FINE FEED AND BRAKE

BACKGROUND

The invention relates to hydraulic systems. More specifically, the present invention relates to a hydraulic system suitable for controlling mechanical systems and a method of hydraulic system operation.

Some mechanical systems are controlled by hydraulic systems. Often, precise movement of a mechanical part may be required. For example, strings of drill pipes are used in surface drilling. The drill pipes are connected to other drill pipes which together are called a drill string. Drill pipes are added to the drill stirng to enable the drill to drill deeper. The drill pipes may be stored in a carousel of drills. The drill pipes may need to be loaded and unloaded from the carousel in order to attach and detach the drill pipes to the drill string. The drill pipes may need to be lined up precisely in order to load and unload the drill pipes into the carousel.

However, in current mechanical systems it may be difficult to precisely align a drill pipe with the carousel. Hydraulic systems may be controlled using various control methodolgies such as the Flanders control methodolgies. The control methodogies provide a way to move the mechanical part based on input parameters such as how fast to pump a pump and what feed pump pressure to use. However, precise control of mechanical systems may be difficult because of cylinder sticktion, moving system friction, and changes to variables such as temperature, mast angel, chain tension, head slide conditions and weather. Moreover, often once the mechanical part is in place the hydraulic system will not hold the mechanical part precisely in place.

Therefore, it would be desirable to provide a hydraulic system and method with a fine feed and brake. SUMMARY

Methods, computer readable media, and apparatuses for a hydraulic system with fine feed and brake are disclosed that move an object with a fine feed to a target position and which may include a brake for holding the object in place.

A method of moving one or more pistons to a target position is disclosed. The method may include pumping hydraulic fluid through a first flow line to move one or more pistons. The method may include on a condition of receiving an indication of the one or more pistons being near the target location, closing a fine feed valve (FFV) to block hydraulic fluid from flowing through the first flow line.

The method may include pumping hydraulic fluid through a second flow line to move the one or more pistons. The second flow line may include a flow restriction valve. The first flow line and the second flow line may be in hydraulic communication with the one or more pistons.

The method may include on a condition of receiving an indication of the one or more pistons being at the target location, closing a fine feed brake valve (FFBV) to block hydraulic fluid from flowing through the second flow line. Closing the FFBV may further include reducing a pumping stroke of a hydraulic pump to approximately zero. The hydraulic pump may provide the pumping through the first flow line and the second flow line.

The method may include on a condition of receiving a signal to start moving the one or more pistons, increasing the pumping stroke of the hydraulic pump, opening the FFV to permit hydraulic fluid to flow through the first flow line, and opening the FFBV to permit hydraulic fluid to flow through the second flow line.

Closing the FFV may include opening a FFV pilot control valve to flow hydraulic fluid in a first pilot line to close the FFV. The flow restriction valve may restrict the flow through the second flow line so that the one or more pistons move at a reduced speed.

Receiving an indication of the one or more pistons being near the target location may include receiving an indication that an object is near the target location. The one or more pistons may be configured to move the object.

Receiving the indication of the one or more pistons being near the target location may include receiving the indication from a rotary head position resolver that a rotary head is near the target location wherein the one or more pistons are configured to move the rotary head.

Closing the fine feed valve (FFV) may further include reducing a pumping stroke of a hydraulic pump by 50 percent or more. The hydraulic pump may provide the pumping through the second flow line.

A hydraulic system with fine feed and brake is disclosed. The hydraulic system may include a hydraulic cylinder comprising a piston. The hydraulic system may include a hydraulic pump configured to pump hydraulic fluid. The hydraulic system may include a first flow line comprising a fine feed valve (FFV). The first flow line may be in hydraulic communication with the hydraulic pump and the hydraulic cylinder. The hydraulic system may include a second flow line comprising a flow restriction valve. The second flow line may be in hydraulic communication with the hydraulic pump and the hydraulic cylinder. The hydraulic system may include a controller configured to close the FFV on a condition of receiving an indication of the piston being near a target location.

The controller may be further configured to close a fine feed brake valve (FFBV) to block hydraulic fluid from flowing through the second flow line, on a condition of receiving an indication of the one or more pistons being at the target location. Closing the FFBV may further include reducing a pumping stroke of the hydraulic pump to approximately zero.

The controller may be further configured to perform the following after receiving a signal to start moving the one or more pistons: increase the pumping stroke of the hydraulic pump, open the FFV to permit hydraulic fluid to flow through the first flow line, and open the FFBV to permit hydraulic fluid to flow through the second flow line.

The controller may be further configured to close the FFV by opening a FFV pilot control valve to flow hydraulic fluid in a first pilot line to close the FFV.

The flow restriction valve may restrict the flow through the second flow line so that the piston moves at a reduced speed.

Receiving an indication of the piston being near the target location may include receiving an indication that an object is near the target location, wherein the piston is configured to move the object.

