Page 87 - Shale Shakers Drilling Fluid Systems

70 SHALE SHAKERS AND DRILLING FLUID SYSTEMS

Blow-Out
Detection &

Control

Blow-out Detection & Control
Adjustable Choke-2500 PSI
The SWACO 2500 psi Adjustable Choke, the first remo-
D-Gasser tely controlled adjustable choke designed for rig crew
operation, provides complete adjustability of choke size
Since its introduction in 1951, the efficiency and relia- for positive pressure control on flowing systems. Origi-
bility of the SWACO D-Gasser has been proven on more nally built for welt killing procedures, particularly with
than 10,000 locations worldwide. It has become the stan- the drill pipe pressure method, it has also found exten-
dard against which alt degassing equipment performance sive use as a throttling valve while drilling with gas-cut
is measured. muds.
The SWACO D-Gasser removes virtually all gases The adjustable choke is ideally suited for any situation
including air and volatile distillates from the drilling fluid
system and vents them at a safe distance from the D- where high pressure flows are to be controlled by res-
Gasser vessel, it also provides maximum control of gas- tricting the flow and so creating back pressures, espe-
cut drilling fluids and effectively reduces the threat of cially where the amount of restriction must be deter-
dangerous and costly well blowouts due to recycling of mined by progressive steps or must be changed as other
the gas-cut mud or gas locking of the rig pumps. conditions change.
The SWACO D-Gasser has only two moving The choke was developed specifically to provide accu-
elements—the float inside the vacuum vessel and the rate surface control of subsurface pressures white circu-
vacuum pump. The float insures that the system will not lating highly abrasive drilling mud and/or well fluids, It
overfill or purnp dry. The pump is used for positive removal allows sensitive adjustment of choke size to maintain
of volatile gases from the vessel and discharges them controlled back-pressure for many hours, even with the
at a safe distance away from the D-Gasser. With proper most abrasive fluids,
return jet sizing, peak flow rates as high as 1000 gpm Choke size is controlled by hydraulic pressure against
can be efficiently degassed. The SWACO D-Gasser is a rubber choke element. Hand regulation of hydraulic
ruggedly built and comes skid-mounted for easy installa- pressure allows extremely accurate setting and maintain-
tion. Corrosion resistant epoxy inside and outside coat- ing of desired differential pressure. If hand manipulation
ings provide Song life with little or no maintenance. of the relief valve is required to assist in dislodging the
Gas-cut mud is drawn into the degassing vessel by a particle, the hydraulic regulator will then return the sys-
vacuum created by the discharge jet and vacuum pump.
The drilling fluid is distributed over the D-Gasser baffle tem to the same hydraulic pressure and relationship of
in a thin, evenly dispersed layer, and the gases are choke size to casing pressure.
throughly removed by the vacuum pump. The vacuum The remote control panel that regulates choke sizes is
pump can then discharge the gas at a safe distance from mounted on a separate skid and may be placed at any
the drilling rig. The degassed mud is returned to the desired distance from the choke valve assembly, it is
drilling mud system through the exclusive SWACO jet. most often installed on the rig floor near the drilling
While the system appears to be too simple to be so controls.
efficient, the design is, however, the result of continued The control pane! contains all valves, regulators,
experience and refinement of the basic vessel since 1951. gauges and pumps required for complete operation, A
Invariably the SWACO D-Gasser returns the mud to its pump stroke counter and pump rate meter are included
original weight and essentially removes all of the gas. for programming certain operations. Relief valves, pulse
For more information, send for Bulletin * E-S3032-BC. dampeners and similar aids provide safe positive control
of the choke. A standby hydraulic pump is also provided
for backup operation.
For more information, send for Bulletin #E-S3033-BC,