Functions of a Drilling Fluid:
The mud system in a drilling operation performs many important functions. These include:
-Clean beneath the bit: To maximize drilling efficiency, the drilling fluid must translate hydraulic horsepower from the main mud pumps into enough velocity to remove drill cuttings away from the face of the bit and allow the cutters to be in contact with the formation. If the cuttings are not removed, they will be ground into smaller particles and adversely affect drilling rate, mud properties, and project costs.
-Carry drilled solids from the bottom of the hole to the surface: Once cuttings are removed from beneath the bit, the fluid must transport them toward the surface faster than they can settle back toward the bottom of the hole. Factors which influence cuttings movement are velocity, cuttings size and shape, and the fluid properties.
-Suspend cuttings when circulation is stopped: Circulation of the drilling fluid stops periodically during operations, such as when making a bit trip. The drilling fluids must be able to suspend cuttings and weighting material while circulation is stopped, but should begin to flow easily when the pumps are switched back on. Properties which affect cuttings suspension are the density and viscosity of the mud and the density of the solids in the mud.
-Allow removal of cuttings by the surface system.
-Control formation pressures.
-Promote borehole stability.
-Cool the bit and lubricate the drill string.
-Help support the weight of the drill string.
-Allow accurate information from the well.
Mud is the common name for drilling fluid. While it is outside the scope of this handbook to offer a detailed discussion of drilling fluids, a brief outline of the general characteristics of drilling fluids is included to establish the basic relationships between drilling mud and solids control. Similarly, any discussion of solids control would be incomplete without establishing an understanding of the nature of mud solids — their size, shape and composition.
The shale shaker is the first stage of solids control equipment in drilling purification system. It can remove cuttings above 75 μm brought from the drilling well to leave the liquid with smaller particles into the tanks below, which will flow into next grade solids control equipment for further treatment.
Stage 2: Desander
KOSUN DS Series Desander is used as the 2nd stage of solids control for drilling fluids, which makes separations between 45 and 75 μm.
Desander Features & Benefits: 1. Polyurethane ( PU ) material or high-chromium cast iron to make desander cones for longer lifespan. 2. Clamp type for easy maintenance. 3. Compact design with small footprint. 4. Flexible options for 1, 2 or 3 pieces of 10″ or 12″ cones for different capacities. 5. Flexible fast connection are available for user assembly.
Stage 3: Desilter
KOSUN DL Series Desilter is used as the 3rd stage of solids control for drilling mud, which makes separations between 15 and 45 μm.
Desilter Features & Benefits: 1. 100% Polyurethane ( PU ) material to make desilter cones for longer lifespan 2. Clamp type for easy maintenance 3. Compact design with small footprint. 4. Flexible options for 8, 10, 12, 16 or 20 pieces of 4″ or 5″ cones for different capacities. 5. Flexible fast connection is available for user assembly.
Stage 4: Decanter Centrifuge
KOSUN DC Series Decanter Centrifuge is used to separate suspended solids ≥2μm in diameter and treat the drilling mud and fluids. It is especially effective when used in oilfield service industry, industrial service industry and especially in environmentally sensitive areas. This type of centrifuge is high in recovery rate, effective in solids control and remarkable in the reduction of cost spent on drilling mud resupplying and management. It is a very sophisticated dynamic balancing machine, able to operate stably with the whirling speed ranging from 0 to 3900 and generate centrifugal force of 3000G. (Editor:Kosun Lily.Wang)
Polyurethane (PU) Material, high-chromium cast iron or ceramic for desander and desilter cones.
Desander cones can be installed between one and three 10″desander cones, each cone can process 500GPM and makes a separation between 45 and 75 microns.
Desilter cones can be installed between eight and twenty 4″or 5″desilter cones ,each cone can process 80 GPM, and makes a separation between 15 and 45 microns.
Mechanical Deck Adjustable while operation for reliable performance.
Compact design with small footprint, with top feed and weir feed two option.
Hook-strip shaker screen for fast screens changing with PWP and PMD screens.
KOSUN MD series hi-volume mud cleaner is the second or third stage separation equipment of drilling liquid, which will handle the solids particle after being treated by the first grade separation equipment. The mud will be recovered and cuttings which are bigger than mud will be removed. Then the cuttings in the underflow will flow into circulation tanks through the screens when the weighted mud passes while the particles that are bigger than mesh will be removed. KOSUN is a mud cleaner supplier in China.
