Coring in unconventional reservoirs with typical unconsolidated formations has introduced additional challenges requiring more-innovative concepts to be developed. These requirements have recently led to widespread attention to wireline continuous coring (WCC), which was modified from the mining industry for petroleum-industry applications. This paper is aimed at identifying and addressing complications experienced in the use of WCC. In addition to the challenges and solutions discussed in this summary, others are covered in the complete paper.
Basic Bottom-Coring Methods
These methods, in the context of petroleum exploration, comprise conventional and WCC methods. Conventional coring is a method of rotary coring by which the inner tube containing the core is retrieved along with the outer-tube assembly to the surface following a conventional drillstring trip.
WCC is a method of coring or drilling by which the same outer assembly is used as the bottomhole assembly and the same core bit is applied for both drilling and coring modes; however, changing the inner assembly can be performed easily by wireline in order to switch to the desired mode.
