DE2220403A1 - Speed sensitive valve - Google Patents

Description

DIPL.-ING. H. MARSCH ι Düsseldorf,

lwdeminksthasse si

.-lJXOr. K. b PAKlN tr postfacd

PATENT LAWYERS phone (0211) 07 22 do

22. 605/612 April 12, 1972

description
to the patent application

the company Schlumberger Technology Corporation,
277 Park Avenue, New York, NY 10017

CONCERNING:

Speed sensitive valve

The invention relates generally to safety valves and, more particularly, to a safety valve mechanism that controls the flow
allows the conveyed fluid to flow through depending on the speed of the fluid and completely interrupts this flow if it falls below at least a lower speed limit.

In the early stages of the development of the petroleum industry, it was common to have pressurized petroleum deposits through it
tapped, that they were drilled and allowed the gas pressure possibly contained in the borehole to escape to a controllable value or a value at which the petroleum products can be recovered by pumping. The effluent gas during this particular period of operation was essentially useless and was generally wasted. Where the oil from the well

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was blown out along with the escaping gas, the oil was collected in surface channels around the wellbore were built around. As the petroleum industry developed rapidly, it was discovered that under pressure stagnant gas in the earth formations can be effectively used to produce other petroleum products that contained therein, and that the gas itself in its natural state or in other physical states, for example in the liquid state, could be sold. Various developments have been made to it to protect against the loss of gas pressure in the petroleum deposits, but most of the early developments related on surface control valves and the like, which are handled manually or mechanically for flow control could.

Although wellbores can now be effectively controlled to prevent unnecessary gas escaping from the deposit, Occasionally, unforeseen events develop which cause the uncontrolled blowing out of a borehole. The production facilities located on the surface can be damaged by mechanical devices that work in the vicinity of the borehole, and there may be other adverse effects from the environment of the borehole surface Blow out the borehole.

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If the well is offshore, for example on a platform, the occurrence is one Explosion or fire and the like are particularly dangerous to the life of the operators as it is difficult is to escape from the production site. Offshore explosions and fires are also related to destruction of the plants are particularly expensive because of the extremely high construction costs of production facilities away from the coast. Also can an oil outbreak, which is due to damage to the control device on the surface of the borehole in the case of a distant one Production facility lead to pollution of an extremely large area of the coastline and thereby lead to cause considerable damage to outdoor enclosures and the like.

Explosions on the surface control device and within of the well below the surface can lead to considerable damage and especially the uncontrolled one Allow outflow from the well.

Boreholes can also blow out due to the faulting of earth strata through which the borehole is made, and the like Damage can result from an inadequate connection between the borehole cement in the borehole and the soil layer through which the borehole passes, so that pressurized fluids outside the borehole casing can flow up to the surface.

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If for any reason a borehole blows out, so the costs to the drilling and producing companies can become extremely large. Such costs can by Production losses may be caused during the time the well is blowing out. Significant costs are also due caused the pressure loss of the oil deposit, the may prevent future production of petroleum products. The loss of pressure in the oil field can also slow down production considerably or make it more expensive by gas lifting processes and relief measures become necessary for effective production.

Obviously, there is a need for underground control mechanisms to provide for the flow, which can be actuated automatically or, if desired, optionally, in order to blow out of boreholes, even if the surface-mounted equipment regulating the current is damaged is or is not in operation. Underground control systems of this type can be capable of explosions and prevent fire, which would otherwise result in damage or malfunction of control systems on the surface occur. In addition, underground control safety devices can be used effectively prevent the pollution of the environment which would otherwise occur if blows out a borehole far from the coast in an uncontrolled manner. Since underground safety valves prevent many such accidents

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can shun and control the pollution for that So important is landscape conservation, it turns out that underground security mechanisms are required for effective operation of the petroleum industry.

Various well safety systems have been developed, both above ground and underground Have safety devices that are either automatic by pilot mechanisms or by remote sensors or, alternatively, when dangerous borehole conditions arise, they can be regulated or respond to the flow of the material being conveyed to stop until the production facility has been made safe for further operation.

Boreholes distant from the coast can have production facilities that provide a safety operation that takes care of the production or interruption in the borehole in the event of storms or other adverse events which would otherwise stop production would affect.

Above-ground and underground safety valves have been developed which permit the closing of above-ground or cause underground control devices for the production flow to interrupt the flow in the event that it becomes too high downhole pressure developed and if the flow control device one. be exposed to excessive production flow

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should. Most of the downhole safety valve devices currently available speak just adjust the speed and stay open so that they can keep the fluid flowing for the duration of the normal or low flow throughput, and they are actuated by forces that occur at high flow rates occur to move the valve assembly into the closed position and thereby interrupt the flow. If the velocity of the fluid were to become abnormally low, a response would only be given to the Sensitivity sensitive valve does not secure the system.

A disadvantage of all types of known safety valves is that the valve seat and the other valve closure are subject to adverse borehole conditions at all times, so that corrosion through the borehole fluid and erosion occurs caused by sand or other foreign matter that coexists with the production stream be flushed up. If the safety valve is eroded or corroded by the production stream, it can do not work properly in the event of subsequent emergency situations. Another disadvantage of the known speed-sensitive Safety valves consists in the fact that it is not possible to check the safety mechanisms.

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to ensure correct function without removing the valve from the borehole. It may also be required remove the drill string from the borehole, which of course is extremely expensive and undesirable.

Over a longer period of time, the production of a certain Occurrence reduce the pressure and thus the flow rate so that the thereby caused Forces are not sufficient to effectively close a speed responsive Ensure safety valve, even if the borehole can continue to promote unrestricted.