KOSUN MD Series mud cleaner for sale by KOSUN can be used alone, and its screen can be combined with the first stage solid control equipment as a parallel standby shale shaker.
KOSUN is a leader in China’s solids control industry and expert in drilling waste management. KOSUN is capable of providing customers with such four series as oil & gas drilling solids control equipment, centrifuges, drilling waste treatment equipment and drilling security equipment, including mud tank, shale shake, vacuum degasser, desilter, desander, mixers, centrifuges pumps, mud gun, jet mud mixing, infusion pumps, increased pump, shear pump, and all other solid control equipment.
At present, KOSUN has directly exported its products to the following regions: All-Russia Region, including Russia, Kazakhstan, Uzbekistan, Azerbaijan, Ukraine, Turkmenistan, Kyrgyzstan,Tajikistan, etc.; East Asia and South Asia, including Pakistan, India, Indonesia, Thailand, Burma, Malaysia, etc.; the Middle East and North Africa, including the United Arab Emirates, Kuwait, Egypt, Algeria, Libya, Sudan, etc.; America, including the United States, Canada, Mexico, Brazil, Columbia, Venezuela, etc.; Australia; Germany in Europe. (Editor:Kosun Lily.Wang)
KOSUN provide desilter,mud cleaner and vertical slurry pump,of course, centrifuge for drilling waste management. KOSUN can offers vertical cuttings dryer and decanter centrifuge to dramatically reduce total volume of drilling wastes to treatment and revover much clean fluids back to the mud circulation system.
KOSUN can offer a complete package of drilling waste managementsystem as well. Abandoned drilling mud from the mouth of the well directly access to the device. And through its sealing strip type pipe, screw conveyor transfers waste drilling mud into cuttings dryer. Then the screen mesh by high-speed rotating and filter by cutting dryer, then the vast majority of the dry cutting slips down by another screw conveyor and discharged from the first mouth exit.
Drilling Waste Management Services:
As part of KOSUN drilling waste management services, we also supply highly skilled staff to ensure equipments are installed correctly and that they are fully operational and well-maintained. KOSUN employees, who trained to provide support swiftly, are on-call worldwide 24 hours a day, everyday, to be available at a moment’s notice.
At present, oversea countries with advanced oil industry commonly count for drilling cuttings waste management technology development. From last century, according processing equipment and facility is still on the head line of the world. There are complicated drilling cuttings portions, steady cuttings character and complicated processing situation, thus it decides the diversity of drilling waste management information system in the international drilling cuttings management.In response to these harmful substances, how to take appropriate drilling waste treatment technology to minimize the environmental impact of waste drilling fluid damage is a very important issue to oil and gas drilling companies currently. (Editor:Kosun Lily.Wang)
The work principle of decanter centrifuge:Centrifuges, like shale shakers and hydrocyclones, are solids control equipment, It achieves the separation goal by dividing the fluid into highdensity and lowdensity streams to separate one from the other. The processing is achieved by accelerated sedimentation. As the drilling ﬂuid passing through a rapidly rotating bowl, centrifugal force moves the heavier particles to the bowl wall, where they are scraped toward the underﬂow discharge ports by a concentric auger, also called a scroll or conveyor, which rotates at a slightly slower rate than the bowl. The separation of the heavier particles divides the processed ﬂuid into two streams: the heavy phase, also called the underﬂow or cake; and the lighter phase, which is called the overﬂow, light slurry or centrate. The heavy phase will be discarded while the lighter one will be returned to the mud tank to be further treated. The removal of these solids in order to control rheology and ﬁlter cake quality is the primary reason for centrifuging weighted drilling ﬂuids. When the ﬁnest solids are not removed, the only alternative means of reducing their concentration is dilution, always an expensive process.
Before hydrocyclones (desanders and desilters) and decanter centrifugebecame available for drilling applications, shale shakers and dilution were the only means of solids control of drilling fluids. Consequently, solids too ﬁne to be separated by the shaker screens in use could be controlled only by dilution which was a costly procedure that generated large quantities of excess drilling ﬂuid. Decanter centrifuge was designed to remove the fine cut and at the same time reduce the drilling cost.
To meet the requirements of the development of modern drilling engineering, KOSUN developed and equipped with the explosionproof variable frequency control system which could adjust separation factor and drum rotational speed.By this new technology,make the centrifuge to adapt property changing of mud duringthe operation process,that make the treatment more effective and perfect.
