Patent Application
20140305508
Not applicable
Not applicable
1. Field of the Invention
The present invention relates to devices for controlling a flow line that has ruptured or that is leaking. More particularly, the present invention relates to a method and apparatus for deactivating a hydraulic system that uses jointed flow lines equipped with a specially configured check valve in each joint of the jointed flow line.
2. General Background of the Invention
In the offshore oil and gas industry, there are certain hydraulic devices that are needed in order to complete jobs in an underwater environment. A hydraulic shear is employed to conduct salvage operations. Such a hydraulic shear is lowered to a seabed area, for example several hundred feet (meters) deep. In this offshore environment, leakage of hydraulic oil has a profoundly disastrous effect on the environment.
Therefore, there exists a need for a simple and straightforward yet workable solution to the problem of leakage of hydraulic fluid from devices that are used in a marine environment.
It is not only important that a leak of hydraulic fluid be detected. It is further important that the hydraulic device be immediately disabled so that leakage is limited to a very minimal quantity.
Patents have issued that relate generally to the detection of leakage. One example is the Brandt patent (U.S. Pat. No. 5,748,077). The Brandt patent (U.S. Pat. No. 5,748,077) shuts down the hydraulic system if the leak is detected and notifies individuals in the area that a leak has occurred. The leak detection system has sensors for measuring hydraulic system parameters and a computer for detecting abnormalities in the system based on values returned by the sensors. Sensors used include an rpm pickup, a pressure transducer, a flow meter and a hydraulic fluid level and temperature switch. Outputs of the sensors are analyzed by the computer to determine if the hydraulic system has a leak. If a leak is detected, the computer sends response signals to a device for engaging or disengaging the prime mover from the hydraulic pump and to another device for actuating a valve to stop hydraulic fluid flow from the reservoir. The computer may also send indicator signals to a display console for activating a warning light, a buzzer or a display.
The Cass patent (U.S. Pat. No. 4,471,797) provides a hydraulic circuit breaker reset device. The system includes a pump, reservoir and an actuator system. The hydraulic circuit breaker is arranged to compare fluid flow to and from the actuator system and to shut off this flow in the event the flow to the actuator system is greater than the flow returning from the actuator system by more than a predetermined differential, thereby indicating a leakage condition. A hydraulic circuit breaker reset device is hydraulically connected to the actuator system and to the circuit breaker. When the circuit breaker is in a shut off condition, the reset device continuously pressure tests the actuator system. If the pressure in the actuator system increases to indicate the absence of fluid leakage, the reset device responds to the pressure increase in the actuator system to provide a reset signal to the circuit breaker. After the circuit breaker is reset to its normal operating position, a timing piston returns the reset device to its normal operating condition.
In one embodiment, the present invention can employ a plurality of hose sections (e.g. 50 ft. (15.24 m) sections) with less than 2.5 gallons (9.46 liters) of total contents within each section. The primary design is to have a check type valve that holds the contents of the hose when there is a breach within any part of the hose, upon hydraulic power unit or “HPU” shutdown.
A specially configured connector joins each hose joint to another hose joint with a threaded connection. The connector contains a specially configured check valve arrangement. The connector is preferably about equal in size to the current connection not to cause any change in function externally due to the fact it has to be spooled up on a hose reel.
The valve of the present invention employs springs that work against each other on a shaft with a plunger or piston in the middle. The springs can be calibrated to a selected pressure flow value. When the flow pushes the plunger or piston in one direction, a circular disk part of the plunger or piston moves to one side of an annular sealing surface and compresses a first spring allowing the flow to pass by the central disk.
When the flow changes direction, the plunger accommodates by moving to the other side of the valve bode compressing the opposing or second spring and allows flow in the other direction, when the flow stops the valve centers due to the equal amount of spring tension and shuts on a sealing area for the plunger.
There is a slight increase of system pressure when using these specially configured check valves of the present invention. For example, if a hydraulic system has two runs of 475 foot (145 m) hose that are one inch (2.54 cm) diameter hose with nine joints of hose, there would be an about 200 psi (1379 kPa) increase in operating pressure.
