Hydraulic fracturing is a stimulation treatment routinely performed on oil and gas wells in low-permeability reservoirs. Specially engineered fluids are pumped at high pressure and rate into a reservoir interval to be treated, causing a vertical fracture to open. The wings of the fracture extend away from the wellbore in opposing directions according to the natural stresses within the formation. Proppant, such as grains of sand of a particular size, is mixed with the treatment fluid to keep the fracture open when the treatment is complete. Hydraulic fracturing creates high-conductivity communication with a large area of formation and bypasses any damage that may exist in the near-wellbore area. Furthermore, hydraulic fracturing is used to increase the rate at which fluids, such as petroleum, water, or natural gas can be recovered from subterranean natural reservoirs. Reservoirs are typically porous sandstones, limestones or dolomite rocks, but also include “unconventional reservoirs” such as shale rock or coal beds. Hydraulic fracturing enables the extraction of natural gas and oil from rock formations deep below the earth's surface (e.g., generally 2,000-6,000 m (5,000-20,000 ft)), which is greatly below typical groundwater reservoir levels. At such depth, there may be insufficient permeability or reservoir pressure to allow natural gas and oil to flow from the rock into the wellbore at high economic return. Thus, creating conductive fractures in the rock is instrumental in extraction from naturally impermeable shale reservoirs.
A wide variety of hydraulic fracturing equipment is used in oil and natural gas fields, such as a slurry blender, one or more high-pressure, high-volume fracturing pumps and a monitoring unit. Additionally, associated equipment includes fracturing tanks, one or more units for storage and handling of proppant, high-pressure treating iron, a chemical additive unit (used to accurately monitor chemical addition), low-pressure flexible hoses, and many gauges and meters for flow rate, fluid density, and treating pressure. Fracturing equipment operates over a range of pressures and injection rates, and can reach up to 100 megapascals (15,000 psi) and 265 liters per second (9.4 cu ft/s) (100 barrels per minute).
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This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.
In one aspect, the embodiments disclosed herein relate to modular pump skids including a base, a prime mover mounted on the base, and one or more hydraulic pump circuits removably mounted on the base and operationally coupled to the prime mover, wherein each hydraulic pump circuit has a hydraulic pump operationally coupled to the prime mover and a hydraulically driven pump fluidly coupled to the hydraulic pump. The hydraulic pump and the hydraulically driven pump may form a closed loop hydraulic pump circuit, where each hydraulic pump circuit may be independent of other hydraulic pump circuits.
In another aspect, embodiments disclosed herein relate to systems that include one or more modular pump skids having a prime mover mounted on a base and one or more hydraulic pump circuits removably mounted on the base and operationally coupled to the prime mover. Each hydraulic pump circuit may include a hydraulic pump and a hydraulically driven pump fluidly coupled to the hydraulic pump, wherein each hydraulic pump circuit is in a closed loop independent of other hydraulic pump circuits. One or more high-pressure fluid conduits may be coupled to the hydraulically driven pump, and a fluid manifold may be coupled to a well, wherein the one or more high-pressure fluid conduits are fluidly coupled to the fluid manifold. The hydraulically driven pump may be configured to inject fluids into the well.
In yet another aspect, embodiments disclosed herein relate to methods that include independently powering at least two hydraulic pump circuits on a modular pump skid with a single prime mover mounted on the modular pump skid, wherein each hydraulic pump circuit comprises a hydraulic pump and a hydraulically driven pump fluidly coupled to the hydraulic pump, providing horsepower, with the prime mover, to each hydraulic pump of the hydraulic pump circuits, redistributing an unused horsepower, when one of the at least two hydraulic pump circuits breaks down, to one or more operating hydraulic pump circuits, flowing a fluid from the hydraulically driven pump to a high-pressure fluid conduit, and injecting the fluid into a well via a fluid manifold fluidly coupled to the high-pressure fluid conduit.
Other aspects and advantages will be apparent from the following description and the appended claims.
