Patent Publication Number: US-2022220837-A1

Title: Remote hydraulic valve control system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a nonprovisional application which claims priority from U.S. provisional application No. 63/135,368, filed Jan. 8, 2021, which is incorporated by reference herein in its entirety. 
    
    
     TECHNICAL FIELD/FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to oilfield equipment and specifically to hydraulic systems for wellhead equipment. 
     BACKGROUND OF THE DISCLOSURE 
     During well completions or during workover, an assembly of valves, commonly referred to as a frac tree, is coupled to the wellhead. The valves of the frac tree are used to allow fluid conduits passing into and out of the well to be selectively opened or closed. Additional valves may be positioned on manifolds to transmit frac fluid to the frac tree. During certain operations, such as hydraulic fracturing, the frac tree may contain large pressures within the well. In some cases, valves of the frac tree may be opened and closed hydraulically. However, due to the hazards involved with wellbore operations including, for example, high pressures and potentially flammable atmospheres, the area around the frac tree may be too dangerous for wellsite personnel to remain in the vicinity to manually operate the valves of the frac tree. 
     SUMMARY 
     The present disclosure provides for a remote hydraulic system for controlling a valve of a wellhead or frac manifold. The remote hydraulic system may include a remote hydraulic skid. The remote hydraulic skid may include a hydraulic reservoir, a hydraulic pump, and an accumulator. 
     The remote hydraulic skid may include a hydraulic manifold operatively coupled to the accumulator. The remote hydraulic skid may include a hydraulic valve operatively coupled to the hydraulic manifold. The hydraulic valve may be operatively coupled to the valve of the wellhead or frac manifold by a hydraulic line. The remote hydraulic system may include a control skid. The control skid may include an interface. The control skid may be operatively coupled to the remote hydraulic skid by a control line. The control skid may be adapted to control the actuation of the hydraulic valve. The remote hydraulic system may include a power supply skid coupled to the remote hydraulic skid to provide the power necessary to drive the hydraulic pump on the remote hydraulic skid. The remote hydraulic skid may be positioned within a threshold distance of the wellhead defining a hazardous zone. The control skid and power supply skid may be positioned outside of the hazardous zone. 
     The present disclosure also provides for a method. The method may include providing a power supply skid and positioning the power supply skid outside of a threshold distance of a wellhead or a frac manifold defining a hazardous zone. The method may include providing a remote hydraulic skid. The remote hydraulic skid may include a hydraulic reservoir, a hydraulic pump, accumulator, and a hydraulic manifold. The remote hydraulic skid may include a hydraulic valve operatively coupled to the hydraulic manifold and having an output port. The method may include positioning the remote hydraulic skid within the hazardous zone. The method may include operatively coupling the hydraulic pump to the power supply skid by a supply umbilical and coupling the output port of the hydraulic valve to a port of a valve of the wellhead or the frac manifold by a hydraulic line. The method may include providing a control skid, the control skid including an interface. The method may include positioning the control skid outside of the hazardous zone and operatively coupling the control skid to the remote hydraulic skid by a control line. The control skid may be adapted to control the actuation of the hydraulic valve. The method may include providing power to the remote hydraulic skid with the power supply skid, actuating the hydraulic valve with the control skid, and providing hydraulic fluid to the valve of the wellhead or the frac manifold. 
     The present disclosure also provides for a remote hydraulic system for controlling a valve of a wellhead or frac manifold. The remote hydraulic system may include an accumulator skid, the accumulator skid including a hydraulic reservoir and a hydraulic pump. The remote hydraulic system may include a remote hydraulic skid. The remote hydraulic skid may include a hydraulic manifold, the hydraulic manifold operatively coupled to the hydraulic pump of the accumulator skid by a supply umbilical. The remote hydraulic skid may include a hydraulic valve, the hydraulic valve operatively coupled to the hydraulic manifold, the hydraulic valve operatively coupled to the valve of the wellhead or frac manifold by a hydraulic line. The remote hydraulic system may include a control skid, the control skid including an interface, the control skid operatively coupled to the remote hydraulic skid by a control line, the control skid adapted to control the actuation of the hydraulic valve. The remote hydraulic skid may be positioned within a threshold distance of the wellhead defining a hazardous zone. The accumulator skid and control skid may be positioned outside of the hazardous zone. 