This method can be used with or without a separate spill mitigation system. The reaction time of a particular human operator can directly affect the amount of hydraulic fluid that is spilled. A computer controlled spill mitigation system can be more consistent and reliable than a human operator.
The present invention includes a method of deactivating an underwater hydraulic device. The method provides a hydraulic device that is capable of being operated under water, the device can have a hydraulic cylinder with a pushrod and a piston. The device can be lowered below a water surface with a hose reel that is located at the water surface area. The hose reel can include first and second hydraulic hoses that connect to the cylinder on opposing sides of the piston. The method includes intermittently monitoring fluid flow in the first and second hydraulic hoses. The method further includes calculating the ratio of the volume of fluid flowing into the cylinder from one side of the piston to the volume of fluid flowing into the cylinder from the other side of the piston. The method of the present invention further includes deactivating the hydraulic device if the ratio varies from a preset ratio or preset value. The hoses can be a plurality of joints, wherein a plurality of said joints house a check valve.
Preferably, the device can be a hydraulic shear.
Preferably, the flow can be measured with first and second flow meters, one flow meter monitoring fluid flow in the first hydraulic hose, the other flow meter monitoring flow in the second hydraulic hose.
Preferably, the hydraulic device can receive hydraulic fluid under pressure from a prime mover and hydraulic pump assembly and the prime mover and pump assembly can be deactivated.
Preferably, the prime mover can be deactivated.
Preferably, the prime mover can include an engine and the engine can be shut off.
Preferably, a controller can continuously monitor flow in the flow meters and continuously calculates the ratio.
Preferably, the present invention further comprises providing a selector switch having multiple selectable switch positions and wherein the ratio can be varied by selecting a different position of the selector switch.
Preferably, the computer can use a different ratio depending upon which switch position is selected and the dimensions of the cylinder and pushrod of the selected device.
Preferably, the volumes can be automatically calculated.
The present invention includes a method of deactivating a hydraulic device. The method provides a hydraulic device having a cylinder with a pushrod and a piston, the device receiving flow from a jointed flow line. The flow line can include first and second hydraulic jointed hoses that connect to the cylinder on opposing sides of the piston. The method further includes intermittently monitoring fluid flow in the first and second hydraulic hoses. The method further includes continuously comparing the volume of fluid that enters a pushrod retraction chamber section of the cylinder with a pushrod extension section of the cylinder. The method further includes deactivating the hydraulic device if the ratio varies from a preset value. The hoses can be a plurality of hose joints, wherein a plurality of said hose joints are connected together end to end with connectors that each house a check valve.
Preferably, the flow can be measured with first and second flow meters, one flow meter monitoring fluid flow in the first hydraulic hose, the other flow meter monitoring flow in the second hydraulic hose.
Preferably, the hydraulic device receives hydraulic fluid under pressure from a prime mover and hydraulic pump assembly and the prime mover and pump assembly is deactivated.
Preferably, the prime mover can be an engine and the engine can be shut off.
Preferably, a controller can continuously monitor flow in the flow meters and continuously calculates the ratio.
Preferably, the present invention further comprises providing a selector switch having multiple selectable switch positions and wherein the ratio can be varied by selecting a different position of the selector switch.
The present invention includes a hydraulic leak detection apparatus. The apparatus of the present invention can include a hydraulic device that can be operated with a prime mover, pump, and hydraulic cylinder having a cylinder, a pushrod, and a piston. The cylinder can have a first chamber that is receptive of hydraulic fluid when extending the pushrod and a second chamber that is receptive of hydraulic fluid when retracting the pushrod. A first hydraulic flow line can supply hydraulic fluid to the first chamber. A second hydraulic flow line can supply hydraulic fluid to the second chamber. At least one of said flow lines can be comprised of separate lengths of hose connected end to end. A computer can continuously monitor the ratio of the volume of fluid entering the first chamber to the volume of fluid entering the second chamber. The computer can operatively connect to the prime mover so that the computer can deactivate the prime mover when the ratio varies from a preset acceptable value of said ratio. At least one of the hydraulic flow lines can be comprised of a plurality of hose joints that are joined together with connectors that each contain a check valve.