The invention is therefore based on the object of creating a new type of safety valve device, which in the Is drilled and effectively disrupts the flow of fluid should the speed of the production stream fall below a predetermined operating level.

The production flow should also be interrupted if the speed is above or below certain limits should fall within a predetermined operating range.

Based on a safety valve to protect a drilling

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loches with a housing and a flow passage, which can be connected in a production line extending through a borehole and normally one open valve in the housing, the valve moving between open and closed positions can be and regulates a flow conveyed through the flow passage, this object is according to the invention solved in that in the housing a low flow device to a flow decrease below a predetermined Speed responds and with such a decrease the valve closes and thus the flow of fluid prevented by the fluid passage

According to a further embodiment of the invention, can the safety valve device also has a high-current device for regulating the closure of the passage in the event of an increase of the flow through the flow passage beyond a predetermined flow rate to the Shut off product flow through the flow passage.

According to a further embodiment, the safety valve arrangement comprise an elongated, substantially tubular housing in which an actuating tubular member is movably arranged with a flow passage. A valve element which, if desired, has a spherical

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ger valve body may be, is supported by a tubular member and has a valve passage that with the Product passage in the open position of the valve communicates to the product flow through the product passage to let through · The valve housing can have a. Have device that cooperates with the valve element, to move it between the "open" and "closed" positions according to the movement of the To reach tubular member in the housing. The tubular member can be in communication with a device for driving of the valve in its closed position, for example by moving it in the closing direction of the valve element is biased by a compression spring or other suitable biasing device between the Tubular member and the housing is arranged. A shut-off device, for example a throttle, can be installed in the pipe structure are provided and causes the build-up of a differential pressure in the pipe structure, which is sufficient Generates force that acts on the pipe structure and against the biasing device to overcome their force or to prevent the valve from closing and to keep the valve element in the open position as long as the Product flow is kept above a predetermined minimum level. If the product flow falls below a predetermined minimum Should the volume drop, the force of the prevails

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Pre-tensioning device via the force of the production flow, which acts on the tubular member, and the valve element is moved to the closed position, so that the further Current of the means of production is cut off.

In a preferred embodiment of the invention are High current devices arranged in the housing and respond to a predetermined pressure differential to a To release actuator which detects the valve operating tube and closes the valve element. The safety valve is therefore closed when the speed of the production stream becomes excessively low or high.

A locking device can pass through the valve housing and the tube are formed, which causes the locking of the tubular member in the position that leads to a closure of the Valve element leads, so that effective an accidental reopening of the valve element after it is automatically closed is avoided. A device can also be provided to unlock the locking mechanism, when a selected pressure occurs downstream of the valve element, substantially the pressure downstream of the valve element balance. Such a release mechanism may take the conventional form of a pressure actuated piston assume that has an unlocking cam, which

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overrides the locking mechanism and allows the biasing means to slide the tubular member into shifts a position so that the connecting elements between the valve element and the housing the valve element move it to its open position.

The operating limits of the safety valve device can be changed by replacing various compression springs or the size of the throttle opening is changed will.

In the following a preferred embodiment of the Invention explained with reference to the drawings; it represent

Fig. 1 is a partial section of a subterranean earth formation with a borehole located therein, which is aligned therewith A drill casing with a drill pipe and a safety valve mechanism; FIG. 2 shows a partial section of the drill housing according to FIG. 1 with a typical connecting piece and a cable insert, and FIG a retraction device with a safety valve mechanism according to the invention connected to its lower end is;

3a and 3b are cross sections of the upper and lower parts of a safety valve mechanism for high / low flow

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measured the invention, with the moving parts in the normal open position; Figures 4a and 4b are sectional views of the upper and lower sections, respectively of the 'safety valve mechanism according to Fig. 3a and 3b, the inner moving parts in the closed Position;

5 is a partial sectional view of the safety valve mechanism, with the unlocking mechanism in an intermediate position is on the move to unlock the latch mechanism and the valve actuating tube and the valve balls are shown in the open position; Fig. 5a is a partial sectional view of the unlocking mechanism of Fig. 5, the position of the unlocking tube and locking fingers being in the fully unlocked position are located;

6 is a sectional view of the upper portion of the safety valve mechanism; wherein the speed responsive valve actuating portion of the mechanism is is in the locked position; Fig. 7 is a partial section of the upper portion of the safety valve mechanism FIG. 6, in which the section which actuates the valve is in the unlocked state; FIG. Fig. 8 is a partial section of the upper portion of the safety valve mechanism showing the lock releasing mechanism is shown in detail;

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Figure 9 is a sectional view of the lower part of the safety valve mechanism with individual parts.

According to FIG. 1, a borehole 12 is in an earth formation 10 introduced and aligned with a drill pipe 14 which is cemented in place in a conventional manner. A Production pipe 16, which is commonly referred to as a pipe string, extends through the drill casing 14 and is sealed against the drill casing by a packer 18, which is at a distance above the production zone of the Earth formation is located. The tubular conduit 16 is open at the lower end, so that the product flow through openings can flow in the housing 14 and directs the product flow up through the pipe rod.

In order to interrupt the flow of product through the pipe 16 in the event of an abnormal decrease in the flow of product, a Safety valve mechanism is provided which closes on a predetermined decrease in the fluid flow rate and stop the product flow. According to the specifically illustrated embodiment, this safety valve mechanism speaks also to an increase in the product flow above a predetermined maximum permissible value of the flow rate to the To interrupt power in this case. Such mechanisms can have the structure illustrated in the drawings, where

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the safety valve mechanism 20 can be installed and removed by conventional cable pulling means 22. The safety valve can be installed in the pipe rod at a height where the temperature is high enough to prevent the To prevent solidification of paraffin which would otherwise inhibit the moving valve parts.

