Dual screen system for connection with screening machine (versions)

Technical field

The invention relates to an improved vibration screening system for the separation of solids and liquids and, in particular, to the separation of cuttings from the drilling fluid. In various embodiments, dvuhsitnye systems are described for attachment for the purpose of upgrading to existing single-deck vibrating screens.

<b>The level of technology</b>

Screening machines for many years used in various industries, including mining and oil, for the separation of solids and liquids. In these industries, when drilling and mining minerals, there are often suspensions of solids and liquids that must be separated from each other. As is well known, the screening machine, as a rule, includes a bed of sieves, over which a solution containing liquids and solids is applied, and then subjected to various separating forces, including gravity and shaking. Each screening separator will use different types and sizes of sieves to allow the separation of different liquids / solids. In addition to this,

Depending on the industry, the sieved solutions from the liquid / solid matter and the commercial purposes of the screening systems, there are different designs of screening machines. If we consider different machines, each machine is endowed with certain functions for use in a particular industry or with specific solids / liquid solutions. The nuances of each main type of solid / liquid solution and each machine generally imply that one type of machine will not be efficient or effective in another industry, since in many cases specific problems occur when working with specific types of materials or solutions . For example, many screening machine designs are designed to optimize the extraction of solid materials from a slurry, however, this format leads to ignoring the quality of the extracted fluid. In fact, in general, it was not considered how to separate the solids and liquids while maintaining or improving the quality of the extracted liquid.

In the specific case of the separation of drilling fluid from drill cuttings at the well site, in recent years the applicant has efficiently introduced vacuum systems to separate the washing fluid from the drill cutting. As described in the applications of the author of the present invention being simultaneously considered and included there by their mention (PCT / CA2009 / 001555, registered on October 29, 2009, PCT / CA2010 / 00501, registered on March 31, 2010 and PCT / CA2011 / 000542, registered on May 11, 2011) , the use of the effect of the vacuum force on the screening system, with its correct application, can be extremely effective in restoring the washing fluid retained in the cuttings, in order to increase the amount of the washed washing fluid,

In addition, the efficiency of screening systems is important from the point of view of minimizing the costs of managing solids in a well. For example, in most drilling units for the simultaneous processing of cuttings coming from the unit, several screening systems are installed. As a common practice, as a rule, there are two or more screens (often 3 or more and, possibly, up to 9 screens) for a drilling unit located near the blowout preventer (BOR, BlowOut Preventer). As the flushing fluid and drill cuttings leave the wellhead, they are transported to the screens, through the channels to the supply tank of each of the screens. Transported drilling mud and flushing fluid are usually divided into separate flows at the wellhead,

As can be understood, the total number of screens that can be used at the well site will have a significant impact on the overall costs of the solids program. That is, the cost of working with solids can be reduced if fewer screens are required.

In addition, in a typical scenario, screening systems can be installed in series, with a large-mesh screen used in the screen located upstream, and a screen with a finer cell can be used in the screen located downstream. It will be understood that the coarse sieve will allow relatively smaller particles of solid matter and washing liquid to pass through it, and a sieve with a smaller cell will allow the washing liquid to pass through it while simultaneously retaining smaller particles on the upper surface of the sieve.

In general, a balance must be maintained between the mesh size of the sieves and the required processing speed. For example, a combination of coarse and coarse sieves is typically used to maintain effective flow rate in the screen, with the result that sufficient volumes of fluid are extracted in a specific period of time. That is, if an overly fine sieve is used, the efficiency of the time required to process the volume of cuttings and flushing fluid becomes unsatisfactory, and / or the separation of the cuttings and flushing fluid may stop due to clogging and / or clogging of the sieve. In this case, if too coarse sieve is used, the efficiency of separation of the liquid / rock is reduced, as due to solid contamination the quality of the extracted washing liquid is reduced.

In the past, various sieves and screening systems have been developed to increase separation efficiency, including three-dimensional screen designs and screening systems. For example, US Pat. No. 6,032,806 describes a “pyramid-like” screen, which has a three-dimensional geometry to increase its surface area. Other screening systems have been developed, which include separate decks for separating solids in different vertical positions within the screen. However, these latter systems remain ineffective in several aspects. For example, two-deck screens are more expensive to manufacture, since for each deck level separate deck systems and fastening systems are required, for example, clamps, wedges or hooks. In addition to this, these systems are often significantly higher than the conventional single-level screen.

There are several different fastening systems that are commonly used to fix the sieve system in a rumble, namely, in the rumble cassette. One such anchoring system is a wedge-based system. The wedge-based system typically contains compression wedges that are located on the sides of the screen cassette, each wedge being inserted into a guide above the position where the screen is located in order to fix the screen in place in the cassette. The compression wedge is typically about 1 inch (25.4 mm) wide and about 12-18 inches long (304.8–457.2 mm), and two wedges are usually used per sieve.

An alternative fastening system is a clamping system using plates, which generally contains plates or strips located on the sides of the screen cassette, which are compressed together using air or hydraulic pressure to clamp the edge of the screen between the plates / strips. Plates or slats are typically about 1 to 1½ inches wide (25.4 to 38.1 mm) wide.