If worn, then Desander Hydrocyclone may be the following two questions:
The first packing (packing) seal leakage serious, packing heavy wear, surface wear sleeve.
Remedy: Remove the packing (packing), with a 90 ° bend thin wire inserted into the cartridge mechanical seals, Oilfield Drilling Mud Decanter Centrifuge is bushings moving wall, if the check of Oilfield Drilling Mud Decanter Centrifuge is to be too deep for-sleeve trench filler cap too tight will lead to severe wear fillers.
Second, DWM Solids Control of polyurethane seals wear serious cause leakage.
Remedy: Replace polyurethane seal (Normally, when the sand pump is running 3-6 months, Drilling Mud Cleaner should be replaced at once polyurethane seals and seal sleeve).
There must be an electrical engineer specializing in operation and maintenance. At present, only a few well-drilling operations abroad with the type of high-speed centrifuge, high performance requirements for drilling special wells, Drilling Mud Cleaner recommended speed centrifuges and centrifuge series of domestic high-speed process, the medium-speed centrifuge drilling into the post-processing of high-speed centrifuge for liquid storage, treatment by high-speed centrifuges, Drilling Fluids Desander used repeatedly into the circulatory system. Drilling Fluids Desander at this time to get a better purification of positive significance to improve the follow-up equipment of DWM Solids Control (drilling sand pump, drilling, downhole equipment, etc.) of the life-saving mud material consumption, improve ROP and other aspects in Dwm control.
Kosun solids control undertakes equipment selection, design and manufacturing according to material data and actual demands of users. We warmly welcome users to visit our Company for field investigation, technical exchange and long-term cooperation.
Solid control system is also called drilling fluids purification system, primarily applied for solids control and solid-fluid separation in drilling fluids so that the drilling mud might be recycled. Consisted of 3-7 module composite tanks and configured with 4 phases of purification equipment, it is fit for 2000-7000 meter oil drilling processes. The whole system is innovative with the bottoms of its purification tanks made to be conical and its edges equipped with mud agitating system to prevent solids from depositing. Besides, its tanks and bins may be comparted or united depending on the demands of drilling processes. Each of them is connected to another via pipe network in which the valves at the bottom of suction pipes are flexible while being opened, but can turn to be a good seal when closed.
The Component of the Solid Control System:
The first main equipment for solid control system should be the vacuum degasser,We could analytics from the function of vacuum degasser. Generally speaking, horizontal vacuum degasser will be used to separate the gas from the drilling solids. What’s the reason to do like that? Because we should do everything to prevent any dangerous elements in oil & gas drilling fields. That’s why we should put the vacuum degasser as the first role.
The second one should be mud cleaner. KOSUN MD Series Mud Cleaner is the second stage separation equipment for drilling fluids, which deals with the mud being treated by the first grade separation equipment. The barite will be recovered and cuttings which are bigger than barite will be removed. Then the barite in the underflow will flow into circulation tanks through the screens when the weighted mud passes while the particles that are bigger than mesh will be removed.
The third equipment, we think it should be shale shaker (with necessary steel frame shaker screen). Actually, after the drilling solids have been transported and fed into vacuum degasser and mud cleaner, the third step is going with shale shaker. Commonly, we still need to be transported the solids onto the shale shaker, or we could say onto the surface of shaker screen. The equipment of transporting we should use is centrifugal sand pump or screw pump; and we may use shear pump to cut the drilling solids into small one if they are in big size. With the different design of the shaker screen’s mesh, we could get the drilling solids separated in different sizes.
The fourth equipment should be the decanter centrifuge. KOSUN DC Series Decanter Centrifuge is used to separate suspended solids ≥2μm in diameter and treat the drilling mud and fluids. It is especially effective when used in oilfield service industry, industrial service industry and especially in environmentally sensitive areas. This type of centrifuge is high in recovery rate, effective in solids control and remarkable in the reduction of cost spent on drilling mud resupplying and management. It is a very sophisticated dynamic balancing machine, able to operate stably with the whirling speed ranging from 0 to 3900 and generate centrifugal force of 3000G. In solid control system, decanter centrifuge has been popularly used, which is also the popular one for drilling waste management. In this step, we could not only get the result of separating, but also we could separate the oil from the drilling solids, even if the oil is just a little part.
Of course, the whole equipment must be mounted on the top of drilling mud tank, which is a kind of basic equipment for both solid control system and drilling waste management (vertical cutting dryer is the core equipment for this system), but it is a kind of powerful equipment.