Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L1/00—Measuring force or stress, in general
  • G01L1/18—Measuring force or stress, in general using properties of piezo-resistive materials, i.e. materials of which the ohmic resistance varies according to changes in magnitude or direction of force applied to the material
• • 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
  • E21B34/00—Valve arrangements for boreholes or wells
  • E21B34/06—Valve arrangements for boreholes or wells in wells
  • E21B34/066—Valve arrangements for boreholes or wells in wells electrically actuated
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L5/00—Apparatus for, or methods of, measuring force, work, mechanical power, or torque, specially adapted for specific purposes
  • G01L5/0061—Force sensors associated with industrial machines or actuators

Definitions

• valve devices In the oil and natural gas industry, a number of valve devices are known that are used in boreholes or in the conveyance of oil and natural gas. Examples of such valve devices are slide valves, butterfly valves, ball valves, blow-out preventers and the like. Such devices may be electrified and use electric actuators to activate the associated valve device.
• electrical actuators may be mounted to the valve devices from the outside by means of an actuator housing.
• a displacement device may be arranged within the actuator housing that is movably held in the actuator housing and that is driven by an electric motor.
• the displacement device has a dynamic connection to a corresponding valve element for displacement of the valve element between, for example, a closed and an open position.
• the electric motor can be a single motor or also a combination of two or more motors.
• Such electric actuators are known, for example, from WO 2011/009471 and WO 2011/006519.
• an electric actuator registers forces and/or pressures that arise therein. These forces and/or pressures are registered both in the case of a static load and in the case of dynamic load changes. Additionally, the forces and/or pressures are registered reliably and with the exclusion of disturbance variables in order to increase the operational reliability of corresponding valve devices.
• At least one force / pressure measurement sensor is used that is arranged between the actuator housing and the displacement device.
• This sensor has, on its interior sides that face each other, two rings coated with a piezoresistive sensor layer that forms one or more measurement surfaces.
• a separating foil ring is arranged between these rings.
• a measurement voltage is applied between the separating foil ring and one of the rings for determining a force / pressure-dependent resistance level.
• piezo-elements for force or pressure measurement.
• Such piezo-elements allow a measurement only if, for example, charges are given off, i.e., if force changes change the electronic charge of the piezo-element. In the event of static loads without a load change, on the other hand, no signal is given off.
• the combination of electric actuator and force / pressure measurement sensor of the above- described type makes it possible to measure forces directly in the drive of the actuator, and thus to measure real loads directly, particularly in the valve device activated by the actuator. This is important, for example, in electric blow-out preventers, in order to detect corresponding loading during the drilling process or during snubbing. Due to this determination of the forces or loads, it is also possible to minimize abrasion on the valve elements of the blow-out preventer or also on other valve devices and in this way, for example, to noticeably increase the operational reliability.
• frictional force / displacement diagrams can likewise be determined that can be measured directly at the valve element or via the displacement device. This means three-dimensional characteristic diagrams can be generated in real time during the operation of the corresponding valve device, whereby these characteristic diagrams allow precise service life statements to be made.
• the piezoresistive sensor layer is a diamond-like carbon (DLC) layer.
• DLC diamond-like carbon
• These layers have special characteristics with respect to hardness, friction coefficient and the like.
• the layers are amorphous and are manufactured, for example, by plasma-supported sputtering on the corresponding interior sides of the sensor rings.
• the layers continue to be flexible, so that given the corresponding flexibility of the sensor rings, the sensor as a whole can be formed in a flexible manner.
• Such DLC layers are also used, for example, for increasing the resistance of steel or the like with respect to wear and tear, which is advantageous particularly in connection with use in the oil / gas industry.
• the high pressure resistance of such a layer is furthermore advantageous in this application area, because, for example, forces of up to 100 tons can arise in the corresponding valve devices.
• the rings can be formed as washers, particularly made of steel.