     The present disclosure also provides for a method. The method may include providing an accumulator skid, the accumulator skid including a hydraulic reservoir and a hydraulic pump. The method may include providing a remote hydraulic skid. The remote hydraulic skid may include a hydraulic manifold and a hydraulic valve, the hydraulic valve operatively coupled to the hydraulic manifold, the hydraulic valve having an output port. The method may include positioning the remote hydraulic skid within a threshold distance of a wellhead or a frac manifold defining a hazardous zone. The method may include operatively coupling the hydraulic manifold to the hydraulic pump of the accumulator skid by a supply umbilical. The method may include coupling the output port of the hydraulic valve to a port of a valve of the wellhead or the frac manifold by a hydraulic line. The method may include providing a control skid, the control skid including an interface, positioning the control skid outside of the hazardous zone, and operatively coupling the control skid to the remote hydraulic skid by a control line, the control skid adapted to control the actuation of the hydraulic valve. The method may include providing hydraulic fluid to the remote hydraulic skid with the accumulator skid, actuating the hydraulic valve with the control skid, and providing hydraulic fluid to the valve of the wellhead or the frac manifold. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure is best understood from the following detailed description when read with the accompanying figures. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. 
         FIG. 1  depicts an overview of a wellsite including a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 1A  depicts a detail view of a valve of a frac tree of the wellsite depicted in  FIG. 1 . 
         FIG. 2  depicts a schematic diagram of a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 3  depicts a process flow diagram of a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 4  depicts a schematic diagram of a remote hydraulic skid consistent with at least one embodiment of the present disclosure. 
         FIG. 5  depicts an overview of a wellsite including a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 6  depicts a schematic diagram of a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 7  depicts a process flow diagram of a remote hydraulic system consistent with at least one embodiment of the present disclosure. 
         FIG. 8  depicts a schematic diagram of a remote hydraulic skid consistent with at least one embodiment of the present disclosure. 
         FIG. 9  depicts aspects of a graphical user interface for a control skid consistent with at least one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     It is to be understood that the following disclosure provides many different embodiments, or examples, for implementing different features of various embodiments. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
       FIG. 1  depicts wellsite  10 . Wellsite  10  may include one or more wells, depicted as wellheads  15 . One or more of wellheads  15  may include a valve assembly coupled to wellhead  15 , depicted as and referred to herein as frac trees  20 . In some embodiments, wellsite  10  may also include one or more frac manifolds  21 , which may be used to supply fluid to frac trees  20  during hydraulic fracturing operations. Each frac tree  20  may include one or more valves including, for example and without limitation, master valves  22 , wing valves  24 , and swab (or crown) valve  26 . In some embodiments, one or more valves of frac tree  20  may be hydraulically operated such that opening and closing of the frac tree  20  valves may be controlled by remote hydraulic system  100 . In some embodiments, any such valves, such as swab (or crown) valve  26  shown in  FIG. 1A , may include hydraulic valve actuator  28 . Hydraulic valve actuator  28  may be adapted to control the opening and closing of swab (or crown) valve  26  as hydraulic fluid is introduced into opening port  31  or closing port  32  as further described below. 
