design

• Main Author: Santoso, Michelle
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39871
• Institution: Institut Teknologi Bandung

In offshore field, deviated wells can recover oil reserves that are located far from the platform. However, deviated wells pose a great challenge in producing hydrocarbon. Gas lift installation in deviated well requires adequate technical handling compared to vertical well, as shown in an offshore field in North West Java, Indonesia. This paper discusses a dynamic performance of multiphase flow in gas lift deviated well using transient simulation to observe detailed important phenomena to prolong the well lifetime and optimizing production rate. An observation is done to multiphase flow behavior and performance in vertical and deviated well with gas lift. Both wells have same configurations. The transient-dynamic model includes liquid holdup, flow regime, production rate, and pressure profile as functions of time and length of pipe. The difference of the dynamic model between deviated and vertical well are analyzed and used as the considerations to optimize gas lift operations in deviated well. The optimization is based on sensitivity analysis of gas injection rate. Compressor limitation and injection gas availability are also considered. Having transient-dynamic model analysis on multiphase flow in the deviated well’s tubing, a thorough dynamic variables can be observed, therefore the optimum production practice can be obtained. The flow regime in deviated well tend to be unstable, changing from one flow regime into another in an instant, considering the amount of gas and liquid occupying the pipe section. Effective production strategy must be designed by determining the optimum production tubing as well as well inclination angle. The last option from the production engineer is to add more platform closer to the targeted reservoir. This scenario will increase capital cost and not a favorable option by the management. The novelty of the observation and transient-dynamic modelling is to enable a longer lifetime production and to enhance the fundamental performance of multiphase flow in gas lift deviated well. This paper could also serve as a recommended practice to design optimum gas lift for deviated well.