Smart Crypto Projects

Centrifuges, along with other cleaning tools, are designed to control solidscontrol solids in the drilling fluiddrilling fluid, as well as to recover barite from weighted drilling fluids.

Centrifuges, along with other cleaning tools, are designed to control solids in the drilling fluid, as well as to recover barite from weighted drilling fluids.

Their purpose consists of:

• Increase the degree of drilling mud purification and thereby reduce the consumption of chemicals for the preparation and treatment of drilling fluids;
• reduce the volume of excess drilling mud, which is formed when drilling wells in clay sediments;
• reduce consumption of barite weighting agent as a result of its regeneration and repeated use on the same rig;
• reduce bit consumption and increase mechanical drilling speed.

The drilling centrifuge is equipped with a cylindrical conical drum, an auger and a drive unit. The rotor-drum and the conveyor-auger rotate at different speeds during operation. This differential deviation is set by the gearbox and is determined by the specifics of the task at hand.

When the centrifuge is in operation, the drilling fluid fed into the drum is subjected to centrifugal force. The heavy particles are deposited on the rotor and then the cuttings are taken out of the unit by a screw conveyor, undergoing dewatering in its conical part. The cleaned liquid can be reused in the circulation system.

Centrifuges are very widespread in drilling practice due to their high cleaning capacity as well as high degree of dewatering of separated solid phase (cuttings). In addition, it is possible to separate (differentiate) the deposited sludge by particle size by smoothly changing the speed of the centrifuge rotor. Hence, there are two main directions of using centrifuges for drilling with unweighted and weighted mud.

1. When drilling with unweighted mud, centrifuges are used as the fourth (usually the last) cleaning step to finish removing from the mud small particles (5-30 microns) of drilled rock, which sand and sludge separators do not catch. As a result, the cuttings are separated from the solution and disposed of, and the cleaned solution is returned to the circulation system. Although centrifuges have a lower throughput capacity than hydrocyclones, they remove up to 40% of the drilled rock, thus significantly increasing the cleaning capacity of the entire system.
2. When drilling with water- and oil-base weighted muds, centrifuges are used to regenerate the expensive weighting agent in two steps. First, the initial product to be discharged is run through a "slow" centrifuge. In the plant, the weighting agent (which requires about half the speed of the centrifuge rotor to settle) is separated from the solution as a fluid slurry and returned to the circulation system. The finely dispersed drilled rock (clay) together with the weighting agent does not settle down (the rotor rotation speed and, accordingly, the separation factor are not enough to start this process). Further, the solution saturated with clay is sent to a high-speed centrifuge, where the cuttings are separated and disposed of. An equal amount of pure diluent is compensated into the circulation system.

The goal of all modern cleanup systems is to reduce overall well costs by effectively removing cuttings while reducing and minimizing drilling fluid losses. Additional objectives include HSE compliance. A key factor in creating the best systems on the market is working with rig designers, contractors, operators and shipbuilders.

In order to maximize the cleaning efficiency of each type of equipment, an individual approach and consideration of many factors is necessary. The amount and size of equipment must be chosen to maximize the effectiveness of the cleaning system in terms of final mud volume accumulated during drilling, total cuttings removed and the degree of mud dilution. The greater the percentage of cuttings removed and mud retained, the greater the efficiency of the cleaning equipment.

As a result of increased economic and regulatory requirements, well construction costs continue to rise. Therefore, modern shaker screens must not only be able to maintain optimum drilling fluid parameters to improve efficiency and reduce non-productive time (NPT), but also significantly reduce waste generation and treatment costs.

The hydraulic cyclone series is a two-stage separation system using a group of hydrocyclones above a vibration screen, which operate as a single unit. Designed to handle the entire volume of mud flowing into the well, the hydrocyclones can be used equally successfully with both weighted and unweighted muds, effectively removing and drying out drill cuttings while saving valuable mud.

The hydrocyclones perform the primary treatment, and the solid phase is sent to a screen in the form of a slurry.

