Patent Application
20160376864
This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present embodiments. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
In order to meet consumer and industrial demand for natural resources, companies often invest significant amounts of time and money in searching for and extracting oil, natural gas, and other subterranean resources from the earth. Particularly, once a desired subterranean resource is discovered, drilling and production systems are often employed to access and extract the resource. These systems may be located onshore or offshore depending on the location of a desired resource. Further, such systems generally include a wellhead assembly through which the resource is extracted. These wellhead assemblies may include a wide variety of components, such as various casings, valves, fluid conduits, and the like, that control drilling or extraction operations.
Additionally, such wellhead assemblies may use fracturing trees and other components to facilitate a fracturing process and enhance production from wells. As will be appreciated, resources such as oil and natural gas are generally extracted from fissures or other cavities formed in various subterranean rock formations or strata. To facilitate extraction of such a resource, a well may be subjected to a fracturing process that creates one or more man-made fractures in a rock formation. This facilitates, for example, coupling of pre-existing fissures and cavities, allowing oil, gas, or the like to flow into the wellbore. Fracturing processes typically use large pumps to inject a fracturing fluid—which is often a mixture including sand and water—into the well to increase the well's pressure and form the man-made fractures. A typical fracturing system includes a fracturing manifold trailer (also known as a missile trailer) with pipes for routing fracturing fluid to and from the large pumps. Other pipes connected to the output of the manifold trailer carry the fracturing fluid to the well.
Certain aspects of some embodiments disclosed herein are set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of certain forms the invention might take and that these aspects are not intended to limit the scope of the invention. Indeed, the invention may encompass a variety of aspects that may not be set forth below.
At least some embodiments of the present disclosure generally relate to modular systems for supplying fracturing fluid and other fluids to wells. In certain embodiments, multiple individual skids include fluid conduits mounted on platforms. The fluid conduits of the multiple skids are connected to form fluid lines spanning the multiple skids. These assembled, multi-skid fluid lines can be used for carrying fluid to and from pumps connected to the lines. For instance, one such fluid line can carry a low-pressure fracturing fluid. Pumps draw the low-pressure fracturing fluid from the fluid line and then pump the fracturing fluid, with a higher pressure, into a different one of the multi-skid fluid lines. The higher-pressure fracturing fluid can then be routed to a well for fracturing.
Various refinements of the features noted above may exist in relation to various aspects of the present embodiments. Further features may also be incorporated in these various aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to one or more of the illustrated embodiments may be incorporated into any of the above-described aspects of the present disclosure alone or in any combination. Again, the brief summary presented above is intended only to familiarize the reader with certain aspects and contexts of the some embodiments without limitation to the claimed subject matter.
These and other features, aspects, and advantages of certain embodiments will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
One or more specific embodiments of the present disclosure will be described below. In an effort to provide a concise description of these embodiments, all features of an actual implementation may not be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
When introducing elements of various embodiments, the articles “a,” “an,” “the,” and “said” are intended to mean that there are one or more of the elements. The terms “comprising,” “including,” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. Moreover, any use of “top,” “bottom,” “above,” “below,” other directional terms, and variations of these terms is made for convenience, but does not require any particular orientation of the components.
Turning now to the present figures, an example of a fracturing fluid delivery system 10 is provided in
The fracturing fluid delivery system 10 includes various components to control flow of a fracturing fluid into the well 14. For instance, the depicted system 10 includes a fracturing tree 20 and a fracturing manifold 22. The fracturing tree 20 is coupled to the wellhead 16 and can be considered part of a wellhead assembly, which includes the wellhead 16 and other coupled components. The fracturing tree 20 can be a conventional fracturing tree positioned vertically above the wellhead 16 or can be a horizontal fracturing tree. Still further, the fracturing tree 20 can include at least one valve that controls flow of the fracturing fluid into the wellhead 16 and, subsequently, down the well 14 to the reservoir 12. Similarly, the fracturing manifold 22 can include at least one valve that controls flow of the fracturing fluid to the fracturing tree 20 by a conduit or fluid connection 26 (e.g., by one or multiple pipes). As depicted in
Fracturing fluid is provided to the fracturing manifold 22 from a supply system 28. In
The fracturing fluid supply system 28 can take many forms, but in at least some embodiments the system 28 is a modular system including pumps for pressurizing fracturing fluid and multiple skids coupled to one another for routing fracturing fluid to and from the pumps. An example of such a modular fracturing fluid supply system 28 coupled to a fracturing manifold 22 is generally depicted in
In operation, one or more blenders 46 of the blending unit 36 can be used to produce the fracturing fluid by mixing fluid 48 (e.g., water) with various additives 50, such as sand (or another proppant) and chemicals. The blended fracturing fluid flows from the blending unit 36 to pumps 54 via the skids 38, 40, and 42. In at least some embodiments, the blending unit 36 is provided at a wellsite with the skids 38, 40, and 42. But in other instances, the blending unit 36 could be provided at a remote location, such as a fracturing factory that services multiple pads.