The third type of attachment system is a hook-based system that pulls the edges of the screen to the sides of the screen cassette to create tension in the screen. This is usually done using cravings that can be attached to the side of the sieve with a hook. A force is applied to the thrust through the hole located in the side of the screen cartridge, which pulls the sieve outward, creating tension in it. As a rule, the force applied by the spring is created by a spring, however in some designs the spring is replaced by a bolt and screw knot, which is adjusted to obtain a predetermined tightening torque, or by an air or hydraulic plunger assembly. In the case of a sieve attachment system with hooks, the sieve can be pulled on a flat surface or on a curved surface, for example, a convex surface. Pyramid-screened sieves are often attached to the screens using hooks. An example of a sieve attachment system using hooks is described in US Pat. No. 6,179,128.

A problem associated with known crashes is the effect of both large and small particles on the sieve. That is, larger particles tend to bump into a sieve with greater force due to the kinetic energy of the particle. Fine meshed sieves with thinner and less durable wire may become unusable more quickly as a result of the stress on larger particles. Thus, a multilayer sieve system with an upper sieve with a larger cell and a lower sieve with a smaller cell has the advantage of protecting the lower sieve from larger particles and potentially damaging, since these particles will move over the upper sieve and will not pass through this sieve to emphasize the fine mesh sieve below.

Another problem is that it is important to ensure that the flow of cuttings and flushing fluid over the screen does not adversely affect the multi-layer screen system, so that it will affect the screen / screen performance. In particular, it is important that the gap between the lower sieve and the upper sieve does not become clogged if the flow of drilling fluid / cuttings through the gap increases due to the volume of material in the rumble.

As a result, there remains a need for systems that increase the efficiency of screening systems to make possible the consistent separation of solids with larger particles and solids with smaller particles. In addition to this, there is also a need for systems that can be used to upgrade existing screening systems, including existing screening systems, to effectively convert single-deck systems into two-deck screening systems.

<b>Summary of Invention</b>

According to the invention, a two-system system is proposed for connection with a vibrating screen for the purpose of modernization.

In one embodiment of the present invention, the two-screen system comprises an upper sieve assembly having a non-rigid connection to the lower sieve assembly, creating a channel between the upper sieve assemblies and the lower sieve assembly, each sieve assembly having a frame and a sieve mesh attached to the frame. with a larger cell than the lower sieve, and the two-sieve system is adapted for a non-rigid connection with a vibrating screen.

In the following embodiment, the top sieve assembly is configured to be detached from the lower sieve assembly. The upper sieve frame may include a plurality of supports for attaching to the plurality of respective supports on the lower sieve frame, and said plurality of supports on the upper and lower sieve frames may be assembled together.

In another embodiment, the dual-screen system further comprises a separate connector assembly located between the nodes of the upper and lower sieves to connect the frame of the upper sieve with the frame of the lower sieve, with the connector assembly creating a channel. In one embodiment, the connector assembly comprises a frame supported by a plurality of supports, this frame being intended for non-rigid connection with the frames of the upper and lower screens. The connector assembly may further comprise a first set of pins protruding from the top of the frame for insertion into the holes in the bottom of the frame of the upper sieve; and a second set of pins protruding from the bottom of the supports for insertion into the holes above the frame of the lower sieve.

In yet another embodiment, the connector assembly comprises a plurality of rods extending parallel to the frames of the nodes of the upper and lower sieves. The plurality of rods may have a first plurality of pins protruding from the top of the rods for insertion into the openings of the bottom frame of the upper sieve; and a second set of pins protruding from the bottom of the rods, for insertion into the holes above the frame of the lower sieve. Alternatively, to ensure that the upper and lower sieve assemblies do not slip, rubber gaskets and / or high-pressure clamping systems can be used.

In one embodiment, the side edges of the frame of the upper sieve are offset relative to the side edges of the frame of the lower sieve. In a further embodiment, the upper sieve frame includes a protrusion extending along one edge of a two-sieve system for directing flow along the edge of a two-sieve assembly.

In another embodiment, the frame of the upper and / or lower sieves are made in the form of a wedge. A channel created by wedge-shaped frames can have essentially constant height.

In the following embodiment, a plurality of two-sieve systems are arranged in a vibrating screen in order to create a continuous flow path through the channels of this set of two-sourced systems from the end upstream along the process to the end downstream. The plurality of two-sieve systems can be located in a vibrating screen in a stepwise manner, with the edge of the upper sieve nodes located higher along the process, shifted relative to the edge of the lower sieve nodes located higher along the process, to increase the flow path between adjacent nodes sieve

In one embodiment, in which the frames of the upper and / or lower screens are made in the form of a wedge, they can be arranged in a vibrating screen in a stepwise manner to create a continuous flow path through the channels. The continuous flow path may be a cascade flow path.

In yet another embodiment, the mesh of the upper sieve is 325 mesh or less, and the mesh of the lower sieve is larger than 30 mesh.

In the following embodiment, the channel has a height of 3 inches (76.2 mm) or less and preferably 2 inches (50.8 mm) or less.

In one embodiment, a two-screen system is designed to be connected for the purpose of upgrading with a roar having an already existing flat bed of a sieve. In this system, two-screen systems of the above-mentioned set of two-screen systems are of such a size in height to obtain a cascade effect between two-second systems.

In another embodiment of the present invention, the dvuhsitnaya system is made with the possibility of fixing on the basis of the vibrating screen using the existing clamping system with wedges at the base of the screen. The dual-system system may include a mounting bracket on each side, the mounting brackets are designed for clamping using wedges of the clamping system using wedges. The two-system system can be made of such dimensions that in order to fix it on the basis of the screen, it is possible to use the existing wedges of the fastening system with clamping using wedges, without modifying this system. The width of at least one of the nodes of the upper or lower sieve is less than the width of the mounting brackets.

