US20180119862A1 - Subsea collet connection system having ejection and secondary unlocking capability - Google Patents
Subsea collet connection system having ejection and secondary unlocking capability Download PDFInfo
- Publication number
- US20180119862A1 US20180119862A1 US15/337,696 US201615337696A US2018119862A1 US 20180119862 A1 US20180119862 A1 US 20180119862A1 US 201615337696 A US201615337696 A US 201615337696A US 2018119862 A1 US2018119862 A1 US 2018119862A1
- Authority
- US
- United States
- Prior art keywords
- collet
- outer sleeve
- connector
- hub
- subsea
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L37/00—Couplings of the quick-acting type
- F16L37/62—Couplings of the quick-acting type pneumatically or hydraulically actuated
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B33/00—Sealing or packing boreholes or wells
- E21B33/02—Surface sealing or packing
- E21B33/03—Well heads; Setting-up thereof
- E21B33/035—Well heads; Setting-up thereof specially adapted for underwater installations
- E21B33/038—Connectors used on well heads, e.g. for connecting blow-out preventer and riser
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/01—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells specially adapted for obtaining from underwater installations
- E21B43/013—Connecting a production flow line to an underwater well head
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L1/00—Laying or reclaiming pipes; Repairing or joining pipes on or under water
- F16L1/26—Repairing or joining pipes on or under water
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L37/00—Couplings of the quick-acting type
- F16L37/002—Couplings of the quick-acting type which can be controlled at a distance
Definitions
- the present invention relates to the connecting of external items to a subsea structure. More particularly, the present invention relates to collet-type connection systems. Additionally, the present invention relates to a collet connection system that has an ejection capability.
- a popular type of connector assembly is a hydraulically-actuated collet connector which utilizes a series of segment clamps which are biased by other mechanical apparatus to releasably secure a pair of abutting flanges into a sealed assembly.
- Collet connectors and other acceptable connector mechanisms are generally utilized for connection of the wellhead valve system with the production system of the wellhead so that the wellhead valve assembly may be disconnected and removed in the event that replacement or repair is necessary.
- a multi-well subsea assembly can include subsea structures such a subsea trees, manifolds, and/or pipeline end terminations. These subsea structures can be interconnected by jumpers. The jumpers mate up with the subsea structures using connectors that mate with hubs on the subsea structures. Production is often routed from the trees in the gathering manifolds and from the gathering manifolds to pipeline end terminations and pipelines to the platform.
- Subsea connectors are known that can be suitably connected through the use of a remotely-operated vehicle (ROV).
- ROV remotely-operated vehicle
- the ROV will travel to the subsea structure, manipulate the hubs, and then apply a torque tool to the actuator of one of the connectors so as to achieve this connection.
- U.S. Pat. No. 4,477,105 issued on Oct. 16, 1984 to Wittman et al., teaches a collet-actuated ball-and-socket connector.
- This connector is for connecting the ends of two pipes.
- a ball coupling member is adapted for connection to the end of one of the pipes.
- a retaining flange is freely disposed about the ball coupling member and engages the outer surface of the member.
- a socket coupling member is adapted for connection to the end of the other of the two pipes and provided for accepting the ball coupling member so as to provide a metal sealing ring for mating with the ball members.
- a collet locking means is mounted about the outer periphery of the socket coupling member and extends generally axially therefrom for permitting insertion of the ball coupling member in mating engagement with the socket coupling member when the collet means is open.
- An actuating means applies a predetermined axial force to the collet locking means for closing the collet means to engage the retaining flange and lock the ball-and-socket coupling members together in a sealed rigid relationship.
- U.S. Pat. No. 4,693,497 issued on Sep. 15, 1987 to Pettus et al., describes a remotely-actuated collet connector which is suitable for joining tubular members with similar or different end preparations or profiles.
- the collet connector includes a housing to support the connector from a first tubular member, a plurality of collet fingers or segments mounted within the housing and around the exterior of the first tubular member, and an actuator ring surrounding the fingers to move the fingers to a release or latch position, and a pressure responsive means for moving the actuator ring.
- Each of the collet fingers has a first engaging surface and an adapter secured to the finger and also has a second engaging surface. The first engaging surface mates with the end profile of the first tubular member. The second engaging surface mates with the end profile of the second tubular member so that when the collet fingers are moved to the latch position they secure the first and second tubular members together.
- the cam ring and the collet segments have sets of camming surfaces whereby a first set is cooperative to pivot the collet segments initially toward the wellhead and whereby a second set serves to urge the collet segments further to clamp the connector to the subsea wellhead.
- the second set of camming surfaces function, the first set no longer functions to rotate the collet segments so as to reduce the power requirements for urging the collet segments into clamping engagement.
- U.S. Pat. No. 6,267,419 shows a remotely actuated clamping connector.
- the clamping connector includes clamp halves linked by a locking stem.
- the locking stem is forced into a pre-stressed state by moving the locking stem from a first relaxed position to a second pre-stressed position and retained in the second pre-stressed position by a locking collet.
- a locking collet through which the locking stem extends is moved from a first unlocked position to a second locked position wedged between the locking stem and one or the other of the clamp halves.
- the locking collet When the locking collet is in the second locked position, it resists movement of the locking stem from the second pre-stressed position to the first relaxed position. The locking collet is then locked in the second locked position.
- U.S. Patent Application Publication No. 2014/0361534 published on Dec. 11, 2014 to K. Bekkevold, describes a connector having a plurality of latching fingers arranged around a cylindrical body and having a central axis. Each finger has a first end region extending beyond an end of the body includes a first latching structure. Each finger is pivotally supported at an intermediate region by a portion of the body and is movable between a non-latching position and a latching position in which the first end region is closer to the central axis than in the non-latching position.
- the connector includes a first actuated member arranged in contact with a plurality of fingers and operable to move the fingers between the non-latching position and the latching position.
