BAKER HUGHES - Drilling Fluids Reference Manual

TABLE OF CONTENTS
• CF-2002, a base fluid designed to conform to the Gulf of Mexico discharge regulations that
came into effect in 2002
• PT-3500, an iso-alkane paraffin
SYN-TEQ® is an alternative to oil-based mud drilling fluids and is environmentally acceptable in
many parts of the world. High lubricity, high resistance to contaminants such as carbon dioxide,
and an ability to maintain a stable wellbore with no sloughing shales are key system attributes. The
system is stable over a wide temperature range; 30°F–500°F (-1°C–260°C) and can be formulated
with low synthetic-to-water ratios. Where oil-based mud performance is desired but environmental
restrictions prevent its use, SYN-TEQ® is a viable alternative. Long-reach and highly deviated
wells benefit from the system’s high lubricity, effective in reducing torque and drag. A low leak-off,
removable filter cake makes SYN-TEQ® an ideal fluid for coring operations and in poorly
producing formations that cannot tolerate significant invasion damage.
NEXES is a "new generation" ester-based emulsion system. It is formulated to meet client
expectations by providing superior drilling performance, and benchmark environmental
compliance. The continuous phase, NX-3500, is a unique ester molecule specifically designed to
address technical concerns that have long plagued other ester base fluids, namely (1) kinematic
viscosity, (2) hydrolysis stability, and (3) elastomer compatibility. In addition to the base fluid,
NEXES employs other components chosen for their optimized performance. NX-3500 is not a
GoM compliant base fluid.
CARBO-DRILL® is Baker Hughes Drilling Fluids’ invert emulsion system in which the external
phase is either diesel, mineral or enhanced mineral oil. This fluid has been used on several
deepwater wells using low aromatic mineral oils as the base fluid. The system delivers optimized
drilling performance, including excellent penetration rates, enhanced lubricity and superior
wellbore stability. Discharge of cuttings generated using CARBO-DRILL® may be regulated by
local environmental agencies.
LOST CIRCULATION
INTRODUCTION
Lost circulation problems in deepwater are aggravated by low fracture gradients, tight casing/hole
clearances, and drilling fluids made more dense and more viscous by low fluid temperatures. Lost
circulation can be more dangerous in deepwater than in shallower water due to the potential for
hydrate formation in the BOP from migrating gas. The risk of lost circulation can be reduced by the
use of hydraulic simulators such as those in ADVANTAGE and PRESMOD. These tools can be used
to establish guidelines for drilling and tripping.
Experience has shown that lost circulation is a greater problem with invert emulsion fluids than with
water based fluids. The reasons are numerous and are stated below:
• Though water base and invert emulsion drilling fluids have similar fracture initiation
pressures, invert emulsion systems have lower fracture propagation pressures. This means
that once losses are initiated they are more difficult to cure with an invert emulsion system.
• Invert emulsion systems’ densities and viscosities are increased to a greater degree by the
colder temperatures at the seabed. These increases intensify surge pressures and can cause
lost circulation.
• Invert emulsion systems are normally considerably more expensive in cost per barrel than
water based fluids. Thus lost circulation is considerably more expensive and more noticeable.
BAKER HUGHES DRILLING FLUIDS
REFERENCE MANUAL
REVISION 2006 13-9