In one embodiment of the present invention, the dvuhsitnaya system is made with the possibility of fixation on the basis of the vibrating screen using the existing clamping system using hydraulic or air pressure, located on the basis of the screen.

In another embodiment, the dual-system system is capable of fixing on the basis of a vibrating screen using an existing fastening system using hooks located on the base of the screen. The hook fastening system can be modified to include the upper and lower hooks, and each of the upper and lower sieve assemblies includes a corresponding hook for attaching to the upper and lower hooks, respectively. At the nodes of the upper and lower sieves, tension can be created using a single tensioner attachment device.

In the following embodiment, the upper and lower sieves are pyramidal sieves.

According to another aspect, the invention proposes a two-screen system for connecting to upgrade with a screen providing support for at least two stepped screens in the form of corresponding support brackets in the screen cassette, the two-screen system comprising: a bottom screen support having dimensions suitable for embeddings between the support arms and below them, with the support of the lower sieve supporting the first lower sieve; the top screen support, loosely connected to the bottom screen support, the top screen support having dimensions suitable for embedding above the support arms, and the top screen support supporting the first top screen; the lower sieve support and the upper sieve support create a pair of twin sieve supports, and the two-sieve system includes a pair of double sieve supports for each stage of the screen.

In one embodiment, adjacent pairs of twin sieve supports are bonded together.

In another embodiment, the screen surfaces are attached to the bottom screen support and the top screen support for each pair of double screen supports.

In one embodiment, each surface of the sieve includes a protrusion located downstream, which is of such dimensions that it overlaps with the edge of the adjacent screen located above along the process, located downstream of the process.

In one embodiment, the coarse sieve is attached to each support of the upper sieve, and the fine-mesh sieve is attached to each support of the lower sieve.

<b>Brief Description of the Drawings</b>

The invention has been described with reference to the accompanying drawings, of which:

FIG. 1 is a front view of a two-system system in accordance with one embodiment of the present invention; FIG.

FIG. 2A is a top view of a top sieve assembly having grooved couplings in accordance with one embodiment of the present invention; FIG.

FIG. 2B is a front view of the top sieve assembly having the connecting elements with grooves according to the first embodiment of the present invention; FIG.

FIG. 2C is a side view of a top sieve assembly having grooved couplings in accordance with a first embodiment of the present invention; FIG.

FIG. 3A is a top view of the bottom sieve assembly having the connecting members according to the first embodiment of the present invention; FIG.

Fig. 3B is a front view of the lower sieve assembly having the connecting members according to the first embodiment of the present invention;

Fig. 3C is a side view of the lower sieve assembly having the connecting members according to the first embodiment of the present invention;

figure 4 shows a side view of the nodes of the upper and lower sieves connected by sliding the connecting elements of these nodes relative to each other, according to the first embodiment of the present invention;

Fig. 5A is a front view of a two-sieve system having an upper sieve assembly, a lower sieve assembly and a central separator, in accordance with a second embodiment of the present invention;

Fig. 5B is a front view of a two-sieve system having an upper sieve assembly with shortened edges, a lower sieve assembly and a central separator, according to a third embodiment of the present invention. The shortened edges allow the clamping mechanism to work with wedges or hydraulic / air pressure, while at the same time allowing to increase the clearance behind the upper sieve, which can occur if the upper sieve has a clamping surface located at the same height as the top of the sieve;

Fig. 5C is a front view of a two-sieve system having an upper sieve assembly, a lower sieve assembly and a core joint system, in accordance with a fourth embodiment of the present invention;

6A is a top view of the top sieve assembly according to one embodiment of the present invention;

Figure 6B is a bottom view of the top sieve assembly according to one embodiment of the present invention;

FIG. 6C is a front view of the top sieve assembly according to one embodiment of the present invention;

FIG. 7A is a top view of the bottom sieve assembly according to one embodiment of the present invention; FIG.

Fig. 7B is a bottom view of the bottom sieve assembly, in accordance with one embodiment of the present invention;

FIG. 7C is a front view of the bottom sieve assembly according to one embodiment of the present invention;

8A shows a top view of a central separator according to the second and third embodiments of the present invention;

Fig. 8B is a bottom view of the central separator according to the second and third embodiments of the present invention;

Fig. 8C is a front view of a central separator according to the second and third embodiments of the present invention;

FIG. 9A is a top view of a core joint system according to a fourth embodiment of the present invention; FIG.

Fig. 9B is a bottom view of a rod-like connecting system, according to a fourth embodiment of the present invention;

FIG. 9C is a front view of a rod joint system according to a fourth embodiment of the present invention; FIG.

figure 10 shows a General front view of a two-system, according to one implementation variant of the present invention;

figure 11 shows a general front view of a partially assembled two-site system, according to one embodiment of the present invention;

Figure 12 shows a frontal section of a known screen, upgraded using four dual-sieve systems, in accordance with one embodiment of the present invention;

FIG. 13 shows a frontal section of a second known screen upgraded using four dual-sieve systems, in accordance with one embodiment of the present invention; FIG.

FIG. 14 is a general top view of a wedge-shaped sieve assembly according to one embodiment of the present invention; FIG.