• the separating foil ring is a steel foil ring. This can be manufactured by laser cutting, for example.
• the separating foil ring can have a connecting contact that extends radially outward from the sensor. Naturally a plurality of these connecting contacts can also be provided. Contacting of the exterior surface of a corresponding ring can take place directly on the exterior surface.
• rings and separating foil ring can be connected to each other at their edges.
• An advantageous connection comes about by gluing, so that the sensor is correspondingly sealed with respect to the outside, which is advantageous in the case of use in the oil / natural gas industry and particularly in the case of maritime wells.
• the sensor layer itself with a further layer, such as, for example, a chromium layer, a doped layer, an insulation layer or the like, in order to protect this layer from external influences.
• a further layer such as, for example, a chromium layer, a doped layer, an insulation layer or the like, in order to protect this layer from external influences.
• the senor has a layer composition that has a thickness of only a few millimeters, for example, 4 to 10 millimeters.
• the sensor can be inserted into the corresponding flux of force between the electric drive and valve element or the displacement device in different locations within the electric actuator.
• the senor can be formed in a flexible manner. As a result, it can be adapted to the corresponding installation location even if there are curvatures in this area. This means that the sensor can do more than only measure force / pressure in a plane, which, for example, could be implemented by flat measurement surfaces of the force / pressure measurement sensor. Additionally, the sensor can also have a measurement surface or measurement surfaces arranged to extend in three dimensions and / or in space. As a result, the sensor is essentially independent of shape or support surface compulsions / requirements regarding its installation location.
• Measurements are made not only in flat areas, but also in three-dimensional areas, in a plurality of planes, in curvatures or along curvatures and, in particular, a plurality of measurement surfaces can be arranged along these areas, either connected to one another or separated from one another. This also applies analogously to measurement surfaces or sensor surfaces in the circumferential direction of the corresponding rings.
• Force-selective measurement is possible due to this versatile manner of measurement. This makes it possible to eliminate disturbance variables that falsify the forces already in the sensor.
• a possible arrangement of the sensor results by having this sensor allocated to a holding device for holding the displacement device in the actuator housing.
• a holding device is formed, for example, by tapered roller bearings or the like, whereby other mounts are also possible.
• the sensor is allocated to a support device for holding the displacement device in the actuator housing.
• a support device can be an at least partially circumferential projection on which the displacement device is supported within the actuator housing.
• the described ring shape of the sensor results from the use of the electric actuator, in which, generally, the displacement device is a ball screw that is driven by one or more electric motors.
• the ball nut may be held in the actuator housing in such a manner that it can rotate, so that the corresponding recirculating ball spindle is displaced in the axial direction with the rotation of the nut.
• the corresponding forces are absorbed by the valve element and the recirculating ball spindle via the recirculating ball nut and transferred to the actuator housing.
• ring shapes are conceivable that are formed with a circular, ellipsoid, generally oval or polygonal shape. It is likewise possible that the sensor has a discoidal shape. Other sensor shapes are within the scope of the present disclosure.
• the present disclosure particularly relates to a use of such a force / pressure measurement sensor in an electric actuator such as that which has been described.
• the present disclosure also relates to the corresponding features of the force / pressure measurement sensor as explained above and in further detail below.
• Figure 1 a longitudinal section through an embodiment of an electric actuator
• Figure 2 a top view onto a force / pressure measurement sensor with a detail "X";
• Figure 3 a side view of the force / pressure measurement sensor according to Figure 2
• Figure 4 a side view similar to Figure 3 for a further embodiment of a force / pressure measurement sensor.
• Such a force / pressure measurement sensor can be used for all electric actuators in the oil / natural gas industry. It can also be retrofitted to existing actuators and allows new control or detection options which have been explained above. A corresponding sensor furthermore requires only two electric connections, but no sealing and no kind of pressure encapsulation, for example, in the oil of the electric actuator, whereby pressure compensation with regard to the ocean depth pressure can be provided in the actuator by means of the corresponding oil pressure.
