BAKER HUGHES - Drilling Fluids Reference Manual

FLUIDS ENVIRONMENTAL SERVICES
• Periodic testing of individual solids control equipment to establish their solids removal
efficiency, following the API R13C rule.
Waste Minimization
In addition to the reduction of the volume of fluids and cuttings, it is also critical to minimize the
amount of other wastes produced as part of the operation in order to mitigate the environmental
impact of drilling activities.
a) Tank cleaning (Rigs, supply boats, onshore tanks).
• Frequent changes in fluid type carried.
• Excess residues in tanks as a result of inefficient design.
• Logistics limitations and poor planning.
• Limited storage space on rigs, vessels and onshore.
• Poor practices.
Tank cleaning of marine vessels, trucks and installation tanks is a major source of waste. Vessel tanks
are frequently cleaned after each shipment. On many occasions the tank is then refilled with a similar
product to the previous shipment, making the cleaning operation unnecessary.
Sharing vessels between operators, who use different base oils, normally necessitates cleaning tanks
between shipments. Most vessels are not able to dedicate tank space to specific product types, which
also leads to tank cleaning between shipments.
Many boat tanks were not designed specifically to carry drilling fluids. In some cases this leads to
excessive volumes being left in the tanks which become non-recoverable volume that ultimately gets
included in the waste stream instead of being recovered for use. Most often this can be avoided by
proper planning.
b) Slop water
• Poor drainage design - no segregation of type of fluid rainwater, waste oil etc. all gathered
into one tank.
• Large oil / water interfaces when displacing to or from the well.
When using OBM, all the drains run into a common collection system. This collects all run-off
including rainwater that may have been contaminated with OBM. The contaminated “slop water” is
then shipped to shore for processing. Additional contaminated water is generated from vessel tank
cleaning, cleaning skips and cleaning big bags once the contaminated cuttings have been removed.
c) Cuttings Transportation Systems
• Use of skips and big bags leads to extensive cleaning with high associated wastes.
Many operators currently use big bags and skips to transport OBM cuttings to waste sites for
disposal. This generates additional waste. Skips can sometimes collect water en route and this water is
contaminated with oil from the cuttings even if they are in big bags. This water then has to be
collected and treated. The skip also has oil contamination within it that requires
cleaning before
shipment, generating more oily slop waste.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 14-22