Production Optimization by Combined Artificial Lift Systems and Its Application in Two Colombian Fields

Abstract

Abstract The application of combined artificial lift systems yields improved production in terms of costs and rates at better conditions than could be expected from using only one of the individual systems. This new approach overcomes restricting conditions such as tubular size, operating depth, water cut and corrosive gases, while preparing the wells for future condition changes as a result of waterflood/pressure maintenance programs in progress. These combined systems were initially designed for two Colombian oil fields. The concept considers a primary system such as rod pumping or ESP combined with gas lift as secondary system. The design envelope provides a wide operating range, allowing individual operation of the primary, the secondary and the combined system, reaching the optimal technical and economical performance while the combined system is operating. The operating envelope is framed in terms of production rate and power consumption. The paper presents the concept of "equivalent depth" (compared to "operating depth"), the design methodology, downhole equipment and field operating conditions and benefits. The long-term benefits are a reduction in production downtime, decrease in the artificial lift investment by the use of downsized equipment and a reduction in the operational cost due to lower power requirements. Actual field data is presented to corroborate these benefits.