• Figure " 1 shows a longitudinal section through an electric actuator 1 according to the application.
• One such electric actuator 1 is, for example, described in more detail in WO 2011/009471 and WO 2011/006519.
• the actuator 1 has at least an actuator housing 3, which is detachably mounted on one side to a valve device 2 partially shown in dashed lines.
• the actuator housing 3 has a plurality of parts that are connected to one another and that enclose an interior.
• a displacement device 5 is arranged in this interior.
• the displacement device 5 can be driven by an electric motor 4.
• the electric motor 4 is formed as a step motor, whereby the stator is coupled to the actuator housing 3 and the rotor is coupled to the displacement device 5.
• a portion of the displacement device 5 is rotated by the rotor, whereby the displacement device 5 furthermore has a ball screw comprising a recirculating ball spindle 26 and ball nut 27.
• the ball nut 27 is rotated by the electric motor 4 by means of a rotating sleeve 28 and is held within the actuator housing 3 in a manner that does not allow axial/longitudinal displacement.
• Holding devices 21 and 22, in the form of tapered roller bearings, are used to rotate the corresponding rotating sleeve 28.
• the rotating sleeve 28 is supported on the actuator housing 3 by means of these mountings.
• the recirculating ball spindle 26 has a dynamic connection to a valve component of the valve device 2, which is not shown. The valve component is slid into its opened or closed position by means of axial displacement of the valve component.
• the recirculating ball spindle 26 is connected to a pintle 29 by means of an adjustment head 25.
• the pintle 29 is connected to the valve component in a dynamic connection in a manner that is not shown.
• Force / pressure measurement sensors 6 and 7 are arranged in the area of the rotating holder of the displacement device 5 on the actuator housing 3. These are constructed with a ring shape and installed in a pre-tensioned manner between the tapered roller bearings 21 ,22 and the actuator housing 3 for tension and pressure measurement. Corresponding electric connections are shown only in part, in particular in Figures 2-4.
• the corresponding sensors do not require sealing or pressure encapsulation in the oil of the actuator.
• the oil of the actuator is used for compensating for the pressure of the ocean depth pressure.
• a corresponding load flow of the tensile / pressure forces from the valve device 2 is effected going directly through the tapered roller bearings 21 , 22 and over the sensors 6,7 on to the actuator housing 3.
• no force deflection occurs.
• both static and dynamic forces / pressures are precisely and reliably registered, and in some cases are registered in real time.
• the sensors are arranged between displacement device 5 and the actuator housing 3 and allocated according to the roller bearings 21 , 22.
• the sensors 6, 7 may be allocated to a support device 23 of the actuator housing 3 for holding the displacement device 5 in the actuator housing 3.
• the electric actuator 1 is only described as an exemplary environment for the use of the sensors 6, 7, although one skilled in the art appreciates that other embodiments are within the scope of the present disclosure.
• the use of the sensors 6, 7, as shown in the following figures, is applicable for the electric actuator as shown in Figure 1 and also for electric actuators having different constructions or other devices where force/pressure measurement is needed.
• electric actuators are used for displacing the valve components of corresponding valve devices in the oil / natural gas industry. Examples of such valves are slide valves, butterfly valves, ball valves, blow-out preventers or the like.
• Figure 2 shows a top view of a force / pressure measurement sensor 6, 7.
• the force/pressure measurement sensor 6, 7 is shown as a layered structure and is formed with a ring shape.
• the force/pressure measurement sensor 6, 7 can essentially be laid between corresponding parts of the electric actuator 1 in the manner of a washer, for example as shown in Figure 1.
• the sensor 6, 7 has two stacked rings 11 , 12, which are shown from the side view in Figures 3 and 4.
• the interior sides 8, 9 of the rings 1 1 , 12 that face each other are coated with a piezoresistive layer as a sensor layer 10.
