Patent ID: 12228079

While embodiments of this disclosure have been depicted and described and are defined by reference to example embodiments of the disclosure, such references do not imply a limitation on the disclosure, and no such limitation is to be inferred. The subject matter disclosed is capable of considerable modification, alteration, and equivalents in form and function, as will occur to those skilled in the pertinent art and having the benefit of this disclosure. The depicted and described embodiments of this disclosure are illustrative examples only, and not exhaustive of the scope of the disclosure.

DESCRIPTION OF ILLUSTRATIVE EMBODIMENT(S)

The following detailed description illustrates embodiments of the present disclosure. These embodiments are described in sufficient detail to enable a person of ordinary skill in the art to practice these embodiments without undue experimentation. It should be understood, however, that the embodiments and examples described herein are given by way of illustration only, and not by way of limitation. Various substitutions, modifications, additions, and rearrangements may be made that remain potential applications of the disclosed techniques. Therefore, the description that follows is not to be taken as limiting on the scope of the appended claims. In particular, an element associated with a particular embodiment should not be limited to association with that particular embodiment but should be assumed to be capable of association with any embodiment discussed herein.

As used herein, “fuel gas” includes any gas that may be combusted, including hydrocarbon gases. Examples of fuel gasses include natural gas, compressed natural gas (CNG), field gas, synthesis gas, liquefied natural gas (LNG), gas residue, sale line gas, hydrogen, methane, propane, butane and combinations thereof. Field gas may include any hydrocarbon gas that is obtained directly from an oil and/or natural gas well or field of wells.

As used herein, the term “fuel consuming asset” includes any equipment or component of a system that consumes fuel gas. The term “fuel consuming asset” further includes any fuel consuming equipment that needs to be fed fuel gas “on-location” because, for example, the equipment is remotely located and/or the equipment needs to operate continuously and therefore taking the equipment offline to refuel or move the equipment results in asset downtime. In one embodiment, the fuel consuming asset may be equipment used in oilfield applications such as, for example, equipment used to provide power for, in construction of, or development of oil and gas fields. The term “fuel consuming asset” may include a number of other equipment including, for example, electrical generators, irrigation pumps, emergency response generators, or any oilfield services equipment (e.g., fracturing equipment, etc.).

In one or more exemplary embodiments there is disclosed herein a new and improved distribution system for fuel gas and associated methods used to distribute fuel gas to a fuel consuming asset.

FIG.1illustrates a fuel gas distribution system100in accordance with an illustrative embodiment of the present disclosure. The fuel gas distribution system100includes a fracking fleet101, a vaporizer and compression system (VCS)200, a distribution line system107, and a liquid fuel gas (LFG) source109. The fracking fleet101further comprises one or more fuel consuming assets111. The VCS200includes a fuel gas inlet114and a distribution outlet112. The LFG source provides liquid fuel gas (LFG) to the VCS200via the fuel gas inlet114. The VCS200provides compressed fuel gas (CFG) to the distribution line system107via the distribution outlet112. The distribution line system107may include a daisy system, a caterpillar system, or any other type of fuel gas distribution system.

FIG.2illustrates a vaporizer and compression system (VCS)200in accordance with an illustrative embodiment of the present disclosure. The VCS200includes a mounting base202, a vaporizer204(e.g., ambient vaporizer), and a compressor206. The vaporizer204and the compressor206are disposed on (e.g., mounted on) the mounting base202. The mounting base202is a trailer and includes a distribution end203and a supply end205. The vaporizer204is mounted on the mounting base202at a location proximal to the supply end205of the mounting base202. The compressor206is mounted on the mounting base202at a location proximal to the distribution end203of the mounting base202.

FIGS.3A-3Dillustrate the vaporizer204.FIG.3Aillustrates a perspective view of the vaporizer204.FIG.3Billustrates a side view of the vaporizer204.FIG.3Cillustrates a top view of the vaporizer204.FIG.3Dillustrates a front view of a vaporizer204at line3D-3D. The vaporizer204is an ambient air vaporizer, which is a heat exchanger that facilities the transfer of atmospheric thermal energy to a medium flowing therein, such as liquefied natural gas. The vaporizer204is constructed of one or more tubes, fins, liners, and other components for housing a medium therein while transferring thermal energy thereto (e.g., a plurality of channels330). Stainless steel, aluminum, or other alloys are used for the construction of the channels330of the vaporizer204, but it is contemplated that other materials may be used depending on pressure, temperature, and containment specifications. In one example, the vaporizer204operates at an internal pressure of 100 psi to 500 psi, but may be configured to withstand over 800 psi, such as about 1000 psi.

The vaporizer204comprises the fuel gas inlet114and a fuel gas outlet216. The fuel gas inlet114provides LFG to the vaporizer204from the LFG source109. The vaporizer204is configured to regasify (or vaporize) the LFG to form regasified (or vaporized) fuel gas (RFG). The fuel gas outlet216is configured to provide the RFG to the compressor206. Certain configurations of channels330may increase the surface area of the channels330. Increasing the surface area of the channels may increase the amount of LFG regasified into RFG, as surface area and regasification are directly related. For example, fin, heat sinks, or the like may be adhered to the exterior surface of the channels330to increase the exterior surface area thereof, thus improving heat transfer.

