Measurement While Coring (MWC)—measurement of core acquisition in real time

Abstract

Coring technology has remained relatively unchanged for decades. One of the primary technology gaps has always been the lack of real-time data at the surface on core recovery. Coretrack has developed the Core Level Recorder (CLR), a core recovery tracking tool that delivers accurate core-to-reservoir correlation. The CLR can be coupled to a mud pulser system to deliver surface readout on the core recovery process delivering accurate core-to-reservoir correlation in real time. The CLR is placed inside the inner core barrel and moves upwards as core is recovered into the barrel recording the amount of rock captured in a time versus distance format. The transmission of this data to surface provides the real-time information on whether or not core is being recovered and accurately records any gaps in the process allowing the core to be correlated to the formation with ±50 mm accuracy.

The CLR has been designed for use in both water and synthetic oil based drilling fluids of up to 125 °C and 10 kpsi with runs carried out in a variety of both on and offshore wells in Oman, Saudi Arabia and Australia. The CLR can be run in deviated holes and in all currently available core barrels. The most common size is for 4 inch core, however it is easily adapted for other barrel diameters.

Real-time data transmission enables the coring technician to accurately state when core is being recovered. This greatly increases the ability to state when core milling or core jams have occurred—a notification that removes unnecessary round trips and brings significant savings.

This paper will present case histories of runs made with the CLR.