BAKER HUGHES - Drilling Fluids Reference Manual

FLUIDS ENVIRONMENTAL SERVICES
operations. The active water-based drilling fluid is dewatered with chemically enhanced
centrifugation, removing the fine drilled solids and returning the clear water to the system.
The solids are discarded to a collection bin and the clear water is returned to the active system.
Depending on chemical content, the solids can be land-farmed on the location, restoring it to original
form, or hauled off to a disposal area.
In areas where solids water content is closely monitored, the use of drying mechanisms has been
implemented to complement the typical centrifugation equipment to further reduce the volume of
waste. The drying systems used include:
• High impact drying shakers.
• Centrifugal cuttings dryers (i.e. Baker Hughes Drilling Fluids’ Typhoon).
• Filter presses.
b) Excess Dilution and Mud Retention on Cuttings (OBM & WBM).
The volume of dilution is a direct function of the efficiency of the solids control equipment. Waste is
generated because of (1) build up of solids in the drilling fluid that result in higher dilution rates
and (2) excess of liquid bonded to the solids particles removed by the solids control equipment. A
balance has to be achieved between these two options to find the preferred specifications that will
maximize the reduction in the volume of waste.
The efficiency of the solids control equipment can have a major impact both on the condition of the
drilling fluid as well as the volume of waste. Wet cuttings obviously weigh more and take up more
space than drier cuttings, which ultimately increases the transport and treatment costs.
Additionally, this is drilling fluid that is effectively being thrown away when it could easily be
retained within the system for further use.
Shakers that aren’t being operated at their optimum can force the driller to cut the pump strokes in
order to prevent mud being discharged over the end of the screens. This can result in poor hole
cleaning and slower ROPs.
By monitoring the SCE and waste management this will ensure the SCE is being run at optimal
efficiency, treatment costs should be reduced and unnecessary fluid losses avoided, which will
ultimately save money.
An efficient solids control system requires continuous actions and monitoring to ensure a proper
operation. At a minimum the following actions should be carried out:
• Adherence to the API R13B rules for solids control systems efficiency determination.
• Definition of the recommended operational parameters for each piece of equipment for each
section. This is an expected set of values (i.e. feed rates, dryness, output weights) for each
piece of solids control equipment and for each section that is at least required to guarantee a
minimum level of efficiency commensurate with the drilling requirements. These values will
be decided in conjunction with the parties in charge of their operation.
• Continuous monitoring of compliance with the recommended parameters.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 14-21