Figure 15A shows a schematic side view of a known screen with a base in a neutral position, upgraded using four flat two-sieve systems, in accordance with one embodiment of the present invention;

Figure 15B is a schematic side view of a known screen in an upward tilting position, upgraded using four flat two-sieve systems, in accordance with one embodiment of the present invention;

Fig. 15C is a schematic side view of a known screen in a downward sloping position, upgraded using four dual-sieve systems, in accordance with one embodiment of the present invention;

16A is a schematic side view of a known screen with a base in a neutral position, upgraded using a combination of flat and wedge-shaped two-sieve systems, according to one embodiment of the present invention;

Figure 16B is a schematic side view of a known screen with a base in an upward tilt position, upgraded using a combination of flat and wedge-shaped double-sieve systems, in accordance with one embodiment of the present invention;

FIG. 16C is a schematic side view of a known screen with a base in a tilt down position, upgraded using a combination of flat and wedge-shaped double-sieve systems, in accordance with one embodiment of the present invention;

Figure 17 is a front view of the base and sieve of a vibrating screen, illustrating the harmonics of the vibration of the edges of the screen compared to the center of the screen, according to one embodiment of the present invention;

FIG. 18 shows a general view of a sieve support system for use in a step screen upgrade, in accordance with one embodiment of the present invention; FIG.

FIG. 18A is an exploded perspective view of a support screen system for use in a step screen upgrade, illustrating a bottom screen support system, a top screen support screen and a screen according to one embodiment of the present invention;

Fig. 18B is a schematic sectional view of a dual sieve support system with a lower sieve support located below the existing sieve support cassettes, according to one embodiment of the present invention;

Fig. 18C shows a schematic cross-section of two adjacent sieves in a stepped sieve system, illustrating the possible flow of material from the lower sieve to the upper sieve, according to one embodiment of the present invention;

Figure 18D shows a schematic cross-section of two adjacent double-sieve nodes in a stepped screen system, illustrating the possible flow of material from the bottom screen to the top screen only, according to one embodiment of the present invention;

FIG. 18E shows a schematic sectional view of two adjacent double-sieve units in a stepped screen system in which the upper screen, located downstream, is offset from the bottom screen, downstream, according to one embodiment of the present invention;

Figure 19A shows an end view of a dual-screen support system adapted for use on the basis of a screen having a clamping system using wedges, in accordance with one embodiment of the present invention;

Figure 19B is an end view of a dual sieve support system adapted for use on the basis of a screen having a clamping system using wedges, in accordance with one embodiment of the present invention;

FIG. 20 is an end view of a dual sieve support system adapted for use on the basis of a screen having an air or hydraulic clamping system using air or hydraulic pressure, in accordance with one embodiment of the present invention;

FIG. 21 is an end view of the screening attachment system using hooks for attaching a single screen to the screen base according to the prior art; FIG.

FIG. 22 is an end view of a dual sieve support system adapted for use on the basis of a screen having a sieve attachment system using hooks, in accordance with one embodiment of the present invention.

Detailed description of preferred embodiments

With reference to the drawings, a two-screen system 10 is described for attachment to an existing vibrating screen.

Two-system

Referring to FIGS. 1 to 3C, the dual-sieve system 10 comprises an upper sieve unit 12 having a coarse mesh that is installed on top of the lower sieve unit 14 having a fine-meshed mesh, where a channel 16 is present between the upper and lower sieves. installing into an existing screen, it upgrades this screen, initially made with the possibility of installing only a single-level screen and having a screen, to which the two-screen system 10 is attached by means of wedges, hydraulic clamps or devices stringing sieves using hooks. The suspension from the extracted washing fluid and cuttings is fed from the wellbore to the upper sieve, with larger particles trapped by the coarse upper sieve, while smaller particles and the washing liquid enter the channel 16 and the lower sieve. The fine mesh of the lower sieve then separates the suspension, trapping the small and medium particles on the lower sieve, and the washing liquid flows through the lower sieve for recovery and reuse. In one embodiment, the mesh size of the upper sieve is 200 mesh or less (typically, about 38-200 mesh), while the size in the lower sieve exceeds 200 mesh. In the preferred case, the bottom sieve is 50 to 100 mesh larger than the top sieve, which will typically be in the range of 200 to 325 and possibly up to 400 mesh. In the preferred case, a larger mesh screen located at the top is strategically selected to remove larger cuttings, in which the speed at the moment of impact due to the high accelerating forces of the screen cassette can cause damage to the wire, which is typically used in smaller mesh screens (i.e., with a higher sieve number). In other words, the goal is to remove as much of the coarse material as possible on the upper deck while simultaneously allowing the finer material to pass through the coarse sieve to extract on the lower deck.

The channel 16 between the upper and lower sieves has a height sufficient to allow the flow of the cuttings to flow through the upper sieve and the lower sieve, but is also maintained at a minimum size in order to obtain a two-sieve system having a small gap to be embedded in an existing screen designed to install a single sieve In one embodiment, the channel 16 has a height of approximately ½ - 2 inches (12.7 - 50.8 mm). However, the height may be greater if the method of fastening the system does not conflict with existing sieve clamping systems.

Each screen assembly typically has a frame 12a, 14a, having transverse elements 12b, 14b and a screen mesh 12c, 14c, supported by the top of the frame and transverse elements. Figures 2 and 3 show one longitudinal element extending along the length and three transverse elements extending across the width; however, in order to support the sieve, other configurations of the longitudinal and transverse elements can be used, which do not necessarily depend on the frame size. Figure 10 illustrates a two-sieve system 10 having one transverse element on each of the upper and lower sieves.

