VACS system reduced operational risk in debris-filled long lateral
An operator in Lea County, New Mexico, identified several 2nd Bone Springs wells as candidates for restimulation and needed a way to remove debris from the lateral section of the well.
The restimulation called for the installation of a 4.250-in. expandable liner that required an extremely clean wellbore prior to running. Due to the low bottomhole pressure and an inability to circulate, the operator had limited options to achieve the required result.
Coiled tubing with energized fluids would not be a financially viable option. The operator turned to Baker Hughes, a GE company (BHGE) for a solution.
Long-lost debris removed
BHGE recommended a cleanout assembly with a 3.500-in. vectored annular cleaning system (VACS™) tool, 1,000 ft (305 m) of 2 7/8-in. tubing with check valves used as a cavity, and a 4.500-in. washpipe shoe with Bowen™ finger catchers. Pumping down the tubing creates a pressure drop at the VACS tool and a low pressure area atthe end of the tool string, which generates a strong suction that pulls debris into the tailpipe.
Sand, shales, and other debris travel up into the shoe and the tailpipe where it is permanently retained in the cavity by the check valves or in the shoe by the Bowen finger catchers. As the well’s fluid move up the cavity, it runs through the VACS filter, ensuring it is clean. The VACS tool assembly can be rotated during operations to wash over hard-packed sand or bridges to optimize the clean out through the horizontal section where bailer rotation is problematic.
During VACS operations, the wellbore was washed down from 8,860 ft to 13,420 ft (2701 m to 4090 m) through the lateral. A total of 37 joints of 2 7/8-in. tubing filled with sand were recovered. This equated to 264 ft (80 m) of completely lost 5.50-in. 17 lbs/ft production casing. A total of 36 slips and miscellaneous plug parts were recovered that had been in the well since the initial stimulation in 2012. Five monel bands were also recovered that were lost
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