Receiving the indication of the piston being near the target location may include receiving the indication from a rotary head position resolver that a rotary head is near the target location. The one or more pistons may be configured to move the rotary head.

Closing the fine feed valve (FFV) may further include reducing a pumping stroke of the hydraulic pump by 50 percent or more. .

The hydraulic system may include at least one of: a deck wrench configured to hold a drill pipe for loosening or tightening, and a carousel configured to hold drill pipes for loading and unloading onto/off a drill string. The piston may be configured to move at least one of the deck wrench or the carousel. The flow restriction valve may be configured to vary the amount of flow restriction based on signals received from the controller.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings wherein: Figures 1A, 1 B and 1C schematically illustrate an example of a hydraulic system and method with fine feed and brake;

Figure 2 schematically illustrates an example of a hydraulic system and method with fine feed and brake, according to another embodiment;

Figure 3 schematically illustrates an example of a hydraulic system and method with fine feed and brake, according to another embodiment;

Figure 4 schematically illustrates an example of a hydraulic system and method with fine feed and brake, according to another emobidment; and

Figure 5 schematically illustrates an example of a hydraulic system and method with fine feed and brake, according to another emobdiment.

DETAILED DESCRIPTION

Figures 1A, 1 B, and 1C schematically illustrate a hydraulic system with a fine feed and brake 100. Illustrated in Figures 1A, 1 B, and 1 C is a first double acting cylinder 106, a second double acting cylinder 108, a fine feed valve (FFV) pilot control valve 1 18, FFV 22, fine feed brake valve (FFBV) 1 12, a first flow restriction valve 1 14, a second flow restriction valve 124, a check valve 126, a first pressure relief valve 130, a bidirectional hydraulic pump 132, a second pressure relief valve 136, flow lines 150, pilot lines 152, an object 160, a sensor 202, a hydraulic pump controller 204, and a controller 200.

The bidirectional hydraulic pump 132 pumps hydraulic fluid through the flow lines 150 which moves the first double acting cylinder 106 and the second double acting cylinder 108. The hydraulic fluid may be restricted by the FFV 122 so that the first double acting cylinder 106 and the second double acting cylinder 108 may move at a slower pace for fine movement control. The hydraulic fluid may be restricted by the FFBV 1 12 so that the movement of the first double acting cylinder 106 and the second double acting cylinder 108 may be restricted or prevented from moving when the first acting cylinder 106 and the second acting cylinder 108 are in the proper position for the object 160.

The first double acting cylinder 106 may include a piston 102. The second double acting cylinder 108 may include a piston 104. The first double acting cylinder 106 and the second double acting cylinder 108 may be double acting cylinders. The first double acting cylinder 106 and the second double acting cylinder 108 may move object 160. The first double acting cylinder 106 and the second double acting cylinder 108 may be connected to flow line 150.7 and a flow line 150.8. In some embodiments, there may be only one double acting cylinder. In some embodiments, the first double acting cylinder 106 and the second double acting cylinder 108 may be single acting cylinders. In some embodiments, the first double acting cylinder 106 and the second double acting cylinder 108 may be another type of hydraulic element configured to be controlled by hydraulic fluid and configured to move object 160.

The FFBV 1 12 may be a 2 port control valve that is by default open. The FFBV 112 may include a solenoid 110 that when activated may switch the FFBV 112 to the closed position. The FFBV 1 12 may be connected to flow line 150.5 and to flow line 150.2. In some embodiments, the FFBV 112 may be by default closed.

The FFV pilot control valve 118 may be a 2 port control valve that is by default closed. The FFV pilot control valve 1 18 may include a solenoid 120 that when activated may switch the FFV pilot control valve 1 18 to an open position. The FFV pilot control valve 118 may be connected to a pilot line 152.1. The FFV pilot control valve 1 18 may be connected to an oil reserve 1 16.

The FFV 122 may be a 2 port control valve that is normally open. The FFV 122 may be connected to a pilot line 152.1 that connects to the FFV pilot control valve 1 18. The FFV 122 may be connected to a pilot line 152.2 that is connected to the first pressure relief valve 130. The FFV 122 may be connected to flow line 150.1. The FFV 122 may be connected to flow line 150.3. In some embodiments, the FFV 122 may be by default closed.

The bidirectional hydraulic pump 132 may be a bidirectional hydraulic pump. The bidirectional hydraulic pump 132 may be connected to flow line 150.6. The bidirectional hydraulic pump 132 may be connected to flow line 150.4. The bidirectional hydraulic pump 132 may be connected to pilot line 152.3. In some embodiments, the bidirectional hydraulic pump 132 may be a single direction hydraulic pump. In some embodiments, the bidirectional hydraulic pump 132 may be driven by a motor (not illustrated) with the power to the motor controlled by hydraulic pump controller 204. The hydraulic pump controller 204 may be controlled by the controller 200. In some embodiments, the hydraulic pump controller 204 may be manually controlled.