The blending unit 36 can also be used to provide other fluids 48, such as a different well stimulation fluid (e.g., an acid or solvent), through the skids 38, 40, and 42 to the pumps 54. Although the system 10 is described at times herein as a fracturing fluid delivery system, and components of the system 10 may be described as fracturing fluid components, it will be appreciated that the fracturing fluid delivery system 10 and its components can also or instead be used to deliver other stimulation fluids into the well. Thus, the fracturing fluid delivery system 10 can also be referred to as a well stimulation fluid delivery system. And while various conduits and operation of the system 10 are described with reference to fracturing fluid by way of example, the conduits and operations described could also be used with a different well stimulation fluid.
The pumps 54 can take any suitable form, and may include truck-mounted pumps or skid-mounted pumps. Regardless of their form, the pumps 54 increase the pressure of the fracturing fluid (or other fluid) received from the blending unit 36 via the skids and then route the fluid back into the depicted skids. The fracturing fluid pumped back into the skids by the pumps 54 can then be routed out through the discharge skid 42 to the fracturing manifold 22 for delivery to one or more fracturing trees 20 coupled to the manifold 22. In other instances, the manifold 22 may be omitted and the fracturing fluid can be routed from the discharge skid 42 directly to the one or more fracturing trees 20.
The flow of fracturing fluid between the pumps 54 and the various skids 38, 40, and 42 may be better understood with reference to
The pumps 54, which are shown in this figure as truck-mounted pumps, are positioned along the skids and connected to the assembled fluid lines. Low-pressure fracturing fluid flows into at least one of the assembled fluid lines at the suction skid 38 (e.g., from the blending unit 36), as generally represented by reference numeral 66, and is routed to the connected pumps 54. The pumps 54 increase the pressure of the fracturing fluid and the resulting high-pressure fracturing fluid is pumped into a high-pressure line of the connected skids. The high-pressure fracturing fluid flows through the high-pressure line and out of the discharge skid 42, as generally represented by reference numeral 70. In the presently depicted embodiment, each of the pumps 54 draws low-pressure fluid from one of the skids 38, 40, and 42 and then reintroduces that fluid into the same skid as high-pressure fluid.
In some instances, the high-pressure fluid has a pressure of at least one order of magnitude greater than the low-pressure fluid. For example, the low-pressure fluid can have a pressure below 300 psi (e.g., 200 psi) and the high-pressure fluid can have a pressure of thousands of psi (e.g., between 5,000 and 15,000 psi). But as used herein, the terms low-pressure fluid and high-pressure fluid (whether fracturing fluid or another fluid) are used as relative terms with respect to the state of the fluid before and after its pressure is increased to a desired level by a pump (e.g., pump 54) of the system 10—these terms do not denote specific pressures or pressure ranges. Similarly, low-pressure and high-pressure are also used to describe different fluid conduits or fluid lines in the system 10 for conveying the low-pressure and high-pressure fluids, respectively, and do not require any specific pressure ratings.
Certain embodiments of the skids 38, 40, and 42 are shown in
The suction skid 38 includes outlet connections 84 for coupling pumps 54 to receive fluid from the conduits 78. Valves 86 (e.g., butterfly valves) can be used to control flow from the conduits 78 through the connections 84 to the pumps 54. The suction skid 38 of
The suction skid 38 also includes inlet connections 94 for coupling the pumps 54 to the fluid conduit 80. Pumps 54 connected across the outlet connections 84 and the inlet connections 94 can draw fracturing fluid from the suction skid 38 (via the outlet connections 84) and then pump the fracturing fluid back into the suction skid 38 (via the inlet connections 94) at a higher pressure. The suction skid 38 also includes valves 96 (e.g., gate valves) coupled to the conduit 80 (more specifically, to a connection block 98 of the conduit 80) for controlling flow of the high-pressure fracturing fluid from the pumps 54 into the conduit 80. This high-pressure fracturing fluid is then routed through the conduit 80 to a pump skid 40 or some other downstream skid.
An example of a pump skid 40 is shown in
The pump skid 40 also includes outlet connections 84 and inlet connections 94 for coupling the skid 40 to pumps 54, and valves 86 and 96 for controlling flow to and from those pumps 54, as described above with respect to the suction skid 38. Pumps 54 coupled to the connections 84 and 94 of the pump skid 40 can draw low-pressure fracturing fluid from the skid 40 out of the conduits 106 and then return the fracturing fluid with a high pressure into the skid 40 (i.e., into the conduit 108). The conduit 108 includes a pipe segment and a connection block 98 mounted on the platform 104. The connection block 98 is shown as a studded connection block that can be coupled to an end of the conduit 80 of the suction skid 38. The conduit 108 receives high-pressure fracturing fluid from the pumps 54 connected to the connections 84 and 94 of the pump skid 40, as well as from the upstream conduit 80 of the suction skid 38.
