The water-based mud closed-loop treatment system is a collection of
cuttings, transmission, dosing, molding, gel breaking, solid-liquid
separation and other technical means, the cuttings discharged from
the solid control system during drilling and the drilling fluid
after drilling Collecting and processing to realize a system that
does not fall into the ground and is harmless. The system is mainly
composed of two parts: the cuttings processing system and the mud
processing system.
The system aims to process the water-based drilling fluid and
cuttings in the drilling process in real time to achieve the clean
production requirements of “the mud does not fall to the ground”.
★ Two-phase centrifuge model and technical parameters
Item |
Unit | LW250×1025B | LW350×1435B | LW450×1845B | LW520×2150B | LW580×2400B |
Throughput | m3/h | 0.5-3 | 3~10 | 8~15 | 15-20 | 20-30 |
Roller diameter | mm | 250 | 350 | 450 | 520 | 580 |
Length-to-diameter ratio | | 4.1 | 4.1 | 4.1 | 4.1 | 4.1 |
Speed | rpm | 5000 | 4000 | 3200 | 3000 | 2800 |
Separation factor | | 3500 | 3136 | 2580 | 2620 | 2546 |
Differential speed | rpm | 1~50 | 1~35 | 1~34 | 1~34 | 1~36 |
Main motor power | kW | 11 | 22 | 30-37 | 45-55 | 75-90 |
Ancillary motor power (kW) | kW | 4 | 5.5 | 7.5 | 15 | 18.5 |
Weight | kg | 1250 | 2500 | 4200 | 5200 | 6500 |
Boundary dimension (L*W*H) | mm | 2500×800×1150 | 3700×1050×1200 | 4300×1150×1450 | 5100×1250×1600 | 5520×1450×1700 |
| Note: The throughput is related to material characteristics. |
After the system treatment, the cuttings become the expected
blocks; the drilling fluid is effectively purified or separated by
pressure filtration, and returned to the solid control system for
reuse or into the clear water tank as well production water. The
system mainly includes 7 functional units: drying sieve unit,
high-speed centrifuge unit, filter press dewatering unit, molding
machine unit, material transfer unit, dosing device, stirring
curing unit
Technical descriptions of the centrifuge
★ Extremely low infrastructure investment and good on-site operating
environment
Compared with the conventional filter-type equipment
(plate-and-frame filter, belt machine, etc.), the high-performance
centrifuge is compact and efficient, covering only about a third of
land, needless of auxiliary gas source, high-pressure water, and
with simpler pipe structures at the inlet and outlet. Moreover, the
operation environment is more humanized, and the skid-mounted
integrated device has the characteristics of compact structure,
convenient installation, low requirements for infrastructure, and
convenient movement. The centrifuge is widely used in the harmless
treatment of oily sludge in oilfield drilling.
★ Stable operation, low failure rate, and low maintenance cost
Compared with the filter type equipment, the centrifuge does not
require any filter cloth or filter screen, so as to avoid the
trouble of clogging and of replacing the filter cloth. The
operation and maintenance costs of the equipment are low.
★ Modular design, easy to operate
Our design philosophy: To lower the requirements on the skills,
educational level, and labor intensity of operators, and realize
one-button start and stop of the control system, fault
self-diagnosis, and safety self-protection.
★ Operator configuration and labor intensity
The high-performance centrifuge is an automatic and continuous
working mode for feeding-separating-slag (liquid) discharging. The
whole process requires no human intervention. Multiple sets of
equipment require only one inspector (in conjunction with other
positions). Unlike frame and plate-and-frame filter, the slag
discharging process does not require manual cutting, greatly
reducing the labor intensity of the operator.
★ Ingenious, unique, and diversified heavy liquid-phase discharging
structure
The heavy liquid phase separated by the three-phase centrifuge can
adopt two different liquid discharging modes, namely gravity
discharging and discharging through the built-in centripetal pump
with pressure, wherein the latter includes liquid layer fixed mode
and the online adjustable mode of heavy phase liquid layer, which
is selected according to the process conditions.
★ High performance wear-and corrosion-resistant cemented carbide
As the oily sludge contains a lot of hard particles and impurities
such as sand, glass, and metal, if the centrifuge does not adopt
reliable wear-resistant configuration, its service life and running
stability will be seriously affected. The wear-resistant solution
is completely targeted. According to the material characteristics
(pH value, corrosive substance, solid particle size hardness,
etc.), cemented carbide or ceramic can be selected, and the
cemented carbide can be either YG6, YG8, or various modified
tungsten-cobalt alloys with the hardness of 89~93 (HRA), which can
fully meet the application fields of the centrifuge.
★ High performance stainless steel
The high-performance three-phase centrifuge can recover oil by
90%~95% and adapts to the liquid density difference (oil and water
comparison) of the gas and oil of different densities (0.1~0.08
g/cm3). The centrifuge needs more than 3000G separation factor to
achieve better separation. To ensure the stability and the service
life of the centrifuge, high-strength corrosion-resistant duplex
stainless steel SAF2205 is used.
★ High-dryness screw conveyor and drum structure
The dehydration of solid particles relies mainly on strong
centrifugal force, high-torque screw extrusion force (pushing
torque), and ultra-long solid particle dehydration length. The
centrifuge can generate centrifugal force exceeding 3000G, 30 ~ 50%
higher than the screw pushing torque of common centrifuges. The
screw pusher torque, and the drum dehydration length is 10 ~ 20%
longer than that of common centrifuges.
★ High torque involute planetary gear differential
The ultra-high pushing torque requires a high-torque involute
planetary gear differential as the foundation. The differential
equipped on the centrifuge features high torque, high speed, low
heat generation, and excellent heat dispersion, which ensure that
the centrifuge can be used for a long time and stably.