Connectors in a two-system system

The nodes of the upper and lower sieves can be a single structure or can be two separate sieve assemblies that are loosely connected to each other. In one embodiment, shown in FIGS. 1 to 4, the nodes of the upper and lower screens are assembled using a plurality of connecting elements 30a, 30b attached to the frame 12a, 14a, and supporting elements 12b, 14b. The connecting elements 30a of the upper sieve extend from the bottom of the frame of the upper sieve and the supporting elements, and each of them has a groove 30c. The connecting elements 30b of the lower sieve extend from the top of the frame of the lower sieve and loosely interface with the groove 30c of the connecting elements of the upper sieve. 4 illustrates how the connecting elements of the upper and lower sieves are connected by sliding the connecting elements towards each other,

Connector system based on a central separator for dual sieves

FIG. 5A illustrates an alternate version of a two-sieve system 10, providing a front view of the top sieve assembly 12 and the bottom sieve assembly 14 connected by a central separator 50. The top view, the bottom view and the front view, respectively, of the assembly are shown in FIGS. 6A, 6B and 6C. 12 of the upper sieve in this embodiment, while FIGS. 7A, 7B and 7C show the top view, the bottom view and the front view, respectively, of the bottom sieve assembly 14. Figures 8A, 8B and 8C additionally show the top view, the bottom view and the front view, respectively, of the central separator 50. The central separator 50 connects the nodes of the upper and lower screens and provides channel 16 between the screens. The central separator 50 has a separator frame 50a, the position of which is coordinated with the position of the frames 12a, 14a and the transverse elements 12b, 14b of the nodes of the upper and lower screens and which is connected to them.

Alternate top sieve with lower wedge guides

FIG. 5B illustrates an alternate version of a two-sieve system 10 in which the side edges 12e on the upper side of the upper sieve frame 12a are offset from the central separator 50 and the lower sieve frame 14a. This facilitates the incorporation of the dual-sieve system 10 into the existing screen and allows it to be aligned with the position of the guides for the wedges on the screen, as discussed in more detail below.

Double Bar Sieve System

Fig. 5C is a side view of a two-sieve system, showing the following variant of connecting the upper sieve unit 12 and the lower sieve unit 14 using rod connectors 60. The rod connectors are additionally shown in Figs. 9A, 9B and 9C, which show a top view, bottom view and front view, respectively. The position of the rod connectors is consistent with the position of at least some of the transverse elements 12b, 14b and at least part of the frames 12a, 14a sieves. Unlike the central separator 50 shown in FIGS. 8A, 8B and 8C, this connection method, in which the rod connectors 60 are used, does not have a separator frame. Instead, the rod connectors 60 are individually attached to the transverse elements and the frames of the upper and lower sieves to connect the two sieves.

FIG. 10 shows a general view of a two-sieve system connected using rod connectors 60. FIG. 11 shows an alternative version of a two-sieve system having rod connectors 60 with connecting elements 62, which can be joined with receiving connecting elements 30 of the lower sieve and connecting elements of the upper sieve (not shown).

To prevent relative sliding of the upper and lower sieve assemblies, when they consist of two parts, a rubber element can be installed between the upper and lower sieve assemblies, which, in combination with pressure from the fastening system (for example, the fastening system using wedges or clamping), supports the upper and the bottom screen in proper orientation relative to each other.

Other methods of joining the upper and lower sieves can be used, as is known to the person skilled in the art, including bolting, welding, rivetting or gluing.

Modernization

Dual-system 10 can be adapted to work in existing screens without any significant modifications needed for the screen. Certain screens may not require modification, while other screens may require repositioning of the mounting system, such as wedge guides, hydraulic equipment or hooks, which fix the sieve system in place in the screen cassette, and / or add a blocking plate on the screen end face. to accommodate a system of greater height, as discussed below.

Fig. 12 illustrates a typical known screen 20 having an inlet end 20a, where a slurry of drilling and rinsing fluid enters the screen, and an outlet end 20b, where separated drilled rock and flushing liquid come out of the screen. The screen also includes a number of boxes 24 of the screen, in this case four, supporting individual screens of the screen, according to the prior art, and a screen 27 of screen for placing inside the boxes and screen of the screen and sending them vibratory movement. The fastening system is depicted as wedge guides 26, which fix the sieves on the beds 24 of the screen. When the slurry containing rock enters from the inlet end 20a of the screen, it usually falls on the contact plate 39, which absorbs the impact and directs the suspension to the top of the first screen located near the inlet end of the screen.

According to the invention, the known screen 20 is upgraded using a series of two-sec systems 10, each screen system having an inlet end 10a and an outlet end 10b and connected to the boxes 24 of the screen by means of wedge guides 26. In this embodiment, each top sieve assembly 12 includes a protrusion 18 at an outlet end for directing the flow of cuttings and flushing fluid from the outlet end to the upper surface 12f of the inlet end of the adjacent upper sieve assembly. The protrusion prevents the flow of drill cuttings and flushing fluid into the gap 28 between the double-sieve systems, or into the channel 16 between the upper sieve unit 12 and the lower sieve unit 14. The protrusion 18 on the upper sieve 12 is also shown in FIGS. 6A and 6B.

If the two-sieve system 10 is installed in an existing screen, and the top surface 12f of the first top sieve 12g is located above the existing contact plate 39, then as a upgrade, a blocking plate 38 or similar device is installed above the contact plate to prevent such a situation. a stream containing rock onto the upper surface 12f of the upper sieve in the first two-sieve system. This ensures that large particles will not come into contact with the first lower sieve.

A further variant of the known screen 20, upgraded using the dual-sec systems of the present invention, is depicted in FIG.

