Implementation of Dissolvable Metals to Isolate Inflow Control Devices and Deliver a Washpipe Free Deep Water Sandface Completion Solution

The introductory use of existing inflow control devices (ICD’s) fitted with innovative dissolvable metal plugging rods to allow the operator to run washpipe free completions to reduce rig time is discussed. This work discusses an ICD washpipe-free application run in a long, deep water horizontal sandface completion in the Egina development. The completion was successfully installed following existing processes for tasks and sub-tasks applied in previous completions in the field. The washpipe-free solution was tailored to the reservoir, and is field-adjustable. The dissolvable plug solution was provided to be used with existing ICD’s available in country, without modification to the ICD housing. Fluid compatibility testing with dissolvable metals was performed establishing dissolution rates under existing reservoir conditions with mud, brine, and cake breaker at field formulations. Introduction of the dissolvable plug solution has provided the operator with an additional option to consider when seeking to further optimize times necessary to run lower completions in deep water wells offshore West Africa. No changes in existing completion procedures were necessary with respect to the procedure for washing down or subsequently placing cake breaker treatment. Running ICD’s with dissolvable plugs was identified as an opportunity to eliminate the need for running lower completion with washpipe. The subject well was run with ICD screens equipped with dissolvable plugs while maintaining full compatibility with the existing upper completion design. Once the well was completed and the tree installed, injectivity testing was successfully performed confirming ICD functionality was re-established. The ICD completion design saved the operator a minimum of 12 hours online rig time, further simplifying running the completion and associated handling times. Offline savings include (1) racking washpipe before running the lower completion, (2) subsequent racking back and laying washpipe upon completing the lower completion, (3) eliminating mobilization of washpipe to/from the rig, and (4) freeing up deck space typically used to accommodate the washpipe. During this saved offline time the auxiliary derrick could be used for other offline equipment preparation, helping provide further savings. Washpipe rental and maintenance costs were eliminated. An important reduction to safety risks related to extensive pipe handling was also achieved. This paper describes laboratory testing, full quality assurance/quality control (QA/QC) and operational procedures, leading to the first successful deployment and excellent functionality of ICD’s with dissolvable plugs in a long deep water horizontal completion eliminating the use of washpipe, while providing associated savings.