Casing Leak Repair to Continue Hydraulic Fractures Stimulation

Abstract

A casing leak repair alternative is presented to allow continued hydraulic fracture treatment of an unconventional formation. Analysis of diagnostic operations, selection of the best alternative, and the results are detailed. This paper details the diagnostic operations (annular circulation test, multifinger caliper log, leak chase with hydraulic packer on Coiled Tubing, fluid transit evaluation, and real-time camera downhole images acquisition) to identify the casing leak zone and the analyzed repair alternatives with the final selection of a casing patch. To verify the pipe body shield strength and burst pressure post-patch expansion, a finite element analysis in dynamic condition was carried out to limit the hydraulic fracture pumping parameters. This paper covers details on repair operations executed, verification analysis to confirm original frac treatment continuity, and lower & upper completion installation. The diagnostics operations allowed pinpointing casing leak detection and selection of possible repair alternatives. The repair was carried out as planned involving many services companies. A solution was implemented with local staff and services considering the COVID context with travel restrictions of the patch owners. Web broadcasting CT surface parameters allowed real-time support from casing patch suppliers during the entire intervention. The completion plan with 24 frac stages performed through the casing patch was successfully executed. The production packer with an OD of 99.5% of the casing patch drift was run through the casing patch and wireline set without any problem. Considering well integrity conditions throughout the entire well production life as the main intervention objective, this paper introduces a successful alternative to repair casing failures on an unconventional well that allowed hydraulic fractures continuity to accomplish the original frac plan. The well production was higher than the Estimated Ultimate Recovery (EUR) expected for the landing zone.