RU2771655C2 - Pressure transfer device and system related to it, complex and application for pumping large volumes of fluids with particles at high pressures - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: invention relates to a pressure transfer device, a system containing a pressure transfer device, a complex containing a system, and the use of a pressure transfer device and complex for pumping fluid with pressure of more than 500 bar. Pressure transfer device (1', 1'') contains pressure chamber case (1', 1'') and at least one connecting channel (3', 3''). In this case, at least one connecting channel (3', 3'') is made with the possibility of connection via fluid to liquid distribution device (2) using connecting means (26', 27'; 26'', 27'') with increase in double action pressure. The pressure chamber case contains pressure cavity (4', 4'') inside the pressure chamber case and at least first channel (5', 5'') for inlet and/or outlet of fluid to pressure cavity (4', 4''), bellows (6', 6'') defining inner volume (7', 7'') inside pressure cavity (4', 4''). In this case, inner volume (7', 7'') communicates via fluid with connecting channel (3', 3''). Pressure cavity (4', 4'') has central axis (C', C'') with axial length (L) determined by a distance between connecting channel (3', 3'') and first channel (5', 5''), and variable cross-sectional area on at least part of axial length (L). Bellows (6', 6'') is made with the possibility of movement in a direction essentially parallel to central axis (C', C'') on part of axial length (L) of pressure cavity (4', 4'').

EFFECT: obtaining a complex for pumping fluids.

16 cl, 2 dwg

Description

The field of technology to which the invention belongs

The invention relates to a pressure transfer device and associated system and application for pumping large volumes of particulate fluids (slurry/slurry) at high pressures, such as pressures above 500 bar and up to 1500 bar or even higher. The pressure transfer device is preferably part of a larger pumping system comprising, in addition to the pressure transfer device, one or more of a double-acting pressurizing liquid distribution device and a flow control assembly (such as a valve block).

The pressure transfer device is suitable for use at high pressures, in the range above 500 bar, and is particularly suitable for hydraulic fracturing in oil and gas wells where part of the fluid is difficult to pump fluids with particles such as proppants. However, the pumping system may also be applied in other well related applications such as pumping drilling fluids in drilling and cementing operations, plugging and abandonment, completion or stimulation, acidizing, or nitrogen circulation operations.

State of the art

Hydraulic fracturing (also fractionation, hydraulic fracturing, or hydrofractionation) is a well stimulation technique in which rock is fractured by the action of a pressurized fluid in the form of a gel, foam, sand, or water. Chemicals may be added to the water to increase fluid flow or improve specific properties of the water, such treated water is referred to as an aqueous-based surface tension agent. This method involves injecting high pressure "fracturing fluid" (a fluid containing sand or other proppants and chemicals) into the wellbore to create fractures in deep formations through which natural gas, oil and brine flow more freely. . Typically, mechanical piston pumps are used to pump the high pressure fracturing fluid. These mechanical pumps have very limited run times due to mechanical wear on the sliding surfaces in the pump caused by sand and particles in the pumped medium. Pumps handling liquids containing particles and/or chemically aggressive liquids at high pressure have sealing surfaces that are damaged by particles and/or abrasive liquid chemicals (compounds). If the seals are damaged, leaks and other problems can accumulate in the pump, reducing its efficiency. In addition, mechanical pumps operate at high speeds, which creates rapid pressure fluctuations throughout the installation (with a large number of cycles), which eventually leads to breakdowns due to structural fatigue. Therefore, the duty cycle of such pumps is very limited and depends on the type of particles, the number of particles, the chemical composition and chemical concentration, as well as the operating pressure. In rotary pumps, rotating seals (shafts) and expensive pump components, such as impellers and turbine wheels, wear out quickly. In piston pumps, the piston wears against the cylinder, leading to leakage, reduced efficiency, and destruction. Another well-known problem with plunger pumps is fatigue cracking of end portions in contact with the fluid. The main reason for this is the combination of stresses from pressure fluctuations and mechanical linear stress from the plungers. They are also limited by the maximum allowable stem load on the drive end, making it necessary to match the plunger size to the required feed rate and pressure.

Plunger/piston pump units are commonly used.

When a plurality of pumps are connected to the same downhole flowline and are in operation at the same time, there is a risk that they form interference patterns that correspond to the natural frequency of the downhole flowline. This results in zigzag oscillatory movements (snake-like) of the flow lines, which can cause damage to equipment and personnel.

In hydraulic fracturing operations, when the pumps are turned off, when hydraulic pressure is no longer applied to the well, small grains of hydraulic fracturing proppants hold the fractures open. Proppants are usually made from a hard material such as sand. The sand may be treated sand or synthetic or natural materials such as ceramics. In hydraulic fracturing, typically a so-called fracturing package (fracturing package) containing a number of trailers or trucks is transported and positioned at the job site. Each truck is equipped with a pump unit for pumping hydraulic fracturing fluid into the well. Thus, there are weight and physical limitations on the equipment used, due to the overall capacity of the trucks on the road and the physical limitations of the trucks.

The prior art, which discloses a system in which a clean hydraulic fluid is separated from the pumped liquid, although not suitable for hydraulic fracturing, is the application EP 2913525 related to a diaphragm pump machine (''pump'') with a hydraulic drive, in especially for water and hard-to-pump materials. The system contains at least two pumping units located next to each other. Each pump unit contains a pump cylinder and a hydraulic cylinder. The pump cylinder (EP 2913525, 1, 2) has a lower first end with a first inlet and outlet for the fluid to be pumped, and an upper second end with a second inlet and outlet for the hydraulic fluid. The pump cylinder (1, 2) contains a bellows (3, 4) closed at its lower end and open at its upper end for communication with the hydraulic fluid. The outer part of the bellows (3, 4) defines the space for the pumped liquid. The bellows (3, 4) of the pump cylinder (1, 2) is configured to be actuated by the hydraulic fluid supplied at its upper end, when expanding and contracting like an accordion to pump the pumped liquid near the lower first end of the pump cylinder (1, 2 ). The hydraulic cylinder (9, 10) is located next to the pump cylinder (1, 2). The hydraulic cylinder (9, 10) has a lower first end connected with a hydraulic drive and an upper second end containing a hydraulic fluid communicating with the upper second end of the pump cylinder (1, 2). The hydraulic drive ends at its upper end with a drive piston (19, 20) slidably mounted in a hydraulic cylinder (9, 10). The hydraulic drives of the hydraulic cylinders (9, 10) of the two pumping units are connected by a hydromechanical connection (25, 27), made with the possibility of extending and retracting the pistons (19, 20) of each hydraulic cylinder (9, 10)

However, the solution in EP 2913525 is not applicable for hydraulic fracturing at high pressures (i.e. over 500 bar) due to the cylindrical pumping chamber. The cylindrical shape of the pumping chamber is not capable of withstanding the high pressure experienced in combination with the high number of cycles when used in hydraulic fracturing. In addition, the bellows are polymeric, which leads to the risk of particles being compressed between the cylindrical wall and the bellows, with the possibility of damage to the bellows. In addition, one hydraulic cylinder is connected to each pump cylinder. The hydraulic cylinder is not designed to pressurize the underside of the piston (19, 20) because the effective area on the underside of the piston (19, 20) is smaller than on the top side of the piston (19, 20). In addition, polymer bellows lack control of the direction of expansion, whereby there is the possibility of the bellows coming into contact with the cylinder wall. This can cause the proppants to rupture and be forced into the base material.

Hydromechanical connections tend to have some disadvantages, including:

- the inability to synchronize with many blocks,

- the impossibility of a smooth increase/decrease depending on pressure and flow (impossibility to provide precise control of pump characteristics),

- the impossibility of an incomplete move,

- the inability to compensate for fluctuations in pressure / fluid flow,

- the impossibility of overlapping and creating a laminar flow,

- creating a pressure drop across the control valve, which leads to oil heating and loss of efficiency in the range of 5-10%.

One of the problems with conventional fractionation pumps is that parts of the system can break down after a few hours and need to be repaired. Thus, it is normal that the hydraulic fracturing complex contains many redundant pumps to provide redundancy. This increases both the cost of maintenance and labor, since one maintenance worker can only work on several trucks.

Thus, the purpose of the present invention is to eliminate at least some of the disadvantages of the known solutions and, more specifically, to protect the moving parts (pistons, seals) from fluid with particles (i.e., the pumped medium) and to prevent damage to moving parts by particles.