- An actuator is operable to force a second end region of each finger toward the body.
- the connector can be connected to a hub by bringing the connector face into contact with a hub face, moving the latching fingers toward the connector until the first latching structures are engaged in corresponding second latching structures on the hub, and then holding the latching structures together in a latching engagement.
- U.S. patent application Ser. No. 14/748,779 filed on Jun. 24, 2015 to the preset Applicant, describes a subsea connection system for connecting to a hub.
- the subsea connection system has a body with an interior passageway suitable for allowing fluids to flow therethrough, a collet having a plurality of collet segments that are movable between a locked position and unlocked position, an outer sleeve overlying the collet, and a translator cooperative with the outer sleeve so as to move the outer sleeve between a first position and a second position.
- the plurality of collet segments are in the unlocked position when the outer sleeve is in the first position.
- the plurality of collet segments are in the locked position when the outer sleeve is in the second position.
- the locked position secures the body in connection to the hub.
- It is another object of the present invention provide a collet connection system which effectively establishes a secure connection between flow passageways within the connectors.
- It is still another object of the present invention provide a collet connection system which avoids the release of polluting elements in the subsea environment.
- the present invention is a subsea connector system that comprises a first connector and a second connector.
- the first connector has a body with an interior passageway adapted to allow a fluid to flow therethrough, a collet having a plurality of collet segments that are movable between a locked position and an unlocked position, an outer sleeve overlying the collet, and a translator cooperative with the outer sleeve so as to move the outer sleeve forwardly so as to cause the plurality of collet segments to be in the locked position.
- the second connector includes a hub having a flow passageway adapted to allow a fluid to flow therethrough, a housing extending around the hub, and an actuator mounted on or in the housing.
- the plurality of collet segments engage the hub when in the locked position.
- the actuator is movable between an extended position and a retracted position.
- the actuator bears on a surface of the outer sleeve when in the extended position or on a surface extending outwardly of the outer sleeve of the first connector.
- the outer sleeve has a flange extending radially outwardly thereof.
- the actuator has an end bearing against the flange. The actuator urges the outer sleeve rearwardly when in the extended position.
- the outer sleeve is movable rearwardly so as to urge the plurality of collet segments toward the unlocked position.
- the actuator includes a plurality of actuators arranged in circumferentially spaced relation around the housing.
- the actuator includes a cylinder formed on an interior of the housing outwardly of the hub, a piston slidably movable in the cylinder, and a piston rod affixed to the piston and having an end extending outwardly which is adapted to selectively bear against the surface of the sleeve.
- the plurality of collet segments and at least a portion of the outer sleeve are received in an interior of the housing when the plurality of collet segments are in the locked position.
- the interior passageway of the body is in fluid communication with the flow passageway of the hub when the plurality of collet segments are in the locked position.
- the outer sleeve has an inner surface that bears against the outer surface of the plurality of collet segments as the outer sleeve moves forwardly and rearwardly. The movement of the outer sleeve rearwardly causes the plurality of collet segments to move to the unlocked position.
- the outer sleeve has a tapered surface at an end thereof that bears against an outwardly tapered surface at an end of the collet segments so as to cause the collet segments to move to the locked position.
- the outer sleeve has a tapered interior surface inwardly of the end thereof.
- the collet segments have an angled surface at an inner end thereof The tapered interior surface of the outer sleeve bears against the angled surface of the collet segments so as to cause the collet segments to move to the unlocked position when the outer sleeve moves rearwardly.
- the translator comprises a hydraulic circuit formed through the body so as to open the space between an exterior of the body in an interior of the sleeve.
- the present invention further includes a first poppet position in the interior passageway of the body at an end of the body and a second poppet position in the flow passageway of the hub adjacent to an end of the hub.
- the first poppet engages the second poppet when the plurality of collet segments are in the locked position.
- the first and second poppets respectively close the interior passageway and the flow passageway when the plurality of collet segments are in the unlocked position.
- the first and second poppets serve to block fluid flow outwardly of the respective interior passageway and flow passageway so as to prevent the release of pollutants into the subsea environment.
- FIG. 1 is a perspective view of the subsea connector system of the present invention showing the connectors as joined together.
- FIG. 2 is a perspective view of the subsea connector system of the present invention with the connectors being separated from each other.
- FIG. 3 is a cross-sectional view of the subsea connector system of the present invention showing the connectors as connected together.
- FIG. 4 is a cross-sectional view of the subsea connection system of the present invention showing the separation of the connectors.
- the subsea connection system 10 includes a first connector 12 and a second connector 14 .
- the first connector 12 as will be described hereinafter, is a collet connection system.
- An interior passageway 14 will extend through the interior of the first connector 12 so as to join with a flow passageway formed in the second connector 14 .
- a flange 16 is affixed to or formed with a sleeve 18 .
- the sleeve 18 along with the flange 16 , will be movable in relation to the mechanism on the interior of the first connector 12 .
- FIG. 1 it can be seen that the flange 16 is adjacent to an upper surface 20 of the second connector 14 .
- the second connector 14 has a housing 22 of a substantially cylindrical shape.
- a flange body 24 will extend outwardly of the housing 22 at the upper end thereof
- An upper end of a piston rod 28 is shown as emerging from the opening 26 . As will be described hereinafter, this end of the piston rod 28 can bear against the flange 16 so as to urge the separation of the first connector 12 from the second connector 14 .
- FIG. 2 shows the action of separating the first connector 12 from the second connector 14 .
- the present invention provides an actuator which serves to force the first connector 12 from the second connector 14 so that these connectors can separate in the subsea environment without external appliances.
- the present invention provides a system for moving the outer sleeve 18 and for unlocking the collet segments.
- FIG. 2 there are a plurality of piston rods 28 that emerge from the openings 26 and bear against the underside of the flange 16 . As such, this causes the sleeve 18 to move rearwardly and to cause the first connector 12 to separate from the second connector 14 .
