The Delaware Basin main form of artificial lift is gas lift due to the higher gas oil ratio. The lift gas used is processed gas that still has a high yield associated with it. As a result, condensate drop out occurs in the gas lift lines to the wells and can cause operational problems, including gas lift valve sticking, tubing casing communication and erosional damage. The well in turn stops flowing due to well/tubing integrity concerns and artificial lift equipment impacts, reducing the lift efficiency of the gas lift system.
Aiming to reduce rig intervention frequency, procedures have been developed to assist production recovery of the impacted wells by cleaning out the valve internals from sand and deposits through steps that become increasingly more intrusive. Starting with rocking the well, condensate flushes and use of condensate to help unload the wells.
The troubleshooting procedures have reduced the need for intervention with a rig for up to 50% of wells that show tubing casing communication or have low lift efficiency due to shallow gas injection. The condensate unloading lift procedure developed by Chevron in the Delaware Basin has been determined to have success for wells with reservoir pressure above 3000 psig to help kick off wells.
Following a structured troubleshooting approach enables a more cost-effective rejuvenation for wells struggling to flow. Following a structured troubleshooting process with defined roles & responsibilities the intervention costs have been reduced and resulted in equipment optimization and metallurgy selection improvements.