Oriented HRSCT: Optimum sidewall-core recovery in Mexico

The recovery of sidewall-cores has historically been very low in Mexico, specially in large holes, where a large hole kit (LHK) needs to be run. The protuberance created by this LHK causes the tool to lean on its side, which creates an oblique contact between the coring bit and the borehole wall (specially in deviated wells) and has a negative impact on the recovery rate. In an attempt to improve the recovery rate, one of the operators decided to convey the HRSCT with Tool Taxis so that the coring bit would penetrate the formation perpendicular, while keeping the tool firmly set. Core recovery on this job was 80.6% with 29/36 cores recovered. In the following eight months, Petromac performed another six jobs, reaching an average core recovery of 91.2%, with a total of 197 recovered cores out of 216 attempts. Oriented Coring improves recovery rate from 35% to over 90% Fig.2. Recovery rates with Petromac System Fig.1. Core-bif orientation with / without Taxis