- the end of the first connector 12 is illustrated as separated from the upper end of the second connector 14 .
- FIG. 3 is a cross-sectional view showing the relationship between the first connector 12 and the second connector 14 when the connectors are locked together.
- the first connector 12 includes a body 30 which has the interior passageway 14 extending therethrough.
- a collet having a plurality of collet segments 32 is located over the end of the body 30 at one end thereof.
- the collet segments 32 are movable between a locked position and an unlocked position. In FIG. 3 , the collet segments 32 are shown in the locked position.
- An outer sleeve 18 overlies the collet having the plurality of collet segments 32 .
- a translator 34 is cooperative with the outer sleeve 18 so as to move the outer sleeve forwardly so as to cause the plurality of collet segments 32 to be in the locked position.
- the second connector 14 has a hub 36 having a flow passageway 38 adapted to allow a fluid to flow therethrough. It can be seen that the plurality of collet segments 32 are engaged with the hub 36 when the plurality of collet segments 32 are in the locked position.
- a housing 40 extends around the hub 36 .
- An actuator 42 is mounted on or in the housing 40 . The actuator 42 is movable between an extended position and a retracted position. The retracted position shown in FIG. 3 .
- the outer sleeve 18 has the flange 16 extending radially outwardly thereof.
- the housing 40 has an interior 46 surrounding the hub 36 .
- both a portion of the outer sleeve 18 and the plurality of collet segments 32 are received in this interior 46 of the housing 40 .
- the interior passageway 14 of the body 30 is in fluid communication with the flow passageway 38 of the hub 36 when the plurality of collet segments 32 are in the locked position.
- the outer sleeve 18 has an inner surface 48 which bears against an outer surface 50 of the plurality of collet segments 32 .
- the outer sleeve 18 moves forwardly and rearwardly. The movement of the outer sleeve rearwardly will operate to cause the plurality of collet segments 32 to move to the unlocked position.
- the outer sleeve 18 has a tapered surface 52 at an end thereof. This tapered surface 52 will bear against an outwardly tapered surface 54 of the collet segments 32 so as to cause the collet segments 32 to move to the locked position.
- the movement of the outer sleeve 18 is carried out by the use of the translator 34 .
- the translator 34 includes a hydraulic circuit 60 so as to allow hydraulic fluid to be injected into a space 62 located between the inner surface of the sleeve 18 and the body 30 .
- the sleeve 18 has a first portion 64 and a second portion 66 that are affixed together. The injection of hydraulic fluid through the channel 60 will fill the space 62 so as to urge the sleeve 18 forwardly and thereby to urge the plurality of collet segments 32 over the hub 36 and into engagement over a shoulder of the hub 36 .
- the translator 34 In order to move the sleeve 18 rearwardly and away from the ends of the collet segments 32 , the translator 34 includes another hydraulic circuit 70 . As such, when hydraulic fluid is introduced through circuit 70 , the fluid will enter a space between the member 72 , the body 30 , and the interior of the sleeve 18 . At the same time, the hydraulic fluid in the space 62 will be evacuated through the hydraulic circuit 60 so that this movement occurs.
- FIG. 3 shows that there is a first poppet 74 and a second poppet 76 .
- the first poppet 74 has an end that is in abutment with the second poppet 76 . Since the internal passageway 14 is intended to be in fluid communication with the flow passageway 38 , the ends of the poppets 74 and 76 abut each other so as to cause the poppets 74 and 76 to be spaced away from the respective shoulders on the interiors of the interior passageway 14 and the flow passageway 38 . The force of abutment between the first poppet 74 and the second poppet 76 will overcome the resistance created by the respective springs.
- the end of the hub 36 is shown in tight abutment with the end of the body 30 so as to be in a tight sealing relationship therewith.
- a seal can be positioned at the end of the body 30 so as to further facilitate the tight sealing relationship between the end of the hub 36 and the end of the body 30 . Since the poppets 74 and 76 are separated from their seated position against the respective shoulders in the interior passageway 14 and the flow passageway 38 , a fluid flow connection is established between the hub 36 and the body 30 .
- FIG. 4 shows the separation of the first connector 12 from the second connector 14 .
- the separation would easily be accomplished by simply moving the collet segments 32 to their unlocked position. This is achieved by injecting hydraulic fluid through the hydraulic circuit 70 so as to fill a space 80 . This urges the outer sleeve 16 rearwardly. The fluid in the space 62 has been evacuated through channel 60 . As the outer sleeve 16 is retracted, a tapered interior surface 82 of the sleeve 16 will bear against an angled surface 84 of the collet segment 32 . This relationship will pivot the forward ends of the plurality of collet segments 32 outwardly so as to separate from the hub 36 .
- the tapered surface 52 at the end of the outer sleeve 16 will travel over the forward end of the collet segments 32 so as to allow the outward movement of the end of the collet segments 32 .
- the first poppet 74 will be seated against the inner shoulder on the interior passageway 14 of the body 30 . This will block fluid flow outwardly of the interior passageway 18 of the first connector 12 .
- the second poppet 76 will be seated against the interior shoulder of the flow passageway 38 of the second connector 14 by the action of the spring. Once again, fluid flow is prevented from leaving the hub 36 by action of the poppet 76 .
- the separation of the ends of the respective poppets 74 and 76 allow the respective springs to cause the poppet 74 and 76 to move to their fluid-sealing positions.
- the plurality of poppet segments 34 are in their unlocked position and separated from the hub 36 .
- the first connector 12 is not separated from the second connector 14 .
- This may be the action of corrosion, adhesion, or other factors.
- the second connector 14 has a particular mechanism so as to cause a positive separation of the first connector 12 from the second connector 14 .
- This mechanism can also serve to force the collet segments open in the rare event of a failure of the hydraulics or hydraulic circuits.
- the second connector 14 has a cylinder 90 formed therein.
