Field Test Results Of A New-Generation Large-Bore Rotary Coring Tool Available to Purchase

Wireline sidewall cores have a well-established role in the formation evaluation program in providing key rock properties. While they provide a subset of the exhaustive information obtainable from continuous core, for reasons of operational efficiency they are often deemed to be the most practical option. Although the ability to perform routine core analysis (RCAL) measurements on sidewall core samples improved significantly with the introduction of the first rotary sidewall coring tools in the 1980s, significant limitations remain related to the relatively small size of the sample. Among other challenges, measurement uncertainty is higher compared with core plugs, and in heterogeneous formations the smaller volume of rock is expected to be intrinsically less representative of bulk reservoir properties. Many special core analysis (SCAL) and rock mechanics methods are not considered to give valid results or cannot be performed owing to insufficient volume of core material. To address the given challenges and improve the range of tests that can be accurately performed on sidewall cores, we introduce a new wireline rotary sidewall coring tool that acquires samples slightly larger than standard laboratory core plugs, 1.5 in in diameter by 3 in in length. Every aspect of the new coring system has been engineered to enable easy and reliable wellsite operation with real-time intelligent drilling control and efficient recovery in a broad range of lithologies. An innovative system of core handling and core preservation techniques ensures the recovery, traceability, and integrity of each core from the moment it is cut downhole until delivery to the laboratory. We provide a laboratory perspective on the expected efficacy of common measurements carried out on the new sidewall cores compared with those from standard rotary sidewall cores, and find that for most analyses we should expect low uncertainty similar to core plugs cut from whole core.