Embodiments usable within the scope of the present disclosure relate, generally, to systems and methods for flowing fluid in association with a wellbore, and more specifically, to systems and methods usable for performing fracturing operations on a formation to stimulate production (e.g., of hydrocarbons) therefrom.
To stimulate and/or increase the production of hydrocarbons from a well, a process known as fracturing (colloquially referred to as “fracing”) is performed. In brief summary, a pressurized fluid—often water—is pumped into a producing region of a formation at a pressure sufficient to create fractures in the formation, thereby enabling hydrocarbons to flow from the formation with less impedance. Solid matter, such as sand, ceramic beads, and/or similar particulate-type materials, can be mixed with the fracturing fluid, this material generally remaining within the fractures after the fractures are formed. The solid material, known as proppant, serves to prevent the fractures from closing and/or significantly reducing in size following the fracturing operation, e.g., by “propping” the fractures in an open position. Some types of proppant can also facilitate the formation of fractures when pumped into the formation under pressure.
Non-aqueous fracturing fluids have been used as an alternative to water and other aqueous media, one such successful class including hydrocarbon-based fluids (e.g., crude/refined oils, methanol, diesel, condensate, liquid petroleum glass (LPG) and/or other aliphatic or aromatic compounds). Hydrocarbon-based fracturing fluids are inherently compatible with most reservoir formations, being generally non-damaging to formations while creating acceptable fracture geometry. However, due to the flammability of hydrocarbon-based fluids, enhanced safety preparations and equipment are necessary when using such fluids for wellbore operations. Additionally, many hydrocarbon-based fluids are volatile and/or otherwise unsuitable for use at wellbore temperatures and pressures, while lacking the density sufficient to carry many types of proppant. As such, it is common practice to use chemical additives (e.g., gelling agents, viscosifiers, etc.) to alter the characteristics of the fluids. An example a system describing use of liquid petroleum gas is described in U.S. Pat. No. 8,408,289, which is incorporated by reference herein in its entirety.
Independent of the type of fracturing fluid and proppant used, a fracturing operation typically requires use of one or more high pressure pumps to pressurize the fracturing fluid that is pumped into a wellbore. Conventionally, such equipment is driven/powered using diesel engines, which can be responsible for significant quantities of noise, pollution, and expense at a worksite. Electric drive systems have been contemplated as an alternative to diesel engines; however, such systems require numerous pieces of equipment, extensive cabling and/or similar conduits, and typically utilize on-site power generation, such as a natural gas turbine engine. Use of turbine engines and similar equipment may be unsuitable when utilizing fracturing fluids that include flammable components. An exemplary electrically powered system for use in fracturing underground formations is described in published United States Patent Application 2012/0255734, which is incorporated by reference herein in its entirety.
A need exists for systems and methods for fracturing and/or stimulating a subterranean formation that can overcome issues of formation damage/compatibility, flammability, proppant delivery, and/or power supply.
Embodiments usable within the scope of the present disclosure include systems and methods usable to perform fracturing operations on a formation using an electrically powered fracturing spread.
A power source (e.g., a turbine generator and/or a grid-based power source) can be used to provide electrical power to one or more Variable Frequency Drives (VFDs), which in turn actuate electric motors, used to power associated high pressure pumps (e.g., fracturing pumps). The pumps are usable to pressurize a fracturing fluid (e.g., water, propane, or other suitable media, typically combined with proppant) prior to injection of the pressurized fluid into a wellbore to fracture the underlying formation.
A high pressure pump can be subject to a maximum rate and/or torque at which the pump can be operated without damaging components thereof, and as such, a single VFD or set of VFDs may provide horsepower in excess of what is required by a pump to operate the pump at a maximum rate. As such, embodiments usable within the scope of the present disclosure can include multiple high pressure pumps associated with a single VFD. In an embodiment, pumps can be provided with a “breakaway” usable to disconnect a selected pump from a VFD to enable the full power thereof to be provided to one or more pumps that remain connected therewith. In a further embodiment, a VFD can be associated with different types of pumps (e.g., a qunitiplex and/or a triplex pump), to enable selective use of one or both types of pumps in a manner that minimizes harmonic resonance.
An advantage of the present disclosure is the improved safety of engines for explosion risk when compared to traditional diesel engines and transmissions.
An advantage of the present disclosure is the elimination, and/or reduction, of engine requirements around the high pressure flammable frac fluid.