- the piston 42 is slidably positioned within the cylinder 90 .
- a piston rod 92 is affixed to the piston 42 so as to travel with the movement of the piston 42 .
- a hydraulic circuit can be established so as to inject hydraulic fluid into the cylinders 90 so as to cause the piston 42 to travel forwardly and cause the piston rod 92 to move upwardly.
- FIG. 4 shows that the end surface 94 of the piston rod 92 bears against the flange 16 . As such, this will force the first connector 12 away from the second connector 14 .
- the present invention provides a back-up or failsafe capability to the connection system 10 .
- the actuator of the second connector 14 can be used so as to force this rearward movement.
- the present invention achieves a proper separation of the first connector 12 from the second connector 14 under emergency conditions.
- the collet segments 32 will separate from the hub 36 and the poppets 74 and 76 will move to a fluid-blocking seated position so that discharge into the subsea environment is prevented.
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Quick-Acting Or Multi-Walled Pipe Joints (AREA)
Abstract
Description
- Not applicable.
- Not applicable.
- Not applicable.
- Not applicable.
- The present invention relates to the connecting of external items to a subsea structure. More particularly, the present invention relates to collet-type connection systems. Additionally, the present invention relates to a collet connection system that has an ejection capability.
- Technology advances related to subsea petroleum exploration have resulted in the development of various conduit and wellhead connector mechanisms which may be remotely controlled for the purpose of achieving connection between mechanical and hydraulic apparatus of wellheads, conduits, and the like. A popular type of connector assembly is a hydraulically-actuated collet connector which utilizes a series of segment clamps which are biased by other mechanical apparatus to releasably secure a pair of abutting flanges into a sealed assembly. Collet connectors and other acceptable connector mechanisms are generally utilized for connection of the wellhead valve system with the production system of the wellhead so that the wellhead valve assembly may be disconnected and removed in the event that replacement or repair is necessary.
- A multi-well subsea assembly can include subsea structures such a subsea trees, manifolds, and/or pipeline end terminations. These subsea structures can be interconnected by jumpers. The jumpers mate up with the subsea structures using connectors that mate with hubs on the subsea structures. Production is often routed from the trees in the gathering manifolds and from the gathering manifolds to pipeline end terminations and pipelines to the platform.
- When dealing with subsea applications, it becomes necessary to simplify or eliminate the use of divers during the locking of a connector in order to secure the connection between the drilling or piping components in the wellhead. Hydraulically-actuated collet connectors have been developed and utilized for this purpose. These collet-type connectors are designed for high pressure in deepwater drilling operations. The collet connectors are secured over the mating sections of the drilling or piping components to be connected by use of hydraulic pressure. Because the hydraulic pressure can be controlled remotely, it is not necessary for divers to lock the collet connector in order to secure the connection.
- There are several problems associated with existing collet connectors. First, there is a possibility that one connector cannot separate from the other connector after the unlocking procedure is completed. Second, it becomes difficult to separate the connectors if the hydraulic system required for the unlocking should be compromised or damaged.
- In prior collet connection systems, the systems were effective in achieving a locking between the connectors. However, in certain conditions, as a result of corrosion, adhesion, or other forces, the connectors do not always separate when the collet segments are unlocked. As a result, external appliances are required in order to completely disengage the connectors. Often, this is a very time-consuming, expensive and difficult procedure. As such, a need has developed so as to be able to eject one connector from the other connector upon an unlocking of the collet segments. It is also important to have an ability to achieve an unlocking of the connectors in the event that the primary locking mechanism should fail.
- In order to allow for the proper connection and disconnection of hubs in the subsea environment, it is necessary to properly join such hubs in the subsea environment. Once the hubs are joined, then a liquid, chemical, or other fluid, can flow through the connector so as to be delivered to the tubing that is connected to the hubs or to a structure that is connected to one of the hubs. Under certain circumstances, it is desirable to release the connection of the hubs in the subsea environment. Unfortunately, when such hubs are disconnected, there will be a release of residual fluid into the subsea environment. This can produce environmental consequences. As such, a need has developed so as to be able to effectively close the interior passageways of the connected hubs upon the release of one hub from the other.
- Subsea connectors are known that can be suitably connected through the use of a remotely-operated vehicle (ROV). Typically, the ROV will travel to the subsea structure, manipulate the hubs, and then apply a torque tool to the actuator of one of the connectors so as to achieve this connection. However, it would be desirable to avoid the need to use the ROV so as to achieve the proper connection. Importantly, it would be desirable to be able to send remote signals so as to carry out the necessary operations whereby the connector can be properly used and manipulated so as to connect the hubs.
- In the past, various patents and patent application publications have issued with respect to collet-type connectors. For example, U.S. Pat. No. 3,523,579, issued on Aug. 11, 1970 to N. A. Nelson, describes a wellhead valve assembly which includes a plurality of hydraulically-actuated valves and an appropriate hydraulic fluid supply system for actuation of the valves. A hydraulically-actuated collet connector is provided for connecting production flow conduits and hydraulic fluid supply conduits to the wellhead valve assembly. The collet connector includes a means for remotely detecting leakage of production fluid or hydraulic fluid in the event that the joint between the wellhead valve assembly and the hydraulic collet connector should fail to properly seal.
- U.S. Pat. No. 4,477,105, issued on Oct. 16, 1984 to Wittman et al., teaches a collet-actuated ball-and-socket connector. This connector is for connecting the ends of two pipes. A ball coupling member is adapted for connection to the end of one of the pipes. A retaining flange is freely disposed about the ball coupling member and engages the outer surface of the member. A socket coupling member is adapted for connection to the end of the other of the two pipes and provided for accepting the ball coupling member so as to provide a metal sealing ring for mating with the ball members. A collet locking means is mounted about the outer periphery of the socket coupling member and extends generally axially therefrom for permitting insertion of the ball coupling member in mating engagement with the socket coupling member when the collet means is open. An actuating means applies a predetermined axial force to the collet locking means for closing the collet means to engage the retaining flange and lock the ball-and-socket coupling members together in a sealed rigid relationship.