According to FIG. 2, the cable pulling device 22 has a connecting piece 24, the outer threaded sections 25 and 26 for receiving inner threaded ends of the pipe rod 16 may contain. An annular receiving shoulder 28 can be in the lower Projection 26 of the connecting piece 24 can be provided to be received by an annular shoulder 30 on a cable pulling tool 32 is designed so that the tool 32 does not fall below the height determined by the annular shoulder 28 can. The tool 32 may have locking pawls 34 that fit into an annular locking groove 36, which is formed in the connecting piece 24. The tool 32 can also be provided with an annular seal 38, which in the Engages with the cylinder surface 40, which forms part of the receiving device for the tool. Usually, the tool 32 can have a catch rib 42 on its upper part Have end that can engage in a conventional installation and removal device.

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During the special cable pull structure and the removal device 32 are shown in FIG. 2, it goes without saying that the structure shown is only explained by way of example is. Any suitable cable pulling tool of the conventional type can be used. Bas tool 32 can have a lower outer threaded portion 44 which has a threaded connection to the internal thread 46 in the upper Cap 47 of an upper housing portion 48 of the safety valve mechanism 20 can be produced so that the safety valve hangs on the tool 32.

3a and 3b, the safety valve mechanism 20 may include a housing formed by a cap section 47j, an upper housing section 48, a locking section 50, a connecting section 51, a spring housing section 52, a valve section 54 and a final cap section 56. The locking portion 50 may be provided with inner threaded portions 58 and 60 for threaded connection with the outer threaded portion 62 of the upper housing portion 48 and the outer threaded portion 64 of the connecting portion 51. Internal thread 63 of Feoergehäuseabscianittes 52 can be connected to the external thread projection 65 of the connecting section 51. The Federgaliaiiseababschnitt 5 2 can be connected to an outer threaded portion 66 at its lower end, where-

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ran the inner threaded section 68 of the valve section 54 can be screwed on. The end cap portion 56 may be provided with an external threaded portion 70 which is connected to the Internal threads 72 in the lower end of the 'valve section 54 can be screwed.

The threaded mechanism 20 can be provided with an internal valve operating tube 74, the lower end of which is shown in detail in FIG. He can have a section 76 have with reduced diameter, which forms an annular shoulder 78 which can receive a compression spring member 80, the is arranged in the spring housing portion 52 and between the shoulder 78 and the upper annular shoulder 82, which by the lower end of the connecting portion 51 is formed. A compression spring 80 tensions the tubular member 74 according to the drawing down forward. Although the illustrated compression spring 80 is designed as a metallic helical spring, any suitable one can be used Biasing means are used in the valve assembly to bias the tubular member 74 downward in one direction to achieve, which is opposite to the product flow, without therefore departing from the scope of the invention. It understands that the mechanism by which the valve element is notified of movement in its closed position, can also be designed differently than by a spring device. For example, closing the valve element

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upon detection of the predetermined flow conditions required for closing the safety valve a servo mechanism can be achieved. A product passage can be formed in the tube 74 and serve to convey the Direct product flow through the valve.

The lower end of the tube 74 can be externally threaded be provided according to FIG. 9, with which the inner threaded portion 88 of a valve and a throttle support element 90 is screwed. The lower end of the tube 74 can also be provided with a throttle recess of enlarged diameter, which is through a generally cylindrical Bore 92 is limited, in which a throttle member 94 is received, which has a narrowed flow passage 96. The annular shoulders 98 and 100 formed in the tube 74, the valve and the throttle support element 90 work together, in order to keep the throttle member 94 substantially in a fixed relationship with respect to the pipe. A ring seal can be provided to provide a seal between the cylinder surface 92 and the tube 74 to be provided, which according to the invention, if desired, as an O-ring or in some other way can be formed. ι

The valve and the throttle support member 90 can be provided with an annular groove 104 in which the valve support elements according to FIG

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Broken line are provided at 106, the support projections in 108 form, with which the pins 110 one rotatable spherical valve member 112 be connected can. The closure member or valve element may be provided with an internal valve passage 114 which extends into the open position of the valve element can be brought to a flow passage 116 in the support element 90 to communicate. The support element 90 can also be provided with an annular seat surface 118, which for receiving a spherical surface 120 on the valve element 112 is suitable. The valve element 112 can also be other than spherical be designed within the scope of the invention.

To the valve element 112 in rotary motion between the positions To offset "open" and "closed", a cam guide can be formed in the valve element, as in FIG Lines at 122 is shown. In the cam guide, a cam element 124 in the form of a pin be received, which is mounted at a fixed distance from the valve portion 54 of the valve housing. When the valve element through the pipe 74 and the valve and the throttle support element 90 under the influence of the spring 80 in the product flow is moved downward in the opposite direction, the engagement between the cam member 124 and the cam guide 122 effective to rotate the valve element 112

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in order to effect 90 from the open position according to FIGS. 3 and 7 into the closed position according to FIG.

Since the product flow through the valve passage 114 is very can be high, it may be necessary that some means for stabilizing the valve element against Shaking forces or vibrations is provided by Flow turbulence could be caused. A facility may also be required to control the flow of liquid to steer smoothly through the valve passage 114. Such a stabilization device can be explained in FIG Take the form where a valve stabilizer 126 is shown which is moveable within the valve portion 54 of the valve housing is arranged and has a seat surface 128 for receiving the spherical work surface 120 of the valve element 112 is suitable. A spring device 130, which if desired as a metallic Can be formed helical compression spring, can between a shoulder formed on the valve stabilizer 126 132 and an annular shoulder 134 extending through the upper end of the end cap portion 56 of the valve housing is limited. The compression spring 130 is effective to engage the valve stabilizer 126 by spring force to bring the valve element 116 and thereby serves to firmly encapsulate the valve element between the sealing surfaces

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and 118 and to improve the sealing ability of the valve element as well as to prevent vibrations of the valve element due to flow turbulence. The valve stabilizer 126 can also be provided with an extension 136 which forms an outer guide surface and in addition serves to maintain positive alignment of the valve stabilizer in any particular position and allowing movement of the valve stabilizer when the valve element is during the opening and closing movements is moved back and forth.

