Imperatives for Implementing Gas-Lifting for Fields with Sand Control: OT Field Experience
Abstract Unconsolidated sandstone formations are normally completed with one form of sand control or the other. The aim is to manage sand production as low as reasonably practicable and protect well and surface equipment from possible loss of containment. There are about 8 broad types of sand control namely; internal gravel pack, external gravel pack, chemical sand consolidation (SCON), open-hole expandable sand screen, cased-hole expandable sand screen, stand-alone screen, pre-packed screen and frac & pack. Gas-lifting targets to increase pressure drawdown required for wells to produce by injecting gas at a pre-determined depth using gas-lift valves installed in the tubing. Whereas gas-lift design targets to optimize the gas-lift injection to ensure stable production, the associated drawdown may challenge the operating envelope of the sand control mechanism in place. The OT field has been in production for about 50 years and has been on gas-lift for about 20 years. There have also been occasional sand production problems in the field; some of which occur in gas-lifted wells. This paper will highlight the outcome of a study that investigated the performance of various sand control mechanisms under gas-lift production and present observed trends to serve as guide in maximizing the performance of such gas-lifted wells with sand control mechanism.