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TUALP Abstract
 

Surath Rath (Master of Science in Petroleum Engineering)
Sensitivity Analysis in Continuous Gas-Lift Design
(113 pp. - Chapter II)
Directed by Dr. Zelimir Schmidt
(200 words)

The gas passage performance of the Altec 1” valve of port size 24/64” has been studied. Various choke sizes considered are 10/ 64”, 16/64” and 20/64”. The TUALP models are tested against both orifice and throttling flow performance data gathered on this valve . The TUALP model predicts the orifice flow performance of the valve with an accuracy of 99% and the throttling flow performance with an accuracy of 60-80%.

Sensitivity analysis is done on important surface and subsurface parameters to optimize the continuous gas-lift installation. The important parameters that are under the direct control of the operator include (i) tubing/flow line size (ii) separator pressure, and (iii) surface gas injection pressure. Sensitivity analysis on these variables yields the basis for completing a continuous gas-lift installation in the most economic/optimal manner. The less controllable parameters that affect the performance of continuous gas-lift are the reservoir parameters. Sensitivity analysis on these parameters is done in order to formulate a procedure for operating continuous gas-lift wells with optimum economics. After analyzing various operational procedures, a procedure is outlined that can replace bracketing below the operating valve. This procedure can also be used to gain advantages of a workover for well stimulation or mandrel change.

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Last updated September 04, 2012