In an annular groove 142 in the end cap portion 56, a sealing ring 140 can be received and abut the cylindrical surface 138 of the valve stabilizer 126 in order to prevent foreign objects which are in the product flow are contained in the annulus between the valve housing and the inner moving parts of the Safety valve arrive. The sealing element 140 is not intended to form a liquid seal, since it is desired in a manner yet to be described that the liquid pressure for valve control purposes in the annulus is transmitted. The fluid communication from the end portion 56 of the valve housing to the valve element can can be established by a liquid passage 144 formed in the valve stabilizer 126 adjacent to

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the valve passage 114 is arranged in the open position of the valve element.

According to Fig. 8, means can be provided to the tubular member 74 in its lower position after the To lock actuation of the valve element 112 in its closed position and according to the invention this can Element according to FIG. 8, where the tubular element 74 is provided with an annular locking groove 146 that delimits a ring shoulder 148. The locking portion 50 of the housing can have multiple locking fingers 150, which each have locking pawls 152 which are in a locking groove 146 during the movement of the Engage tubular element 74 in its lowermost position. The locking fingers 150 can be spring-loaded in such a way that that the locking shoulders 154 of the pawls 152 come into engagement with the annular shoulder 148 during locking and lock the pipe section 74 in its lower position. Also within the scope of the invention, other mechanical Means are provided to hold the valve element in its closed position until the Valve should be opened. A servomechanism according to page 15, line 30 or another system can be used will be to select the valve or automatically upon recovery to open the "safety mode".

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After the tube 74 has been moved downward to close the valve element 112 and the pawls 152 in the Locking groove 146 engaged does not cause a change in pressure upstream from valve element 112 the reopening of the valve element. After the automatic emergency locking of the tube 74 in the locked position of the valve, the pipe can then be unlocked when the valve element moves should be reached in the open position in order to allow the product stream to flow through again. It is according to the invention an unlocking device is provided which, as shown in FIG. 8, has an annular unlocking piston 156, which can be movably arranged in an annular space between an inner wall 160 of the upper housing portion 48 and an outer cylindrical surface 162 which is the upper end of the tube 74 limited above the locking groove 146. The unlocking piston 156 may include an inner sealing member 164 and an outer seal 166 to provide the seal between the unlocking piston and the cylinder surfaces 162 and upright.

To unlock the connection between the pawls 152 and the annular shoulder 148, which is delimited by the locking groove 146 is, an unlocking projection 168 can be formed integrally with the unlocking piston, the one

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front cam surface 170 which can engage the opposing cam surfaces 172 formed on the upper end of each of the locking fingers 150. When the unlocking piston 156 is moved downward, the cam surface 170 moves into engagement with the cam surfaces 172 and actuates the spreading fingers outward so that the locking shoulders 154 of the spreading fingers are separated from the annular shoulder 148 formed on the tube 74. During the unlocking movement, the unlocking tube 156 moves after its intermediate position according to FIG. 5 into a completely unlocked position according to FIG. 5a, where the cam surface 170 moves past the cam surfaces 172, and the enlarged section of the projection 168 is arranged in the grooves 169, which are limited next to the ends of each spreading finger 150. A reverse tapered cam surface 171 can also be disposed on the release tab 168 and can engage the tapered cam surfaces 173 on the splay fingers. After the unlatching movement has occurred, the protrusion 168 is located in the grooves 169 and the surfaces 171 and 173 prevent the piston 156 from moving freely upward so that they ensure that the pawls 152 do not re-engage the shoulder 148 can and the tube 74 lock again. When a predetermined pressure has been introduced into the chamber 15B , the

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Piston 156 is pushed upward with sufficient force to engage cam surfaces 171 and 173 by spreading fingers 150. to separate. The piston then returns to its position according to FIG. 8. After the unlocking movement, the tube is 74 is released and can be moved upward to move the valve element 112 to its open position and resume fluid flow through the valve enable.

The unlocking piston 156 can be designed to move by fluid pressure, either by the Product flow or an actuating fluid is applied that is dispensed under pressure from a source which is arranged downstream of the safety valve. While the valve 112 is arranged in the "production mode" according to FIG. 9, the pressurized flow product stops the unlocking piston 156 at the upper limit of its travel, where further movement upwards through a retaining shoulder 174 according to FIG. 8 is prevented.

The safety valve mechanism according to the invention can also have a speed responsive portion, which responds to an increase in the product flow in order to interrupt it. Such a mechanism can according to Fig. 5 and 6, where a high speed

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End actuated tube 175 moveable in the upper housing section 48 is arranged. The tube 175 is provided with an enlarged lower portion 176, the one annular abutment shoulder 177 for the abutment of an annular shoulder 178 forms through the lower end of the outer thread projection 62 of the upper housing portion 48 is formed. That through high speed actuated tube 175 can also be provided with an enlarged piston portion 180 which has an annular sealing member 181 which provides a dynamic seal between the piston portion and an inner cylinder wall 182 which is arranged in the lower portion of the valve housing. The actuator tube 175 can also be with a be provided lower projection 183, which in the upper portion of the valve operating tube 74 during the movement of the Tube 175 engages downward.