In some embodiments, the plurality of channels330are subdivided into channel groups340. In the illustrated embodiments, the channels330are subdivided into a first channel group340a, a second channel group340b, and a third channel group340c, though greater or fewer channel groups340are contemplated by this disclosure. The subdivision into channel groups facilitates fluid travel paths of predetermined lengths to achieve sufficient heat transfer. In one example, all channel groups provide the same travel path length and process the same volume of fluid per unit time. The fuel gas inlet114provides the LFG to a vaporizer inlet350of the vaporizer204. The vaporizer inlet350provides the LFG to the channels330. In the illustrated embodiment, the vaporizer inlet350provides the LFG to the channels330of the first channel group340avia a first vaporizer inlet350a, the vaporizer inlet350provides the LFG to the channels330of the second channel group340bvia a second vaporizer inlet350b, and the vaporizer inlet350provides the LFG to the channels330of the third channel group340cvia a third vaporizer inlet350c.

The RFG is provided to the fuel gas outlet216via a vaporizer outlet360. In the illustrated embodiment, the vaporizer outlet360provides the RFG to the fuel gas outlet216from the channels330of the first channel group340avia a first vaporizer outlet360a, the vaporizer outlet360provides the RFG to the fuel gas outlet216from the channels330of the second channel group340bvia a second vaporizer outlet360b, the vaporizer outlet360provides the RFG to the fuel gas outlet216from the channels330of the third channel group340cvia a third vaporizer outlet360c.

The channels330are support by vertical supports332and horizontal supports334. The vertical supports332are coupled to the mounting base202via mounting brackets336. The vertical supports332are coupled to the channels330through vertical support connectors333. The horizontal supports334are coupled to the channels330through horizontal support connectors335. In some embodiments, the vaporizer204is generally oriented horizontally. In some embodiments, the vaporizer204is angled upward toward the compressor206at an angle θ of about 5° to about 10°, such as about 7° to about 8°, with respect to the mounting base202. The generally horizontal orientation of the vaporizer204(and, consequently, the general horizontal orientation of the channels330) increases the efficiency of the vaporizer204by about ˜15-20% relative to a vaporizer in a vertical orientation, aided in part by the increase heat flow across the vaporizer from the compressor206. The horizontal orientation of the vaporizer204may cause an increase in the accumulation of ice on the vaporizer204during the regasifying process. The vertical supports332and horizontal supports334provide additional support to the channels330of the vaporizer204to compensate for the additional weight of the accumulated ice, thereby allowing the vaporizer204to be positioned in a more advantageous position relative to the compressor206for increased heat transfer. In some examples, the vertical supports332and horizontal supports334and u-beams or I-beams formed from a metal, such as steel or aluminum. The vertical supports332and horizontal supports334are positioned at predetermined intervals, which may vary based on design considerations. In one example, a cowling may be affixed to a vertical support332and/or a horizontal support334closest to the compressor206. The cowling facilitates containment of, and directing of, heated gases from the compressor206towards the vaporizer204. Other support structures for the cowling are also contemplated, such as an independent stand or bracket that does not provide support to the channels330. In some instances one or more fans (such as fan210) are also utilized to increase directing of heated gases from the compressor206to the vaporizer204. The one or more fans may be used with or without a cowling. The cowling may extend between the compressor206and the vaporizer204, and may optionally cover some or all of the vaporizer204and/or the compressor206.

The compressor206further comprises an exhaust208, a fan210, and the distribution outlet112. The compressor206is configured to compress the RFG provided from the vaporizer204into a compressed fuel gas (CFG). The distribution outlet112is configured to supply the CFG to the fuel consuming assets111via the distribution line system107. The distribution outlet112is disposed at a location on the compressor206proximal to the distribution end203of the mounting base202. An increase in the outlet pressure of the compressor206may increase the displacement value of the VCS200.

The compressor206is configured to burn fuel gas in order to compress the RFG provided by the vaporizer204. The exhaust208is configured to emit air and gases produced during the compression process from the compressor206.

The fan210is disposed between the compressor206and the vaporizer204. The fan210may include one or more fans, such as about 5 fans. The exhaust208is disposed at a location proximate to the fan210. The fan210is configured to direct heat from the compressor206towards the vaporizer204. In one example, the heat from the compressor206may be thermal energy removed by a cooling system of the compressor. Additionally or alternatively heat may be extracted directly from the mechanical components of the compressor206by the fan210, and/or the heat may be thermal energy from the exhaust208. A distance DI separates the fan210from the vaporizer204. The distance DI is about 2 inches to about 10 inches, such as about 6 to about 10 inches, such as about 6 inches to about 8 inches. However, other distances are also contemplated, based on the volumetric flow rate of the fan210, as well as the amount of thermal energy transferred by the fan.

