Reduce the amount of MOC before disposal
Among Alaska’s more stringent environmental regulations is a
requirement to strip cuttings of free fluid prior to disposal. In addition to
causing higher treatment, transportation, and disposal costs, leaving MOC adds
cost for lost fluid. An operator planned to use a water-based gel mud to drill
the surface sections and the VERSACLEAN mineral oil-based drilling fluid system
to drill the 12 1/4-in intermediate and 8 1/2-in production sections of the
well. For this reason, the operator wanted to lower MOC as much as possible to
conserve fluid, while still using a cost-effective solution.
Install the SCREEN PULSE separator on four primary shakers
M-I SWACO, a Schlumberger company, recommended using the SCREEN PULSE separator to comply. The SCREEN PULSE separator uses pulses of compressed air to quickly generate a vacuum under the discharge end shaker screen, sucking excess fluid from the cuttings and returning it to the active system. The separator's ability to return a high volume of fluid to the fluid system was the deciding factor, and the technology was installed on four primary shakers on an enclosed shaker floor.
To see exactly how effective the SCREEN PULSE separator was, the operator drilled while alternating the separator on and off at scheduled intervals. The SCREEN PULSE separator was run only on the synthetic-based mud sections. Data from the separator were analyzed to ensure that it performed up to the operator's expectation.
Saved USD 137,200 in recovered fluid and USD 47,000 in disposal costs
The SCREEN PULSE separator enabled the operator to achieve its drilling objectives and cut costs by reducing synthetic-based mud loss and associated disposal costs for oil-wet cuttings.
During the 20 days that the SCREEN PULSE separator ran, the MOC was reduced by an average of 26%. The total volume of synthetic-based mud recovered was 529 bbl [84.1 m3], collected at an average of 26 bbl/d [4.1 m3/d]. Additionally, the operator reduced waste by 326,000 lbm [147,871 kg], saving an estimated total of USD 137,200 in recovered fluid and USD 47,000 in disposal costs.