More specifically, the aim of the present invention is to provide uniform and shock-free pumping of large flows at high pressures, to reduce wear on all components in the flow loop, and at the same time to allow the plant to be easily integrated and adapted to any desired flow-to-pressure ratio without the need for mechanical modifications or changes. In addition, the ability of the present invention to synchronize with multiple units minimizes the risk of possible yaw oscillations. More specifically, one of the objectives of the invention is to provide a hydraulic fracturing system that can operate at high pressures with high volumetric flow.

Another goal is to create a system in which the pumped liquid is separated from as many moving parts as possible.

More specifically, the goal is to minimize the risk of damage to the bellows.

Another object is to provide a pumping system that has a reduced weight, for example, the pumping system should be able to be placed and transported on standard trucks or trailers, forming part of the so-called hydraulic fracturing systems used in hydraulic fracturing.

Another goal is to provide a system that does not require an external bellows guide system.

Another goal is to provide fully stepless speed/amplitude control of the bellows in order to avoid pressure peaks, flow peaks and fluctuations.

Another goal is to provide a pumping system for all pressure and flow configurations commonly used in hydraulic fracturing or other high pressure pumping industries without the need for mechanical rework.

Another object of the invention is to prevent sedimentation in the lower part of the head cavity of the pressure transmission device.

Another object of the invention is to provide an improved system for controlling and synchronizing multiple units to eliminate the problems associated with conventional systems.

Another goal is to provide a solution that can be used in new installations and connected to existing installations, for example when upgrading existing systems.

Disclosure of the essence of the invention

The invention is set forth and characterized in the independent claims, while the dependent claims disclose other characteristics of the invention.

The present invention provides significant improvements over known solutions. The pumping system and its associated components enable pumping at pressures up to 1500 bar and higher at high volume flow. For example, the design is capable of pumping 1 m ³ /min at 1000 bar or 2 m ³ /min at 500 bar, or any other flow to pressure ratio in between. The pressure transfer device of the present invention provides flexibility in pump flow and pressure requirements, such as lower flow at high pressures and higher flow at reduced pressure with essentially laminar flow in all embodiments. The pressure transfer device is preferably part of a larger pumping system comprising, in addition to the pressure transfer device, one or more double acting pressurizing liquid distribution devices and a flow control assembly (such as a valve block). The hydraulic pump unit typically pressurizes the double-acting pressurizing liquid distributor, wherein the double-acting pressurizing liquid distributor pressurizes the pressure transfer device. The bellows in the pressure transmission device functions as a ''piston'' between the hydraulic pressure side, i.e. the double acting pressurizing liquid distribution device and the hydraulic pump unit on one side, and the pumped medium on the other side. The bellows functions as an extension of the piston in a double acting pressurizing fluid distribution device. The bellows in the pressure transfer device separates the clean hydraulic fluid (inside the bellows) from the dirty particulate fluid (outside the bellows). Thus, the pumping system may be a positive displacement pump where volume changes in the headspace are achieved using a bellows such as, for example, a sealed bellows that is radially rigid and axially flexible. This arrangement results in the bellows moving in a substantially axial direction, while movements in the radial direction are not possible or limited.

In all aspects of the invention, the bellows is intended to be a fluid barrier separating the internal volume of the bellows and the volume between the outside of the bellows and the inside of the headspace. That is, the outer diameter of the bellows is fixed, while axially it is flexible, providing an annular gap (the size of the gap, for example, at least corresponds to the diameter of the particles in the fracturing fluid) between the inner surface of the pressure chamber body and the bellows at all positions of the bellows and at all pressures.

The bellows is preferably rigidly connected at the top of the pressure chamber, and the bellows is surrounded by the pressure chamber in all directions, i.e. below, radially and possibly partially on its upper side in a part not forming part of the connection channel for hydraulic fluid entering and leaving internal volume of the bellows. The total volume of the pressure chamber is constant, while the internal volume of the bellows varies. As the bellows expands and retracts within the compression cavity, the available remaining volume of the head cavity changes. The volume of hydraulic fluid enters the interior of the bellows and displaces the volume of fluid being pumped out of the pressure chamber.

The pumping system may be a positive displacement pump in which volume changes in the pressure transmission device are achieved using a sealed bellows that is radially rigid and axially flexible. When the bellows is in the first position, i.e. in the compressed state, the free volume in the head cavity is the largest, and when the bellows is in the second position, i.e. in the expanded state, the free volume in the head cavity is the smallest. The ratio of the dimensions of the inner surface of the pressure cavity and the outer surface of the bellows is made in such a way that in all positions of the bellows a gap is formed between the inner surface of the pressure cavity and the outer surface of the bellows, which prevents particles from sticking between the inner surface of the pressure cavity and the bellows. Thus, the fracturing fluids surround the bellows and the gap is formed such that its minimum dimension is greater than the largest proppant particle size. The radial stiffness of the bellows ensures that the bellows does not come into contact with the inner surface of the pressure chamber housing. Hydraulic fluid entering the internal volume of the bellows through the connection channel exerts pressure on the barrier and due to the rigid properties of the bellows and/or possible internal guide, all movement of the bellows is in the axial direction. The pressure of a pumped fluid, such as a fracturing fluid, is increased by filling the internal volume of the bellows with hydraulic fluid, which increases the displaced volume of the bellows, resulting in a decrease in the free volume of the head cavity outside the bellows and an increase in the pressure of the fluid being pumped. The pumped liquid then exits through the first passage and further out through a flow control assembly such as a valve block.

The pressure transmission device has no sliding surfaces in contact with the pumped liquid. In this way, the service life of the parts is increased as there are no vulnerable parts in sliding contact with any abrasive pumped liquid. The pressure transmission device is pressure balanced so that the control hydraulic pressure is the same as the pressure in the pumped liquid, i.e. the fracturing fluid, and as such, the bellows does not have to withstand the pressure difference between the internal hydraulic control pressure and the pressure in the fluid being pumped.

The pressure transfer device can operate under pressure supplied from the double acting pressurizing liquid distribution device, wherein the double acting pressurizing liquid distribution device is pressurized by a hydraulic pump unit. The double acting pressurizing fluid distribution device is part of a closed hydraulic circuit volume with the internal volume of the bellows and is capable of supplying and diverting a large volume of high pressure hydraulic fluids into the internal volume of the bellows.

It is clear that in all hydraulic systems there is some level of internal hydraulic fluid leakage, however, in the present specification and claims, the term closed loop hydraulic system is used for such a ''closed'' system to distinguish it from systems that are not defined by finite volume. .

The bellows can be returned to the first position, i.e. to the compressed state, by means of the supply pressure of the liquid being pumped. The pumped liquid, i.e. the supply pressure from the supply pump supplying the liquid, provides the pressure by which the bellows is compressed to the first position. In this compression phase, the pressure of the pumped liquid is equal to the pressure of the hydraulic fluid in the internal volume of the bellows, and the result of the creation of a pressure difference in the volume by the double acting pressurizing liquid distribution device will be retraction. Retracting the double-acting pressurizing fluid distribution device creates a differential volume which, by compressing the bellows, compensates for the volume of pumped fluid supplied and pressurized by the feed pump (mixer) (i.e., the feed pump delivers fracturing fluid). into the pressure cavity). In a state of stretch, i.e. when the bellows begins to expand under the action of pressurized fluid filling the internal volume, the pressure of the hydraulic fluid is equal to the pressure of the pumped liquid (ie, the supply pressure in the intake manifold and/or and in the pumped liquid reservoir). When the pressure in the headspace exceeds the supply pressure, the first valve closes, and when the pressure exceeds the pressure in the exhaust manifold, the second valve opens and fluid flows into the well. This compression and expansion of the bellows occurs sequentially in the pressure transmission device.

The invention relates to a pressure transmission device for pumping a fluid medium with particles at a pressure above 500 bar, containing a pressure chamber body and at least one connecting channel, wherein at least one connecting channel is made with the possibility of connection by means of fluid connection with the device liquid distribution with double acting pressurization, wherein the pressure chamber housing comprises:

- a pressure chamber inside the pressure chamber body and at least a first channel for inlet and/or outlet of fluid into the pressure chamber,

- a bellows that defines the internal volume inside the pressure cavity, and the internal volume is in fluid communication with the connecting channel,

moreover, the pressure cavity has a central axis with an axial length determined by the distance between the connecting channel and the first channel, and a varying cross-sectional area at least on a part of the axial length, and the bellows is movable in a direction essentially parallel to the central axis, on a part of the axial the length of the pressure cavity. The bellows is preferably radially rigid and flexible in the axial direction and is designed to be stretchable and retractable for at least part of the length of the head cavity.

The pressure transfer device may be a pressure transfer device for hydraulic fracturing, such as devices used in hydraulic fracturing operations.

