Gas Lifted Wells Optimization Based on Tubing Head Pressure Fluctuation

摘要

The paper describes how to evaluate the gas lifted well performance with respect to optimum gas lift injection rate based on tubing head pressure fluctuation analysis. Well and reservoir is a complex system with multiple performance parameters. In industrial practice to acquire some of these parameters surveillance activities are required. Well performance parameters such as rates and pressures are fluctuating with time. These fluctuation characteristics' analysis allows describing certain reservoir and well system parameters and well performance evaluation. The fluctuation is impacted by various factors. For example, fluid flow in porous media characteristics, non-equilibrium fluid inflow behavior, flow composition, flow regime, etc. The particular described method is based on tubing head pressure fluctuation analysis. Applying various fluctuation analysis methods on the common production properties oscillations allows evaluating actual well performance parameters. The study performed demonstrates the ability to define the optimum regime for the gas lifted wells based on the tubing head pressure or production rate fluctuation analysis without any dedicated surveillance activities. Such an approach was applied in the gas lifted wells production flow rate analysis at various gas lift injection rates - below, above, and at the optimum gas lift rate. The study was applied in Oily Rocks offshore oil field. The obtained results proved the approach being feasible, not requiring dedicated or additional surveillance, and hence, being cost effective.