Eccentered NMR tool successfully descended by gravity in high deviation well, while eliminating stick-slip motion thanks to Wireline Express conveyance system.
The logging program included an NMR tool (MRIL-XL) to be run in a highly deviated well (69°) in Mexico. With the conventional setup, the drag due to the weight of the magnet on finned standoffs, prevents gravity descent in deviations over 60deg. The normal “solution”, pipe conveyed logging, involves much more logging time, particularly as two latches were needed per descent in this instance. To save time, mitigate risks and improve data quality by eliminating stick-slip, the operator decided to convey the toolstring with Petromac’s conveyance system – Wireline Express.
This was the first time that a MRIL-XL was conveyed fully on wheels. A tailored configuration of Tool Taxis generated the optimum standoff, which allowed removal of the finned standoffs. This resulted in low drag coefficient (0.18), very smooth tool motion and much enhanced data quality.
By using Wireline Express the operator obtained an exceptional logging dataset while saving rig-time and controlling intrinsic operational risks.
CHALLENGE
MRIL-XL measurement is directional and must be run eccentered for optimal data quality. The standard configuration utilizing finned standoffs results in high drag and limits gravity descent at high deviations. Additionally, high drag induces stick-slip motion, further compromising data quality at slow logging speeds.
SOLUTION
A bespoke configuration was designed to convey the whole toolstring on wheels with the Tool Taxis.
RESULTS
MRIL-XL descended by gravity to TD, while controlling operational risks such as differential sticking. Additionally, enhanced data was acquired thanks to smooth tool motion while logging up.
