Gas-lift allocation optimization using generalized reduced gradient approach

Continuous gas-lift is one of the most common artificial lift methods. High-pressure gas is injected into the tubing continuously, to lighten the oil column, which results in production enhancement. As a result of gas limitation it is impossible to make all the network wells produce at the maximum rate, hence the need to determine proper gas allocation. Gas allocation optimization is a nonlinear function maximization the decision variables of which are gas injection rates for each well, which are subject to the physical restrictions. In this work, Gas-lift performance curve (GLPC) is plotted and compared for different pressure drop correlations, by means of nodal analysis simulation. In this way, the most efficient correlation, especially for vertical two-phase flow was found to produce more precise pressure drop information. The generalized reduced gradient (GRG) method is also used as an efficient tool for network optimization to select the most proper gas allocation for each well.

کلیدواژه ها:

gas-lift ، GLPC ، Quadratic programming ، GRG