     Remote hydraulic system  100  may be positioned at wellsite  10 . In some embodiments, such as shown in  FIGS. 1-4 , remote hydraulic system  100  may include power supply skid  101 , remote hydraulic skid  131 , and control skid  161 . In some embodiments, as shown in  FIG. 1 , remote hydraulic skid  131  may be positioned near frac tree  20 . In some embodiments, power supply skid  101  and control skid  161  may be positioned a distance away from remote hydraulic skid  131  to, for example and without limitation, allow an operator of control skid  161  to remain a safe distance away from frac tree  20  while a wellbore operation is underway. Thus, the operator may be able to operate remote hydraulic system  100  and thereby control the operations of valves of frac tree  20  during such a wellbore operation. For example and without limitation, in some embodiments, control skid  161  may be positioned outside of the defined hazardous zone  30 . Hazardous zone  30  may be defined as an area within a threshold distance about frac tree  20 , wherein the threshold distance may be defined based on anticipated conditions around frac tree  20 . For example and without limitation, in some embodiments, hazardous zone  30  may be identified as a Class I or Class II location as defined by the NEC, wherein Class I locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures, and Class II locations are those that are hazardous because of the presence of combustible dust. In some embodiments, the threshold distance may also take into account the presence of equipment containing high-pressure fluids including, for example and without limitation, frac tree  20  and frac manifold  21 . In some cases, for example and without limitation, hazardous zone  30  may be defined as extending between 25 and 150 feet from frac tree  20  and frac manifold  21 . In some cases, for example and without limitation, hazardous zone  30  may be defined as extending 50 feet from frac tree  20  and frac manifold  21 . 
     In some embodiments, as depicted in  FIGS. 2 and 3 , power supply skid  101 , remote hydraulic skid  131  and control skid  161  may be operatively coupled to allow control of valves of frac tree  20  and frac manifold  21 . Although a single power supply skid  101  and a single remote hydraulic skid  131  are depicted, any number of power supply skids  101  and remote hydraulic skids  131  may be used and controlled by a single control skid  161  without deviating from the scope of the present disclosure. 
     In some embodiments, power supply skid  101  may include one or more systems for generating, storing, and supplying electric power to remote hydraulic skid  131 , control skid  161 , and any other pieces of wellsite equipment desired. For example and without limitation, in some embodiments, power supply skid  101  may include one or power supplies including, for example and without limitation, generator  181  and solar panels  183 . Generator  181  may, in some embodiments, be driven by a diesel motor. Because generator  181  is positioned outside of hazardous zone  30 , the possible negative effects of operating a heat-generating device and possible fire or explosion hazard proximate frac tree  20  is reduced. Thus, generator  181  may be operated without regard for the status of frac tree  20  including, for example and without limitation, continuously. Similarly, solar panels  183  may operate to passively generate electricity. 
     In some embodiments, power supply skid  101  may include energy storage device  185 . Energy storage device  185  may be any device suitable for storing electrical power, such as may be generated by generator  181  and solar panels  183 . Energy storage device  185  may be, for example and without limitation, one or more of batteries, kinetic energy storage devices, or capacitor banks. In some embodiments, power supply skid  101  may include controller  187 . Controller  187  may, in some embodiments, control the operation of power supply skid  101  including controlling operation of generator  181 , charging of energy storage device  185 , conditioning power from solar panels  183 , and supplying electric power to remote hydraulic skid  131  and control skid  161 . In some embodiments, controller  187  may be positioned in control skid  161  or may be controlled at least in part by control skid  161 . In some embodiments, power supply skid  101  may be connected to main power supply  189  to, for example and without limitation, use the utility grid for electric power to operate remote hydraulic system  100  or charge energy storage device  185 . 
     In some embodiments, remote hydraulic skid  131  may include hydraulic fluid reservoir  103 . Hydraulic fluid reservoir  103  may be a tank used to store hydraulic fluid  104  for use in remote hydraulic system  100 . Remote hydraulic skid  131  may include one or more pumps  105  positioned to pump hydraulic fluid  104  from hydraulic fluid reservoir  103  to charge accumulator bottles  108 . In some embodiments, pumps  105  may be, for example and without limitation, positive displacement pumps such as piston pump, screw pump, or progressing cavity pump. Pumps  105  may transfer hydraulic fluid into supply line  107 . 