- U.S. Pat. No. 4,693,497, issued on Sep. 15, 1987 to Pettus et al., describes a remotely-actuated collet connector which is suitable for joining tubular members with similar or different end preparations or profiles. The collet connector includes a housing to support the connector from a first tubular member, a plurality of collet fingers or segments mounted within the housing and around the exterior of the first tubular member, and an actuator ring surrounding the fingers to move the fingers to a release or latch position, and a pressure responsive means for moving the actuator ring. Each of the collet fingers has a first engaging surface and an adapter secured to the finger and also has a second engaging surface. The first engaging surface mates with the end profile of the first tubular member. The second engaging surface mates with the end profile of the second tubular member so that when the collet fingers are moved to the latch position they secure the first and second tubular members together.
- U.S. Pat. No. 4,708,376, issued on Nov. 24, 1987 to Jennings et al., shows a collet-type connector having an upper body member having a plurality of collet segments, a cam ring movable relative to the upper body member to move the collet segments into a detachable connection with the connector of a subsea wellhead. The cam ring and the collet segments have sets of camming surfaces whereby a first set is cooperative to pivot the collet segments initially toward the wellhead and whereby a second set serves to urge the collet segments further to clamp the connector to the subsea wellhead. When the second set of camming surfaces function, the first set no longer functions to rotate the collet segments so as to reduce the power requirements for urging the collet segments into clamping engagement.
- U.S. Pat. No. 6,267,419, issued on Jul. 31, 2001 to Baker et al., shows a remotely actuated clamping connector. The clamping connector includes clamp halves linked by a locking stem. The locking stem is forced into a pre-stressed state by moving the locking stem from a first relaxed position to a second pre-stressed position and retained in the second pre-stressed position by a locking collet. A locking collet through which the locking stem extends is moved from a first unlocked position to a second locked position wedged between the locking stem and one or the other of the clamp halves. When the locking collet is in the second locked position, it resists movement of the locking stem from the second pre-stressed position to the first relaxed position. The locking collet is then locked in the second locked position.
- U.S. Patent Application Publication No. 2014/0361534, published on Dec. 11, 2014 to K. Bekkevold, describes a connector having a plurality of latching fingers arranged around a cylindrical body and having a central axis. Each finger has a first end region extending beyond an end of the body includes a first latching structure. Each finger is pivotally supported at an intermediate region by a portion of the body and is movable between a non-latching position and a latching position in which the first end region is closer to the central axis than in the non-latching position. The connector includes a first actuated member arranged in contact with a plurality of fingers and operable to move the fingers between the non-latching position and the latching position. An actuator is operable to force a second end region of each finger toward the body. The connector can be connected to a hub by bringing the connector face into contact with a hub face, moving the latching fingers toward the connector until the first latching structures are engaged in corresponding second latching structures on the hub, and then holding the latching structures together in a latching engagement.
- U.S. patent application Ser. No. 14/748,779, filed on Jun. 24, 2015 to the preset Applicant, describes a subsea connection system for connecting to a hub. The subsea connection system has a body with an interior passageway suitable for allowing fluids to flow therethrough, a collet having a plurality of collet segments that are movable between a locked position and unlocked position, an outer sleeve overlying the collet, and a translator cooperative with the outer sleeve so as to move the outer sleeve between a first position and a second position. The plurality of collet segments are in the unlocked position when the outer sleeve is in the first position. The plurality of collet segments are in the locked position when the outer sleeve is in the second position. The locked position secures the body in connection to the hub.
- It is an object of the present invention to provide a collet connection system that allows for the ability to eject one connector from another connector.
- It is another object of the present invention to provide a collet connection system which avoids the need for external appliances in order to achieve a proper separation of the connectors.
- It is another object of the present invention provide a collet connection system which effectively establishes a secure connection between flow passageways within the connectors.
- It is another object of the present invention to provide a collet connection system which can provide a secondary unlocking of the connectors.
- It is another object of the present invention to provide a collet connection system in which the ejection of one connector from the other connector is achieved in a simple, fast, and efficient manner.
- It is still another object of the present invention to provide a collet connection system that can effectively operate as a vertical connector in a subsea environment.
- It is still another object of the present invention provide a collet connection system which avoids the release of polluting elements in the subsea environment.
- These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.
- The present invention is a subsea connector system that comprises a first connector and a second connector. The first connector has a body with an interior passageway adapted to allow a fluid to flow therethrough, a collet having a plurality of collet segments that are movable between a locked position and an unlocked position, an outer sleeve overlying the collet, and a translator cooperative with the outer sleeve so as to move the outer sleeve forwardly so as to cause the plurality of collet segments to be in the locked position. The second connector includes a hub having a flow passageway adapted to allow a fluid to flow therethrough, a housing extending around the hub, and an actuator mounted on or in the housing. The plurality of collet segments engage the hub when in the locked position. The actuator is movable between an extended position and a retracted position. The actuator bears on a surface of the outer sleeve when in the extended position or on a surface extending outwardly of the outer sleeve of the first connector.
- The outer sleeve has a flange extending radially outwardly thereof. The actuator has an end bearing against the flange. The actuator urges the outer sleeve rearwardly when in the extended position. The outer sleeve is movable rearwardly so as to urge the plurality of collet segments toward the unlocked position.
- The actuator includes a plurality of actuators arranged in circumferentially spaced relation around the housing. In particular, the actuator includes a cylinder formed on an interior of the housing outwardly of the hub, a piston slidably movable in the cylinder, and a piston rod affixed to the piston and having an end extending outwardly which is adapted to selectively bear against the surface of the sleeve.