Advantages of a two-bit system

The two-sieve system is preferably modular, which allows the top and / or bottom sieves to be replaced, based on the properties of the treated slurry, in order to optimize the separation of the cuttings from the washing liquid. This allows the operator to select the optimal mesh size, screen material, configuration, and inclination angle for both the top screen assembly and the bottom screen assembly. It also makes it possible for the operator to easily restore and / or replace the components of the top screen assembly or the bottom screen assembly without the need to replace the entire two-screen system if the screen assemblies are not permanently bonded into one unit. It is important that it allows you to replace only the necessary components of the sieve due to uneven wear of the nodes of the upper and lower sieves in a two-sieve system.

In the prior art, a sequence of screens is often used to gradually separate the washing liquid from the cuttings as the suspension passes through this sequence. When replacing a single screen in a screen with a two-screen system in accordance with the present invention, the two-screen system is potentially capable of processing double the volume of suspension during the same time, essentially with the same energy consumption requirements as the one-screen system. This reduces the number of screens required and reduces the associated requirements in time, cost, and space. Thus, a two-sieve system creates a more efficient and cost-effective system for separating washing fluids and cuttings. In field tests, when the roar, which is difficult to cope with the flow rate of 0.5 m³/ min of drilled rock / flushing fluid using a single mesh screen of 200 mesh according to API standard (American Petroleum Institute, American Petroleum Institute), had an installed two-screen system with an upper screen according to standard 80 API and a lower screen according to standard 200 API, a two-screen system was capable of handle suspension costs over 1.5 m³/ min

Inclined sieve

In one embodiment, the top sieve assembly or the lower sieve assembly is tilted to obtain a “wedge-shaped” sieve 40, shown in FIG. 14, to create in the rumble a node with a sieve tilted up or down. Similarly, the flat node 12 of the upper sieve and the node 14 of the lower sieve shown in FIGS. 1, 2A and 3A, the node 40 of the wedge-shaped sieve has a frame 40a with a transverse element 40b and a mesh 40c sieve, the difference being that the frame, the transverse element (elements) and the sieve are inclined at an angle relative to the horizontal to obtain a thick end 40d and a tapered end 40e. Preferably, the angle of the screen is between –6 and +6 degrees.

In the following embodiment, both the top sieve unit and the lower sieve unit are inclined. Sieves can be tilted in the same direction or in opposite directions. Dual-sieve systems 10 installed in screens 20 shown in FIGS. 12 and 13 have wedge-shaped upper and lower sieves, where the lower sieves are tilted down and the upper sieves are tilted up.

Benefits of Inclined Screen

The node with a wedge-shaped sieve changes the dynamics and flow rate of drilling fluid and cuttings in the sieves. When the screen is tilted down, the flow rate increases, which is especially useful when the suspension on the sieve is viscous or similar to lard. Tilting the sieve assembly upwards decreases the flow rate, giving the suspension more time to pass through the sieve, which can increase the degree of separation of the washing fluid from the cuttings. The angle of inclination and direction of inclination of the nodes of the upper and lower sieves can be changed independently, based on the properties of the suspension, in order to optimize the processing efficiency in the rumble. This design is intended for applications with both single and dual screens and has not been previously considered.

In the prior art, there are screening cassettes that can be tilted in an upward or downward direction to change the flow rate of the suspension moving through the screens of the screen. If it is possible to individually modify individual sieves and screen angles, it is possible to further individualize the flow rate at various points on the screen screens. In addition, changing the angle of the screen sieve allows you to adjust the flow in the screens in which the screen cassette cannot be tilted. On Figa, 15B and 15C depicts the famous rumble 20 with an inclined cassette 22, containing four bed 24 rumble. 15A, the cassette is depicted in a neutral position; on Fig.15V cassette depicted in the tilt up position; and in FIG. 15C, the cassette is depicted in a tilt down position. As you can see, when the cassette is tilted, all the beds of the 24 screens rotate, at the same angle as the screen cassettes, and in the system there is no possibility to individually modify each bed of the rumble. In contrast, and in accordance with the following embodiment of the present invention, the same screens 20, the cassette 22 of which is in the neutral position (Fig. 16A), the upward tilt position (Fig. 16B) or the downward inclination position (Fig. 16C) , are upgraded using a combination of flat two-sieve systems 10 and either wedge-shaped twin sieves 42 with upward slope or wedge-shaped twin sieves 44 with slope downward to further individualize the flow rate of the suspension moving through the sieves.

In the known vibrating screen sieves 32, as depicted in FIG. 17, the edges of the screen assembly 32a are held in place on the bed of screen 24 using a mounting system 26, which may include wedges, hydraulic clamps or tension hooks, while the center 32b of the screen is not directly pressed to the bed of the rumble, maintaining contact in the center of the bed depends on the pressure at the edge and the intrinsic rigidity of this center. When the bed and fastening system vibrate with a given frequency and amplitude, shown by arrow 34, the sieve edges tend to vibrate with the same frequency and amplitude, while the center of the sieve, being farther away from the fastening system, usually vibrates with reduced frequency and the amplitude shown by arrow 36. This often causes the vortex of the cuttings in the center of the sieve, instead of moving in a relatively straight line along the sieve, creating more wear in the center of the sieve compared to the edges of the sieve. When the center of the sieve wears out, it is necessary to replace the entire sieve, even though the sieve edges may still serve. The use of a wedge-shaped sieve affects the harmonics of the vibrations, since the center of the sieve is narrower than the periphery of the sieve, and the effect of vortex in the center of the sieve is reduced, prolonging the service life of the sieve.

