This paper chronicles the progression of liner refracs on mature wells in the South Texas Eagle Ford Shale.Operational issues,strategies to mitigate the risk,and well results will be reviewed.Liner refracs involve running and cementing smaller casing as a liner inside previously stimulated 5 1/2-in.cased hole lateral completions.This method of isolating existing perforations has been successfully appliedto allow subsequent refrac plug and perf operations.The operational steps to execute these deploymentsimpose more risk than completing new wells and significant failures have occurred.Fit for purposeequipment,best practices,and a steep learning curve have been employed to mitigate the risk and improvethe overall economic benefits of the program.An account of the failures and efforts to prevent these issuesis provided.From the summer of 2018 through 2019,15 liner refracs have been executed in high temperature wells inDewitt County,Texas.Three of the wells with operational issues are presented along with the approach toprevent reoccurrence.One well was eventually lost when the production casing was inadvertently damagedwhile attempting to mechanically cut the installed liner.This prompted an alternative deployment method,and the development of an anchor system which has now been used on six wells.The smaller geometry andtools required in liner refracs impose additional challenges.This study outlines this operator's approach tominimize the risk and reduce failure frequency.Dramatic increases in pressure and production have beenobserved on the liner refracs.The wells that have been executed successfully,have exceeded return oninvestment expectations.Liner refracs provide a tool to capture production and reserves from existing wells and enhance fielddevelopment.Lessons learned and alternative methods to execute liner refracs are considered in this fieldstudy.
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