When properly used, hydrocyclones reduce drilling fluid costs as well as drilling waste disposal costs.

With a rugged design designed for oilfield and industrial environments, centrifuges are effective in environmentally sensitive areas because they meet cuttings moisture requirements. They are also characterized by high mud recovery rates and effective solids control, resulting in significant reductions in overall drilling fluid costs for the operator and less waste for disposal.

Decanting centrifuges recover up to 95 percent of the barite in weighted muds, which is returned to the active circulation system while removing the smaller lightweight solids fraction. In chemical dewatering systems, centrifuges significantly reduce the volume of liquid phase discharge and significantly increase the overall efficiency of the treatment system.

MI SWACO is the global market leader in chemicals and equipment for drilling fluid preparation, treatment and disposal systems.

The company was founded in 1939.

The MI SWACO brand was formed in 2004 by the merger of M-I Drilling Fluids and Swaco Cleaning Equipment. In 2006, with the acquisition of the Canadian company, the range was supplemented with oilfield reagents.

In August 2010 MI Swaco became a part of the company Schlumberger, which had been operating in Russia since 1929.

The head office of MI Swaco is located in Houston, USA. Today, the company has 13,000 employees in 75 countries. The annual turnover is about two billion dollars.

M-I SWACO has been represented in Russia and Central Asia for over 20 years. M-I SWACO in Russia has 23 regional offices, 12 regional warehouses, equipment repair shops, scientific-technical and training centers.

M-I division - drilling fluids, reservoir drill-in fluids, completion fluids.

SWACO division - drilling mud cleaning equipment (shakers, hydrocyclones, centrifuges), downhole pressure control systems. Cuttings and drilling waste disposal systems to prevent environmental contamination: cuttings re-injection, drilling cuttings drying, cuttings collection and isolation system for offshore drilling, thermal phase separation system to recover synthetic or mineral bases of drilling fluids.

M-I Production Chemicals - Oilfield Solutions. Corrosion inhibitors, bactericides, anti-turbulence additives, hydrate inhibitors, demulsifiers, defoamers, wax deposition inhibitors, oxygen and hydrogen sulfide absorbers.

M-I SWACO offers a full range of water-based, hydrocarbon-based, synthetic-based drilling fluids, additives, and engineering services, including proprietary software, field experience databases and laboratory capabilities.

M-I SWACO's advanced real-time software systems can help reduce wellbore complications before conditions lead to bottomhole contamination and HSE issues, resulting in higher costs and disruption. Our software packages can track downhole conditions in real time and, using innovative methods, are the first in the industry to display results in an interactive 3D format showing downhole conditions. These software systems also allow customers to select the optimal mix of colmatants that are optimally sized, providing a host of calculations during operations.

M-I SWACO's well productivity offering includes reagents and services focused on the continuity of the initial formation opening process and the completion and production stages. It is at this stage that reservoir damage can be minimized, unproductive time can be reduced through wellbore cleanup, downhole conditions can be created to improve completion operations, well life can be extended, etc.

The goal of all modern cleanup systems is to reduce overall well costs by effectively removing cuttings while reducing and minimizing drilling fluid losses. Additional objectives include HSE compliance. A key factor in creating the best systems on the market is working with rig designers, contractors, operators and shipbuilders.

M-I SWACO offers an industry-leading portfolio of cost-effective technologies designed to reduce the environmental impact of offshore and onshore drilling operations. Next-generation drilling waste management technologies include vacuum collection systems and fully automated CLEANCUT and CLEANBULK enclosed pneumatic cuttings collection and transport systems for containment, treatment, temporary storage and transport of waste water, and drilling cuttings contaminated with synthetic drilling mud and oil-based drilling fluids. Drilling waste management solutions also include advanced thermal desorption technologies, including the onshore HAMMERMILL desorption unit and its modular offshore version based on a direct mechanical heating process, and the compact thermal phase separation technology THERMICAL PHASE SEPARATION (TPS).