An advantage of the present disclosure is the elimination of diesel engines running away.
An advantage of the present disclosure is the faster response times to upsets.
An advantage of the present disclosure is the ability to have greater control of pump rate, including micro second kickouts, and the ability to soft start.
An advantage of the present disclosure is the improved reliability of systems.
An advantage of the present disclosure includes the improved life span of pumping equipment, and the elimination of engine and line pulsations.
An advantage of the present disclosure is the reduced maintenance requirements resultant from the elimination of engine and transmission requirements in some embodiments.
An advantage of the present disclosure is the improved ability to operate in extreme cold weather.
An advantage of the present disclosure includes real time diagnostics, which can be utilized for predictive maintenance.
An advantage of the present disclosure is the reduction in manual labor, with some embodiments configured to be managed from a remote location.
An advantage of the present disclosure includes reductions and/or elimination of emissions from pump equipment in some embodiments.
An advantage of the present disclosure includes reductions and/or elimination of noise from pump equipment in some embodiments.
An advantage of the present disclosure includes reduction in traffic to well site in some embodiments.
In various embodiments, disclosed systems can be used with medium voltage (e.g., 4160 volts), enabling smaller, lighter power conduits to be used, facilitating transport, installation, and safety, while minimizing line loss and the required amperage to operate the system.
In various embodiments, VFDs and/or similar components can be positioned a selected distance (e.g., 30 meters) from the high pressure pumps, thereby minimizing risks of ignition when pumping a flammable medium, such as propane and/or other hydrocarbon-based fracturing fluids. Separation of potential ignition sources from flammable components can eliminate the need to utilize explosion-proof measures (e.g., explosion-proof housings, pressurized environments, etc.)
In the detailed description of various embodiments usable within the scope of the present disclosure, presented below, reference is made to the accompanying drawings, in which:
One or more embodiments are described below with reference to the listed FIGURES.
Before describing selected embodiments of the present invention in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. The disclosure and description herein is illustrative and explanatory of one or more presently preferred embodiments of the invention and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, order of operation, means of operation, equipment structures and location, methodology, and use of mechanical equivalents may be made without departing from the spirit of the invention.
As well, it should be understood the drawings are intended illustrate and plainly disclose presently preferred embodiments of the invention to one of skill in the art, but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views as desired for easier and quicker understanding or explanation of the invention. As well, the relative size and arrangement of the components may differ from that shown and still operate within the spirit of the invention as described throughout the present application.
Moreover, it will be understood that various directions such as “upper”, “lower”, “bottom”, “top”, “left”, “right”, and so forth are made only with respect to explanation in conjunction with the drawings, and that the components may be oriented differently, for instance, during transportation and manufacturing as well as operation. Because many varying and different embodiments may be made within the scope of the inventive concept(s) herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and non-limiting.
The fracturing fluid and proppant storage vessels 104, 106, may be shown proximate to the low pressure manifold 108 of system 100, where the fracturing fluid and/or proppant can be injected (e.g., as a slurry). A plurality of high pressure pumps 112 (each powered using an associated electric motor) may be shown, the pumps 112 being usable to pressurize the fracturing fluid and/or proppant (e.g., at the high pressure manifold 110 of system 100) prior to flowing the fracturing fluid and/or proppant to the wellhead 102 (and subsequently into the wellbore to the formation). While the depicted diagram may show eight high-pressure pumps 112 and associated motors 114, it should be understood that any number of high pressure pumps 112 can be used depending on the nature of the operation. Conceptually,
A plurality of Variable Frequency Drives (VFDs) 116 may be shown spaced a selected distance (e.g., 30 meters) from the high pressure pumps 112. Placement of the VFDs 116 a safe distance from the high pressure pumps 112 can allow propane or a similar flammable medium to be used as a fracturing fluid while minimizing the risk of ignition created by the proximity of VFDs 116 or similar potential ignition sources. By placing the VFDs 116 remote from the high pressure pumps 112, the need for explosion proof housings, pressurized environments, and/or use of similar explosion-proof measures can be eliminated.