The following is a description of the figures in the accompanying drawings. In the drawings, identical reference numbers identify similar elements or acts. The sizes and relative positions of elements in the drawings are not necessarily drawn to scale. For example, the shapes of various elements and angles are not necessarily drawn to scale, and some of these elements may be arbitrarily enlarged and positioned to improve drawing legibility. Further, the particular shapes of the elements as drawn are not necessarily intended to convey any information regarding the actual shape of the particular elements and have been solely selected for ease of recognition in the drawing.
In one aspect, embodiments disclosed herein relate to a modular fracturing pump pad system. The modular fracturing pump pad system may also be interchangeably referred to as a modular pump skid system in the present disclosure. As used herein, the term “coupled” or “coupled to” or “connected” or “connected to” may indicate establishing either a direct or indirect connection and is not limited to either unless expressly referenced as such.
A modular pump skid system, according to embodiments herein, may refer to a system in which the elements of hydraulic fracturing pumps are modularized and deployed on connectable modular skids that can be secured together to a well site to form interchangeable hydraulic fracturing pumps in a closed loop. The modular pump skid system elements may be modularized in a way such that the conduit manifolds/flow functionality is made up when the modular pump skid systems are connected in the closed loop. Further, the modular pump skid system elements may be held on units having standardized uniform connections, such that different types of pump element units may be connected together using the same connection type. The reduction of using non-uniform connections that must be made up and pressure tested may significantly reduce the complexity, design, time, and weight of the system. Additionally, the modular pump skid system may be used to direct fluid produced from or injected into a well.
In some embodiments, a modular pump skid may be loaded onto a base and connected to other modular pump skids. Additionally, each modular pump skid may have multiple hydraulic pump circuits held on the modular pump skid, where each hydraulic pump circuit may be in a closed loop. The hydraulic pump circuits may include a hydraulic pump fluidly coupled to a hydraulically driven pump to form the closed loop. In such embodiments, the base holding various components of the fracturing pump may be transported to a wellsite such that the equipment on the base (e.g., fluid conduits, pumps, valve manifolds, etc.) may all be pre-rigged and dropped on location in rigged-up condition. By using modular pump skids according to embodiments of the present disclosure for hydraulic fracturing wellbore operations, equipment may be pre-rigged and dropped on location in any condition, including ready-to-use, thereby reducing installation time in the field. According to embodiments of the present disclosure, a modular pump skid may include piping or a body having one or more flow paths formed therethrough to interconnect with other modular pump skids or a fluid manifold. As used herein, fluids may refer to proppant, frac fluids, liquids, gases, and/or mixtures thereof. Other instruments and devices, including without limitation, sensors and various valves may be incorporated within a modular fracturing pump pad system.
Conventional hydraulic fracturing pumps in the oil and gas industry typically consume a large amount of space and resources of a rig area. Conventional hydraulic fracturing pumps may use elements that are individually designed and sized with pipes, flow lines, diesel engines, and other conduits being used to interconnect the conventional hydraulic fracturing pumps to fracturing operations. Furthermore, pipes, flow lines, and other conduits being used to interconnect the conventional hydraulic fracturing pumps are not uniform and take valuable time to make up and pressure test. Additionally, the sheer number of pipes, hoses, and other fluid connections represent safety hazards for on-site workers. These additional components needed to interconnect the conventional hydraulic fracturing pumps adds to the weight, installation costs, and overall cost of the conventional hydraulic fracturing pumps. However, using modular pump skids according to one or more embodiments of the present disclosure may overcome such challenges, as well as provide additional advantages over conventional fracturing pumps.
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Each modular pump skid 201a, 201b, 201c, 201d may have one or more hydraulic pump circuits (202, 203) removably disposed on a base or chassis 214. As used herein, a hydraulic pump circuit may refer to a set of fluidly connected pumps, including a hydraulic pump 202 and a hydraulically driven pump 203, and connections 224 between the pumps (202, 203). The hydraulically driven pump 203 may be, for example, a dual acting long stroke cylinder pump, or a hydraulic motor driving a traditional reciprocating plunger pump, or various other types of reciprocating plunger or piston pumps. The connections 224 between the hydraulic pump 202 and the hydraulically driven pump 203 may be fluid conduits such as hydraulic lines or hoses.
