A novel hydraulically-powered, Self-Reciprocating Valve Pump (SRVP) was piloted in a Western Colorado gas well for deliquification operations. The objective was to pump fluids from a deep gas well and later retrieve and redeploy the SRVP without a workover rig. This paper will describe the SRVP technology, areas of applicability, and pilot program, including the completion design, deployment/retrieval workovers, performance, teardowns, learnings, and future plans.
Gas production wells tend to load up with produced or condensed liquids that create an impediment to flow and reduce or stop gas production. Pumps are typically used when the reservoir pressure is too low for less intrusive artificial lift methods or when significant amounts of fluid must be removed. Pumps can suffer from reliability issues and considerable installation/deployment costs because a workover rig is typically required for intervention. Unfavorable producing conditions and tortuous wellbore trajectories further tend to decrease run lives. These issues can make economical hydrocarbon production impossible. The SRVP was developed to overcome these challenges.
The SRVP is installed downhole inside a concentric tubing string and is powered by injecting a high pressure fluid. The injected (power) fluid causes the SRVP to reciprocate, driving a piston pump to produce formation liquids and power fluid back to surface up the concentric string by production tubing annulus. Removal of the produced fluids decreases backpressure on the formation, enabling gas production up the casing. Because there is no mechanical linkage to surface for pump operation, the SRVP can be deployed in highly-deviated and/or small-diameter wells that standard artificial lift methods would struggle with. Additionally, the SRVP is designed to be pumped into and out of the well following initial installation, greatly reducing deployment costs.
Three industry-first SRVPs were installed consecutively in a concentric flush-joint tubing string and were powered with a compact surface pumping unit. The SRVP proved the ability to lift 20 to 40 BFPD net fluids up the concentric string by production tubing annulus from more than 12,000 ft vertical depth while gas was produced up the casing. The SRVP was retrieved and redeployed several times either hydraulically and/or with slickline. System design, operation, and performance were continuously improved through the duration of the pilot program. Run life steadily increased to 50+ days with the third installation.