Sieve support system

Figure 18B shows the cross section of the support system 100 sieves in the cassette 22 of the screen. As shown in Fig. 18B, each sieve is supported by support brackets 102 sieves on both sides of the screen cassette and, as a rule, the sieves are held in place by wedges 104. The wedge 104 will usually be fixed between the flat top surface of the sieve and the corner bracket 106 protruding from the side of the screen cassette above the support brackets sit. Accordingly, by moving the wedges into the space below the corner brackets and the sieve, you can lock the sieve in place.

In order to efficiently upgrade an existing screen using an existing wedge system by installing a dual sieve support system 100, it is preferable that the upper sieve does not completely occupy the wedge space, as a result of which similar wedges (or at least narrower wedges) can be used . Accordingly, as shown in FIG. 18B, it is preferable that the support system 100a of the lower sieve is below the support arms 102 of the sieve. However, the use of an angle profile or equivalent on the side of the top sieve, as shown in Fig. 5B, can compensate for this.

As shown, the lower screen support system 100a has a smaller width compared to the screen size of the cassette 22, which allows the upper surface of the lower screen support system 100a and the lower screen 108 to be positioned below the support brackets 102 screens. The supports 100c, 100d are configured to provide a vertical separation distance between the lower sieve 108a and the upper sieve 108b and the seat providing support for the system on the support arms 102 of the sieves. For clarity, the other supports in the middle part, which may be included, are omitted in FIG. 18B.

In various embodiments, the sieve support system is welded, hammered or glued together to provide support to two layers of sieves, and it can be assembled as a single frame.

As shown in FIG. 18A, the upper sieve 108b is fitted to the upper sieve support 100b. Similar sieves fit under the full surface of the upper frame and the surface of the lower frame.

Dual screens for use in screening with stepped or cascade screens

As described above, some screening systems provide a stepped configuration in the screening cassette, with the result that the drilled rock descends in stages as it passes through the individual screens of the screen base. In such screens with step or cascade sieves, a two-sieve system of the present invention can be used. As shown in FIGS. 18 and 18A, the support system 100 of dual sieves for use in a stepped screen may contain a sequence of separate support systems that are offset from each other vertically. FIG. 18 shows the assembled support system of dual sieves, and FIG. 18A shows the support system of dual sieves with a partial spatial separation of parts.

Fig. 18C shows how a stream of drilling and flushing fluid can move forward in a sequence of stepped frames. It is important that the upper and lower sieves 108a, 108b will include an extension 108c, which extends past the edge of the support frame 100a, 100b, to ensure that the drill / wash fluid flows to the next sieve. In addition, it is preferable that there is a first gap 109 between the upper sieve support frame 100b and the upper sieve 108b located downstream of the process, with the result that if the volume of washing liquid / drill rock on the bottom sieve 108a is high, such the volume of material can flow from the lower screen area to the screen located downstream through the first gap 109.

In another embodiment, shown in Fig. 18E, the second gap or channel 109b ', located between the lower sieves 108a, 108a', located above and below along the process, can be increased due to the offset of the end face 108bi ' the upper sieve 108b 'located downstream of the process, relative to the upstream end 108ai' of the lower screen 108a 'located downstream of the process. The extension 108c on the upper screen 108b located upstream of the process ensures that the drill / wash fluid from this screen flows to the top screen 108b 'located downstream of the process, instead of flowing to the bottom screen 108a', located downstream. This option allows you to reduce the difference in height between the stepped sieves located above and below along the process, while still making it possible for an effective flow to exist between the screens above and below along the process. The smaller difference in height means that the upper sieve has a lower profile, which makes it possible to better integrate a two-sieve system into the existing system of fastening to the clatter boxes. For example, if the mounting system is a clamping system using wedges, a lower profile allows larger wedges to be used to hold the two-system system in place. As shown in FIG. 18E, between the upper sieves 108b, 108b ′ located above and below along the process,

Alternatively, as shown in Fig. 18D, the stepped sieves can be positioned so that the drill / wash fluid from the lower and upper sieves 108a, 108b located upstream of the process will flow only to the upper sieve 108b ', downstream of the process, and will be prevented from proceeding directly to the bottom sieve 108a 'located downstream of the process.

It is important that when placing sieves with a larger cell and, consequently, sieves with a smaller cell that are stronger on the upper surfaces on the lower surfaces will be protected from larger cutting particles and, therefore, the service life of the sieves with a smaller cell may be is increased.

It should be noted that it is possible to embed more than two supporting sieve systems, if considerations on space make such a configuration possible.

Double screens for screening machines with a flat screen bed

In yet another embodiment, for the purpose of modernization, two-sieve systems can be installed in a screen having a flat, non-cascade bed of a sieve to obtain a two-system system having a cascade effect between adjacent sieves. In this case, a two-sieve system located upstream will rise above the normal bed level of the sieve, and each subsequent two-sieve system located downstream will be at a lower level, with the result that the drilled rock may descend down the steps . In this case, as schematically shown in Fig. 18, additional supporting elements 110 will be included, with the result that each two-sited system is located at a different height. In this case, the screen having a flat sieve bed can be upgraded, to allow the passage of the rock through the resulting gap 109, as described above. Moreover, the upper sieve can be tilted up at an angle of approximately 1 ° -3 ° in the direction of flow. This ensures that on the flat or cascade decks, the outlet end of the first upper screen going above is above the inlet side of the next screen.