Preferably, the hydraulic device can be a power tong.
Preferably, each of said first and second flow lines can have a flow meter interfaced with said computer so that the flow meters continuously transmit flow data to the computer.
Preferably, the present invention further comprises a selector switch that enables the computer to compare the said ratio with a selected one of a plurality of ratios, each ratio of the plurality of ratios corresponding to different hydraulic cylinder configurations.
Preferably, the present invention further comprises a selector switch that enables the computer to compare the said ratio with a selected one of a plurality of ratios, each ratio of the plurality of ratios corresponding to different hydraulic cylinder dimensions.
Preferably, the computer can be programmable to designate any ratio as the acceptable value.
Preferably, the acceptable value can be a range.
Preferably, further comprises a hose reel that enables the device to be lowered to a sea bed area.
Preferably, multiple hydraulic flow lines can be part of the hose reel.
Preferably, each of said first and second hydraulic hoses can have a flow meter interfaced with a computer or controller so that the flow meters continuously transmit flow data to the computer.
Preferably, each flow meter can be in a said hydraulic hose in between the hose reel and the device.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
From control station 29, the line 31 exits to supply pressurized hydraulic fluid to hose reel 40. A first flow meter 45 is placed in flow line 31 or at the junction of flow lines 25, 31 as shown in
Line 32 also receives flow from control station 29 to communicate with hose reel 40. The flow line 32 carries a second flow meter 46. Return flow is able to travel from the hose reel 40 to the flow line 32 through the flow meter 46 and then to the control station 29. From the control station 29, the flow in line 32 communicates with the return line 26 for returning fluid to hydraulic tank or reservoir 22. Flow meters 45, 46 can be commercially available CT Series flow meters from Webster Instruments of Milwaukee, Wis.
The hose reel 40 provides flow lines 41, 42 which enable a hydraulic cylinder on implement 11 to either open jaw 30 or close jaw 30 by either extending a pushrod or retracting the pushrod. This is accomplished by connecting one flow line 41 to hydraulic cylinder on one side of a piston (that is on implement 11 and that operates jaw 30) and by connecting the other flow line 42 to the hydraulic cylinder on the other side of the piston.
The prime mover can be either an engine 20 or an electric motor 44 (see
The computer or controller 33 is part of the control station 29. The control station 29 can provide a key switch for enabling the control station 29 to be activated or deactivated. A rotary cam switch 74 can be provided to pre-program controller 33 for a number of different configurations (e.g., dimensional changes) of cylinder, pushrod and chamber sections of hydraulic cylinder of implement 11. The cam switch 74 enables an operator to dial in or select a particular hydraulic cylinder by selecting a pre-programmed cam switch position. Such a rotary cam switch is commercially available from Control Switches International, Inc.
A start button 75 can be provided for enabling use of control station 29. Lamps 76, 77 can be provided to indicate whether or not the control station 29 has been activated or is deactivated. For the diesel engine 20, a valve (e.g., solenoid operated valve) 64 is provided in flow line 65 which supplies diesel fuel from tank 23 to engine 20. This solenoid operated valve 64 is closed in a situation where a leak is detected (e.g., see leakage/damage at 70 in
In one embodiment, the method and apparatus can be provided with a display which may include a leak detection visual and/or audible alarm. A display console can be provided for controller 33 which can include a selector or cam switch 74, on-off button 75, indicator lamps 76 and 77, along with default program button. Controller 33 can be operatively connected to a computer (e.g., a notebook computer) for programming operating values into controller 33 regarding its operations.
