Executive summary

Gas lift diagram

Executive Summary

Gas Lift design is the most critical stage of the Continuous Gas Lift project. There are several factors that must be taken into consideration such as the depth of injection, daily injection gas volume, the compressor’s size and horsepower requirements and several other factors. This project will be the extension of the GPI where a specific problem has been selected and passed through the screening phase to come up with the application of continuous gas lift as the proper method oil production enhancement. A block diagram has been constructed to be used as the road map for the design process. The block diagram illustrates the design aspects and alternatives in details.

The project reveals the general concept, advantages and limitations of utilizing Gas Lift in oil wells. All design procedures, flow parameters, and variables will be covered in this project. The design process is carried out in an attempt of solving the problem of one specific oil well located in United Arab Emirates. This phase involves use of correlations, iterations and simulation to predict the Gas Lift performance. To evaluate the performance of the Gas Lift, a reliable industry-standard method was used. This method is also known as NODAL System Analysis (NSA).

There are two design scenarios which are based on the Gas Supply. The first scenario takes the assumption of having an unlimited or sufficient gas supply while the second scenario is when the gas supply is limited and not sufficient to reach the maximum production rate possible. The main objective would be determining the operating GLR and the recommended depth of continues gas injections considering any of the two scenarios and the financial aspect associated with them to assess their feasibility. The design is then followed for valve spacing and selection of the proper valves and compressor.

This would be the “control” alternative. The control’s purpose is to compare and evaluate the performance of the Gas Lift alternatives and determine the most efficient one. Each injection valve will be analyzed to determine the most suitable alternative for both scenarios: Unlimited Gas Supply (GLR = Optimum) and Limited Gas Supply (GLR<Optimum).

The design of the injection valve depths will be implemented using a specially designed EXCEL spread sheet that will aid in the calculations. This EXCEL spreadsheet is considered one of the most important outcomes of this project. The spreadsheet contains several equations and correlations with programming codes of Visual Basic Applications (VBA) to help obtaining detailed results since there are many trial-and-error and iterations used during calculations. The EXCEL sheet has been developed to be used for any continuous gas lift design in the future. A discounted cash flow analysis based on available equipments, gas supply and brake horsepower requirement will be developed. Risk assessment and environmental and safety analysis will also be developed to ensure safe operation practices and procedures during the implementation of the Gas Lift.