The tube 175 is according to FIG. 5 by a compression spring 184 in Rest position held between an inner shoulder 185 within the upper housing section 48 and a lower Surface 186 of a support ring is arranged by a locking pawl, which is in close contact with the outer Cylinder surface 188 of the actuating tube 175 is located. Of the Support ring is provided with a plurality of openings 189 which receive a plurality of generally spherical pawls 190 which are in the

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Are locking engagement with an annular locking groove 191, which is limited in the outer circumference of the actuating tube 175 and serves to secure the actuating tube against free movement. An inner surface 192 of reduced diameter holds the locking pawls 190 for locking within the locking groove 191. A cylindrical surface 193 is formed in the upper housing portion 48 and cooperates with the outer cylindrical surface of the actuator tube 175 to form an annular chamber 194 that is slightly larger than that The diameter of the spherical pawl member is 19o. When the actuating tube 175 is pushed down in the manner explained below, an annular cam surface 195, which acts on the pawl 190, moves it and the annular pawl receiver 187 down to the lower end of the cylinder surface 192 have reached below the cylinder surface 192, they are moved outwardly by the cam surface 195 in the movement according to ^v FIG. The pressure difference at which the valve closes can be changed simply by replacing the spring 184 with a compression spring with a different pressure value.

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The upward movement of the actuating tube is limited by the annular shoulder 178 »which is caused by the lower end of the threaded projection 62 of the housing portion 48 is formed, which in engagement with the on the Actuating tube trained annular shoulder 177 can reach. An annular sealing member 198 is disposed in the groove, which is formed in the threaded projection 62 to provide a dynamic seal between the housing portion 48 and the To form the cylinder surface 188 of the actuating tube 175. The annular seal 198 cooperates with the seal 181 and defines a sealed chamber 199 into which an actuation pressure fluid from the annulus between the Pipe linkage and the safety valve flows in through several openings 200. The pressure of the entering chamber 199 Fluid, of course, corresponds to the pressure of the container or housing. When the pressurized production stream flows through the open spherical body 112 upwards, it passes through the throttle constriction 96, so that a pressure is generated which is slightly less than the pressure below the throttle constriction, so that a pressure drop occurs. Of the Reduced pressure through orifice 96 acts on the lower surface of the high speed actuated tube 175 and creates an upward bias while the container pressure acts downward on the piston 180 and a results in downward bias. The downward

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Adjusted preload is not sufficient to fix the tube 175 down against the combined forces of the opposing upward bias of the underneath Pressure standing product stream and the upward tension to push, which is mechanically through the compression spring 184 is generated. The tube 175 therefore remains in the static position according to FIG. 6 and the product flow generated continues upwards through a product passage 201 in the tube 175.

When the speed of the product flow exceeds the predetermined maximum level for which the safety valve mechanism is designed, the pressure drop generated at the throttle 96 is much greater, so that a much greater force from the pressurized fluid in the pressurized chamber is exerted, which generates a resultant force of sufficient magnitude to move the piston 180 downward against the upward spring force of the spring 184 to press. When the spring 184 has been overcome, the tube moves slowly downward as the pressure differential increases until the spherical bodies 190 clear the lower part of the annular surface 192 to have. Once this is done, the spring 184 pushes the spherical bodies against the cam surface 195 and moves them

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radially outward, so that the spherical bodies are separated from the annular locking groove 191 and that on high Speed responsive tube from the opposing one Influence of the compression spring 184 is released. When this is done the piston member 180 and tube are down have been driven and have brought the projection 183 into contact with the upper contact surface 202 of the tube 74, so that the pipe is moved downwards and the rotation of the valve element 112 causes in its closed position. When the tube 74 has been moved down enough to the To move the valve body to the closed position, the annular locking groove 146 is also moved sufficiently downward to cause spherical bodies 152 to engage annular shoulder 148 and thereby the tube 74 secure against unintentional upward movement.

The pipe is moved upward to its locked position when a pressure medium is introduced into the pipe string above the safety valve mechanism in the manner described below will.

When the Sicherheitsventilmechaaismus of the invention, however, the open position in accordance with Figo 3b and 9 befittde £ ₀ so the Produktionsstrota flows from Boiurloehgefaäuse into the open lower end of the Sicherheitsvetttilinaeaanisiatss 20 under the

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Reservoir pressure. Since the valve element 112 is in its open position in the conveying mode, the pressure of the fluid is restricted by the valve passage 114, the flow passage 116 and the Passage 96 of the throttle 94 is transferred into the product flow passage 84. The product stream then flows through the passage 201 in the pipe 175 and through the passage of the cable pulling tool into the pipe rod 16.

When the pressurized product stream passes through the narrowed opening of the throttle passage 96, will a pressure drop across the throttle creates a force acting on the tube 74 in one of the biases of the compression spring 80 generated in the opposite direction. The force acting through tube 74 is sufficient during normal product flow to overcome the spring force of the compression spring 80 and the tubular member 74 in its uppermost position hold where an annular shoulder 196 of the valve and a support member 90 in engagement with a holding surface 198 which is formed by the lower end of the spring housing portion 52 of the valve housing.

