Decrease transportation and discarding costs by enabling compliant
overboard disposal
Atwood Oceanics was drilling offshore in the Gulf of Mexico, where
regulations require using a centrifuge and dryer to treat cuttings that will be
disposed overboard. A sample of cuttings from each piece of equipment must be
tested every 500 ft [152 m] and analyzed with a mass-balance retort. These
results are then used to calculate the well's average ROC, which must remain
below 6.9% for overboard disposal.
If the ROC is too close to the regulatory requirement, drilled cuttings
are sent to a cuttings box, causing increased rig time and expenses on shipping
and disposal as well as restricting the ROP to the available volume in the
cuttings boxes on the location in a given time. During cuttings treatment,
however, if the discharge from the dryer is too dry, there will be issues with
sticking and equipment packoff.
Deploy reduced-footprint COMPACT VERTI-G low-profile cuttings
dryer
The operator requested that M-I SWACO install its COMPACT VERTI-G
low-profile cuttings dryer on its Advantage rig in the Gulf of Mexico. The
COMPACT VERTI-G dryer is a high-capacity vertical centrifuge with a screen mesh
basket and dedicated centrifuge to help reclaim more fluid. With a maximum
drying rate of 61 metric tons per hour, the COMPACT VERTI-G dryer dries
cuttings to less than 5% ROC, reducing the volume of discarded waste.
The dryer includes hard-faced, adjustable, rotating flights that brush
cuttings to the screen surface, helping to prevent blinding and decrease
potential downtime. This separation is achieved by strategically deploying 327
gn [3,206 m/s2] at the base of the cone to keep solids moving through the
system and also by spending more time in the fluid-removal stage of the
treatment compared with conventional drying techniques.