The pressure chamber thus has a different cross section, for example at least two different cross sections in the longitudinal direction. Preferably, the transition zones between different cross sections are smooth or smooth (no sharp edges). Such smooth or smooth transition zones prevent sedimentation and allow higher pressure operation without weak points in the headspace. That is, the forces applied to the pressure cavity arise as a result of internal pressure. The geometry is optimized to make these forces as uniform as possible.

The connection passage is thus adapted to suck in hydraulic fluid and/or discharge pressurized hydraulic fluid into and out of the pressure chamber.

The first channel is adapted for launching/discharging the pumped liquid into and out of the pressure chamber.

In accordance with one aspect, the bellows may be connected to the inner surface of the pressure cavity. Preferably, the bellows is connected at the top of the pressure cavity by means providing a tight connection between the bellows and the inner surface of the pressure cavity. In this way, the flow of fluids from the internal volume of the bellows into the pressure cavity is prevented.

The bellows has a shape adapted to the shape of the pressure chamber, so that in all operating positions the bellows is prevented from contacting the inner surface of the pressure chamber body. This means that the maximum expansion of the bellows in the axial and radial directions in all operating positions is less than the constrictions formed by the inner surface of the pressure chamber body.

In one aspect, the headspace narrows towards the first passage, thus forming a natural funnel through which sediment/proppants/sand can exit with the fluid. Therefore, the first channel of the pressure chamber body is preferably shaped to prevent the formation of sediment (proppant/sand, etc.) by tilting the pressure chamber towards the first channel. Thus, the first channel may preferably be located at the bottom of the head cavity, so that deposits can exit through the first channel under the action of gravity.

In one aspect, the head cavity may be elongated, ovoid, elliptical, round, spherical, spherical or oval, or have two parallel sides and at least a portion of a cross section smaller than the cross section in the parallel portion.

In another aspect, the head cavity may be circular in shape. In yet another aspect, the head cavity may have a plurality of bulges (eg, like an inflatable Michelin man).

In one aspect, the bellows has less radial and axial extension than the inner surface of the pressure chamber body (determining the radial and axial extension of the pressure chamber), which provides a gap between the outer circumference of the bellows and the inner circumference, i.e. the inner surface, of the pressure chamber in all operating positions of the bellows. Thus, during operation of the pressure transfer device, fluid surrounds at least two sides of the bellows at all pressures.

According to one aspect, the bellows may be cylindrical, harmonica shaped, or concertina shaped. The design of the bellows cylinder ensures minimal stresses on the bellows, since its entire surface is constantly in a hydraulically balanced state. Thus, the bellows can have an accordion-like sidewall for axial flexibility and a sealed end cap connected to the sidewall of the bellows. Thus, an accordion-like side wall may comprise a plurality of circumferential folds or folds in a contiguous manner. Adjacent folds or bends can be, for example, welded to each other or connected to each other by other suitable means of fastening, such as glue, mechanical connections. Adjacent folds or folds may be formed in such a way as to prevent entrapment of fracturing fluid particles between adjacent folds or folds in the bellows during retraction and expansion of the bellows. This can be achieved by setting such an operating range of the bellows, i.e. predetermining the maximum expansion and retraction of the bellows so that the gaps between adjacent pleats or between pleats and the inner surface of the head cavity are always larger than the largest expected particle size. In this way, the risk of particles being trapped is minimized.

The bellows is preferably made of a sufficiently rigid material: metal, composite, hard plastics, ceramics, or combinations thereof, and the like to provide bellows tightness and radial stiffness and axial flexibility. The bellows preferably moves in a substantially axial direction, while movements in the radial direction are not possible or limited. The bellows material is chosen to withstand large pressure changes and chemicals in the pumped liquid, thereby minimizing structural fatigue and the risk of damage. If the bellows is made of metal, it can be used at higher temperatures than bellows made from more temperature sensitive materials (i.e. materials that cannot operate at higher temperatures).

It is clear that other parts forming part of the overall system can also be made from appropriate materials depending on the requirements of specific projects, such as metal (cast iron, steel, special steel or the examples above). However, other materials may be used, such as composite, hard plastic, ceramic, or alternatively combinations of metals, composite, hard plastic, ceramic.

In one aspect, the bellows may comprise a guiding system coinciding with or parallel to the central axis of the pressure cavity, the bellows being stretched and retracted axially and longitudinally along the central axis.

In one aspect, the guide system may include a guide.

The pressure transfer device may further comprise a bellows position sensor that monitors the position of the bellows and/or a temperature sensor that monitors the temperature of the control fluid in the closed volume of the hydraulic circuit. In addition, pressure sensors may be used.

The bellows may include a guide system containing a guide. The guide may be connected to the bottom of the bellows and may be guiding in the pressure chamber housing. The guide in the pressure chamber body can then form part of the inlet and outlet for hydraulic fluid into and out of the internal volume of the bellows. The guide may coincide with or parallel to the central axis of the pressure cavity, and the bellows may be stretched and retracted in the axial direction longitudinally along the central axis.

The bellows position sensor may be a linear position sensor. The bellows position sensor may be placed in the connecting channel and contain axial through holes for free flow of fluid.

In one aspect, when the bellows position sensor is a linear sensor, the reader may be rigidly connected to the bellows position sensor and the magnet may be rigidly connected to the rail, and the reader may be an inductive sensor that can read the position of the magnet in such a way that that the bellows position sensor can track the relative position of the magnet, and thus the bellows, in an inductive manner.

In one aspect, the inductive sensor may be an inductive rod capable of sensing the position of the magnet and thus the bellows.

In one aspect, the inductive sensor may include an inductive rod configured to sense the position of a magnet attached to the guide so that the bellows position sensor tracks the relative position of the magnet, and thus the bellows, in an inductive manner.

The pressure transfer device may further comprise an additional sealed barrier within the bellows. This can be used to further reduce or minimize the risk of fluid leakage between the interior of the bellows and the headspace containing the fluid being pumped. This additional hermetic barrier may be a bellows, a bellows, an impermeable layer of material, and may have the same or a different shape as the previously mentioned bellows.

In one aspect, the pressure transfer device may further comprise an external barrier between the bellows and the inner surface of the pressure chamber housing. This outer barrier may be particle-proof (mesh) or fluid-tight, and may be made of a compliant material, a bellows like the previously mentioned bellows, a mesh, and the like.

In addition, the invention relates to a system containing:

- the pressure transmission device disclosed above, and

- a hydraulic pump unit pressurizing and actuating a double-acting pressurizing liquid distributor and a double-acting pressurizing liquid distributor pressurizing and actuating the pressure transmitting device,

- a flow control unit configured to distribute the fluid between the inlet manifold, the pressure chamber and the outlet manifold.

The system may be a hydraulic fracturing system, such as a system used in hydraulic fracturing operations.

The system may further comprise a control system for controlling the operating range of the pump bellows, configured to decide whether the bellows operates within a predetermined operating range of bellows positions determined by maximum constraints such as the maximum retraction position and the maximum extension position of the bellows, the control system being configured to the ability to compare the position by calculating whether the volume of hydraulic fluid is outside the predetermined operating range of the bellows position or not, and/or by monitoring the positions of the bellows and the dual acting pressurizing fluid distribution device and comparing with the predetermined operating range of the bellows positions. The system may be configured to control the oil supply system valve based on the operating range, drain or add hydraulic fluid to the closed volume of the hydraulic circuit to maintain the system at the desired positions and avoid malfunctions, thereby increasing the life of the system components. Thus, the control system compares the signals from the bellows position sensor and the double acting boost liquid distributor position sensor in the double acting boost liquid distributor to decide if the system is operating within predetermined operating ranges.

In addition, the control system can, based on input from the potential temperature sensor(s), decide when to use the oil system valve to replace (add, drain) oil in a closed hydraulic circuit system.

The desired operating range of the bellows position can be determined by the specific physical end positions of the bellows for both compressing and expanding the bellows. Alternatively, instead of physical end positions, the end positions may be software-controlled positions indicating the end positions. A signal can then be transmitted to the control system indicating that the bellows has reached its end position(s). The physical or software controlled positions indicating the end positions may be an integral part of the bellows, for example as part of a guide system or a bellows position sensor, or be separate from the bellows. The control system can then decide whether the bellows has reached its end position. If the bellows has not reached its end position, the control system may decide that the (expected) signal is not being read and command the oil supply valve to drain or add hydraulic fluid to the closed volume of the hydraulic circuit.

The control system also provides partial stroke capability when handling large proppants and/or during startup. This is critical in situations where a plant is shut down unplanned while the fluid being pumped is still a slurry, allowing the proppants to precipitate out of the slurry and sediment. Therefore, a partial stroke is used to resuspend the proppants in the drilling fluid (slurry).