     In some embodiments, pumps  105  may be driven by electric motors  106 . Electric motors  106  may be explosionproof electric motors as understood in the art. By selecting explosionproof electric motors, operation of pumps  105  by electric motors  106  within hazardous zone  30  may be safer than the operation of other pump arrangements including, for example, diesel motors, due to the reduced likelihood of, for example and without limitation, ignition of flammable gases within hazardous zone  30 . Electric motors  106  may be supplied with electric power from power supply skid  101  via umbilical  191 . In other embodiments, pumps  105  may be pneumatically driven, in which case rather than electric power, pneumatic power is supplied from power supply skid  101 . 
     In some embodiments, with reference to  FIGS. 2-4 , remote hydraulic skid  131  may include relief valve  109 , which may be used to avoid overpressurization of accumulator bottles  108 . In some embodiments, remote hydraulic skid  131  may include filter  111  positioned to filter hydraulic fluid  104  as it passes through remote hydraulic skid  131 . 
     In some embodiments, remote hydraulic skid  131  may include hydraulic manifold  133 . Hydraulic manifold  133  may receive hydraulic fluid from accumulator bottles  108 . Hydraulic manifold  133  may be operatively coupled to control valves  135   a - d . In some embodiments, for example and without limitation, control valves  135   a - d  may be pneumatically, hydraulically, or electromechanically actuated via hydraulic control valves such as a directional control shuttle valve. Each of the control valves  135   a - d  may be operatively coupled to an opening and closing port of a valve of frac tree  20  (or frac manifold  21  as discussed above), shown in  FIGS. 3, 4 , such as master valve  22 , wing valves  24 , and swab valve  26 , via a respective hydraulic line  137   a - h . In some embodiments, when one or more of control valves  135   a - d  are opened, high-pressure hydraulic fluid from hydraulic manifold  133  may flow through the respective hydraulic line  137   a -h and into the corresponding valve of frac tree  20 , thereby causing the respective valve of frac tree  20  or frac manifold  21  to open or close. 
     Because umbilical  191  carries only electric power, the complexity associated with rigging up remote hydraulic system  100  and any adverse effects caused by running individual hydraulic lines to control valves  135   a - d  may be reduced. Additionally, because remote hydraulic skid  131  includes hydraulic pumps  105 , hydraulic fluid reservoir  103 , hydraulic manifold  133 , and control valves  135   a - d , without being bound to theory, the pressure drop between hydraulic manifold  133  or accumulator bottles  108  and frac tree  20  may be reduced from the amount of pressure drop associated with multiple hydraulic lines that extend outside of hazardous zone  30 , which may allow for a reduction in the amount of hydraulic hose that needs to be installed and retrieved, increase the responsiveness of valves of frac tree  20  and reduce pressure demand on accumulator bottles  108 . 
     In some embodiments, each control valve  135   a - d  may be controlled by control skid  161 . Control skid  161  may include interface  163  to allow an operator to control the operation of control valves  135   a - d . In some embodiments, interface  163  may include one or more manual controls. In other embodiments, interface  163  may include one or more digital controls including, for example and without limitation, a touchscreen interface as discussed further herein below. In some embodiments, control skid  161  may electrically, pneumatically, or hydraulically control the actuation of control valves  135   a - d  via one or more corresponding control lines  165   a - d . In some embodiments, for example and without limitation, control skid  161  may electrically actuate control valves  135   a - d , which may be pneumatically or hydraulically actuated. In some embodiments, control skid  161  may control the operation of pump  105 . 
     Although four control valves  135   a - d  are depicted in  FIG. 3 , remote hydraulic skid  131  may include any number of control valves within the scope of the present disclosure. Additionally, although  FIG. 3  depicts only a single frac tree  20 , remote hydraulic skid  131  may be configured to control the valves of multiple frac trees  20  within the scope of the present disclosure. 
     In some embodiments, as shown in  FIG. 5-8 , remote hydraulic system  200  may be positioned at wellsite  10 . In such an embodiment, remote hydraulic skid  231  may be positioned near frac tree  20 . In some embodiments, accumulator skid  201 , transfer pump skid  253 , and control skid  261  may be positioned a distance away from remote hydraulic skid  231  to, for example and without limitation, allow an operator of control skid  261  to remain a safe distance away from frac tree  20  while a wellbore operation is underway. Thus, the operator may be able to operate remote hydraulic system  200  and thereby control the operations of valves of frac tree  20  during such a wellbore operation. For example and without limitation, in some embodiments, control skid  261  may be positioned outside of the defined hazardous zone  30 . 