Additionally, each of the modular pump skids 201a, 201b, 201c, 201d may include a prime mover 204, such as a turbine or engine, mounted on the base and operationally coupled to the hydraulic pump circuits (202, 203) via an optional pump drive 215, such as a gearbox. A fuel supply (not shown) may feed directly into the prime mover 204. Multiple hydraulic pump circuits (202, 203) may be provided on each of the modular pump skids 201a, 201b, 201c, 201d in a closed loop, such that if one hydraulic pump circuit (202, 203) fails or is otherwise shut down, the other hydraulic pump circuits (202, 203) may continue to operate.
The closed loop may be formed by the hydraulic pump 202 fluidly coupled to the hydraulically driven pump 203 such that fluid is circulated between the hydraulic pump 202 and the hydraulically driven pump 203. In conventional open loop systems, once fluids are used at the hydraulic driven pump, the fluids are dumped into a tank and are not returned to the non-discharge side of the hydraulic pump. As such, the closed loop hydraulic pump circuits may use less fluid than open loop systems. However, in some embodiments, a closed loop hydraulic pump circuit may spend small amounts of fluid for heating/cooling purposes. For example, the closed loop systems formed by the hydraulic pump 202 and the hydraulically driven pump 203 may have flushing circuits that feed into the low pressure side of the hydraulic pump 202 to help trade hot and cold oil out of the hydraulic pump circuit (202, 203) as heat builds over time. Further, the power from the prime mover 204 that was going to the downed hydraulic pump circuit (202, 203) may be redistributed to the remaining operating hydraulic pump circuits (202, 203) on the respective modular pump skid (201a, 201b, 201c, 201d).
In some embodiments, the closed loop hydraulic pump circuits may use a hydraulic pump with a swash plate to dictate the flow to the hydraulically driven pump. In such embodiments, the swash plate may be moved to a selected position to allow an amount of fluid flow between the pumps. In contrast, open loop systems may use control valves that choke off flow to the hydraulically driven pump. Thus, hydraulic pumps in open loop system may provide fluid flow and pressure to the hydraulically driven pump, but offer less control than a pump in the closed loop hydraulic pump circuits using a swash plate.
In some embodiments, the modular pump skids 201a, 201b, 201c, 201d may be coupled to at least one wellhead 205 by using a manifold skid 206. The manifold skid 206, in some embodiments, refers to a modular skid that is purpose built for connection to the wellhead 205, and may include an outlet head (which may be referred to as a fracturing head or goat head in fracturing operations) for connection to the wellhead 205 and one or more gate valves. It is further envisioned that the modular pump skids 201a, 201b, 201c, 201d may be coupled directly to the wellhead 205 without the manifold skid 206. For example, flow lines from the modular pump skids 201a, 201b, 201c, 201d may be coupled to the outlet head for connection to the wellhead 205 and may include one or more gate valves.
In one or more embodiments, a frac blender 209 may provide hydraulic blended pressure (e.g., 100-120 PSI) to low-pressure fluid conduits 208 to each of the modular pump skids 201a, 201b, 201c, 201d, which may then be distributed to the hydraulically driven pumps 203. For example, silos 210 may provide sand to the frac blender 209 via a conveyor belt 211. In addition, one or more water and chemical storage units 213 may feed a fluid (water with or without chemicals) to either a hydration unit 212 and/or directly to the frac blender 209. The frac blender 209 may then mix the sand from the silos 210 and the fluids from the one or more water and chemical storage units 213 to form a fracturing fluid to pump into the wellhead 205. From the hydraulically driven pumps 203, a treated pressure (e.g., 15k PSI) may exit the modular pump skids 201a, 201b, 201c, 201d through high-pressure fluid conduits 207. The high-pressure fluid conduits 207 of each modular pump skids 201a, 201b, 201c, 201d may be in fluid communication with the manifold skid 206. For example, the high-pressure fluid conduits 207 may inject fluids into or receive fluids from the manifold skid 206. Each high-pressure fluid conduit 207 may be integrated with the base of the modular pump skids 201a, 201b, 201c, 201d.