The M-I SWACO Solution Processing System (FPS) is a complete solution for solids control, from shakers to centrifuges to DEGASATOR* units, strategically integrated into one skid-mounted unit. It should also be noted that the solution processing system (FPS*) has a 24-hour service team, supported by a system supervisor and on-duty maintenance engineers.

History

The use of drilling fluids for drilling wells was first suggested in 1833 by French engineer Fauvelle. Observing a rope drilling operation in which the drilling apparatus encountered water, he noticed that spouting water very effectively removes drill cuttings from the well. He invented an apparatus in which it was supposed to pump water under the drill rod, from where the drill cuttings were washed out with water to the surface between the drill rod and the wellbore.

Types of drilling fluids

Drilling fluid formulations have changed as oil production has evolved. Over the centuries they have changed from "drilling mud" to multicomponent mixtures with adjustable in a wide range technological properties. Today there are four main types of muds - water-based, hydrocarbon-based, gaseous muds and foam. The search for the optimal drilling fluid recipe - inexpensive but effective - continues.

Water-based fluids are divided into:

- clayless drilling compositions, such as ordinary process water, all sorts of suspensions and polymer-based muds, and so on;

- clay drilling fluids based on mineralized or fresh water, as well as fluids containing gypsum, clay particles and chlorine elements.

Main Functions and Purpose of Drilling Fluids

1. Cooling and lubricating the surfaces of the drill bit. Since the work of this tool is always associated with the appearance of a lot of friction, it is necessary to use lubricating compositions that simultaneously reduce the temperature of the tool in order to increase its wear resistance;

2. Bottom-hole cleaning. Many drilling fluids make it possible to effectively wash the drilled rock out of the borehole and bring it to the surface. The quality of such cleaning depends on the physical and chemical properties of the particular composition, as well as on the geological features of the drilled rocks, therefore, in the process of preparation it is necessary to take into account the composition of rocks of a particular field;

3. Formation of a purification layer on the walls of the wellbore. The casing formed on the walls of the wellbore is characterized by low permeability, which provides stability in the upper sandy zone of the geological section and makes it possible to separate the wellbore from highly permeable layers;

4. Prevention of water, gas and oil manifestations;

5. Protecting the walls of the well against collapses that occur when drilling rocks based on unstable clay;

6. Such an important sphere of drilling compositions application as providing qualitative opening of productive horizons stands apart. Many of today's drilling fluids prevent contamination of the reservoir during drilling-in and avoid complete plugging, which makes it very difficult to develop;

7. Reducing the cost of fixing the well with strings;

8. Obtaining data necessary for analysis during the operation of exploratory wells. This is also one of the auxiliary functions of such compositions, because together with them the cuttings and particles of rocks, which are the subject of study, are brought to the surface;

9. Increasing the resistance to corrosive effects of equipment and pipes;

10. Ensuring compliance with the requirements of industrial safety and minimizing the harm caused to the environment.

Drilling Fluid Circulation in the Well

Most drilling fluids in drilling operations circulate through the following cycle:

1. The drilling fluid is mixed and stored in special tanks.

2. The mud pump pumps the mud from the tank through the drill string and into the hole.

3. The drill mud travels through the pipes to the bottom of the hole, where the drill bit breaks the rock.

4. The mud then begins to return to the surface, carrying the rock particles (cuttings) that have been separated by the bit.

5. The mud rises through the annulus, the space between the borehole wall and the drill pipe. A typical diameter of the drill pipe is about 12.7 cm. At the bottom of a deep well, it may be about 20 cm in diameter.

6. At the surface, the drilling fluid passes through a return line, a pipe that leads to a vibrating screen.

The sieve consists of a series of vibrating metal grids that are used to separate the mud from the cuttings. The solution flows through the screen and returns to the sieve.

The slurry particles fall into a trough for removal. They may be cleaned before being discharged, based on environmental and other considerations. Some cuttings particles are sampled by geologists for condition studies inside the well.