     In some embodiments, as depicted in  FIGS. 6 and 7 , accumulator skid  201 , remote hydraulic skid  231 , transfer pump skid  253 , and control skid  261  may be operatively coupled to allow control of valves of frac tree  20  and frac manifold  21 . Although a single accumulator skid  201  and a single remote hydraulic skid  231  are depicted, any number of accumulator skids  201 , remote hydraulic skids  231 , and transfer pump skids  253  may be used and controlled by a single control skid  261  without deviating from the scope of the present disclosure. 
     In some embodiments, accumulator skid  201  may include hydraulic fluid reservoir  203 . Hydraulic fluid reservoir  203  may be a tank used to store low or no pressure hydraulic fluid  204  for use in remote hydraulic system  200 . Accumulator skid  201  may include one or more pumps  205  positioned to charge accumulator bottles  208  of accumulator skid  201 . In some embodiments, pumps  205  may be, for example and without limitation, positive displacement pumps such as piston pump, screw pump, or progressing cavity pump. Pumps  205  may output hydraulic fluid into supply umbilical  207  for supply to remote hydraulic skid  231  as further discussed below. 
     In some embodiments, accumulator skid  201  may be positioned near to remote hydraulic skid  231  within wellsite  10  such that the length of supply umbilical  207  may be reduced. By reducing the length of supply umbilical  207 , without being bound to theory, the pressure drop along supply umbilical  207  may be reduced from the amount of pressure drop associated with a supply umbilical that extends outside of hazardous zone  30 . 
     In other embodiments, such as shown in  FIG. 5 , accumulator skid  201  may be positioned outside of hazardous zone  30 . By using a single, larger supply umbilical  207  as opposed to a plurality of smaller hydraulic lines directly connecting between an accumulator skid positioned outside hazardous zone  30  and frac tree  20 , the total pressure drop for each line, the complexity of the system, the time required to rig up or down the system, and the weight of the system may be reduced. 
     Additionally, by locating remote hydraulic skid  231  at a location nearer to frac tree  20 , the response time of the valve may be reduced as compared to a system where remote hydraulic skid  231  is positioned outside of hazardous zone  30  as there is a shorter distance for the hydraulic fluid to travel and there is less fluid resistance in the hose. 
     In some embodiments, with reference to  FIGS. 6 and 7 , accumulator skid  201  may include relief valve  209 , which may be used to avoid overpressurization of accumulator bottles  208 . In some embodiments, accumulator skid  201  may include filter  211  positioned to filter hydraulic fluid  204  as it passes through accumulator skid  201 . 
     In some embodiments, remote hydraulic skid  231  may include hydraulic manifold  233 . Hydraulic manifold  233  may receive hydraulic fluid from supply umbilical  207 . Hydraulic manifold  233  may be operatively coupled to control valves  235   a - d . In some embodiments, for example and without limitation, control valves  235   a - d  may be pneumatically, hydraulically, or electromechanically actuated hydraulic control valves such as a directional control shuttle valve. Each of the control valves  235   a - d  may be operatively coupled to an opening and closing port of a valve of frac tree  20  (or frac manifold  21  as discussed above), shown in  FIG. 7  as master valve  22 , wing valves  24 , and swab valve  26 , via a respective hydraulic line  237   a - h . In some embodiments, when one or more of control valves  235   a - d  are opened, high-pressure hydraulic fluid from hydraulic manifold  233  may be allowed to flow through the respective hydraulic line  237   a - h  and into the corresponding valve of frac tree  20 , thereby causing the respective valve to open or close. 
