;6b. Depth shift core data to logs: The depth correlation of log data to core data is frequently characterized by numerous abrupt changes in the amount to be shifted. Every [[trip]] with the core barrel is potentially a change in the relative core or log depth, even if continuous cores are taken. Zones flagged as lost core zones often are not where they were interpreted to be. Because of this, automatic depth shift procedures generally do not work when shifting core data to well log data. An overlay procedure is recommended where the core is segmented by core run and again where missing data occurs within a core. The core is then usually shifted by segments. Segments can separate or overlap. Separation is caused by incomplete or poor core recovery, and overlap can be caused by poor core-handling procedures. Review of the field [[core description]] can help clarify some of these problems. (For more information on cores, see [[Conventional coring]], [[Core handling]], and [[Core description]].) | ;6b. Depth shift core data to logs: The depth correlation of log data to core data is frequently characterized by numerous abrupt changes in the amount to be shifted. Every [[trip]] with the core barrel is potentially a change in the relative core or log depth, even if continuous cores are taken. Zones flagged as lost core zones often are not where they were interpreted to be. Because of this, automatic depth shift procedures generally do not work when shifting core data to well log data. An overlay procedure is recommended where the core is segmented by core run and again where missing data occurs within a core. The core is then usually shifted by segments. Segments can separate or overlap. Separation is caused by incomplete or poor core recovery, and overlap can be caused by poor core-handling procedures. Review of the field [[core description]] can help clarify some of these problems. (For more information on cores, see [[Conventional coring]], [[Core handling]], and [[Core description]].) |