Production optimization in continuous gas-lift flow is achieved once the correct amount of gas has been injected through the operating valve, under stable flow condition. More than 80% of the active wells offshore Lake Maracaibo operates with artificial gas-lift methods. For this reason and because of the need to increase oil production, PDVSA E&P decided to carry out field tests using the gas jet pump concept. The pump is wireline retrievable, installed as deep as 12000 feet, with crude oil gravity ranging from 25 °API to 35 °API and for 23/8″ to 31/2″ tubing.

The need to increase the pressure drawdown in the wellbore, which increases the liquid production in already optimized continuous gas-lift wells, was done by installing a gas-lift jet pump in the circulating sliding sleeve or in the operating mandrel. The gas injected (power fluid) from the annulus to the jet orifice converts the energy, from potential to kinetic by lowering its pressure due to the area change, and creating a suction force at the throat. The production fluid and the gas injected are mixed in the throat, recovering its potential energy in the diffuser section.

The results obtained showed that this new technology could increase the pressure drawdown or liquid production up to 30% of its original oil production in some wells. It also performed successfully when a gas-lift jet pump is installed in a high gas/oil ratio sand near the production zone, having the capability to produce without gas injection (autolift). There is no field data information available on gas-lift jet pumps. It is the objective of this article to present the results and the experiences gained during the test field. Selection criteria used for well candidates are also highlighted.

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