     In some embodiments, remote hydraulic skid  231  may include return reservoir  239 . Return reservoir  239  may, in some embodiments, receive hydraulic fluid that returns from a valve of frac tree  20  when the valve is opened or closed. In some embodiments, return reservoir  239  may be fluidly coupled to transfer pump skid  253  via return umbilical  255 . Transfer pump skid  253  may include transfer pump  257 , positioned to pump hydraulic fluid from return reservoir  239  to hydraulic fluid reservoir  203 . 
     In some embodiments, each control valve  235   a - d  may be controlled by control skid  261 . Control skid  261  may include interface  263  to allow an operator to control the operation of control valves  235   a - d . In some embodiments, interface  263  may include one or more manual controls including, for example and without limitation, buttons, dials, or other components. In other embodiments, interface  263  may include one or more digital controls including, for example and without limitation, a touchscreen interface as discussed further herein below. In some embodiments, control skid  261  may electrically, pneumatically, or hydraulically control the actuation of control valves  235   a - d  via one or more corresponding control lines  265   a - d . In some embodiments, for example and without limitation, control skid  261  may electrically actuate control valves  235   a - d , which may be pneumatically or hydraulically actuated. In some embodiments, control skid  261  may control the operation of pump  205  and transfer pump  257 . 
     Although four control valves  235   a - d  are depicted in  FIG. 7 , remote hydraulic skid  231  may include any number of hydraulic control valves within the scope of the present disclosure. Additionally, although  FIG. 7  depicts only a single frac tree  20 , remote hydraulic skid  231  may be configured to control the valves of multiple frac trees within the scope of the present disclosure. 
     In some embodiments, remote hydraulic system  200  may include accumulator skid  201 , remote hydraulic skid  231 , transfer pump skid  253 , and control skid  261 . With reference to  FIGS. 5-8 , in order to operate remote hydraulic system  200  at wellsite  10 , accumulator skid  201 , remote hydraulic skid  231 , transfer pump skid  253 , and control skid  261  may be transported to wellsite  10 . Remote hydraulic skid  231  may be positioned relatively close to wellhead  15  with which remote hydraulic system  200  will be utilized, while accumulator skid  201 , transfer pump skid  253 , and control skid  261  may be positioned a distance away from wellhead  15  outside of hazardous zone  30 . Supply umbilical  207  and return umbilical  255  may be operatively coupled to remote hydraulic skid  231  from accumulator skid  201  and transfer pump skid  253 , respectively. Hydraulic lines  237   a - h  may be operatively coupled between control valves  235   a - d  and opening ports  31  and closing ports  32  of valves of frac tree  20 . Control lines  265   a - d  may be operatively coupled between control skid  261  and remote hydraulic skid  231 . Pump  205  may be activated to charge accumulator bottles  208  such that hydraulic fluid may be supplied to remote hydraulic skid  231 . As desired, one or more of control valves  235   a - d  may be opened to supply hydraulic fluid to the valves of frac tree  20  in order to open or close valves of frac tree  20  using control skid  261 . 
       FIG. 9  depicts an example of graphical user interface  300  for control skid  161 / 261  consistent with at least one embodiment of the present disclosure. In some embodiments, graphical user interface  300  may be adapted for use in a digital, touchscreen-based embodiment of interface  163 . GUI  300  may include one or more controls adapted to allow an operator to control the operation of remote hydraulic system  100 / 200 . In some embodiments, GUI  300  may provide one or more screens for user interaction with remote hydraulic system  100 / 200 . For example and without limitation, in some embodiments, GUI  300  may include status overview display  300   a  as shown in  FIG. 9 , wherein visual indicators  303  display the status of valve of frac tree  20 . In some embodiments, GUI  300  may be used to control multiple frac trees  20 . In some embodiments, elements of GUI  300  as discussed herein may be color-coded to allow for association with particular frac trees  20  or otherwise assist with visual identification thereof. 
     The foregoing outlines features of several embodiments so that a person of ordinary skill in the art may better understand the aspects of the present disclosure. Such features may be replaced by any one of numerous equivalent alternatives, only some of which are disclosed herein. One of ordinary skill in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. One of ordinary skill in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.