- The plurality of collet segments and at least a portion of the outer sleeve are received in an interior of the housing when the plurality of collet segments are in the locked position. The interior passageway of the body is in fluid communication with the flow passageway of the hub when the plurality of collet segments are in the locked position. The outer sleeve has an inner surface that bears against the outer surface of the plurality of collet segments as the outer sleeve moves forwardly and rearwardly. The movement of the outer sleeve rearwardly causes the plurality of collet segments to move to the unlocked position. The outer sleeve has a tapered surface at an end thereof that bears against an outwardly tapered surface at an end of the collet segments so as to cause the collet segments to move to the locked position. The outer sleeve has a tapered interior surface inwardly of the end thereof. The collet segments have an angled surface at an inner end thereof The tapered interior surface of the outer sleeve bears against the angled surface of the collet segments so as to cause the collet segments to move to the unlocked position when the outer sleeve moves rearwardly.
- In the present invention, the translator comprises a hydraulic circuit formed through the body so as to open the space between an exterior of the body in an interior of the sleeve. The present invention further includes a first poppet position in the interior passageway of the body at an end of the body and a second poppet position in the flow passageway of the hub adjacent to an end of the hub. The first poppet engages the second poppet when the plurality of collet segments are in the locked position. The first and second poppets respectively close the interior passageway and the flow passageway when the plurality of collet segments are in the unlocked position. As such, when the first connector is separated from the second connector, the first and second poppets serve to block fluid flow outwardly of the respective interior passageway and flow passageway so as to prevent the release of pollutants into the subsea environment.
- The foregoing Section is intended describe, with particularity, the preferred embodiment of the present invention. It is understood that modifications to this preferred embodiment can be made within the scope of the present claims. As such, the Section should not be construed, in any way, as limiting of the broad scope of the present invention. The present invention should only be limited by the following claims and their legal equivalents.
-
FIG. 1 is a perspective view of the subsea connector system of the present invention showing the connectors as joined together. -
FIG. 2 is a perspective view of the subsea connector system of the present invention with the connectors being separated from each other. -
FIG. 3 is a cross-sectional view of the subsea connector system of the present invention showing the connectors as connected together. -
FIG. 4 is a cross-sectional view of the subsea connection system of the present invention showing the separation of the connectors. - Referring to
FIG. 1 , there is shown thesubsea connection system 10 in accordance with the teachings of the present invention. Thesubsea connection system 10 includes afirst connector 12 and asecond connector 14. Thefirst connector 12, as will be described hereinafter, is a collet connection system. Aninterior passageway 14 will extend through the interior of thefirst connector 12 so as to join with a flow passageway formed in thesecond connector 14. Aflange 16 is affixed to or formed with asleeve 18. Thesleeve 18, along with theflange 16, will be movable in relation to the mechanism on the interior of thefirst connector 12. InFIG. 1 , it can be seen that theflange 16 is adjacent to anupper surface 20 of thesecond connector 14. - The
second connector 14 has ahousing 22 of a substantially cylindrical shape. Aflange body 24 will extend outwardly of thehousing 22 at the upper end thereof There are a plurality ofopenings 26 that are formed in theupper flange 24. Theseopenings 26 are illustrated as located directly below the lower surface of theflange 16. An upper end of apiston rod 28 is shown as emerging from theopening 26. As will be described hereinafter, this end of thepiston rod 28 can bear against theflange 16 so as to urge the separation of thefirst connector 12 from thesecond connector 14. -
FIG. 2 shows the action of separating thefirst connector 12 from thesecond connector 14. In subsea connections, it is important to be able to eject thefirst connector 12 from thesecond connector 14. The present invention provides an actuator which serves to force thefirst connector 12 from thesecond connector 14 so that these connectors can separate in the subsea environment without external appliances. Also, the present invention provides a system for moving theouter sleeve 18 and for unlocking the collet segments. - As can be seen in
FIG. 2 , there are a plurality ofpiston rods 28 that emerge from theopenings 26 and bear against the underside of theflange 16. As such, this causes thesleeve 18 to move rearwardly and to cause thefirst connector 12 to separate from thesecond connector 14. The end of thefirst connector 12 is illustrated as separated from the upper end of thesecond connector 14. -
FIG. 3 is a cross-sectional view showing the relationship between thefirst connector 12 and thesecond connector 14 when the connectors are locked together. Thefirst connector 12 includes abody 30 which has theinterior passageway 14 extending therethrough. A collet having a plurality ofcollet segments 32 is located over the end of thebody 30 at one end thereof. Thecollet segments 32 are movable between a locked position and an unlocked position. InFIG. 3 , thecollet segments 32 are shown in the locked position. Anouter sleeve 18 overlies the collet having the plurality ofcollet segments 32. Atranslator 34 is cooperative with theouter sleeve 18 so as to move the outer sleeve forwardly so as to cause the plurality ofcollet segments 32 to be in the locked position. - The
second connector 14 has ahub 36 having aflow passageway 38 adapted to allow a fluid to flow therethrough. It can be seen that the plurality ofcollet segments 32 are engaged with thehub 36 when the plurality ofcollet segments 32 are in the locked position. Ahousing 40 extends around thehub 36. Anactuator 42 is mounted on or in thehousing 40. Theactuator 42 is movable between an extended position and a retracted position. The retracted position shown inFIG. 3 . - In
FIG. 3 , it can be seen that theouter sleeve 18 has theflange 16 extending radially outwardly thereof. Thehousing 40 has an interior 46 surrounding thehub 36. InFIG. 3 , with the plurality ofcollet segments 32 in the locked position, both a portion of theouter sleeve 18 and the plurality ofcollet segments 32 are received in this interior 46 of thehousing 40. In this configuration, theinterior passageway 14 of thebody 30 is in fluid communication with theflow passageway 38 of thehub 36 when the plurality ofcollet segments 32 are in the locked position. - The
