Offshore Brazil, a major operator encountered severe lost circulation at a depth of 4,245 m. Cementing to address lost circulation often involves pulling the BHA out of the hole, which increases downtime, NPT, and operational complexity. Conventional technologies lack sufficient port size, limiting their effectiveness for complex lost circulation treatments. These treatments frequently fail after placement, necessitating BHA removal, with contamination extending to the lower assembly. To meet the challenge, the operator required a drilling valve that would enable placement of lost circulation material (LCM) or cement slurry without compromising BHA integrity.
To address lost circulation, the operator deployed the WELL DEFENDER valve as part of the drilling BHA to address the client’s lost circulation challenges. The WELL DEFENDER valve's enlarged ports and proprietary material design allowed for the effective placement of cement slurry into the annulus while isolating the BHA from contamination.
During the operation, the customer experienced full lost circulation at 4,245 m. The BHA was pulled back into the casing shoe, and the WELL DEFENDER valve was activated at 3,397 m using a 2.500-in activation ball. Parameters confirmed successful BHA isolation, with no signal from the MWD and RSS tools. Cement slurry was pumped through the WELL DEFENDER valve's bypass ports into the annulus, and the rig squeezed the cement into the formation. After waiting 12 hours for the cement to harden, a circulation test confirmed the successful treatment of losses. The WELL DEFENDER valve was deactivated using a 2.448-in deactivation ball, restoring flow to the bit.
The treatment with cement was repeated a second time when lost circulation started again while drilling a new formation at 4,285 m. The WELL DEFENDER valve was reactivated, and cement slurry was successfully placed into the annulus. The tool’s reliable functionality ensured that the BHA remained uncontaminated, and the customer was able to resume drilling without delays.
The WELL DEFENDER valve's robust design, including its industry-leading total flow area (TFA) with enlarged ports, proved critical in handling complex fluid treatments. Its simplified activation and deactivation process provided the client with confidence in its performance, reducing NPT and enabling efficient lost circulation treatment.