While
Each VFD 116 may be shown in operative association with two high pressure pumps 112 (via the associated electric motors 114). As described above, the maximum rate at which a high pressure pump 112 can be operated is typically limited to the maximum torque able to be withstood by the components thereof. As such, a single VFD 116 may produce horsepower in excess of that which is required to operate a high pressure pump 112 at its maximum rate, and in an embodiment, the horsepower output of a VFD 116 can be generally sufficient to operate two high pressure pumps 112 at a rate suitable for performing a fracturing operation. For example, four conventional VFDs 116 may output approximately 10,000 horsepower, which may be sufficient to operate eight high pressure pumps 112 at approximately their maximum rate. It should be understood that the type and quantity of VFDs 116 and/or pumps 112 and/or electric motors 114 can be selected such that the output of the VFDs 116 is generally equal to the horsepower requirements to operate the associated pumps 112.
As described above, in various embodiments, one or both pumps 112 coupled with a VFD 116 can include a breakaway or similar means for decoupling from the VFD 116, such that the entirety of the output from the VFD 116 can be used to drive a single pump 112 (e.g., at an enhanced rate), and/or to enable a second pump 112 to be used as a backup/redundant pump in the case of a fault or failure of a first pump. Additionally or alternatively, two pumps 112 associated with a single VFD 116 can include different types of pumps, such that a desired type of pump 112 can be selected for use (e.g., depending on operational conditions, wellbore conditions, types of equipment present/available, etc.). For example, selection between a quintiplex and/or a triplex pump can be used to minimize harmonic resonance.
The depicted VFDs 116 are shown in communication with a power source, which can include one or more generators, one or more power storage devices, one or more grid power sources, or combinations thereof. In an embodiment, the incoming power 118 can include a medium voltage source (e.g., 4160 volts), allowing use of smaller and lighter conduits, less line loss, lower amperage, etc. Depending on the characteristics of the VFDs 116, power source 118, motors 114, and/or pumps 112 used, the need for a separate transformer (e.g., to alter the incoming voltage and/or the voltage transmitted between components) can be obviated.
It should be understood that while
The fracturing fluid and proppant storage vessels 206,208 are shown proximate to the low pressure manifold 214 of the system 200, where the fracturing fluid and/or proppant can be injected (e.g., as a slurry). A plurality of high pressure pumps 212 may each be powered using an associated electric motor 216 and may each be mounted on an associated trailer 218 (as shown). The pumps 212 may be usable to pressurize the fracturing fluid and/or proppant (e.g., at the high pressure manifold of system 200) prior to flowing the fracturing fluid and/or proppant to the wellhead 202 (and subsequently into the wellbore to the formation). While the depicted diagram shows eight high pressure pumps 212 and associated motors 216, it may be understood that any number of high pressure pumps 212 can be used depending on the nature of the operation.
A plurality of Variable Frequency Drives (VFDs) 210 may be shown in association with the depicted high pressure pumps 212. Specifically, each trailer 218 may be shown having one VFD 210 mounted thereon, adjacent to two high pressure pumps 212 and associated motors 216. While
Due to the horsepower limitations of a typical high pressure pump 212, described previously, each VFD 210 is shown in operative association with two high pressure pumps 212. As described above, in various embodiments, one or both pumps 212 coupled with a VFD 210 can include a breakaway or similar means for decoupling from the VFD 210, such that the entirety of the output from the VFD 210 can be used to drive a single pump 212 (e.g., at an enhanced rate), and/or to enable a second pump 212 to be used as a backup/redundant pump 212 in the case of a fault or failure of a first pump 212. Additionally, or alternatively, two pumps 212 associated with a single VFD 210 can include different types of pumps 212, such that a desired type of pump 212 can be selected for use (e.g., depending on operational conditions, wellbore conditions, types of equipment present/available, etc.).
The depicted VFDs 210 are shown in communication with one or more power sources 220, which can include one or more generators, one or more power storage devices, one or more grid power sources, or combinations thereof. In an embodiment, the incoming power can include a medium voltage source (e.g., 4160 volts), allowing use of smaller and lighter conduits, less line loss, lower amperage, etc. Depending on the characteristics of the VFDs 210, power sources 220, motors 216, and/or pumps 212 used, the need for a separate transformer (e.g., to alter the incoming voltage and/or the voltage transmitted between components) can be obviated.
It should be understood that while
In the depicted embodiment, use of two high pressure pumps 212 and a single VFD on a single trailer can enable the two pumps 212 to be operated via the VFD using a single tie line. Using a reduced number of lines for system 200 in this manner may enable the manifold trailer to be reduced in size (e.g., one half of its conventional length), reducing the footprint of system 200 and facilitating transport thereof.