• the sensor layer 10 can cover the entire interior side 8, 9 of the corresponding sensor or ring 1 1 , 12.
• detail "X” shows a localized coating as the sensor layer 10, which forms different sensor areas 20. These form corresponding measurement surfaces 19 for measuring a resistance in the area of the sensor area 20.
• the sensor areas 20 can have different shapes and can also be connected to one another, which allows force- selective measurement.
• the corresponding shapes of the rings 11 , 12 are congruent, with a separating foil ring 13 arranged between the rings 11 , 12, as shown in Figure 4.
• This separating foil ring 13 has at least one connecting contact 14 that extends radially outward.
• a measurement voltage can be applied to the connecting contact 14 and to an exterior side 16, 17 of one of the rings 11 , 12. Due to the applied measurement voltage, a current flows through the sensor layer 10, and the resistance determined from the applied voltage and the resulting current depends on the force / pressure applied to the measurement sensor 6, 7.
• the piezoresistive sensor layer 10 on the interior sides 8, 9 of the rings 11 , 12, which may be a piezoresistive layer, may be made of a diamond-like carbon layer, also called a DLC layer.
• Additional layers 24 can be applied on the interior sides 8, 9 or on the exterior sides 16, 17 of the rings 11 , 12.
• the layers 24 can, for example, be formed from chromium, a doped material, an insulation material or the like.
• a structure made of a conductive material can be arranged in order to supply the sensor areas or measurement surfaces with voltage. As a result, a separate measurement of each sensor area or each measurement surface can take place.
• the corresponding structures may, in some embodiments, be manufactured from chromium.
• temperature compensation may take place if at least one further unloaded measurement surface is used to determine the resistance in addition to the loaded measurement surface or measurement surfaces of the sensor.
• the corresponding sensors may be connected to one another along an edge 15, for example, by gluing.
• a thickness 18 of the entire sensor 6, 7 lies in the range of a few millimetres, for example, in the range of 4 to 20 millimetres.
• corresponding sensors in a ring shape are coupled directly to the tapered roller bearings as holding devices 21 , 22 for tensile and pressure measurement and installed in a pre-tensioned manner.
• a measurement of the resistance of the sensors is made via the electric lines.
• Such a sensor needs no additional sealing and also no kind of pressure encapsulation in the oil of the actuator.
• a corresponding load flow of the tensile / pressure forces can be transferred directly through the sensors via the tapered roller bearing and into the actuator housing without any deflection. In this way, both static and dynamic forces / pressures can be registered precisely and reliably in real time.
• the sensor can also be coupled to a support device 23 within the actuator housing 3, if such a support device 23 is used for holding the displacement device 5.
• Figure 4 is a view similar to Figure 3 for a further embodiment of the sensor. This differs from the sensor 6, 7 as shown in Figure 3 in particular due to a multiple-part construction of the separating foil ring 13.
• a one-piece separating foil ring 13 is used, while this is constructed of three adjacent rings in Figure 4.
• the two outer rings are conductive rings with corresponding connecting contacts 14 that stick out radially outwards on opposite ends of the rings, also refer to the arrangement according to Figure 2.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Mining & Mineral Resources (AREA)
• Engineering & Computer Science (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Environmental & Geological Engineering (AREA)
• Fluid Mechanics (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Indication Of The Valve Opening Or Closing Status (AREA)
• Force Measurement Appropriate To Specific Purposes (AREA)

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• 2012
  • 2012-09-10 GB GB1505962.9A patent/GB2520895B/en not_active Expired - Fee Related
  • 2012-09-10 EP EP12759369.7A patent/EP2941628A1/de not_active Withdrawn
  • 2012-09-10 US US14/434,086 patent/US20150369004A1/en not_active Abandoned
  • 2012-09-10 WO PCT/EP2012/003799 patent/WO2014037025A1/en active Application Filing

Patent Citations (7)

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