A plurality of flow meters 45 and 46 can be used to measure flow to and from the monitored hydraulic systems (e.g., shears 11 and reel drive motor 38). The flow meter 45 sends a signal to controller 33 which is proportional to the rate of fluid flow in flow line 31. The flow meter 46 sends a signal to controller 33 which is proportional to the rate of fluid flow in flow line 32.
Leak detection 10 system can go through various pre-leak detection monitoring checks which are designed to ensure that the connected hydraulic systems (e.g., shears 11 and reel drive motor 38) are operating correctly. In one embodiment leak detection system 10 will shut off hydraulic power to the hydraulic pump 21 if one or more pre-monitoring exceptions are found.
Pre-monitoring exceptions can include, but are not limited to:
If an exception condition is found, including satisfaction of the time periods for existence of such exception, the leak detection system 10 shuts down the identified leaking hydraulic system (e.g., shears 11 and/or reel drive motor 38). Shutting down a hydraulic system can include shutting off the flow of hydraulic fluid from the reservoir tank 22 to pump 21 and shutting off power to pump 21. The hydraulic fluid flow can be shut off at reservoir tank 22 by turning a valve in line 27 to a closed position.
If a leaking exception condition satisfying leaking parameters has been found, the leaking hydraulic system (e.g., shears 11 or reel drive motor 38) causing the leaking event to be identified may be shut down and the indicator or display signals are sent to console to warn that a leaking event has been identified. Leak detected light 76 or 77 can be provided and turned on and optionally an auditory alarm can also be issued.
In one embodiment, following the completion of the various pre-leak detection monitoring checks, leak detection system 10 can monitor one or both connected hydraulic systems (shears 11 and/or reel drive motor 38) by monitoring flow though flow meters 45 and 46 and comparing such monitored flow to certain predefined flow amounts for the particular hydraulic system being monitored.
In one embodiment leak detection system 10 provides a predefined startup period of time from activation of a hydraulic system to beginning of monitoring operations of flow meters 45 and 46. Such predefined start up period of time allows the monitored hydraulic system time to stabilize before leak detection system 10 begins looking for leaking exceptions in monitoring conditions. In one embodiment such predefined start up period of time can be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 25, 30, 35, 40, and/or 50 seconds. In various embodiments such predefined period of time can be a range between any two of the specified time periods.
Exceptions for leak detection can be identified by leak detection system 10 where a measured parameter falls outside of the predefined allowed ranged for such measured parameter. Additionally, preferably leak detection system 10 requires that the exception be present for a predetermined period of time before considering that an identified leaking exception is considered a leaking event and acting accordingly, such as by shutting down pump 21 and/or the hydraulic system (e.g., shears 11 or reel drive motor 38) causing the identified leaking exception to be present.
In one embodiment leak detection system 10 can be user programmed regarding the frequency of sampling of which the system accepts signals from the plurality of flow meters 45 and 46. Although “continuous” is used in this specification it is anticipated that, in any given time period, only a finite number sampling of measurements can be taken by leak detection system 10.
In various embodiments embodiment sampling rates can be at least 1, 5, 10, 50, 100, 120, 150, 200, 300, 500, 1000, 2000, or 3000 Hertz. In various embodiments sampling rates can be a range between any two of the specified sampling rates.
In one embodiment leak detection system 10 responds or reacts rapidly to an identified leaking event, such as by shutting off power to pump 21 along with shutting off fluid flow from reservoir 22 to pump 21. With the occurrence of such an event, leak detection system 10 can also issue a warning signal such as be lighting lamp 76 or lamp 77, along with possibly issuing a audible warning signal such as a siren.
In one embodiment, after a leaking event is determined, leak detection system 10 will shut down the flagged hydraulic system (shears 11 or reel drive motor 38). This can occur after determining a leaking exception exists for a predetermined time. In one embodiment such predefined period of time that the leaking exception must exist before a leaking event can be identified, can be at least about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 25, 30, 35, 40, 50, and/or 60 seconds. In various embodiments such predefined period of time can be a range between any two of the specified time periods. In various embodiments the user can program this predefined period of time and/or range into leak detection system 10.