In one aspect, the system may comprise two pressure transfer devices, and the dual acting pressurizing fluid distribution device may be configured to sequentially pressurize the two pressure transfer devices such that one pressure transfer device is pressurized and drained (fluid drained). fracturing) while the other pressure transfer device is depressurized and filling (filling with new fracturing fluid) occurs, and vice versa. Pressure relief and filling operations can be assisted by a feed pump. The system may further comprise two double-acting pressurizing liquid distribution devices configured to operate individually so that they can pressurize the two pressure transfer devices at the same time, i.e. synchronously, or asynchronously, i.e. with overlap.

In another aspect, the system may include four pressure transfer devices and two double acting pressurizing liquid distribution devices, each of the double acting pressurizing liquid distribution devices being configured to successively pressurize and drain the two pressure transfer devices such that the two the pressure transfer devices are pressurized and drained, while the other two pressure transfer devices are depressurized and filled, and vice versa.

In addition, a trailer, container or module can be further provided containing the pressure transmission device disclosed above and/or the system disclosed above used for hydraulic fracturing, along with the engine and necessary fittings.

The system may further comprise a bellows position sensor configured to monitor the axial extension of the bellows and thus the amount of fluid entering and exiting the internal volume of the bellows, as well as a double-acting pressurizing liquid distributor position sensor monitoring the position of the liquid distributor with double acting pressurization, wherein the signals from the bellows position sensor and the double acting pressurizing liquid distributor position sensor are monitored by the control system and compared to predetermined operating ranges for bellows stretch and double acting liquid distributor position with double acting pressurization. This is done because it is advantageous to know and be able to control the axial tension position of the bellows (the bellows must never be fully compressed or stretched). Thus, such an input value is important for the control system. For example, if there is a hydraulic fluid leak from a closed hydraulic circuit system, there is a risk of damage to the bellows if it is compressed or stretched too much (ie, outside a predetermined operating range). Excessive compression can result in proppants or sand being trapped between adjacent folds or bends in the bellows and/or an increase in pressure drop, while excessive tension can result in, for example, increased fatigue of the bellows structures or potential collision with the bottom surface of the pressure chamber housing, which reduces the life expectancy of the bellows.

The volume flowing in and out of the internal volume of the bellows is monitored using a bellows position sensor, providing high accuracy and controlled acceleration/deceleration of the bellows at the point of reversal of the double acting pressurizing fluid distributor, which also results in a smooth and soft seating of the valves, that is, smoother movement of the valves in the flow control system. The slow and controlled movement of the valves prevents or minimizes the risk of damage to the valve seats in the flow control system. Thus, in order to achieve this, the system is able to track the position of the double acting pressurizing liquid distributor using the position sensor of the double acting pressurizing liquid distributor, wherein, as the end position is approached, the output speed of the unit is reduced in order to dampen/ dampen the speed of the valve element before entering the valve seat.

A double-acting pressurizing liquid distribution device that controls the volume to and from the bellows and also functions as a pressure booster or pressure booster, preferably a double-acting hydraulic cylinder/plunger pump in which the hydraulic pressure entering the a pump that exerts a push/compressive force on an area that is a fixed factor of times the secondary area. The secondary area is the area acting on the fluid entering and leaving the internal volume of the bellows. This design provides double, triple or even quadruple (or more) working pressure on the secondary area. A hydraulic pump system driving a double-acting pressurizing liquid distributor having a pressure range of eg 350 bar can, for example, supply 700-1400 bar to the internal volume of the bellows and thus the same pressure to the pressure chamber. In order to be able to satisfactorily function and operate the pressure transmission device and the double acting pressurizing liquid distribution device at the above high pressures, the system should preferably be configured to control and position the bellows with high precision. The closed volume of the hydraulic circuit (for example, the volume of oil) providing the operation of the bellows is preferably made with the possibility of volume control by means of an oil supply valve in order to ensure that the bellows operates in predetermined operating ranges / areas of operation, and the hydraulic fluid in the closed volume of the hydraulic The circuit must be constantly monitored for temperature and replaced with cooled (fresh) fluid as needed, during/during/during pumping, albeit at a reduced flow rate of the entire system.

The double acting pressurizing liquid distribution device is preferably a double acting device, i.e. the primary side defined by the first zone of the piston of the double acting pressurizing liquid distribution device operates with a differential pressure of 350-400 bar, and on the secondary side defined by the second zone of the piston , there may be increased pressure, for example, up to 1050 bar or higher, which is close to the pressure at which the pressure transmission device, ie the bellows and the pressure chamber, operates.

More specifically, the dual acting pressurizing fluid distribution device is capable of delivering and drawing a large amount of high pressure hydraulic fluid to and from at least the first pressure transfer device and the second pressure transfer device pumping particulate fluids at high volumes and pressures above 500 bar, and the double-acting pressurizing liquid distribution device is controlled by changing the supply flow through at least the first control fluid channel and the second control fluid channel, while the double-acting pressurizing liquid distribution device comprises:

- a hollow cylinder body with a longitudinal extension, wherein the cylinder body comprises at least a first part and a second part having a first area (a1) of a perpendicular cross section, and a third part having a second area (a2) of a perpendicular cross section different from the first area ( a1) perpendicular cross section,

- stock, and

- the rod has a cross-sectional area corresponding to the first area (a1) of the perpendicular cross-section, wherein the first part of the rod and the first part of the cylinder body form the first plunger chamber, and the second part of the rod and the second part of the cylinder body form the second plunger chamber, and

- the rod further comprises a protruding part, the cross-sectional area of which corresponds to the second area (a2) of the perpendicular cross section, and the protruding part and the third part of the cylinder body form the first outer chamber and the second outer chamber,

- the protruding part forms the first piston area, and

- the rod forms a second piston region, different from the first piston region, wherein the first part of the rod, at least for part of its length, is made with a first internal recess extending from the first end surface of the rod, while the first internal recess is in pressure communication with the first plunger chamber, and

- the second part of the rod, at least on a part of its length, is made with a second internal recess extending from the second end surface of the rod, while the second internal recess is in pressure communication with the second plunger chamber.

The pressure transmission device may be driven by a hydraulic pump unit, such as a variable displacement bi-directional pump, which drives a double acting pressurizing fluid distribution device. The hydraulic pump unit can have two flow directions and adjustable output. The hydraulic pump unit may be driven, for example, by any engine suitable for operation with such hydraulic pump units, such as diesel engines or other known motors/motors. However, it is clear that the described hydraulic pumping unit can be replaced by a plurality of hydraulic pumps controlled by a proportional control valve to pressurize the double-acting pressurizing fluid distribution device and the pressure chamber.

The pressure transmission device is preferably pressure balanced, which means that the bellows is hydraulically actuated by directing some amount of oil or other hydraulic fluid into and out of the internal volume of the bellows, moving the bellows between the first position, i.e. the compressed state, and the second position, then is in a stretched state. In operation, the pressure of the hydraulic fluids in the internal volume of the bellows will be the same as in the hydraulic fracturing fluid (ie, the pumped medium) in the pressure chamber outside the bellows. The fluid or medium to be pumped, such as the fracturing fluid, is located below the bellows in a gap formed between the outer side of the bellows and the inner surface of the pressure chamber housing.

The pressure transfer device and the double acting pressurizing liquid distribution device do not have sliding surfaces in contact with the pumped liquid. In this way, the service life of the parts is increased as there are no vulnerable parts in sliding contact with any abrasive pumped liquid.

In addition, the invention relates to a set for pumping large volumes of fluids with particles at high pressures, containing at least two trailers, each trailer contains at least one system disclosed above.

The control system, which may be computer-based, further enables the use of a plurality of parallel pumping systems acting as one by connecting them via a field bus. This can be done by arranging the pumping systems in parallel and using the control system to operate the individual pumping systems asynchronously. This minimizes the risk of yaw oscillations due to interference.

In addition, the invention relates to the use of a pressure transmission device as disclosed above, a system as disclosed above, or a kit as disclosed above in the extraction or production of hydrocarbons.

In addition, the invention relates to the use of the pressure transmission device disclosed above, the system disclosed above, or the kit disclosed above in hydraulic fracturing operations.

In addition, the invention relates to the use of the pressure transmission device disclosed above, the system disclosed above, or the kit disclosed above, in any of the following operations: plugging and shut-in, well drilling, completion or stimulation, cementing, acidizing, nitrogen circulation.

