Mr. Erik Milito - The House Committee on Natural Resources ...

C.1 General Practices While Drilling
Annex C
(informative)
Drilling the Well
<strong>The</strong> following practices help maintain efficient drilling results and provide hole quality conditions suitable for primary
cementing:
— using a drilling fluid of sufficient density to contain formation fluids;
— use of high viscosity sweeps to reduce potential for annular pack off or excessive gumbo deposition;
— controlling drilling fluid losses using LCM as needed;
— minimizing static gelled drilling fluid with flat gel strength drilling fluid rheology;
— preventing excessive drilling fluid filter cake buildup with low fluid loss drilling fluids;
— preventing balling on the BHA due to gumbo;
— rotating pipe while breaking circulation to reduce lost circulation potential on connections;
— while on diverter, the rig should pump out of the open hole and assess trip fill by monitoring each stand while
circulating through the trip tank;
— controlling rate of penetration (ROP) to prevent overloading the wellbore with cuttings and minimizing the
opportunity for gumbo accumulation;
— monitoring drilling fluid gas content and volume to verify flow potential.
C.2 Monitoring and Maintaining Wellbore Stability
Having a stable wellbore prior to, during, and after the cement job is crucial to cement job success. If losses or gains
occur during a cementing operation the possibility of obtaining a successful cement job is greatly diminished.
Corrective action should be considered to stabilize the wellbore prior to the cementing operation. Certain corrective
measures are best applied prior to running the casing or liner string into the well. <strong>The</strong> following indicators are used to
identify potential flows and losses, contributing to wellbore instability:
— changes in pit volume—monitor trend;
— changes in flow rate—monitor trend;
— changes in pump pressure;
— ROP—monitor trend;
— torque and drag;
— changes in weight on bit (WOB)—monitor trend;
— pressure while drilling (PWD) data;
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