The annular space between the valve housing wall and the inner moving parts of the safety valve is under the Pressure of the reservoir which passes through the sealing ring 140

2 ü 9 tU 5/0 9 2 1

which acts on the lower surface which is delimited by the annular unlocking piston 156. Since a reduced pressure due to the limited by the upper end of the unlocking piston 156 area If the throttle acts, the fluid pressures acting on the piston 156 are not in equilibrium and generate a resultant force urging the piston upward into engagement with the retaining surface 174. The valve and the throttle support element 90 are together with the valve element 112 in their uppermost positions by the Tube 74 moves and valve stabilizer 126 is through the spring 130 is biased to its uppermost position and holds a stabilizing tension for the spherical Valve element 112 upright. The decreased pressure over the constriction 96 in the throttle 94 is connected to the downward facing surfaces of the responsive at high speed Transfer tube 175 and piston 180. At the same time, this works under the high pressure of the reservoir stagnant fluid, the pressure of which is transmitted through openings, down onto the piston 180 and is generated a resulting downward force on that piston created by the upward biasing force the compression spring 184 is overcome. At the speed conditions of normal operation or at lower Speed remains the same as that of the valve at high

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celt actuating device according to Flg. 6 locked.

If the product flow for any reason, for example 'by reducing the reservoir pressure, by closing the product control valves at the surface or by creating pressure in the pipe string, ■ "· · ■ close to the pressure in the reservoir comes, the resulting force acting on the pipe, which is generated by the pressure drop at the throttle 94, not sufficient to overcome the bias of the compression spring 80. The compression spring then becomes the tubular element 74 push down and thereby the valve and the support element 90 for the throttle and consequently the spherical valve body 112 move down and cause the cam 124 through the cam groove 122, the valve element in its moved closed position according to FIG. 4b. The downward movement of the tube and valve assembly is limited under this condition by the annular retaining shoulder 179 which limits on the valve stabilizer 126 and can come into engagement with the shoulder surface 134.

If in the closed valve position of the safety valve according to FIG. 4b, the housing under the safety valve should remain below reservoir pressure even in a reduced pressure condition, that fluid pressure becomes

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act through the annular space formed between the valve housing wall and the inner moving parts of the valve is and will press on the lower surface which is delimited by the annular unlocking piston 156, so that the unlocking piston according to FIG. 8 remains in its uppermost position.

If the pressure conditions of the product flow reach a normal value again after the spherical body 112 has been closed, the valve construction remains in a closed position because of the locking between the stops 152 of the spreading fingers 150, which remain in engagement with the annular shoulder 148 of the tube 74, so that the tube member does not move again can move up what is obviously the opening of the valve element according to FIG. 8 would allow.

The safety valve can optionally be opened by an actuation pressure above the valve body 112, if whose pressure is greater than the reservoir pressure. Such fluid pressure creates a resultant force that acts on the upper surface bounded by the annular unlocking piston 156 and is greater than that by the reservoir pressure generated force that lies on the lower surface of the piston 156. The piston therefore moves down and causes the cam surface 170 of the unlocking projection

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168 in engagement with the cam surfaces 172 of the spreading fingers 150 arrives and thereby pushes the spreading fingers outward and the shoulders 154 of the locking stops 152 from the annular shoulder 148 of the tubular element release. After the expanding fingers have been unlocked from the tubular element, there is essentially pressure equalization inside the valve because of the balance between the reservoir pressure and that in the pipe string Actuating pressure introduced above the valve for the unlocking movement. The compression spring 80 holds this condition biases the tubular element further down and holds the spherical valve body 112 in its closed position.

It is then necessary to keep the fluid pressure above of the valve element by draining it on the surface by operating the flow control valves so that the reservoir pressure is greater than ^ the actuation pressure above the safety valve. If there is a sufficient pressure difference at the throttle, to produce a force acting on the pipe that is sufficient in order to overcome the bias of the compression spring 80, the valve member, the valve and the throttle support element 90 and the tubular member 74 pushed upwards and the valve member 112 is due to the cooperation of the cam

20984 5/0921

and the groove 122 is rotated to the open position · This movement can be slow so that any bumping the valve parts is prevented, which would otherwise cause damage to the valve. During the Upon opening, the unlocking projection 168 remains in engagement with the splay fingers 150 until a sufficient resultant Force has been developed to cause the release tab to push the spreading fingers outward to unlock them. As a result, the pipe cannot come back be locked, which would otherwise happen when the piston moves up with a small pressure difference could move. After the valve member 112 has been fully opened and the full product flow is set again does the valve stay at rest until the flow of pressurized fluid? back to the predetermined Minimum level has been reduced, which is required to automatically switch the valve into its closed To take position.

Although the high and low flow valve actuators work together, the operation will each system is explained separately for simplification.

Assuming the safety valve 112 is in the open position or in the delivery mode and there are

209845/0921

normal operating conditions and a valve on the surface should suddenly open to the maximum Allow flow from the reservoir and the flow velocity is greater than the velocity for which the If valve actuation mechanisms have been designed for high-speed response, there will be a pressure drop take place at the throttle 94, which exerts sufficient force on the throttle to the low speed actuated section opened or left in the operating state by generating a relatively weak bias acting on the lower portion of the piston 180 compared to that by the reservoir pressure the orifices 200 exerted on the upper portion of the piston 180. If this is done, it will be by high Speed actuated tube 175 is moved downwards by the resulting force acting on piston 180, so that the spring 184 is compressed and the downward movement of the locking member 187 and the locking stops 190 causes. After the locking stops have been moved down a sufficient distance are to release the cylinder surface 192 according to FIG. 7, the cam surface 195 of the groove 191 presses the stops radially outwards, so that the stops are pulled out of the locking grooves and the valve operating tube 175 from release the bias of the compression spring 184 completely.

209845/0921

When the tube 175 is completely under the force of the spring 184 is relieved, the pressure of the reservoir lying on the piston 180 pushes the tube 175 downward, so that its Extended portion 183 engages the upper end of the valve actuating tube 74 with sufficient Force is applied to move the tube 74 downward and stop the valve.es 112 from rotating to its closed position cause and completely interrupt the product flow. By the pressure of the reservoir acting on the piston 180 a bias is maintained to hold the valve in its closed position. In addition, will the low speed responsive safety mechanism when the valve element 112 is closed by the high speed responsive mechanism preventing the valve from reopening should the fluid pressure in the reservoir suddenly drop.