The system can be controlled by an electromechanical control system. The pump control input may include one or more of the following:

- pressure sensors in the low pressure hydraulic system (clean oil) and slurry/mud supply lines

- position sensors in the double acting device to increase the head of the fracturing fluid, including the position of the piston / plunger and the position of the bellows

- temperature sensors in the closed volume of the hydraulic circuit and low pressure hydraulic system

- human-machine interface (HMI, Human Machine Interface) for entering the desired values of flow, power, volume, flow

- well data (values of pressure, flow, pulsations)

- filter condition, oil level

The pressure transmission device (via a double-acting pressurizing fluid distribution device) is controlled by issuing variable commands based on input data to hydraulic pumping units, such as bi-directional axial piston pumps.

In general, the invention and the electromechanical control system that may form part of the invention may have advantages over known solutions, including:

- Variable pressure, power and flow; since the conditions of the pumping task can change, the system is able to adapt to specific conditions. For example, if the pressure increases, the system is able to automatically adjust the flow to the maximum allowable power output. Given a given pressure, the electromechanical control system is able to vary the flow to maintain that pressure. Given flow, the electromechanical control system is capable of varying pressure and power up to system limits. You can also combine control parameters.

- Possibility of incomplete stroke; when the system is taken out of service without first washing out the sludge/slurry, sedimentation occurs. To avoid clogging, the system is able to ''re-suspend'' the pumped medium by means of pulsation.

- Smooth change; The ideal smooth change for a system varies with pressure and flow.

- Smooth on / off; the system is able to gradually increase the flow in order to prevent pressure peaks when turning on/off the pumping system.

- Synchronization of multiple units; moreover, the ''fracturing complex'' (fracturing complex) includes several units that pump simultaneously. This leads to situations in which pressure fluctuations in the system sometimes coincide in frequency with the harmonic vibrations of the pipeline, causing damage and potentially dangerous situations (the yaw oscillations described above). By synchronizing the blocks and thus controlling the output oscillation frequency, this problem is eliminated. It also allows individual units to increase or decrease feed rates depending on system superheat limits without changing overall system performance.

- Operation of pressure transmission devices with overlap to achieve a stable laminar flow of the pumped medium (eg, fracturing fluid) down into the well. For example, if each system contains four pressure transfer devices connected in pairs with two double acting pressurizing liquid distribution devices. This makes it possible to create an asynchronous drive system that can provide a practically pulsation-free flow (laminar flow).

- Smoothing pulsations; in the case of using a hybrid ''fracturing system'' with a combination of conventional pumping systems and a pressure transmission device and systems according to the present invention, it is possible to counteract the pulsations generated by conventional pumping systems by pulsing the pressure transmission device and system according to the present invention in opposite phase .

- No minimum flow; Hydraulic pump units, such as the bi-directional axial piston pump, function as an infinite variable drive (IVT) and can thus change the flow rates steplessly from zero to maximum.

- An electromechanical control system allows direct drive of a double-acting pressurizing liquid distributor from a hydraulic pump unit, such as a bi-directional axial piston pump. This provides faster response times and less pressure drop across the overall system, improving efficiency and reducing heat generation in the system.

- Complete control over the expansion and retraction of the bellows throughout the stroke is achieved. This makes it possible to detect faults, internal leaks, and eliminate damage to the bellows by preventing it from exceeding the specified operating parameters.

Various terms are used in the description and in the claims for the pumped liquid. This term should be understood as the fluid in the pressure chamber outside the bellows, e.g., hydraulic fracturing fluid, fracturing fluid, fracturing or hydrofractionation fluid, or drilling fluid, stimulation fluid, acid, cement slurry, etc. d.

In addition, different terms are used for the position of a double acting pressurizing liquid distributor or the position of a rod or piston in a double acting pressurizing liquid dispenser. They should be understood as the position of the rod or piston relative to the outer shell of the double acting pressurizing liquid distribution device.

These and other characteristics of the invention will be apparent from the following description of a preferred embodiment, given by way of non-limiting example with reference to the accompanying drawings, in which:

Brief description of the drawings

In FIG. 1 shows the working arrangement of a pressure transmission device and related system in accordance with the present invention;

In FIG. 2 shows in more detail a double-acting pressurizing liquid distribution device used in conjunction with a pressure transmission device according to the present invention;

Implementation of the invention

In FIG. 1 shows a general view of the working arrangement of the pressure transmission device and related system in accordance with the present invention. Disclosed is a pressure transmission device for well stimulation specifically designed for pumping very high pressure fluids (500 bar and above) at high flow rates (e.g., 1000 liters/min or more for the particular system disclosed in FIG. 1), such as drilling fluids. containing large amounts of abrasive particles. In FIG. 1 shows two identical arrangements having a common double-acting pressurizing liquid dispenser 2, where the elements of the arrangement on the left side are indicated by a single apostrophe ('), and the elements in the identical arrangement on the right side are indicated by a double apostrophe ('').

In FIG. 2 shows in more detail a double-acting pressurizing liquid distribution device 2 used in conjunction with a pressure transmission device 1', 1''. Shown is a pressure transmission device 1'' for pumping fluid at a pressure above 500 bar, comprising a pressure chamber body and a connecting channel 3', 3'', wherein the connecting channel 3', 3'' is configured to be connected to a liquid distribution device 2 with double-acting pressurization by fluid connection means in the form of a first valve port 26', 26'' and a second valve port 27', 27'', and optionally via an oil supply valve 16', 16''. The body of the pressure chamber contains a pressure cavity 4', 4'' and the first channel 5', 5'' connecting the pressure cavity 4', 4'' with the well through the flow control system 13. The first channel 5', 5'' acts as an inlet and/or outlet for the pumped fluid or liquid. In addition, a bellows 6', 6'' is shown located inside the pressure cavity 4', 4'', in which the internal volume 7', 7'' of the bellows 6', 6'' is in fluid communication with the connecting channel 3', 3'', and the internal volume 7', 7'' is fluidly separated from the pressure cavity 4', 4''. The cross-sectional area along the length L', L'' of the pressure cavity, measured in the longitudinal direction between the connecting channel 3', 3'' and the first channel 5', 5'', changes. The bellows 6', 6'' is movable in a substantially longitudinal direction, which in the drawing coincides with the central axis C', C'' of the head cavity 1', 1''.

The pressure transmission device 1' , 1'' comprises a bellows, for simplicity shown in the form of a hydraulically sealed bellows 6', 6'', containing an internal guide 9', 9'' and a bellows position sensor 12', 12'' with an inductive rod 43', 43'', configured to determine the position of the magnet 10', 10''. The magnet 10', 10'' can be rigidly connected to the guide 9', 9''. The guide 9', 9'' is guided in turn by itself in the pressure chamber body, for example along the longitudinal protrusion of the connecting channel 3', 3''. In the example described, the guide 9', 9'' is connected to the lower end of the bellows 6', 6'' at one end and is guided in the pressure chamber body at the upper end. The guide 9', 9'' and therefore the magnet 10', 10'' follow the movement of the bellows 6', 6''. A bellows position sensor 12', 12'', such as a measuring rod 43', 43'', may comprise means for detecting and determining the position of the magnet 10', 10'' (and thus the guide 9', 9'' and bellows 6', 6''), for example by inductively detecting the position of the magnet. Although the description discloses that the magnet 10', 10'' is connected to a guide 9', 9'', which moves relative to the fixed measuring rod 43', 43'', the magnet 10', 10'' can be fixed and, for example , the guide 9', 9'' can be configured for inductive position detection. In addition, other sensors than the linear encoder described above may be used, provided they are able to track the exact position of the bellows 6', 6''.

The bellows 6', 6'' is placed in the pressure cavity 4', 4'' with a given gap with the inner surface of the pressure chamber housing. The control fluid is directed into and out of the inner volume 7', 7'' of the bellows 6', 6'' through the connecting channel 3', 3'' in the upper part of the pressure chamber 4', 4'' (i.e. in the upper part of the housing pressure chamber). The bellows 6', 6'' is rigidly attached in the upper part of the pressure chamber 4', 4'' to the inner surface of the pressure chamber housing by means known to those skilled in the art. The connecting passage 3', 3'' is connected to a double-acting pressurizing liquid distribution device 2 and optionally to an oil supply valve 16', 16''.

The pressure transmission device 1', 1'' may further comprise an air vent (not shown) for venting air from the pumped fluid. The air vent can be any vent capable of venting or venting excess air from a closed system, such as any suitable valves (flaps) and the like.

The fluid to be pumped, such as fracturing fluid with particles, enters and exits the pressure chamber 4', 4'' through the first channel 5', 5'' on the bottom of the pressure chamber 4', 4'' (i.e., in the pressure chamber housing ). The first channel 5', 5'' communicates with a flow control device 13 such as a valve block. The flow control device 13 is described in more detail below.