It should be noted that the ATEX Directive requires equipment and protective systems intended for explosive atmospheres to be designed and manufactured to minimize the occurrence and limit the severity of accidental explosions.
In some embodiments, a medium voltage may be provided to system componentry. In some embodiments, medium voltage provided to system componentry may be in the range of 600 volts to 35,000 volts. In some embodiments, medium voltage provided to system componentry may be in the range of 3500 volts to 7500 volts. In some embodiments, medium voltage provided to system componentry may be 4160 volts.
The process of determining the type and size of these hazardous areas is called area classification. Guidance on assessing the extent of the hazard is given in the NFPA 497 or NFPA 499 standards published by the National Fire Protection Association for explosive gas or dust atmospheres respectively, or RP 500 and RP 505 standards published by the American Petroleum Institute for explosive gas or dust atmospheres respectively, and IEC 60079-10-1 or IEC 60079-10-2 standards published by the International Electrotechnical Commission for explosive gas or dust atmospheres respectively.
While various embodiments usable within the scope of the present disclosure have been described with emphasis, it should be understood that within the scope of the appended claims, the present invention can be practiced other than as specifically described herein.
This application is related to: I. U.S. Provisional Patent Application Ser. No. 62/010,302, filed Jun. 10, 2014;II. U.S. Provisional Patent Application Ser. No. 62/036,284, filed Aug. 12, 2014;III. U.S. Provisional Patent Application Ser. No. 62/036,297, filed Aug. 12, 2014;IV. United States Application for patent application Ser. No. 14/199,461, filed Mar. 6, 2014;V. United States Application for patent application Ser. No. 14/511,858, filed Oct. 10 , 2014;VI. U.S. Provisional Patent Application Ser. No. 61/774,237, filed Mar. 7, 2013;VII. U.S. Provisional Patent Application Ser. No. 61/790,942, filed Mar. 15, 2013;VIII. U.S. Provisional Patent Application Ser. No. 61/807,699, filed Apr. 2, 2013;IX. U.S. Provisional Patent Application Ser. No. 61/870,350, filed Aug. 27, 2013;X. U.S. Provisional Patent Application Ser. No. 61/915,093, filed Dec. 12, 2013;XI. United States Application for patent application Ser. No. 14/735,745, filed Jun. 10 , 2015; andXII. United States Application for patent application Ser. No. 14/511,858, filed Oct. 10, 2014.XIII. Each of the fore mentioned applications are incorporated by reference in the entirety. The application claims priority to: I. U.S. Provisional Patent Application Ser. No. 62/010,302, filed Jun. 10, 2014;II. U.S. Provisional Patent Application Ser. No. 62/036,284, filed Aug. 12, 2014;III. U.S. Provisional Patent Application Ser. No. 62/036,297, filed Aug. 12, 2014;IV. United States Application for patent application Ser. No. 14/199,461, filed Mar. 6, 2014;V. United States Application for patent application Ser. No. 14/511,858, filed Oct. 10, 2014;VI. U.S. Provisional Patent Application Ser. No. 61/774,237, filed Mar. 7, 2013;VII. U.S. Provisional Patent Application Ser. No. 61/790,942, filed Mar. 15, 2013;VIII. U.S. Provisional Patent Application Ser. No. 61/915,093, filed Dec. 12, 2013;IX. U.S. Provisional Patent Application Ser. No. 61/807,699, filed Apr. 2, 2013;X. U.S. Provisional Patent Application Ser. No. 61/870,350, filed Aug. 27, 2013;XI. United States Application for patent application Ser. No. 14/735,745, filed Jun. 10, 2015; andXII. United States Application for patent application Ser. No. 14/511,858, filed Oct. 10, 2014.
Number | Date | Country | |
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62010302 | Jun 2014 | US | |
62036284 | Aug 2014 | US | |
62036297 | Aug 2014 | US | |
61774237 | Mar 2013 | US | |
61790942 | Mar 2013 | US | |
61870350 | Aug 2013 | US | |
61807699 | Apr 2013 | US | |
61889187 | Oct 2013 | US | |
61915093 | Dec 2013 | US |
Number | Date | Country | |
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Parent | 14735745 | Jun 2015 | US |
Child | 15179616 | US | |
Parent | 14199461 | Mar 2014 | US |
Child | 14735745 | US | |
Parent | 14511858 | Oct 2014 | US |
Child | 14199461 | US | |
Parent | 14199461 | Mar 2014 | US |
Child | 14511858 | US |