In one or more embodiments, each of the modular pump skids 201a, 201b, 201c, 201d may be placed adjacent to each other to create a more compact work site for a smaller footprint. Each of the modular pump skids 201a, 201b, 201c, 201d may be include closed loop systems formed by individual hydraulic pumps (202a-202c) fluidly coupled to hydraulically driven pumps (203a-203c). A schematic example of a modular pump skid 201 in a closed loop is illustrated in
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The prime mover 204 may be used to power all the individual hydraulic pump circuits (202a-202c and 203a-203c) on the modular pump skid 201. With the individual hydraulic pump circuits (202a-202c and 203a-203c) being a closed loop, a redundancy may be provided in case one of the individual hydraulic pump circuits breaks down, as the unused power from that individual hydraulic pump circuit may be shifted to the remaining operational hydraulic pump circuits, and fracturing operations may continue. For example, if the first individual hydraulic pump circuit (202a, 203a) goes down, the second individual hydraulic pump circuit (202b, 203b) and the third individual hydraulic pump circuit (202c, 203c) may continue operate without a loss in power and efficiency. Further, the downed first individual hydraulic pump circuit may be simultaneously repaired while the second individual hydraulic pump circuit (202b, 203b) and the third individual hydraulic pump circuit (202c, 203c) continue to operate. Once the downed first individual hydraulic pump circuit is repaired, the first individual hydraulic pump circuit may be turned on and operate without stopping the operations of the second individual hydraulic pump circuit (202b, 203b) and the third individual hydraulic pump circuit (202c, 203c).
Additionally, a lost horsepower (“HP”) from the first hydraulic pump circuit (202a, 203a) being down may be redistributed by the prime mover 204 to the second hydraulic pump circuit (202b, 203b) and the third hydraulic pump circuit (202c, 203c). For example, if the modular pump skid 201 has five hydraulic pump circuits running at 2000 HP each (i.e., 10k total HP) from the prime mover 204 and one hydraulic pump circuit goes down, the prime mover 204 may automatically or manually redistribute the 2000 HP from the downed hydraulic pump circuit to the other four operational hydraulic pump circuits such that the remaining four operational hydraulic pump circuits may operate at 2500 HP. This setup has the advantage of maximizing the use of the prime mover 204 output HP while also allowing for the prime mover 204 to run at a fixed speed.
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In one or more embodiments, the hydraulic pump 202 is fluidly coupled to the hydraulically driven pump 203. For example, a first side 223a of the piston chamber 223 may be connected to a first side A of the hydraulic pump 202 and a second side 223b of the piston chamber 223 may be connected to a second side B of the hydraulic pump 202. In the closed loop, the first side A and the second side B of the hydraulic pump 202 may trade as inlets and outlets during operations. As the prime mover 204 powers the hydraulic pump 202, the hydraulic pump 202 may direct fluids between the first and second sides 223a, 223b of the piston chamber 223 to move the piston 219 and plunger 218 configuration and drive the hydraulically driven pump 203. For example, if fluids are discharging out of the first side A of the hydraulic pump 202 to the hydraulically driven pump 203, the second side B of the hydraulic pump 202 is receiving fluids from the hydraulically driven pump 203 as an inlet/suction. Additionally, once the piston 219 and plunger 218 configuration reaches the end of the stroke, the hydraulic pump 202 operation may switch such that the second side B is now discharging fluids, while the first side A is the inlet/suction. In such manner, fluid flow is maintained in a closed loop system between the hydraulic pump 202 and the hydraulically driven pump 203.
A tank 221 may be fluidly coupled to the hydraulic pump 202 to bleed off any excess hydraulic pressure from the hydraulic pump circuit (202, 203). The tank 221 may also provide fluids to the hydraulic pump 202 while receiving any discharge fluid from the closed loop (e.g., overpressure, circulation of hot fluid from the system, etc.). The tank 221 may be a hydraulic excess tank that does not recirculate hydraulic pressure to the hydraulically driven pump 203. It is further envisioned that a cooling circuit (e.g., radiator) may be coupled to the tank 221 to aid in keeping the fluids and the closed loop operating at the desired temperatures.