In one embodiment benchmark conditions in known non-leaking conditions to be expected when taking sampling measurements can be automatically programmed into the method and apparatus. In one embodiment predefined exception conditions can be programmed into leak detection system 10 based on actual operating conditions of the hydraulic system being monitored (e.g., shears 11 and/or reel drive motor 38). In one embodiment, the default predefined button can be provided in leak detection system 10, and a method of programming predefined conditions for flow meters 45 and 46 can be as follows:
(1) Shear System
With hydraulic shear system 11, hydraulic power can be supplied by pump 21 though lines 31 and 32 which respectively flow through lines 41 and 42. The ratio of flow measured by flow meter 45 to compared to flow meter 46 (or vice versa) can be calculated by controller 33 and such ratio be set in the method and apparatus as the ideal predefined ratio in a non-leaking condition.
For any particular movement of the piston inside of the hydraulic cylinder of implement 11, the amount of hydraulic fluid entering/leaving one chamber is less than the amount of hydraulic fluid entering/leaving the other chamber. The difference is a result of the pushrod taking up part of the volume of one chamber section. Although not expected to be a 1:1 ratio, because the pushrod has a substantially uniform cross sectional area the ratio of the amount of fluid exchange between the two chamber sections is expected to be constant regardless of the position of piston in the cylinder. In a preferred embodiment the ratio can be 1:2.28 and measured variations from this ratio can be used by leak detection system 10 to identify leaking exceptions for shear 11 and, if such identified leaking exception persists, a leaking event for shear 11.
(2) Driving Motor for Hose Reel
For reel drive motor 38 hydraulic power can be supplied by pump 21 though lines 31 and 32 which power reel drive motor 38 to outlay or take up lines 41 and 42. The ratio of flow measured by flow meter 45 to 46 can be calculated by controller 33 and such ratio be set as a predefined ratio in a non-leaking condition. However, this ratio in a non-leaking situation is expected to be 1:1 and this step can be omitted for programming the leak detection parameters for reel drive motor 38.
Unlike shears 11, reel drive motor 38 operably connected to hose reel 40 (and rotating reel 40 to outlet and take up of flow lines 41 and 42) will have input and output lines which, in a non-leaking condition, are expected to have a 1:1 ratio of hydraulic fluid entering and exiting driving motor 38.
For any particular movement of the piston inside of the hydraulic cylinder, the amount of hydraulic fluid entering/leaving one chamber section is less than the amount of hydraulic fluid entering/leaving the chamber section. The difference is a result of the pushrod taking up part of the volume of chamber section. Although not expected to be a 1:1 ratio, because the pushrod has a substantially uniform cross sectional area the ratio of the amount of fluid exchange between the two chamber sections is expected to be constant regardless of the position of the piston in the cylinder. In a preferred embodiment the ratio can be 1:2.28 and measured variations from this ratio can be used by leak detection system 10 to identify leaking exceptions for shear 11 and, if such identified leaking exception persists, a leaking event for shear 11.
In one embodiment, where the push rod has a diameter Dr and the piston has a diameter DP the ratio between the two flow rates will be the same as the ratio of the cross sectional areas on either side of the piston, and can be calculated by the formula:
In this embodiment a user can enter the diameter of the rod “Dr” and the diameter of the piston “DP” and the method and apparatus can calculate the ideal predefined ratio in a non-leaking condition from which allowable variations can be looked for by the method and apparatus.
Customizing Allowable Variations from Predefined Non-Leaking Ratios
In various embodiments a user can custom program leak detection system 10 to allow a variation of a selected amount from the predefined ratio in a non-leaking condition for either the hydraulic shear system 11 and/or reel drive motor 38. In various embodiments such can be a symmetrical variation from the initial predefined ratio and can be an allowable percentage variation from the initial predefined ratio. In various embodiments this allowable percentage can be at least about 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 15, 18, 20, 25, 30, 35, 40, and/or 50 percent. In various embodiments such exception variations can differ from variations above compared to variations below the user selected value in a non-leaking condition (e.g., the initial predefined ratio).