The first flow restriction valve 114 may be a flow restriction valve. The first flow restriction valve 114 may be configured to restrict the flow of pilot line 152.1.

The second flow restriction valve 124 may be a flow restriction valve. The second flow restriction valve 124 may be configured to restrict the flow of flow line 150.2. The second flow restriction valve 124 may include a variable control to adjust the amount of flow restriction. The variable control may be manual or automatic. In some embodiments, the second flow restriction valve 124 may have approximately a 3.5 mm orifice.

The check valve 126 may be a check valve in the flow of flow line 150.9 and flow line 150.10. The check valve 126 may permit the flow in flow line 150.9 to flow to flow line 150.10, but restrict the flow in flow line 150.10 from flowing to flow line 150.9. The first pressure relief valve 130 may be pressure relief valve. The first pressure relief valve 130 may include a control that is in communication with pilot line 152.4. The first pressure relief valve 130 may be configured to move to at least a partially open position if the pressure is high in the first flow line 150.10. The first pressure relief valve 130 may be configured to move to an open position if the pressure is high in the pilot line 152.2.

The flow lines 150 may be flow lines that permit hydraulic fluid to flow through the lines. The pilot lines 152 may be pilot lines that permit hydraulic fluid to flow through the lines.

The object 160 may be an object such as a rotary head for a carousel of drill pipes for surface drilling. A sensor 202 may be a sensor that detects the location of one or more of the following: the object 160, the first double acting cylinder 106, a piston 102, a second double acting cylinder 108, or a piston 104. The sensor 202 may send a signal when one or more of the above are either near or at a target location or both. The sensor 202 may send the signal to the controller 200. In some embodiments, the sensor 202 may be a control that is manually operated. In some embodiments, the sensor 202 may send the signal to a different device than the controller 200 such as a solenoid.

The controller 200 may be configured to control the hydraulic system with a fine feed and brake 100. The controller 200 may be in communication with the solenoid 110, the solenoid 120, the solenoid 134, the hydraulic motor controller 204, the sensor 202, and may be in communication with other devices.

Referring to Figure 1A, in operation, the hydraulic system with fine feed and brake 100 may move an object 160 into a target position (not illustrated) as follows. An electric motor (not illustrated) may be energized to turn the bidirectional hydraulic pump 132. The bidirectional hydraulic pump 132 may pump the hydraulic fluid through flow line 150.4. The second pressure relief valve 136 may be closed. The FFV 122 may be open. The FFBV 112 may be open. In some embodiments, the FFBV 112 may be closed. The second flow restriction valve 124 may be configured to restrict the flow of hydraulic fluid from flow line 150.4 to flow line 150.2.

The hydraulic fluid may be pumped into the first double acting cylinder 06 and the second double acting cylinder 108 through flow line 150.7 to move object 160. Hydraulic fluid may flow out of the first double acting cylinder 06 and the second double acting cylinder 108 through flow line 150.8.

The hydraulic fluid may flow through flow line 150.11. The first pressure relief valve 130 may open from pressure from the pilot line 152.4. The hydraulic fluid may flow through flow line 150.6 and return to the bidirectional hydraulic pump 132.

Thus, piston 102 and piston 104 may extend and move object 160. In some embodiments, the object 160 may be a rotary head for pipe sections of a surface driller.

The pistons 102 and 104 may continue to extend. An indication may be received that the object 160 is close to a target position (not illustrated). The indication may be received from a rotary head position resolver that indicates that a rotary head has been moved by the pistons 102 and piston 104 to a position near a target position. In some embodiments, the indication may be received that piston 102 and/or piston 04 is near a target position.

As illustrated in Figure 1 B, in response to receiving an indication that an object 160 is near a target position, the FFV pilot control valve 118 may be energized to open the FFV pilot control valve 118. For example, the controller 200 may be configured to respond to receiving from sensor 202 an indication that an object 160 is near a target position by energizing the solenoid 120. The opening of the FFV pilot control valve 118 may increase the pressure in pilot line 152.1 and close FFV 122. The hydraulic fluid will not be able to flow through flow line 150.3. The piston 102 and piston 104 may continue to move at a reduced speed from the hydraulic fluid flowing through flow line 150.2.

Thus, the object 160 may be moved at a reduced rate after an indication is received that the object 160 is near a target position.

In some embodiments, the current to a motor that controls the bidirectional hydraulic pump 132 may be reduced in conjunction with the FFV 122 being closed. In some embodiments, the indication that the object 160 is near a target position will only be received in some modes of moving the object 160. In some embodiments, the power to the motor may be reduced by between 20% and 90%. In some embodiments, the feed pressure may be increased by increasing the current to the solenoid 134 of the second pressure relief valve 136 in conjunction with the FFV 122 being closed.

