Sanding problems in the operator’s gravelpack completions affected productivity in mature wells in deepwater Gulf of Mexico—a common challenge for operators in the region that impacts the entire field lifespan. Due to asphaltenes and fines migration, the sand screen did not function optimally, restricting production. The operator sought a solution to cut as many openings in the production tubing as possible to effectively stimulate and restore well productivity.
The operator engaged with SLB, and in nine months, a custom solution was developed, qualified, and deployed by leveraging the ReSOLVE iX™ intelligent extreme wireline intervention service to enable a slot cutting solution. To do this, a scissor opening assembly was developed using a rotatable cutting blade on one arm and a fixed anchor to provide the necessary stability on the other. During initial testing, six slots were simultaneously cut along the production tubing using six stacked tractor drives. Conventional tools, however, are only equipped with one blade to cut each slot separately. At the end of this development phase, the operator witnessed a comprehensive system integration test (SIT) to validate the technology.
The 3½-in-OD, 9.2-lbm/ft3 tubing was built with a corrosion-resistant alloy (CRA), 25Cr material, which is significantly more challenging to cut than carbon steel. Because of the slot cutter’s versatility, seven drive sections were conveyed, providing seven cutting sections and multiple cuts along the BHA to minimize the number of runs. The phasing (90° orientation) between cutter assemblies also provided a high distribution of cuts across the perimeter of the tubing to enable a more effective stimulation treatment. As a result, only three runs were required to cut 275 slots precisely spaced across 130 ft, optimizing cutting efficiency.
The ReSOLVE iX service instrumentation and real-time surface readout enabled cutting precision and quality control. The job planning addressed all key risks such as debris management, slot positioning confirmation, vertical slot distribution, tight restrictions, and HSE risks. Additionally, a remote team of technical experts was able to provide continuous monitoring support for the field crew and shore-based customers due to the real-time transmission of downhole performance data supplied by the tool throughout the operation.
The entire operation was completed in less than five days compared with the previous standard of 14 days using an alternative mechanical puncher, saving the operator nine rig days and reducing CO2 emissions. The flow area, distribution of cuts, and degree of perforation created by the slot cutter helped the operator net a 70% increase in productivity index, with the area from an additional 275 slots in the tubing dramatically reducing production flow resistance. As a result, the operator changed its entire field intervention strategy, optimizing opex investment.