In various embodiments the lower limit can be one of the specified allowable variations, and the upper limit can be a different one of the specified allowable variations.
In various embodiments such user selected predefined parameters may be changed from time to time as the user desires.
At different points in time the user can use the default program button to calculate another predefined ratio for either hydraulic system (shear 11 or drive motor 38) as either hydraulic system's non-leaking characteristics may change over time. In one embodiment such predefined variations can be numerically entered into controller 33 by a computer.
As disclosed herein it is anticipated that leak detection system 10 can have programmed multiple sets of ratios for flow in flow meters 45 and 46 based on the different hydraulic systems which flow meters 45 and 46 are measuring flow in relation to. For example, when reel drive motor 38 is operating to lay out or take up hoses 41 and 42 (respectively lowering or raising shears 11), hydraulic shears 11 will not be operating. Accordingly, the values programmed for reel drive motor 38 are used by leak detection system 10.
During operations, leak detection system 10 system can go through various checks for catastrophic leaking events which are designed to ensure that the connected hydraulic systems (e.g., shears 11 and reel drive motor 38) do not suffer a catastrophic leaking event. In one embodiment leak detection system 10 will shut off hydraulic power to the hydraulic pump 21 and/or hydraulic systems if one or more pre-monitoring exceptions are found.
Catastrophic monitoring exceptions can include, but are not limited to:
If one or more of the above catastrophic leak detection monitoring exceptions are found, leak detection system 10 can turn off power to pump 21, shut down the hydraulic systems, and issue a warning signal indicating the identification of a catastrophic leak detection event. The pressure exerted by the hydraulic fluid can be monitored by pressure transducers in flow lines 31, 32, 41, and 42.
In
Plunger or piston 63 is mounted within body 16, attached to a pair of spaced apart flow through disks 19, 28 (see
Disk 66 of piston/plunger 63 has an annular groove 68 fitted with an o-ring 85. When o-ring 85 registers upon annular surface/sealing surface 49, flow through valve body 16 bore 56 is halted. Springs 83, 84 are calibrated so that if a selected flow pressure value is overcome, the piston or plunger 63 moves toward a disk 19 or 28 and the plunger/piston leaves sealing surface 49 to open the flow. Thus, if a leak occurs in any length or joint of hose (e.g., 13 or 14 or 41 or 42) the pressure will drop below the preselected pressure value and wherein the springs 83, 84 center disk 66 on sealing surface 49 to close flow and stop any further leakage.
The hydraulic control system of the present invention provides a valve arrangement that works in two directions. Flow from either direction of hose joint 13 or 14 will open the valve bore 56 as long as sufficient pressure is available to overcome spring pressure. Conversely, in the event of leakage a pressure drop below a preset minimum pressure value will enable springs 83, 84 to center disk 66 on sealing surface 49 to halt flow.
Incorporated herein by reference are U.S. patent application Ser. No. 13/741,074, filed 14 Jan. 2013, and International Patent Application No. PCT/US 13/21457, filed 14 Jan. 2013. The present invention is preferably used with the inventions disclosed therein.
The following is a list of parts and materials suitable for use in the present invention:
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise. All materials used or intended to be used in a human being are biocompatible, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
Priority of U.S. Provisional Patent Application Ser. No. 61/812,618, filed 16 Apr. 2013, which is hereby incorporated herein by reference, is hereby claimed. Incorporated herein by reference are U.S. patent application Ser. No. 13/741,074, filed 14 Jan. 2013, International Patent Application No. PCT/US2013/021457, filed 14 Jan. 2013, U.S. Provisional Patent Application Ser. No. 61/586,530, filed 13 Jan. 2012, and U.S. Provisional Patent Application Ser. No. 61/727,324, filed 16 Nov. 2012.
| Number | Date | Country | |
|---|---|---|---|
| 61812618 | Apr 2013 | US |
