Artificial lift encompasses approximately 96% of the US oil well market. Of the wells that use artificial lift, 10% use gas lift for production. As gas is injected into the well, the viscosity of the fluid and pressure is reduced, promoting flow to the surface. In typical gas lift valve systems, dummy valves are installed in side-pocket mandrels to isolate the annulus from the tubing where pressurization is required to test the tubing, test the annulus, set a hydraulic packer, or activate an isolation device. Then intervention would be required to remove the dummy valves and install a live gas lift system. This can be a time-consuming process and can pose risks to existing infrastructure while hindering production time.
This paper presents a newly developed nano-engineered disintegrable composite (DNEC) and its use in gas lift valves. The DNEC gives gas lift valves the flexibility to be installed as dummy valves, but switching to a live valve without intervention. The switch from a dummy valve to a live valve occurs through an in-situ disintegration of the DNEC plug. This eliminates multiple intervention trips and enables immediate production of these wells under optimized gas lift conditions.
The nano-engineered composite plug is lighter than aluminum, but as strong as some mild steel. The DNEC plug has pressure rating of 5,000 psi and will disintegrate in brine during the cleanup process, within 12 to 50 hours, making it an ideal tool for offshore gas lift valve applications. To date, more than 1,000 gas lift valves equipped with DNEC plugs have been successfully installed. The nanostructured composite material, the valve design, the lab test data and a successful case history will be presented.