Driven by the double acting pressurizing liquid distribution device 2, the pressure chamber 4', 4'' in combination with the bellows 6', 6'' pumps fluid by drawing in and expanding the bellows 6', 6'' between its minimum and maximum predetermined limitation. Keeping the bellows within this minimum and maximum predetermined limit increases the life of the bellows. In order to ensure that the bellows 6', 6'' operate within a predetermined limit, this movement is monitored by a bellows position sensor 12', 12''. Dynamic movement of the bellows beyond these minimum and maximum specified limits can greatly reduce the life of the bellows. Without this control, the bellows 6', 6'' will be overstressed over time as a result of internal leakage, especially in the double acting pressurizing liquid distribution device 2, either due to excessive stretching (ultimately colliding with the pressure chamber 4', 4' ') or excessive compression (retraction), as a result of which the particles in the fluid deform or pierce the bellows 6', 6'' or create a pressure drop. The central guide system 9', 9'', shown simplified as the guide 9', 9'', provides linear retraction and expansion of the bellows 6', 6'', ensuring that the bellows 6', 6'' does not collide with the side walls of the headspace 4', 4'', while providing accurate position readings from the bellows position sensor 12', 12''. Thus, the pressure chamber 4', 4'' is specifically designed to withstand high pressures and cyclic loads and at the same time ensure that sediment build-up is prevented. The predetermined distance between the outer part of the bellows 6', 6'' and the internal dimension of the body of the pressure chamber provides a balance between the internal pressure of the bellows 6'', 6'' and the pressure of the pumped medium in the pressure cavity 4', 4''.

This pressure chamber is designed to withstand the cyclic loads to which this system is subjected and to accommodate the bellows and the bellows positioning system. The connecting channel 3', 3'' is a through cylindrical hole formed by machining and honing in the base material of the ''body'' of the pressure cavity 4', 4'', and is part of the guide system 9', 9'', like cylinder and piston designs. The pressure cavity 4'', 4'' is preferably shaped to prevent stress concentrations. The internal guide system 9', 9'' of the bellows provides linear movement of the bellows 6', 6'' without the need for an external guide.

The first channel 5', 5'' of the bottom in the pressure cavity 4', 4'' is shaped to prevent the accumulation of sediment by tilting or narrowing the pressure cavity 4', 4'' in the direction of the first channel 5', 5''. Therefore, the accumulation of sediment is prevented because the sediment or particles of the pumped liquid flow naturally, that is, under the influence of gravity, from the pressure cavity 4'', 4'', passing through the first channel 5', 5''. Without this slanted or conical shape, sediment accumulation may lead to problems during start-up of the pressure transfer device, or deposits may accumulate and eventually surround the lower portions of the outer portion of the bellows 6', 6''.

The double-acting pressurizing liquid distribution device 2, which increases the pressure, comprises a hollow cylinder with a longitudinal projection, the cylinder comprising a first part and a second part having a first perpendicular cross-sectional area a1, and a third part having a second perpendicular cross-sectional area a2, different from the first area a1 of the perpendicular cross section. The double-acting pressurizing fluid distribution device comprises a rod that is movably mounted like a piston within a cylinder. The rod has a cross-sectional area corresponding to the area a1 of the first cross-section and forms the second piston region 31', 31'', and while the rod, when located inside the hollow cylinder, forms the first plunger chamber 17' and the second plunger chamber 17'' in the first and second parts. The rod further comprises a protruding portion 30 having a cross-sectional area corresponding to the second perpendicular cross-sectional area a2, and a protruding portion defining the first piston area 30', 30'' and the first outer chamber 44' and the second outer chamber 44'' in the third portion. . The part of the stem forming the first and second plunger chambers 17', 17'', at least over a part of its length, is made with a first recess 40'' communicating in pressure with the first plunger chamber 17', and a second recess 40'' communicating pressure with the second plunger chamber 17''.

The first plunger chamber 17' includes a first plunger passage 18' which communicates with the internal volume 7' of the bellows 6'', optionally via a first oil supply valve 16'. Similarly, the second plunger chamber 17'' comprises a second plunger passage 18'' which communicates with the internal volume 7'' of the bellows 6'', optionally via a second oil supply valve 16''. The volumes within the first and second plunger chambers 17', 17'' are changed by extending and retracting the stem 19 from or into the respective first and second plunger chambers 17', 17''. The stem 19 may include a double acting pressurizing liquid dispenser position sensor 21 . The first and second seals 22', 22'' may be positioned between the stem extension 30 and the first plunger chamber 17' and the second plunger chamber 17'', respectively. Said first and second seals 22', 22'' may be vented and cooled by a separate or common lubrication system 23', 23''.

Rod 19 is driven back and forth to alternately deliver pressurized fluid, such as oil or other suitable hydraulic fluid, into first inlet/outlet port 24' and out of second inlet/outlet port 24'', and vice versa, to opposite direction. The first and second inlet/outlet channels 24', 24'' communicate with the hydraulic pump unit 11.

The first and second valves 16', 16'' of the oil supply system are located between the bellows 6', 6'' and the double-acting liquid distribution device 2 with increasing pressure and are shown for simplicity in the form of two three-way valves, which may contain the first and second actuators 25 ', 25'' driving the first and second three-way valves, respectively. The arrangement of the first and second valves 16', 16'' of the oil supply system and their connection to various pressure transmission devices G, 1'' are identical. Thus, the system on the left side, i.e., will be described in more detail in the following. system connected to the first channel 18' of the plunger. The valve 16' of the oil supply system, shown in the drawings for simplicity as a three-way valve, contains three channels, including the first valve channel 26' in communication with the first plunger channel 18', the second valve channel 27' in communication with the connecting channel 3' of the device pressure transmission and a third valve passage 28' communicating with the oil reservoir 29'. Similarly, with reference to the pressure transmission device 1'' on the right side, the oil supply valve 16'' in communication with the second plunger port 18'' has three ports, including the first valve port 26'' in communication with the second port 18'' of the plunger, a second valve port 27'' communicating with the connection port 3' of the pressure transfer device 1'', and a third valve port 28'' communicating with the oil reservoir 29''.

The hydraulic pump unit 11 may comprise bi-directional axial piston pumps which are controlled by position data from both bellows position sensors 12', 12'' and the position sensor 21 of the double acting pressurizing fluid distribution device 2 and possibly according to input data from human-machine interface (HMI) and/or control system. The hydraulic pump unit 11 may be driven, for example, by a motor, such as any of the standard motors used in the relevant fields of technology.

A flow control assembly 13, such as a valve block, may be a common flow control assembly for identical systems on the left side and right side of the drawing. With respect to the system, on the left side, the flow control unit 13 may comprise a pump channel 36' communicating with the first channel 5'' of the pressure transfer device 1', an inlet 35' communicating with the pumped liquid through the inlet manifold 14 of the flow control unit 13, and the outlet channel 37', communicating with the outlet manifold 15 of the node 13 flow control. In order to be able to switch and operate with different inputs and outputs, the flow control assembly may include a supply valve 38' containing a check valve that provides the supply of working fluid when the pressure in the intake manifold 14 is greater than the pressure in the pressure chamber 4', and less than the pressure in the outlet valve 39'. The intake manifold 14 communicates with the feed pump and mixer. The mixer prepares the fluid to be pumped and the feed pump pressurizes the intake manifold 14 and distributes said fluid mixture to the pressure transfer devices 1', 1'' (pressure spaces 4', 4''). The mixer usually mixes the pumped liquid with particles such as sand and proppants. Such a feed pump and mixer are known to those skilled in the art and will not be described in more detail in this application.

Similarly, for the system on the right side of the drawing, the flow control assembly 13 may include a pumping passage 36'' communicating with the first passage 5'' of the pressure transmission device 1'', an inlet 35'' communicating with the pumped liquid through the inlet manifold 14, and an outlet port 37'' in communication with the outlet manifold 15. In addition, to enable switching and operation with different inputs and outputs, the flow control assembly may include a supply valve 38'' containing a check valve that allows the supply of working fluid, when the pressure in the intake manifold 14 is greater than the pressure in the pressure chamber 4″, and an exhaust valve 39″ allowing fluid to be discharged into the exhaust manifold 15 when the pressure in the pressure chamber 4″ is higher than the pressure in the exhaust manifold 15 , for pumping fluids at high pressures and flow rates, for example, into a well.

