Coiled Tubing Deployed ESP Retrievable Completion Application in Algeria – A Success Story

Abstract

It is well known in the oil industry that on jointed tubing conveyed Electric Submersible Pump (ESP) completions there is always the likelihood of well re-completion either after the useful life or a premature failure of the ESP is reached. The re-completion becomes a significant downside versus conventional completion systems (naturally flowing wells). Most of these ESP replacement / re-interventions are usually associated with the need of a workover rig or snubbing unit and the related cost, logistics scheduling and operating time bound to it. In an attempt to evaluate a different cost-efficient alternative to address this ESP re-intervention work a Coiled Tubing Deployed ESP System / Project was initiated in Algeria to deploy the ESP systems via fit-for-purpose Coiled Tubing Deployed Retrievable ESP (CTDRESP) cable after the installation of the permanent downhole completion, with the intention to reduce the overall intervention cost, reduce the production deferment by: a) eliminating the need of having a rig on location, which have availability challenges re rig schedule) b) reducing the time required to connect the well back to production but not requiring the removal of flow lines and pipeline on the surrounding areas of the well), in a brown oil field located in an area where artificial lift systems are widely required for sustained production. This paper documents the first fit-for-purpose Coiled Tubing Deployed Retrievable ESP completion application in North Africa region, where +/-59m (194 ft) of BHA (Tail Pipe, Seal Stack and ESP assemblies) were deployed and run into the well using 1.5in Tubing Deployed Retrievable ESP (CTDRESP) system with a specialized sub-surface safety valve installed at landing nipple at +/- 64m (209ft) successfully. Oil production was successfully resumed after ESP installation with 99% oil ratio at surface, proving this practical and cost-efficient type of ESP deployment application in a well not capable to flow naturally. With the implementation of this technology the operating company in this region has enabled an alternative method to service its ESP wells, saved operating related costs, and reduced production deferral with a safe and cost-efficient alternative that also considers reduced personnel workforce and rigless approach (rather than full scale workover rig unit). This paper will review the project concepts, job planning, utilization of a sleeve style safety valve in the completion, well control and contingency considerations prior to reviewing the successful installation of the completion. Sharing the lessons learned will enable optimized future utilization of this technology.