Operating instructions

INTRODUCTION
1-2 15 Nov 09
SAFETY
Section 2 of this manual contains relevant safety information relating to both operation and
maintenance of this equipment. Be sure this information is read and understood by all personnel.
DO NOT operate the equipment if defective or faulty mechanical or electrical components are
detected.
EQUIPMENT USE
The degasser and associated components are designed exclusively for releasing entrained gases
from slurries. Derrick Corporation does not authorize any other use of this equipment. Intended
usage of equipment includes compliance with the operating, maintenance, and safety procedures
included in this manual.
DESCRIPTION AND OPERATION
The ACD-1500 degasser (Figure 1-2) is designed to be immersed in a drilling fluid tank. For
proper functioning, the fluid level in the mud tank should be higher than the pump bolting flange.
The degasser uses impact/turbulence combined with a large surface area of exposure to liberate
gas from the mud. Entrained gases are removed from drilling fluid by exposing a thin film of the
mud to the atmosphere. Drilling fluid is pumped by the centrifugal pump at the bottom of the
degasser up through the pump riser and delivered to the impact plate, which disperses the liquid
horizontally against the interior surface of the spray tank. The mud spreads evenly across the
horizontal surface of the spray tank, allowing the bubbles to break free from the mud. Degassed
mud flows out the discharge outlet and returns to the tank. Mud is continuously circulated from the
tank through the degasser and back to the tank. This recirculation process maximizes gas
removal.
The removed gas exits the vent at the top of the spray tank. An optional exhaust fan at the top of
the spray tank assists in drawing gas away from the vent. The fan’s discharge flange may be
connected to a pipe to transport the gas farther from the degasser.
The gap between the impact plate and riser opening is adjustable to control the thickness of the
dispersed film. The ACD-1500 degasser processes up to 1500 gallons per minute (gpm),
depending on the impact plate gap, which is adjustable within a 1” range (1/4” to 1-1/4”) in 1/4”
increments. Forcing the mud through the small gap between impact plate and pump riser causes it
to strike the walls of the spray tank with considerable force, producing turbulence that assists in
liberating gas from the mud.
Maximum process throughput is achieved with the largest impact plate gap, while flow is
diminished with a smaller gap. Generally, the higher the flow the lower the release of entrained
gas. The impact plate gap is adjusted to meet the mud conditions. High gas content may warrant
a small gap to maximize removal of entrained gas, while a larger gap may be suitable when gas
content is lower and higher flow is desired.
MAJOR COMPONENTS
The degasser (Figure 1-3) consists of a skid-mounted spray tank, electric motor-driven centrifugal
pump, impact plate, electrical control panel, vent, and exhaust fan (optional). These components
are described in the following paragraphs.