The flow control unit 13 distributes the pumped liquid between the inlet manifold 14, the pressure chamber 4', 4'' and the outlet manifold 15 using two check valves, one for inlet and one for outlet, and an inlet/outlet channel located between them. An inlet valve 38', 38'' located between the inlet port 35', 35'' and the pump port 36', 36'' allows fluid to fill the head cavity 4', 4'' when the bellows 6', 6'' draw in, i.e. the liquid being pumped provides pressure from below, helping to retract/compress the bellows 6', 6''. Auxiliary fluid pressure in the pressure transfer device in the intake manifold 14, as a rule, is in the range of 3-10 bar when filling the pressure chamber 4', 4'' and preparing for the next portion of the high pressure fluid pumped into the well. When the bellows 6', 6'' begins to expand (i.e. pressurized fluid fills the internal volume 7', 7'' of the bellows 6', 6''), the inlet valve 38', 38'' closes as soon as the pressure reaches the supply pressure in the intake manifold 14, thereby causing the exhaust valve 39', 39'' to open, releasing the contents of the pressure chamber 4', 4'' through the exhaust passage 37', 37'' and into the exhaust manifold 15. This occurs sequentially, respectively, in the layout on the left side of the drawing and on the right side of the drawing.

The hydraulic pump unit 11 uses bi-directional axial piston pumps in a closed volume of a hydraulic circuit that is common in the art, also called swash plate axial piston pumps. Swashplate pumps contain a rotating set of cylinders containing pistons. The pistons are connected to the swashplate by means of a ball joint and pressed against a fixed swashplate which is angled to the cylinder. The pistons suck in fluid for half a turn and push fluid out for the other half. The greater the slope, the farther the pump pistons move and the more fluid they pump. Such pumps are variable in capacity and can switch between pressurizing the first inlet/outlet port 24' and the second inlet/outlet port 24'', thus directly driving the double acting pressurizing liquid distribution device(s) 2 .

The oil supply valve 16', 16'' is simplistically represented as a three-way valve. However, other arrangements may be used, such as a set of two or more valves. The oil supply valve is controlled by a control system that can determine if the correct volume of hydraulic fluid is circulating between the internal volume 7', 7'' of the bellows 6', 6'' and the first and second plunger chambers 17' 17'' using position sensors in the bellows and in the double acting pressurizing liquid distributor. At the same time, it allows the system to change the oil in this closed volume of the hydraulic circuit if the oil temperature reaches operating limits. This is done by isolating the second valve port 27', 27'' from the double-acting pressurizing fluid distributor and opening communication between the first valve port 26', 26'' and the third valve port 28', 28'', thereby allowing positioning of the piston 30 or the rod 19 of the double acting pressurizing fluid distribution device 2 depending on the position of the bellows 6', 6''. The control system operating the oil supply valves 16', 16'' monitors the position of the bellows 6', 6'' with respect to the position of the plunger 19 and adds or removes oil from the system when the system reaches the maximum deflection limit. This takes place preferably automatically by stopping the bellows 6', 6'' at a certain position and thus allowing the plunger 19 to return to the “bellows position”. The position of the plunger bellows 19 generally corresponds to a position where the volumes of the first plunger chamber 17' and the second plunger chamber 17'' are the same, which in most situations is the position where the bellows 6', 6'' is in the middle position. Thus, the plunger 19 is preferably positioned relative to the actual position of the bellows 6', 6''.

The double acting pressurizing liquid distribution device 2 can be controlled, for example, by controlling the flow from, for example, the hydraulic pump unit 11 through the first inlet/outlet port 24' and the second inlet/outlet port 24''. The protruding portion 30 comprises a first end (i.e., the first piston area 30'') in fluid communication with the first inlet/outlet port 24', and a second end (i.e., the first piston area 30'') in fluid communication with fluid medium with a second inlet/outlet channel 24''. The rod 19 further defines a second piston area 31', 31'' which is smaller than the first piston area 30', 30''. The rod 19 separating the first and second plunger chambers 17', 17'' is used to change the volumes of the first and second plunger chambers 17', 17'' by extending and retracting the rod 19 into/out of the first and second plunger chambers 17', 17' ', respectively. The stem 19 is partially hollow and includes a first recess 40' and a second recess 40''. The first and second recesses 40', 40'' are separated from each other. Thus, no fluid can flow between the first and second recesses 40', 40''. The first recess 40' is in fluid communication with the first plunger chamber 17', and the second recess 40'' is in fluid communication with the second plunger chamber 17''.

The function of the double acting pressurizing fluid distributor 2 is to ensure that a fixed volume of hydraulic fluid, such as oil, fills/outflows from the bellows 6', 6''. At the same time, it acts as a pressure booster (pressure booster or pressure booster). In the illustrated double acting pressurizing liquid distribution device 2, the pressure is increased by a larger first piston area 30', 30'' than the second piston area 3G in the first plunger chamber 17' and the second piston area 31'' in the second plunger chamber 17' ', respectively. The ratio between the first piston area 30', 30'' and the second piston area 31', 31'' is fixed and depends on how different the first and second piston areas are. Thus, the fixed pressure in the first or second outer chambers 44', 44'' provides a fixed pressure, amplified by the pressure difference between the first and second areas of the pistons. However, the inlet pressure can be changed to give different outlet pressures, but the ratio is fixed. The pressure buildup is important to allow fluids to be pumped well above the maximum normal pressure range in the industrial hydraulic pump units 11 that power the system and are adjusted to achieve the most suitable industrial pressures.

The double acting pressurizing liquid distribution device 2 may include a double acting pressurizing liquid distribution device position sensor 21 that continuously communicates with a common control system that can actuate oil supply valves 16', 16'' to replenish or drain hydraulic oil. fluid from the closed volume of the hydraulic circuit based on the input signal from the position sensor 21 of the double-acting pressurizing liquid distributor in the double-acting pressurizing liquid distributor 2, and the position sensor of the bellows 12', 12''. In the drawings, the double acting pressurizing liquid distributor position sensor 21 is located between the stem 19 and the inner walls of the first or second plunger chamber 17', 17'', so that the double acting pressurizing liquid distributor position sensor 21 is able to continuously monitor the position of the stem. 19 and transmit signals to the control system comparing the position of the bellows 6', 6'' and the piston or rod 19 in the double acting pressurizing fluid distribution device 2. However, the position sensor 21 of the double acting pressurizing liquid dispenser can be installed in other locations, including outside the double acting pressurizing liquid dispenser 2, as long as it can track the position of the stem 19. As such, any leakage or an overflow of hydraulic fluid in either of the first or second plunger chambers 17', 17'' can be detected and repaired (e.g., using an oil supply valve 16', 16'' to return the stem to the zero deflection position according to the position of the bellows , as described above).

In particular, the first and second plunger chambers 17', 17'' are subjected to extreme pressures. All transitions are shaped to avoid stress concentration. The stem 19 in the double acting pressurizing liquid dispenser is preferably a hollow stem to compensate for the inflation of the shell (shell = outer walls of the double acting pressurizing fluid dispenser 2) during the pressure cycle. Preferably, the inflation of the hollow rod is slightly less than that of the shell, to prevent any extrusion gap between the hollow rod and the shell from being exceeded. If this gap is too large, then leakage occurs through the first and second seals 22', 22'', resulting in unequal volumes of hydraulic fluids in the first and second plunger chambers 17', 17''. The thickness of the shell and walls of the hollow rod, i.e. the walls surrounding the first and second recesses 40', 40'' are chosen so that they deform similarly/equally in the radial direction and that the first and second seals 22', 22'' are protected, which ensures a long service life of the first and second seals 22', 22''.

The control system has three main functions. The first main function of the control system is to control the output characteristics of the pressure transfer device 1', 1'': the pressure transfer device 1', 1'' is capable of providing flow based on a number of parameters such as: flow, pressure, power, or combinations thereof. In addition, if two double-acting pressurizing liquid distribution devices 2 are used, the pressure transfer device 1', 1'' can deliver a pulsation-free flow of up to 50% of the maximum theoretical flow by operating the two double-acting pressurizing liquid distribution devices 2 overlapping, so that one of them works instead of the other (smoothly increasing to double speed) when the other reaches the point of change of direction. In this way, a low flow rate is achieved at high pressures and a high flow rate at reduced pressure, in all embodiments with substantially laminar flow. This is achieved due to the excess performance of the hydraulic pump unit 11. As the flow rate increases, the possibility of overlapping operation decreases, therefore, the number of pulsations increases. The variable displacement hydraulic pump unit 11, in combination with the pressure sensors and the bellows position sensor 12', 12'' and the dual acting pressurizing liquid distributor position sensor 21, are key to the flexibility of the system. The control system, which may be computer-based, further enables the use of a plurality of parallel pumping systems acting as one by connecting them via a field bus. This can be done by arranging the pumping systems in parallel and using the control system to operate the individual pumping systems asynchronously. This minimizes the risk of yaw oscillations due to interference.