The hydraulic pump 202 or the prime mover 204 may incorporate a control valve and have a control system 222 to operate the various components of the modular pump skid 201. The control system 222 may be a computing system (e.g., as described below with reference to
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In some embodiments, the modular pump skid 201 may include one hydraulic pump 202 for each hydraulically driven pump 203. For example, the modular pump skid 201 may have five hydraulic pumps 202 each fluidly coupled to a corresponding hydraulically driven pump 203 removably mounted on a second end 214b of the base or chassis 214. While it is noted that five hydraulic pumps and five hydraulically driven pumps are used for an example, this is merely for example purposes only and any number of hydraulic pumps and hydraulically driven pumps may be used without departing from the scope of the present disclosure. Additionally, the five hydraulic pumps 202 may be in fluid communication with the five hydraulically driven pumps 203 via fluid conduits 224, such as hydraulic lines or hoses, extending from the five hydraulic pumps 202 to the five hydraulically driven pumps 203. In some embodiments, a connection block may be provided between the hydraulic pumps 202 and the hydraulically driven pumps 203 to avoid long and custom individual fluid conduits 224. The connection block may be used such that the fluid conduits 224 extend from the five hydraulic pumps 202 to the connection block and a second set of fluid conduits extend from the connection block to the five hydraulically driven pumps 203. In embodiments having an open loop configuration between the hydraulically driven pumps 203 and hydraulic pumps 202, a manifold (e.g., including one or more control valves) may be used in place of the connection block.
Embodiments disclosed herein may also operate using multiple open loop circuits rather than the multiple closed loop circuits described herein, where open loop circuit systems may have hydraulic pumps generate bulk pressure and flow, and a control valve to control flow to the hydraulic drive pump to create a motion profile. By using multiple open loop circuits, similar redundancy may be achieved, but may include increased complexity of components and increased fluid and cooling capacity needed. Although embodiments of the present disclosure may be configured in an open loop, a closed loop system configuration may advantageously reduce the amount of hydraulic fluid needed for operation, lower the weight of the system, and more efficiently use hydraulic fluid (compared with discharging energy as heat in an open loop system).
Additionally, the hydraulically driven pumps 203 may include a discharge line 227 and a feed line 228. The discharge line 227 may be at an end of the hydraulically driven pumps 203 distal to the hydraulic pumps 202 while the feed line 228 may be at an end of the hydraulically driven pumps 203 adjacent to the hydraulic pumps 202.
In one or more embodiments, the modular pump skid 201 may include a tank 229 and a radiator 230. For example, the tank 229 may be placed adjacent to the first end 214a of the base or chassis 214. In some embodiments, the tank 229 may be a hydraulic tank on a ground surface or on the base or chassis 214. The tank 229 may provide hydrostatic pressure to the prime mover 204. The radiator 230 may be disposed on top of the tank 229 to aid regulating a temperature of the prime mover 204 and other components of the modular pump skid 201.
According to embodiments of the present disclosure, modular pump skid systems may be configured to a pressure rating of any job requirement. For example, a main pressure rating limitation of the modular pump skid system may correspond with the wellheads. Furthermore, the modular pump skid systems may be rated up to 15,000 psi but is not limited to 15,000 psi (in some cases the pressure rating may go up to 20,000 psi or more). One skilled in the art will appreciate how various equipment within the modular pump skid system may have different pressure ratings. For example, the hydraulic pumps may have a pressure rating of 15,000 psi while the wellheads and the manifold skid may have a pressure rating of 10,000 psi. In some embodiments, the hydraulic pumps of the modular pump skid system may be pressure rated higher than the wellheads and the manifold skid, which may have pressures ratings from 5,000 psi up to 15000 psi, for example, and can change from job to job. In a non-limiting example, each long stroke cylinder, such as described above, may include dual-acting cylinders and provide 1000 horsepower per 48-inch stroke, with two strokes per cylinder, along with 12000 horsepower per modular pump skid system. Other combinations of HP, stroke, and number of cylinders per modular pump skid system may be used to provide a desired output pressure and/or flow rate without departing from the scope of the present disclosure.