The flow of air and gases emitted from the exhaust208increases the air flow and the ambient temperature around the vaporizer204. The efficiency of the vaporizer204to regasify LFG is dependent on the air flow and ambient temperature around the vaporizer204. An increase in the air flow around the vaporizer204increases the efficiency of the vaporizer by reducing the likelihood of ice buildup on the vaporizer204, as well as by increasing the transfer of thermal energy to the medium (e.g., LNG) within the vaporizer. The reduction in the likelihood of ice buildup may be due to the removal of moisture in the air by flowing dry air and gases past the vaporizer204. In addition, an increase in the ambient temperature around the vaporizer204increases the efficiency of the vaporizer204by increasing the temperature differential between the ambient air and the LFG in the vaporizer204.

The fan210has an air flow of about 1 cfm to about 10,000 cfm. The temperature of the air and gases emitted from the exhaust208may create a temperature differential of about-220° C.-300° C. between the air and gases and the vaporizer204. The increase in the air flow and the temperature differential increases the capability of the vaporizer204to form RFG by a multiple of about 2 to about 4, relative to conventional systems, thus reducing the hardware required on location. The increase in the capability of the vaporizer204reduces the surface area taken up by the vaporizers by at least 40%, such as by at least 50%, such as by at least 60%. Further, the increase in the air flow and the temperature differential increases the displacement value of the fracking fleet to at least about 75%, such as at least 80%, such as at least 90%. Thus, using configurations described herein results in reduced hardware costs, reduced operating costs, reduced footprint, and reduced transportation costs, relative to conventional systems.

As the fan210flows the air and gases emitted from the compressor206through the vaporizer204, the air and gases are cooled by the vaporizer204. As the air and gases cool, the density of the air and gases may increase. The angle of the vaporizer204with respect to the mounting base202enables the air and gases, as the air and gases cool, to continue to flow around the components of the vaporizer204which are distal from the fan210. The extended use of the air and gases emitted from the compressor206further increases the efficiency of the vaporizer204. While the vaporizer204is illustrated in a horizontal orientation, it is to be noted that other orientations are also contemplated. For example, the vaporizer204may be oriented vertically to reduce the footprint of the mounting base202.

Optionally, the vaporizer204may be enclosed in a shroud. The shroud captures the air and gases emitted by the compressor206in an area surrounding the vaporizer204. The capture of the air and gases emitted by the compressor206maintains an increased temperature differential (by trapping heat near the vaporizer204) between the ambient temperature and the vaporizer204, which may further increase the efficiency of the vaporizer204. Additionally or alternatively, a shroud may be positioned between the fan210and the vaporizer204, to facilitate directional funneling of thermal energy to the vaporizer204, further improving thermal efficiency.

In some embodiments, the vaporizer204may include a water jacket. The water jacket may surround the vaporizer204to provide an increased temperature differential between the vaporizer204and the ambient temperature around the vaporizer204, which may further increase the efficiency of the vaporizer204.

FIG.4is a flow diagram of a method400of distributing a fuel gas to a fuel consuming asset111. At operation401, a liquefied fuel gas (LFG) is provided to a vaporizer204. The LFG may be provided to the vaporizer204by a LFG source via a fuel gas inlet114.

At operation402, the vaporizer204regasifies the LFG into a regasified fuel gas (RFG). The efficiency of the vaporizer204is influenced by the air flow and ambient temperature surrounding the vaporizer204.

At operation403, the RFG is provided to the compressor206by the vaporizer204. The RFG may be provided to the compressor via a fuel gas outlet216.

At operation404, the RFG is compressed into a compressed fuel gas (CNG) by the compressor206. At operation405, the compressor emits exhaust gases and thermal energy. The exhaust gases and thermal energy emitted by the compressor206are the result of the compressor206burning fuel gas to perform the compression operation, as well as waste energy from the compressor operations.

At operation406, the exhaust gases and/or thermal energy emitted by the compressor206are directed from the compressor206toward (and through) the vaporizer204. The flow and the temperature of the gases directed from the compressor206to the vaporizer increase the efficiency of the vaporizer204.

At operation407, the compressed fuel gas is provided to a fracking fleet101. The compressed gas may be provided to the fracking fleet101via a distribution outlet112and a distribution line system107.

As would be appreciated by those of ordinary skill in the art with the benefit of the present disclosure the methods and systems disclosed herein provide several advantages. For example, the vaporizer and compression system (VCS) may lead to a reduction in equipment surface area of at least about 40%. Further, the efficiency of the vaporizer may be improved by a multiple of about 2 to about 4, which may result in an increase of the displacement value to at least 70%. As would be appreciated by those of ordinary skill in the art, having the benefit of the present disclosure, this is not intended to be an exhaustive list of all advantages and benefits of the methods and systems disclosed herein and other advantages are apparent to those of ordinary skill in the art, having the benefit of the present disclosure.

As would be appreciated, numerous other various combinations of the features discussed above can be employed without departing from the scope of the present disclosure. While the subject of this specification has been described in connection with one or more exemplary embodiments, it is not intended to limit any claims to the particular forms set forth. On the contrary, any claims directed to the present disclosure are intended to cover such alternatives, modifications and equivalents as may be included within their spirit and scope. Accordingly, all changes and modifications that come within the spirit of the disclosure are to be considered within the scope of the disclosure.