The second main function of the control system is to provide full control of the movement of the bellows 6', 6'' in all cycles with respect to the double acting pressurizing fluid distribution device 2 . This is relevant when closing/setting the valves in the flow control assembly 13 (for example, in the inlet 35', 35'', the pump 36', 36'', the outlet 37', 37'', the inlet valve 38', 38' ', outlet valve 39', 39'') because there is a combination of factors that must be present in synchrony for this system to function with such extreme pressures and flows. As far as the spring is concerned, it is important for the 6', 6'' bellows to work within design parameters, i.e. not to stretch or compress excessively to increase life.

The third main function of the control system is associated with the valve 16', 16'' of the oil supply system of the control system, which operates when the control system determines the difference between the positions of the double-acting liquid distribution device 2 and the bellows 6', 6'', or determines that the temperature is outside the specified limits. The double acting pressurizing fluid distribution device 2 has generally the same advantages and disadvantages as a hydraulic cylinder, it is reliable and accurate, but it has some degree of internal leakage at the first and second seals 22', 22'', which accumulates over time as an addition or decrease factor in the closed volume of the hydraulic circuit between the first and second plunger chambers 17', 17'' and the internal volume 7', 7'' of the bellows 6', 6''. To solve these problems, both the bellows 6', 6'' and the double-acting pressurizing liquid distributor 2 are equipped with position sensors 12', 12'', 21, which continuously monitor the position of these units in order to ensure their synchronization. in accordance with the established management program. Over time, the internal leakage of the system accumulates, and when the position deviation between the bellows 6', 6'' and the double-acting pressurizing liquid distribution device 2 reaches the maximum allowable limit, the first and/or second valves 16', 16'' of the oil supply system add or select the required volume to return the system to synchronization (and control, preferably automatically, in relation to the known position of the bellows 6', 6''). In addition, there may be a problem that the liquid in the closed volume of the hydraulic circuit between the pressure transfer device 1', 1'' and the double acting pressurizing liquid distribution device 2 generates heat by friction when flowing back and forth. In addition, the first and second seals 22'', 22'' in the double acting pressurizing liquid distribution device 2 also generate heat, which is dissipated in the liquid (eg oil) in the closed volume of the hydraulic circuit. This problem can be solved using the same system as for internal leakage compensation. The hydraulic volume of the closed circuit can be replaced by a valve 16', 16'' of the oil supply system.

Thus, at least one of the objects of the invention is achieved in the invention as disclosed in the drawings, i. the pressure transfer device and the fracturing system can operate at high pressures with high volume flow.

In the foregoing description, various aspects of the invention are disclosed with reference to illustrative embodiments of the invention. For purposes of explanation, systems and configurations have been outlined that provide a complete understanding of the system and its operation. However, this description is not to be taken in a limiting sense. Various modifications and variations of the illustrative embodiments, as well as other embodiments of the system that are obvious to those skilled in the art to which the disclosed subject matter pertains, are considered to be within the scope of the present invention.

List of reference designations

Claims (23)

1. A system for pumping large volumes of fluids with particles at high pressures, comprising: device (2) distribution of liquid with increasing pressure of double action; a pressure transmission device (1', 1'') for pumping a fluid medium with particles at a pressure above 500 bar (50 MPa), comprising a pressure chamber body and at least one connecting channel (3', 3''), wherein at least at least one connecting channel (3', 3'') is connected by fluid connection means (26', 27'; 26'', 27'') to a double-acting pressurizing liquid distribution device (2), wherein the housing pressure chamber contains: - a pressure cavity (4', 4'') inside the pressure chamber body and at least a first channel (5', 5'') for inlet and/or discharge of fluid into the pressure cavity (4', 4''), - bellows (6', 6''), which defines the internal volume (7', 7'') inside the pressure cavity (4', 4''), and the internal volume (7', 7'') of the bellows is part of the volume of the closed hydraulic circuit with a double-acting pressurizing liquid distribution device (2) and is in fluid communication with the connecting channel (3', 3'') so that the control fluid in the form of pressurized hydraulic fluid from the liquid distribution device (2) with increasing double-acting pressure, it can enter and leave the internal volume (7', 7'') of the bellows (6', 6''), moreover, the pressure cavity (4', 4'') has a central axis with an axial length (L'; L'') determined by the distance between the connecting channel (3', 3'') and the first channel (5', 5'') , wherein the bellows (6', 6'') is movable in a direction parallel to the central axis (C, C'') on part of the axial length (L', L'') of the head cavity (4', 4'') . 2. System according to claim. 1, in which the cross-sectional area of the pressure cavity (4', 4'') varies over at least part of the axial length (L', L''). 3. The system according to claim 1 or 2, in which the bellows (6', 6'') are rigid in the radial direction and flexible in the axial direction, so that any movement of the bellows (6', 6'') is possible in its axial direction. 4. The system according to any one of paragraphs. 1, 2 or 3, in which the pressure cavity (4', 4'') tapers towards the first channel (5', 5''). 5. The system according to any one of the preceding claims, wherein the bellows (6', 6'') has a smaller radial and axial extension than the inner surface of the pressure chamber housing (4', 4''), which ensures the formation of a gap (8', 8'') between the outer circumference of the bellows (6', 6'') and the inner circumference of the pressure cavity (4', 4'') in all operating positions of the bellows (6', 6''). 6. System according to any one of the preceding claims, wherein the first channel (5', 5'') is located in the lower part of the pressure cavity (4', 4''). 7. A system according to any one of the preceding claims, wherein the pressure cavity (4', 4'') is ovoid, elliptical, round, spherical, spherical or oval in shape. 8. System according to any one of the preceding claims, in which the bellows (6', 6'') has a shape adapted to the shape of the pressure cavity (4', 4'') so that in all operating positions the bellows is prevented from contacting the inner surface pressure chamber body. 9. The system of claim. 7, in which the bellows (6', 6'') has a cylindrical shape, the shape of an accordion, or the shape of a concertina. 10. System according to any one of the preceding claims, wherein the bellows (6', 6'') comprises a guide system (9', 9'') comprising a guide (9', 9''), wherein the guide (9', 9 '') is connected to the lower part of the bellows (6', 6'') and made with the possibility of its direction in the body of the pressure chamber, forming part of the connecting channel (3', 3''), and the guide (9', 9'') coincides with or parallel to the central axis (C, C'') of the pressure cavity (4', 4''), and the bellows (6', 6'') is made with the possibility of stretching and retracting in the axial longitudinal direction along the central axis (C, C ''), and the pressure transmission device further comprises a sensor (12', 12'') of the position of the bellows (6', 6''), configured to track the position of the bellows (6', 6''). 11. The system according to any one of the preceding claims, further comprising: - a hydraulic pumping unit (11) configured to pressurize and actuate the liquid distribution device (2) with double-acting pressurization, - a flow control unit (13) configured to distribute the fluid between the inlet manifold (14), the pressure chamber (4', 4'') and the outlet manifold (15). 12. The system of claim. 11, further comprising a control system for controlling the operating range of the pump bellows (6', 6'') and configured to decide whether the bellows operates within a predetermined operating range of bellows positions determined by maximum restrictions, such as a maximum retract position and a maximum extension position of the bellows, wherein the control system is configured to determine whether the volume of hydraulic fluid is outside a predetermined operating range of bellows positions or not, and/or monitor the positions of the bellows and the dual acting pressurizing fluid distribution device and compare with specified operating range of bellows positions. 13. The system according to claim. 11 or 12, further comprising a supply pump for supplying a fluid medium with particles into the pressure cavity, and the system contains two pressure transmission devices (1', 1''), and the liquid distribution device (2) with increasing pressure double-acting is made with the possibility of sequential increase in pressure and release / decrease in pressure using a supply pump in two devices (1', 1'') of pressure transmission due to the operation of a hydraulic pump unit (11), so that pressure increase and release in one device ( 1', 1'') pressure transfers are possible during depressurization and venting in another pressure transfer device (1', 1'') and vice versa. 14. Kit for pumping large volumes of fluids with particles at high pressures, containing at least two trailers, each of the trailers contains at least one system according to any one of the preceding paragraphs. 11, 12 or 13. 15. The use of the system according to any one of paragraphs. 1-13 in any of the following operations: hydrocarbon production or production, fracturing operations, plugging and shut-in, well drilling, completion or stimulation, cementing, acidizing, nitrogen circulation. 16. Use of the kit of claim 14 in any of the following operations: hydrocarbon production or production, fracturing operations, plugging and shut-in, well drilling, completion or stimulation, cementing, acidizing, nitrogen circulation.

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