According to embodiments of the present disclosure, fluid conduits of the modular pump skid system may have an inner diameter ranging from, for example, 4 inches to 8 inches. One skilled in the art will appreciate how the fluid conduits are not limited to the range of 4 inches to 8 inches and may be any desired inner diameter based on the job requirements. As such, the fluid conduits may be as small as ¾ inch (e.g., a 1 inch flow line) or as large as 30 inches (API 6A has regulations up to a 30 inch inner diameter, 3000 psi capacity). In such a case, the ends of the fluid conduits may have an upset section to transition from a larger inner diameter at the ends to a smaller inner diameter.
In one or more embodiments, the modular pump skid systems may be deployed in at least two ways. In a first way, modular pump skid system may be loaded onto a truck and unloaded on site via a crane, for instance. Once unloaded, the modular pump skid systems can be placed in proximity to one another and secured together, such as by bolts and/or hydraulics, to form a unitary pump structure. The end portions (inlet(s) and outlet(s)) of fluid conduits of the modular pump skid system may be connected together by any known mechanisms, including flanges, clamps, grayloc hubs, KL4 connectors, etc. In some embodiments, modular pump skid systems may be removably mounted and deployed on flatbeds. The fluid conduit connections between multiple modular pump skid systems on a truck may be made up before the trucks are driven to the site. In a non-limiting example, the modular pump skid system may be modularized and deployed on connectable skids to reduce the number of connections to other equipment. Additionally, the modular pump skid system may be sized and weighted to be transportable down a department of transportation (“DOT”) regulated road. For example, in some embodiments, the modular pump skid system may be sized and weighted to meet shipping truck width/length requirements (e.g., up to 8½ feet wide and up to 42 feet long). Overall, a modular pump skid system according to embodiments of the present disclosure may minimize product engineering, risk associated with non-uniform connections, reduction of assembly time, hardware cost reduction, and weight and envelope reduction.
Implementations herein for operating the modular pump skids (201, 201a, 201b, 201c, 201d) may be implemented on a computing system (e.g., control system 222 as described in
In some embodiments, inputs for the computing system may be a swash plate position, hydraulic bearing/operational condition, hydraulic suction and inlet pressure, hydraulic fluid temperature, linear variable differential transformer (LVDT) position from the cylinder on where the cylinder is at any given moment (or some other position sensing solution), frac pump suction pressure and inlet pressure, vibration monitoring, and various other operational parameters of the modular pump skid (201, 201a, 201b, 201c, 201). The closed loop may provide the modular pump skid (201, 201a, 201b, 201c, 201) with the benefits of being able to generate only what fluids are needed for a certain motion profile for each hydraulically driven pumps (203). In contrast, open loops may be more of a “choke” system where the control valve regulates the flow to get a motion profile and any flow not used is rejected as heat.
Any combination of mobile, desktop, server, router, switch, embedded device, or other types of hardware may be used with the modular pump skids (201, 201a, 201b, 201c, 201d). For example, as shown in
The computing system 800 may also include one or more input devices 810, such as a touchscreen, keyboard, mouse, microphone, touchpad, electronic pen, or any other type of input device. Additionally, the computing system 800 may include one or more output devices 808, such as a screen (e.g., a liquid crystal display (LCD), a plasma display, touchscreen, cathode ray tube (CRT) monitor, projector, or other display device), a printer, external storage, or any other output device. One or more of the output devices may be the same or different from the input device(s). The input and output device(s) may be locally or remotely connected to the computer processor(s) 802, non-persistent storage 804, and persistent storage 806. Many different types of computing systems exist, and the aforementioned input and output device(s) may take other forms.
The computing system 800 of
Data may also be presented through various audio methods. In particular, data may be rendered into an audio format and presented as sound through one or more speakers operably connected to a computing device. Data may also be presented to a user through haptic methods. For example, haptic methods may include vibrations or other physical signals generated by the computing system. For example, data may be presented to a user using a vibration generated by a handheld computer device with a predefined duration and intensity of the vibration to communicate the data.
While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the disclosure should be limited only by the attached claims.