outer sleeve 18 has aninner surface 48 which bears against anouter surface 50 of the plurality ofcollet segments 32. Theouter sleeve 18, as will be described hereinafter, moves forwardly and rearwardly. The movement of the outer sleeve rearwardly will operate to cause the plurality ofcollet segments 32 to move to the unlocked position. In particular, theouter sleeve 18 has a taperedsurface 52 at an end thereof. Thistapered surface 52 will bear against an outwardly tapered surface 54 of thecollet segments 32 so as to cause thecollet segments 32 to move to the locked position. Ultimately, it can be seen that the end of thesleeve 18 will entirely overlie the back surface of the forward and of thecollet segment 32 so as to securely lock thecollet segments 32 over thehub 36. This closed relation is further enhanced by the fitting of thesleeve 16 within theinterior 46 of the housing for of thehousing 40. - The movement of the
outer sleeve 18 is carried out by the use of thetranslator 34. In particular, thetranslator 34 includes ahydraulic circuit 60 so as to allow hydraulic fluid to be injected into aspace 62 located between the inner surface of thesleeve 18 and thebody 30. In particular, it can be seen that thesleeve 18 has afirst portion 64 and asecond portion 66 that are affixed together. The injection of hydraulic fluid through thechannel 60 will fill thespace 62 so as to urge thesleeve 18 forwardly and thereby to urge the plurality ofcollet segments 32 over thehub 36 and into engagement over a shoulder of thehub 36. In order to move thesleeve 18 rearwardly and away from the ends of thecollet segments 32, thetranslator 34 includes anotherhydraulic circuit 70. As such, when hydraulic fluid is introduced throughcircuit 70, the fluid will enter a space between themember 72, thebody 30, and the interior of thesleeve 18. At the same time, the hydraulic fluid in thespace 62 will be evacuated through thehydraulic circuit 60 so that this movement occurs. -
FIG. 3 shows that there is a first poppet 74 and a second poppet 76. The first poppet 74 has an end that is in abutment with the second poppet 76. Since theinternal passageway 14 is intended to be in fluid communication with theflow passageway 38, the ends of the poppets 74 and 76 abut each other so as to cause the poppets 74 and 76 to be spaced away from the respective shoulders on the interiors of theinterior passageway 14 and theflow passageway 38. The force of abutment between the first poppet 74 and the second poppet 76 will overcome the resistance created by the respective springs. Also, the end of thehub 36 is shown in tight abutment with the end of thebody 30 so as to be in a tight sealing relationship therewith. A seal can be positioned at the end of thebody 30 so as to further facilitate the tight sealing relationship between the end of thehub 36 and the end of thebody 30. Since the poppets 74 and 76 are separated from their seated position against the respective shoulders in theinterior passageway 14 and theflow passageway 38, a fluid flow connection is established between thehub 36 and thebody 30. -
FIG. 4 shows the separation of thefirst connector 12 from thesecond connector 14. In normal use, the separation would easily be accomplished by simply moving thecollet segments 32 to their unlocked position. This is achieved by injecting hydraulic fluid through thehydraulic circuit 70 so as to fill aspace 80. This urges theouter sleeve 16 rearwardly. The fluid in thespace 62 has been evacuated throughchannel 60. As theouter sleeve 16 is retracted, a taperedinterior surface 82 of thesleeve 16 will bear against anangled surface 84 of thecollet segment 32. This relationship will pivot the forward ends of the plurality ofcollet segments 32 outwardly so as to separate from thehub 36. The taperedsurface 52 at the end of theouter sleeve 16 will travel over the forward end of thecollet segments 32 so as to allow the outward movement of the end of thecollet segments 32. In this configuration, it can be seen that the first poppet 74 will be seated against the inner shoulder on theinterior passageway 14 of thebody 30. This will block fluid flow outwardly of theinterior passageway 18 of thefirst connector 12. Similarly, the second poppet 76 will be seated against the interior shoulder of theflow passageway 38 of thesecond connector 14 by the action of the spring. Once again, fluid flow is prevented from leaving thehub 36 by action of the poppet 76. The separation of the ends of the respective poppets 74 and 76 allow the respective springs to cause the poppet 74 and 76 to move to their fluid-sealing positions. - It has been found that, under certain circumstances, the plurality of
poppet segments 34 are in their unlocked position and separated from thehub 36. However, thefirst connector 12 is not separated from thesecond connector 14. This may be the action of corrosion, adhesion, or other factors. As such, for purposes of assuring a proper ejection of thefirst connector 12 from thesecond connector 14, thesecond connector 14 has a particular mechanism so as to cause a positive separation of thefirst connector 12 from thesecond connector 14. This mechanism can also serve to force the collet segments open in the rare event of a failure of the hydraulics or hydraulic circuits. - In particular, the
second connector 14 has acylinder 90 formed therein. Thepiston 42 is slidably positioned within thecylinder 90. Apiston rod 92 is affixed to thepiston 42 so as to travel with the movement of thepiston 42. A hydraulic circuit can be established so as to inject hydraulic fluid into thecylinders 90 so as to cause thepiston 42 to travel forwardly and cause thepiston rod 92 to move upwardly. -
FIG. 4 shows that theend surface 94 of thepiston rod 92 bears against theflange 16. As such, this will force thefirst connector 12 away from thesecond connector 14. In other circumstances, however, there could possibly be a failure of the 60 and 70. As such, it would not be possible to move thehydraulic circuits outer sleeve 18 rearwardly so as to cause the plurality ofcollet segments 32 to separate from thehub 36. As such, the present invention provides a back-up or failsafe capability to theconnection system 10. In particular, if there is a failure of the 60 or 70 such that the rearward movement of thehydraulic circuits outer sleeve 18 was not possible, then the actuator of thesecond connector 14 can be used so as to force this rearward movement. As thepiston rod 92 urges against theflange 16, the force of this urging forces theouter sleeve 18 to move rearwardly and, as a result, causes the interior taperedsurface 84 of theyouter sleeve 18 to bear against theangled surface 84 of thecollet segment 32 so as to force thecollet segments 32 to pivot outwardly and separate from thehub 36. As such, the present invention achieves a proper separation of thefirst connector 12 from thesecond connector 14 under emergency conditions. - As the
second connector 14 drops away from thefirst connector 12, thecollet segments 32 will separate from thehub 36 and the poppets 74 and 76 will move to a fluid-blocking seated position so that discharge into the subsea environment is prevented. - The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.