The movement of the actuating tube 74 into a position in which the closing of the valve element 112 is effected, also causes the locking stops of the spreading fingers 150 to move for engagement with the locking groove of the tube 74 and prevents inadvertent opening of the valve element if the pressure conditions suddenly change should change.

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After the valve has been closed by actuation of the high speed responsive valve actuation system, the valve can be easily opened be reopened by applying a sufficiently high pressure one. Fluid is introduced into the linkage, to overcome the pressure of the reservoir outside the safety valve mechanism. The pressure introduced into the pipe string passes through passage 201 and acts onto the lower end of the piston 180 so that the piston and the actuating tube 175 are pushed upwards. Under In this condition, the link 187 and the stops 190 are in the position shown in FIG. if the locking groove 191 moves past the stops 190, causes the upward directed by the spring 184 generated force that the annular cam shoulder presses the stops into the locking groove 191. The stop member 187 moves up into the in 6, where the cylinder surface 192 prevents the stops from disengaging from the groove. In this condition, the tube 175 is locked again in the uppermost position and it does not move downward unless the velocity of the fluid becomes high enough to return to a predetermined one To generate pressure drop across the throttle.

209845/0321

The valve remains closed, however, but can easily be reopened by applying sufficient pressure in the piping and safety valve mechanism is inserted over the spherical body to the piston 156 to drive down and to spread the spreading fingers outwards, so that the connection between the stops 152 and the annular shoulder 148 of the tube 7 4 is interrupted. The pressure above the valve element can then decrease until operation is resumed in the desired flow range. ·

Assume the reservoir pressure remains at an optimal level, but a test should be performed to determine whether the safety valve is operational. In this case it is only necessary adjust the flow control device on the surface to control the flow of the product flow through the safety valve below or above the predetermined minimum or maximum volume to reduce or increase, which for the automatic actuation of the safety valve is required. When the valve is ready for actuation by a lower Flow is ready for operation, the compression spring 80 biases the tubular element 74 downward and causes the closing of the Spherical body 112 in the manner described above. For high flow actuation, the tube 175 and the press

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2220A03

Spring 80 the element 74 down to the ball element close. After a successful test has been completed, the safety valve can be opened again to remove the Letting the product flow through by simply reducing the flow pressure in the piping above the safety valve is introduced in the manner described. The test procedure is simple, reliable and very cheap. It is just required to remove the safety valve from the borehole for repair or replacement when testing delivers a corresponding result. The replacement or repair can be done quickly and cost-effectively as it is not required to remove the pipe string from the borehole. The cable pulling tool 32 can be unlocked and in a conventional manner Way can be pulled out together with the safety valve attached, and after the repair or Replacement process, the tool can be reinserted into the borehole in a simple, conventional manner.

It appears that a novel flow safety valve mechanism which acts in the borehole to interrupt the flow of product, if this should for some reason fall below a predetermined operating level. In the exemplary embodiment described, the product flow is also interrupted when it should rise above an allowable maximum level. The safety

209845/0 9 21

The safety valve mechanism also acts to close the product flow passage through the tubing at a cell-wave slowing down of the product flow, for example by closing a surface valve or could be caused by the build-up of sufficient back pressure in the pipe rod, wherein the product flow can at least temporarily fall below a predetermined minimum value. The novel valve can also be tested in a simple and effective manner to ensure that it is operational at all times ensure without an expensive test procedure or the To require removal of the pipe string from the borehole. Also by interrupting the product flow simply closing the valve, the product flow can only be prevented or reduced by the valve, while the surface flow control mechanism is serviced or repaired without the Endangering personnel. It is also a protection against unintentional reopening of the safety valve in several respects achieved as both the low speed and high speed systems operate when the valve is automatically closed by the high speed responsive system.

After an interruption in an emergency, a test procedure

20984S / Q921

or a repair procedure for the flow regulator on the Surface, the safety valve mechanism described can be opened again in a simple manner by in the Rphrgestänge above the safety valve pressure is supplied in the manner described. One such reopening can be effectively achieved without jerking the valve parts, otherwise what would happen if the valve parts were suddenly subjected to the pressure of the reservoir. The described Safety valve is suitable for easy connection with a conventional cable pulling tool, so that it can be put in place and removed from it by conventional cable pulling equipment can be. With this feature, the pipe rod does not have to be removed if the safety valve is cleaned, to be repaired or replaced. The safety valve can also be inside the pipe or in another Flow systems of various types can be used without departing from the scope of the invention. It understands finally, that a number of features or sub-combinations of features can be changed without to leave the scope of the invention. Accordingly, only one specific embodiment has been described above, which is not intended to limit the scope of the invention in any way.