Alternatively, a two-screen system can be used in a screen with flat bed sieves without positioning the dual sieves in a cascade manner. A known rumble will usually have a single sieve extending from the end of the rumble located upstream of the process to the end of the rumbler downstream of the process and there may be one bed of sieve or a plurality of bed sieves set up as parallel decks one on top of another or in a different configuration. The two-sieve system of the present invention can be used in such a rumble by replacing one or more sieves with one or more dual sieves that run along the entire bed of the sieves. In this embodiment, there will be no gap between adjacent sections of the upper sieves, or adjacent sections of the lower sieves, since each upper sieve will be essentially

In another embodiment, the bed of the sieve may be curved instead of flat, for example, convex. In addition, a two-sieve system may include one or more three-dimensional sieves, for example, a pyramidal sieve. Such a sieve can be used to increase the surface area of ​​the sieve.

Alternative mounting systems

As discussed in the prior art section, single sieves corresponding to the prior art are attached to screening systems using various fastening systems, which can include clamping systems using wedges, clamping systems using hydraulic pressure plates, and sieve tension with hooks. Screening systems having any of these anchoring systems can be upgraded to install the two-screen system of the present invention, including two-screen systems manufactured as a single structure (i.e., a single-element two-screen system) or several structures (i.e., a two-element two-screen system). An exemplary dvukhsitnoy system of the present invention, which is held in place using a clamping system using wedges, shown in FIG.

FIG. 19A shows an end view of another embodiment of a two-sieve system 10 having a channel 16 between the top sieve unit 12 and the bottom sieve unit 14, the two-sieve system being adapted to be fixed in an existing screen 22 with a wedge clamping system. On each side of the screen cassette is a support bracket 102 sieves to provide support for the mounting bracket 108e, which extends from each side of the two-sieve system. The mounting bracket may contain one or more elements connected to one or both of the lower and upper sieve frames 12a, 14a. On the left side of the two-sieve system, FIG. 19A shows a wedge 104 holding the support system of dual sieves in place between the support bracket 102 sieves and the upper bracket 110, which is typically attached to the screen cassette. There is no wedge on the right side, which allows inserting or removing a two-screen system into the screen rack. The top sieve assembly may be smaller in width than the screen cassette, as a result of which it does not reach the edges of the screen cassette, which creates a gap G between the edge of the top screen assembly and the screen screen wall, allowing the wedge with height H to fix the two-screen system, moreover the height H has the same magnitude that could be used to fix a conventional one-way system in the same rumble cassette.

Alternatively, FIG. 19B illustrates a two-system system 10 in which the top sieve assembly 12 extends to the screen of the screen cartridge. Accordingly, a shorter wedge having a height H will be needed to fix the two-screen system in the screen cassette._oneif the support bracket 102 sieves and the top bracket 110 do not move.

FIG. 20 illustrates a two-screen system 10 adapted for use in a screen cassette 22 having a clamping system using hydraulic or air pressure. The clamping system includes a plunger 116 at each end of the screen 22 cassette, which moves down to clamp the mounting bracket 108e of the two-system system 10 between the plunger and the support bracket 102 sieves. On the left side of FIG. 20, the plunger is shown in the clamping position, in which it holds the two-si system in place, while on the right side the plunger is in the open position, which is used to insert or remove the two-si system. This drawing shows the various supporting elements 12b, 14b of the upper and lower sieves.

FIG. 21 illustrates a prior art sieve hook system for securing and tensioning a single sieve 32. On each side of the screen cartridge, the hook sieve system includes a hook 124 attached to a bar 126 that passes through an opening 128 in the wall 22b of the cassette rumble The hook is attached to the corresponding hook 122 of the sieve, located on the edge of the sieve, which allows you to stretch the sieve with great force to fix it in place in the cassette and to ensure its tension. FIG. 21 illustrates a spring system 130 for creating tension in a sieve clamping system with hooks. However, as known to a person skilled in the art, other types of systems can be used to apply force to the joint, for example, a bolt-and-screw assembly or an air or hydraulic plunger assembly.

The hook fixing system according to the prior art can be adapted to fix the two-screen system 10 of the present invention in the screen cassette. One variant of such a procedure is shown in FIG. 22, where the hook 124 is provided with both upper and lower hooks 124a, 124b, which are adapted to be connected with corresponding hooks 122a, 122b in the upper sieve unit 12 and the lower sieve unit 14, respectively. In this embodiment, the upper hook 124a and the corresponding hook 122a are inverted, i.e. are in reverse position, compared with the lower hook 124b and the corresponding hook 122b. Alternatively, the upper hook and the lower hook may have the same orientation in order to use the same corresponding hook 122a, 122b in the nodes of the upper and lower sieves. Besides,

Test results

Tests were carried out to determine the difference in the fluid retention ratio in the rock for a single sieve corresponding to the prior art compared to the dual sieves of the present invention using the same screen and the same wash liquid / rock mixture . The test was carried out in accordance with industry standards. The results showed that the single screen had a retention factor in the rock (measured in m³ solution / m³ rocks) 0.894, while twinned sieves had a lower retention rate of 0.818. During the test, the single screen was inclined against the direction of fluid / rock flow at an angle of +2 tilt units in the rumble, while twin screens were inclined in the direction of flow at an angle of –1. This difference in the angle of the screen will in fact provide the advantage of a one-hole system for separating the cuttings from the washing liquid compared to a two-screen system, since the rock / liquid will be held on a single sieve for a longer period of time due to the slope against the direction of flow.

Although the present invention has been described and illustrated with reference to preferred embodiments and preferred uses thereof, it should not be so limited as modifications and changes can be made without going beyond the full intended scope of the invention, as will be understood by those skilled in the art. in the art.