BAKER HUGHES - Drilling Fluids Reference Manual

RESERVOIR APPLICATION FLUIDS
A well-conditioned fluid will be easier to displace from a wellbore. The mud should be circulated
and conditioned at normal flow line temperatures while reducing its viscosity and gels, but not to
the point where it can no longer suspend weight material. When adjusting the rheology, the flow
characteristics of the mud improve, making it easy to circulate and evenly disperse the solids prior
to removal.
Surface Pits and Equipment Clean-up
Attention should be made to ensure the well and / or circulating system is not re-contaminated after
the clean up. It is important that all areas coming into contact with the well are cleaned prior to the
well clean up.
Pit management and cleaning is a critical element for providing clean brine all through the well.
With increasing restriction on pit access and pressure on time, management of pits and cleaning
needs to be carefully considered by the rig team. Draft plan including pumping schedules and pit
requirements must be discussed with all relevant personnel.
Right pit washing tools will reduce the requirement for pit entry and reduce waste generated. The
effectiveness of these systems relies on use of an effective detergent at ambient surface
temperatures. All areas that require cleaning shall be cleaned by circulating a detergent pill for a
minimum of 20 minutes, and then flushed with sea / drill water.
Pit cleaning not only carries HSE risks associated with pit entry and waste volumes generated, poor
cleaning of pits and surface lines can seriously affect clean up efficiency. Effective isolation
between pits is very important to avoid contamination.
The suggested checklist is a guideline for checking out equipment / areas that should be cleaned.
The list has to be adjusted to the actual and relevant equipment on rig.
AREA / EQUIPMENT
Pits – (All where Completion fluid
will be stored)
Sand traps
Degasser
Mud Cleaner
Mud Ditches
Pumps
Header Box
Shakers
Gumbo
Poor Boy
Trip Tank
Trip Tank Fill Line
Trip Tank Overflow Line
Standpipe Manifold
Top Drive
Chicksans
CLEANED
PRIOR TO
PUMPING
CLEANED
DURING
PUMPING
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 6-91