45/0921

Claims (22)

Claims 1. Safety valve for protecting a borehole with a housing with a flow passage, which can be connected in a production line extending through a borehole, and a normally open valve in the housing, with the valve between open and closed Positions can be moved and regulates the throughput through the flow passage, characterized in that that in the housing (47, 48, 50, 51, 52, 54, 56) a responsive to low throughput device at a decrease in the throughput below a predetermined speed, the valve (112) closes and thus interrupts the flow of fluid through the flow passage. 2. Safety valve according to claim 1, characterized in that that the device responding to low throughput includes a device (74, 94, 80, 90, 112, 124, 122) which drives the valve in the closed position, and has means which open a predetermined flow rate is responsive to the operation of the rest position causing device to prevent when the product flow is above the predetermined speed, and the valve 209845/0321 2220-03 keeps open. * · 3. The safety valve of claim 2 in which the low flow rate responsive device having an actuator which moves the valve from the open to the closed position brings, characterized in that the device driving the valve is a biasing device (80) for the actuator which brings the valve (112) into the closed position and the low flow rate responsive device the low flow rate responsive actuator presses against the pretensioning device at a product throughput above a predetermined value. 4. Safety valve according to claim 3, characterized in that that the biasing device is a spring member (80) between the through low Throughput actuated 'organ (74) and the housing (52, 78, 82) is arranged. 5. Safety valve according to one of claims 1 to 4, characterized in that a constriction (94) is formed in and in the flow passage a pressure differential is formed and the device responsive to the low flow rate this pressure difference responds and the closing 209845/0921 of the passage regulates " 6. Safety valve according to claim 3 to 5, characterized in that that the actuated by low flow member comprises a tubular member (74) which is movable is arranged in the housing and forms part of the flow passage and which on the predetermined Throughput responding device (92, 94, 96) comprises a device which the constriction (94) forms in the tubular member responsive to low throughput and this against the biasing device (80) pushes when the product flow exceeds a predetermined flow rate. 7. Safety valve according to one of claims I to 6, characterized in that the valve has a spherical shape Has valve body (112) and the housing contains a device (122, 124) which the spherical body at its longitudinal displacement according to the device responding to low throughput a rotation notifies. 8. Safety valve according to one of claims 1 to 7, characterized in that a releasable locking device (50, 150, 152, 74, 154, 148) is provided that the valve is closed after it has been closed State holds. 209843/0921 9. Safety valve according to claim 8, characterized in that a device (156) is provided in order to unlock the locking device in the closed position of the valve in the event of an increase in pressure downstream of the valve. 10. Safety valve according to claim 9, characterized in that the unlocking device has a piston (156) which responds to an increase in pressure downstream of the valve in its closed position and moves from a retracted position moved to an unlocked position of the locking device. 11. Safety valve according to claim 3 and 10, characterized in that the locking device has a Means (150, 152, 146) carried by the housing (50) for low throughput to lock responsive actuator (74) in the closed position of the valve device (112) and the piston (156) has cam means (170, 172) for engaging the locking means in the unlocked position of the piston and for unlocking the low flow rate actuator. 12. Safety valve according to claim 5, 10 or 11, characterized 20984S / 0921 characterized in that the piston (156) is subjected to opposing forces caused by the Fluid pressures in the passage upstream of the valve (112) and downstream of the constriction (94) and in both directions between its withdrawn and its unlocked position. 13. Safety valve according to one of claims 1 to 12, characterized in that a high throughput responsive means (175, 62, 48, 180) to an increase in fluid flow rate the flow passage over a predetermined value responds and closes the passage and thus the product flow through the passage. 14. Safety valve according to claim 13, characterized in that that the device responsive to high throughput is a high throughput actuated organ (175) to operate the valve from the open in its closed position and the closing of the passage according to an increase in the fluid flow rate caused by the flow passage above a predetermined value. 15. Safety valve according to claim 14, 5 or 6, characterized characterized that the respond to high throughput de device responds to a pressure difference generated in the constriction (94) and the closure
the passage regulates. 16. Safety valve according to claim 3, 14 or 15, characterized in that the operated by high throughput organ drives the responsive to low throughput organ and the valve of the open in the
closed position with an increase in the flow of fluid through the flow passage
moved beyond a predetermined value. 17. Safety valve according to claim 14 to 16, characterized in that that the actuator responsive to high throughput is responsive to an increase in pressure downstream responds from the valve in its closed position and the movement of the valve from its closed position Permitted position in the open position. 18. Safety valve according to claim 13 to 17, characterized in that the actuated by high throughput
Organ includes a high flow rate responsive tube (175) forming part of the flow passage and movable between a retracted position and a valve actuating position;
a device operated by high throughput 2098A5 / 0921 if-3 22204C Holding tube in the retracted position provides a facility for an increase in fluid flow rate responds beyond a predetermined value and the device retaining the actuating tube releases and.this pipe into the valve actuating Position moved. 19. Safety valve according to claim 18, characterized in that the device retaining the pipe a groove (191) intended for pawls in the high-throughput tube (175), one in the Groove-received locking device (190), which is a releasable connection with the high throughput forms actuated tube, and a biasing means (184) between the housing (48) and the locking device is arranged, and the movement of the high flow rate actuated tube opposes a predetermined force in the retracted position in its actuating position. 20. Safety valve according to claim 18, 19, characterized in that that the device for unlocking a piston (180) on the responsive to high throughput Having tube (175) movable in a cylinder in the housing having a piston actuation chamber (199) and a device (200) forms the connection between the piston-actuating chamber and 209845/0921 so the product flow with the pressure of the reservoir and the tube operated by high throughput subject to a pressure difference that depends on the flow rate depends on the flow passage. 21. Safety valve according to claim 15 and 20, characterized in that the piston (180) is downstream is arranged by the constriction (96). 22. Safety valve according to claim 6 and one of the claims 18 to 21, characterized in that the tube (175) operated by a high throughput has a Has shoulder portion associated with the low flow rate responsive tube (74) in motion to the high flow rate operated tube operated position according to an increase in flow can come into engagement above a predetermined value and the valve of its open in its moved closed position. 23 «Safety valve according to one of claims 18 to 22, characterized in that the high flow rate actuated tube has means which act on a Increase in the fluid pressure above the pressure of the reservoir downstream of the valve in its closed Position and that through high 2 09845/0921 Flow actuated tube from its actuated position to its retracted position brings. 20984 5 / 09-2