In some embodiments, a fracturing fluid delivery system includes multiple pump skids 40 connected in series with the suction skid 38 and the discharge skid 42. In such cases, a first pump skid 40 can be coupled to the suction skid 38, as described above, and each additional pump skid 40 can be coupled to a previous pump skid 40 in a similar manner. The fluid conduits 106 and 108 of the additional pump skids 40 receive fracturing fluid from the upstream skids, and pumps 54 can be coupled across connections 84 and 94 to draw fluid from and inject the fluid back into the additional pump skids 40.
A discharge skid 42 is depicted in
The discharge skid 42 includes connections 84 and 94 for connecting pumps 54 to the skid 42, and valves 86 and 96 for controlling flow to and from the pumps 54. These pumps 54 draw low-pressure fluid from the discharge skid 42 (from the fluid conduits 116, which can receive the fluid from upstream conduits 78 and 106) and reintroduce that fluid to the discharge skid 42 (into the conduit 118) as a high-pressure fluid. A connection block 98 of the conduit 118 facilitates connection to an output end of an upstream high-pressure fluid conduit segment (e.g., the conduit 108 of a pump skid 40). In operation, the conduit 118 receives high-pressure fluid from pumps coupled across the connections 84 and 94 of the skid 42, and also from upstream high-pressure fluid conduit segments of other skids.
The fluid flowing in the high-pressure fluid line can be output to a fracturing tree 20 or manifold 22 through a distribution head 122 of the discharge skid 42. As depicted in
The various skids 38, 40, and 42 can be coupled directly to one another or coupled together with intervening fluid conduit segments. By way of example, a suction skid 38 is shown coupled directly to a pump skid 40 in
While
In at least some embodiments, the high-pressure fluid conduit segments of the skids 38, 40, and 42 include or are connected to valves and chokes to regulate the pressurized fluid flow from the pumps 54 for isolation and to reduce pulsation of the conduits. In one embodiment, high-pressure lines from the pumps 54 are connected to the inlet connections 94 via a choke and one or more valves. Further, the fluid conduit segments of the skids 38, 40, and 42 may include heavy-walled pipe to reduce vibration from operation of the system 10.
Each of the skids 38, 40, and 42 can be considered a module of the fracturing fluid delivery system 10, and these modular skids can be arranged and connected in any suitable fashion. Several examples of different modular arrangements are generally depicted in
In another embodiment generally depicted in
In other embodiments, the quantity of the modular skids can be varied. For example, the number of pump skids 40 can be selected based on the pumping capacity needed for a given application. While the arrangements shown in
Various embodiments have been described above as having multiple low-pressure fluid lines extending across multiple skids with pumps connected to opposite sides of each skid. But in at least one embodiment, a series of skids may include just one low-pressure fluid line. An example of this is depicted in
Further, while certain embodiments have been depicted in which fluid enters one end of a series of skids and is discharged at the opposite end, other arrangements may also be used in full accordance with the present techniques. For instance,
The modularity of the fluid distribution systems described herein may allow greater flexibility in designing and deploying a fluid delivery apparatus at a wellsite. Particularly, whereas a conventional missile trailer has connections for eight or ten pumps, the presently disclosed modular systems are configurable to the number of pumps needed for a particular fluid injection operation. These modular systems can also positioned at a wellsite, connected to fracturing trees on wellheads at the wellsite, and pressure tested before arrival of pumping trucks and crews. The individual skids can each be smaller than a traditional missile trailer. This facilitates positioning and handling of the system during installation or removal. In at least some cases, a crane can be used to lift and position different skid modules in desired locations. The flexibility in positioning offered by the modular design may also facilitate the use of the present system in remote areas (e.g., in mountainous terrain or jungles), urban spaces (e.g., near buildings or utilities), or environmentally-sensitive areas. The modules can also be more easily positioned on a previously existing multi-well pad to avoid existing structures and obstructions (e.g., production equipment).
Further still, missile trailers are typically pulled by a truck on public roadways and may have size and weight constraints due to government regulations. For example, missile trailers typically range between 14.6 and 16.2 meters to comply with certain government regulations. But the individual skids of the presently disclosed system can be delivered to a wellsite and then connected to have a total length greater than that of a conventional missile trailer. For example, in one embodiment, the distance between the intake connection 90 and the discharge connections 124 or 128 is greater than seventeen meters. The greater total length allows pump trucks connected to the skids 38, 40, and 42 to be spaced further apart from one another, which makes it easier to position the pump trucks and increases access to the connected trucks and the skids. Further, with increased spacing, fire-resistant barriers can be installed between the pump trucks. The modularity also allows the use of heavier components compared to a conventional missile trailer, such as thicker-walled piping, larger-diameter flow bores, and larger valves that are more resistant to wear from abrasive and corrosive fluids to which they are exposed, which may result in lower operating expenses compared to missile trailers.
While the aspects of the present disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. But it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