Claims (20)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15/337,696 US9970582B1 (en) | 2016-10-28 | 2016-10-28 | Subsea collet connection system having ejection and secondary unlocking capability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US15/337,696 US9970582B1 (en) | 2016-10-28 | 2016-10-28 | Subsea collet connection system having ejection and secondary unlocking capability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| US20180119862A1 true US20180119862A1 (en) | 2018-05-03 |
| US9970582B1 US9970582B1 (en) | 2018-05-15 |
Family
ID=62022185
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US15/337,696 Active US9970582B1 (en) | 2016-10-28 | 2016-10-28 | Subsea collet connection system having ejection and secondary unlocking capability |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US9970582B1 (en) |
Family Cites Families (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3523579A (en) | 1968-11-15 | 1970-08-11 | Acf Ind Inc | Subsea wellhead valve system and collet connector mechanism therefor |
| US4477105A (en) | 1981-04-30 | 1984-10-16 | Hughes Tool Company | Collet actuated ball and socket connector |
| US4491346A (en) * | 1982-11-01 | 1985-01-01 | Dril-Quip, Inc. | Apparatus for releasably connecting tubular members in end-to-end relation |
| US4708376A (en) | 1986-01-31 | 1987-11-24 | Vetco Gray Inc. | Hydraulic collet-type connector |
| US4693497A (en) | 1986-06-19 | 1987-09-15 | Cameron Iron Works, Inc. | Collet connector |
| US4823878A (en) * | 1987-10-08 | 1989-04-25 | Vetco Gray Inc. | Guidelineless reentry system with fixed rollers |
| US6267419B1 (en) | 1998-10-19 | 2001-07-31 | Cooper Cameron Corporation | Remotely actuated and locked hub clamp |
| US6805382B2 (en) * | 2002-03-06 | 2004-10-19 | Abb Vetco Gray Inc. | One stroke soft-land flowline connector |
| US8186393B2 (en) * | 2008-07-24 | 2012-05-29 | Deere & Company | Fluid coupler including valve arrangement for connecting intake conduit of sprayer to transfer conduit of nurse tank during refill operation |
| NO20111776A1 (en) | 2011-12-27 | 2013-06-28 | Fmc Kongsberg Subsea As | Undervannskonnektor |
| CN104334823B (en) * | 2012-04-05 | 2017-03-01 | 国民油井华高公司 | Wellsite connector with piston driven sleeve and method of use |
| EP2722479B1 (en) * | 2012-10-17 | 2016-04-27 | Vetco Gray Scandinavia AS | Subsea arrangement |
-
2016
- 2016-10-28 US US15/337,696 patent/US9970582B1/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| US9970582B1 (en) | 2018-05-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9617819B2 (en) | Subsea collet connection system | |
| US10156114B2 (en) | Poppet assembly for use in a subsea connection system | |
| US4200312A (en) | Subsea flowline connector | |
| US9309739B2 (en) | Stab connector assembly and methods usable for establishing a fluid connection | |
| US5829480A (en) | Locking device for undersea hydraulic coupling | |
| US4768538A (en) | Radial seal hydraulic coupler | |
| US4188050A (en) | Remote-controlled flowline connector | |
| US11441707B2 (en) | Hands free gasket retention mechanism | |
| US4469136A (en) | Subsea flowline connector | |
| CA1319166C (en) | Connector for fluid carrying conduits | |
| WO1991015704A1 (en) | Radial seal fluid couplers | |
| US6123103A (en) | Pressure balanced coupling with split body | |
| US5868524A (en) | Clamp system and method for connecting tubular bodies together | |
| US9890885B2 (en) | Collet connection system for a subsea structure | |
| AU742028B2 (en) | Undersea hydraulic coupling with locking mechanism | |
| US7806187B2 (en) | Connector assembly for connecting a hot stab to a hydraulic hose | |
| US6202690B1 (en) | Pressure balanced undersea hydraulic coupling | |
| US7762525B2 (en) | Pressure-balanced undersea hydraulic coupling | |
| US8668230B2 (en) | Apparatus and methods for splicing conduits and hoses subsea | |
| US9970582B1 (en) | Subsea collet connection system having ejection and secondary unlocking capability | |
| WO2017222560A1 (en) | Collet connection system for a subsea structure | |
| US4326328A (en) | Method of releasably connecting a pair of pipes | |
| US20050212286A1 (en) | Junction plate assembly for undersea hydraulic couplings | |
| US20240141768A1 (en) | Dynamic manifold locking system | |
| JPS5911799B2 (en) | fitting |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: TRENDSETTER ENGINEERING, INC., TEXAS Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:COX, BRENT;PARTRIDGE, JEFFREY;REEL/FRAME:040899/0821 Effective date: 20161214 |
|
| STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
| FEPP | Fee payment procedure |
Free format text: MAINTENANCE FEE REMINDER MAILED (ORIGINAL EVENT CODE: REM.); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
| FEPP | Fee payment procedure |
Free format text: SURCHARGE FOR LATE PAYMENT, SMALL ENTITY (ORIGINAL EVENT CODE: M2554); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY |
|
| MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: M2551); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY Year of fee payment: 4 |
|
| MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YR, SMALL ENTITY (ORIGINAL EVENT CODE: M2552); ENTITY STATUS OF PATENT OWNER: SMALL ENTITY Year of fee payment: 8 |