As illustrated in Figure 1 C, in response to receiving an indication that an object 160 has reached a target position, the solenoid 110 of FFBV 112 may be energized to close FFBV 112. For example, the controller 200 may be configured to respond to receiving from sensor 202 an indication that an object 160 has reached a target position by energizing the solenoid 110. The hydraulic fluid will not be able to flow through flow line 150.5. The hydraulic fluid will also not be able to flow through flow line 150.1 since FFV 122 is closed. The piston 102 and piston 104 may stop moving. Thus, the object 160 may be held stationary. In some embodiments, an advantage provided by the FFBV 1 12 is that the object 160 may be held in place and not slip. In some embodiments the bidirectional hydraulic pump 132 may be turned off or the speed reduced.

An indication may be received to begin moving the object 160 again. For example, the controller 200 may receive an indication to begin moving the object again or to begin moving piston 102 and piston 104 again. In some embodiments, the indication may be received from an operator. In some embodiments, the indication may be received from another controller 200 or may be generated by the controller 200. The indication may be an indication to begin moving piston 102 and piston 104 in the same direction, or it may be an indication to move the piston 102 and piston 104 in an opposite direction. In some embodiments, the object 160 may be removed while piston 102 and piston 104 are stopped.

In some embodiments, the bidirectional hydraulic pump 132 may be controlled to pump in an opposite direction. The hydraulic fluid may move through flow line 150.6, through flow line 150.9, and through the check valve 126, and finally through flow line 150.8 into the first double acting cylinder 106 and the second double acting cylinder 108. The hydraulic fluid may then flow out of the first double acting cylinder 106 and second double acting cylinder 108 through flow line 150.7. The hydraulic fluid may flow through one or both of flow lines 150.1 and 150.5 depending on whether one or both of the FFV 122 and the FFBV 112 are open.

In some embodiments, the FFBV 112 may be de-energized by turning off solenoid 110 as illustrated in Figure 1 B. In some embodiments, the FFV pilot control valve 1 18 may be de-energized which will open the FFV 122. The hydraulic fluid will then be permitted to flow to the first double acting cylinder 106 and the second double acting cylinder 108. In some embodiments, the FFBV 112 is opened first and then the FFV 122 is opened. In some embodiments, the FFV 122 is opened first and the FFBV 1 12 may remain closed for a period of time.

In some embodiments, the FFBV 112 may be opened and the FFV 122 may be opened, and the bidirectional hydraulic pump 132 may be set at 50 percent and the solenoid 200 may be de-energized. The hydraulic system with a fine feed and brake 100 may provide the advantage that when piston 102 and piston 104 are started to move again they may not drop down.

Piston 102 and piston 104 may move out of the first double acting cylinder 106 and the second double acting cylinder 108, respectively, when the bidirectional hydraulic pump 132 is pumping in a first direction. Piston 102 and piston 104 may move into the first double acting cylinder 106 and the second double acting cylinder 108, respectively, when the bidirectional hydraulic pump 132 is pumping in a second direction. In some embodiments, piston 102 and piston 104 may be biased to move in a direction such as to return into the first double acting cylinder 106 and the second double acting cylinder 108, respectively.

Figure 2 schematically illustrates a hydraulic system with a fine feed and brake 190, according to another embodiment. The hydraulic system with a fine feed and brake 190 comprises only the first double acting cylinder 106.

Figure 3 schematically illustrates a hydraulic system with a fine feed and brake 192, according to another embodiment. The hydraulic system with a fine feed and brake 190 may be configured so that piston 102 and piston 104 move in different directions, which may result from the different configuration of flow line 150.7 and flow line 150.8.

Figure 4 schematically illustrates a hydraulic system with a fine feed and brake 194, according to another embodiment. As illustrated in Figure 4, the bidirectional hydraulic pump 132 (see Figure 1 ) may be replaced by a single direction hydraulic pump 195.

Figure 5 schematically illustrates a hydraulic system with a fine feed and brake 196, according to another embodiment. As illustrated in Figure 4, the FFV pilot control valve 1 18 (see Figure 1 ) may not be present and the FFV 122 (see Figure 1 ) may be replaced with a FFV 197 that includes a solenoid 198. Other embodiments of the hydraulic system with a fine feed and brake are readily apparent.

The various illustrative logics, logical blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic controller (PLC) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

Further, the steps and/or actions of a method or algorithm described in connection with the controller 200 disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium may be coupled to the processor, such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. Further, in some aspects, the processor and the storage medium may reside in an ASIC. Additionally, the ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal. Additionally, in some aspects, the steps and/or actions of a method or algorithm may reside as one or any combination or set of instructions on a machine readable medium and/or computer readable medium. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion. The computer readable recording medium may be limited to non-transitory computer readable recording medium.

Although described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions.