Field of Disclosure
The disclosure relates generally to the field of hydrocarbon processing plants. More specifically, the disclosure relates to the efficient design, construction and operation of hydrocarbon processing plants, such as LNG processing plants.
Description of Related Art
This section is intended to introduce various aspects of the art, which may be associated with the present disclosure. This discussion is intended to provide a framework to facilitate a better understanding of particular aspects of the present disclosure. Accordingly, it should be understood that this section should be read in this light, and not necessarily as admissions of prior art.
In a time when competition for LNG production contracts is increasing, there is a tremendous need to enhance the profitability of future LNG projects. To do so, LNG producers may identify and optimize the key cost drivers and efficiencies applicable to each project.
Rendering projects economical in locations with high costs and low on-site labor productivity may require minimizing the scope and extent of site labor required to construct and commission the LNG plant. Modularization techniques are being employed to tackle this challenge by shifting scope from being built on-site to being built in specialized fabrication yards. However, for large scale LNG projects the modularization of construction scope can still result in significant site integration costs. Accordingly, there is a recognized need in the plant construction industry to remove additional work scope from the plant site compared to other modularization methods currently deployed by industry.
The LNG train 10 shown in
Additionally, in ambient air-cooled LNG train designs the air-cooled heat exchangers 34 are generally installed in a bank or banks on top of the central piperack structure. The size and number of these heat exchangers may establish the length and width of the central piperack 12 and, as a result, the overall footprint of the LNG train. This layout results in a significant number of labor-intensive large bore piping connections at the interfaces between air cooler piperack modules and pipe segments running through the piperack modules, and these connections usually are finished at an operating site rather than a manufacturing site.
Another attempt to modularize the design of an LNG train uses small capacity LNG trains (˜2 MTA) and uses a single natural gas treatment module that performs the functions of the AGR unit, the dehydration unit, and the HHC unit. However, if a higher capacity of LNG is required to be processed, multiple identical modular trains must be used, which results in the duplication of module interconnections and associated work scope at the LNG site. Therefore, a need exists for a modularized design for a high-capacity hydrocarbons processing plant, such as an LNG train, in which the amount of work to assemble modular parts thereof at an operating site is minimized.
In an aspect, a hydrocarbon processing plant is disclosed. A piperack structure has a major axis parallel to the major axis of the train with which it is associated. A first multipurpose module, substantially pre-assembled prior to being transported to an operating site, has a major axis that is parallel to the major axis of the piperack. The first multipurpose module contains: process components that perform a function related to hydrocarbon processing or handling; piping systems that connect the process components directly to a second, where the second multipurpose module is adjacent the first multipurpose module, and wherein at least part of the piping systems are aligned with the major axis of the piperack structure; and at least one heat exchanger located in the first multipurpose module and operationally connected to process components in the hydrocarbon processing plant.
The present disclosure also provides a method of hydrocarbon processing plant. A piperack structure has a major axis parallel to the major axis of the train with which it is associated. A first multipurpose module, substantially pre-assembled prior to being transported to an operating site, has a major axis that is perpendicular or substantially perpendicular to the major axis of the piperack. The first multipurpose module contains: process components that perform a function related to hydrocarbon processing or handling; piping systems that connect the process components directly to a second module, where the second module is adjacent the first multipurpose module, and wherein at least part of the piping systems are aligned with the major axis of the piperack structure; and a plurality of heat exchangers located in the first multipurpose module and operationally connected to process components located in the hydrocarbon processing plant. The plurality of heat exchangers are aligned with the major axis of the first multipurpose module.
The present disclosure further provides a method of constructing a hydrocarbon processing plant. A train is provided at an operating site. The train has a major axis. A piperack structure is provided at the operating site. The piperack structure has a major axis that is parallel to the major axis of the train. A heat exchanger bank is provided that runs along the major axis of the train. A first multipurpose module is substantially pre-assembled at a manufacturing site that is separate from the operating site. The first multipurpose module includes: process components that perform a function related to hydrocarbon processing or handling; piping systems; and a plurality of heat exchangers operationally connected to process components in the train, wherein the plurality of heat exchangers are aligned with the major axis of the first multipurpose module. The first multipurpose module is transported to the operating site. The first multipurpose module is operationally connected, at the operating site, to the train such that (a) the major axis of the first multipurpose module is either parallel or substantially perpendicular to the major axis of the piperack, (b) the piping systems connect the process components directly to a second module that is adjacent the first multipurpose module, and (c) at least part of the piping systems are aligned with the major axis of the piperack structure.
The foregoing has broadly outlined the features of the present disclosure so that the detailed description that follows may be better understood. Additional features will also be described herein.
These and other features, aspects and advantages of the disclosure will become apparent from the following description, appending claims and the accompanying drawings, which are briefly described below.
It should be noted that the figures are merely examples and no limitations on the scope of the present disclosure are intended thereby. Further, the figures are generally not drawn to scale, but are drafted for purposes of convenience and clarity in illustrating various aspects of the disclosure.
For the purpose of promoting an understanding of the principles of the disclosure, reference will now be made to the features illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is thereby intended. Any alterations and further modifications, and any further applications of the principles of the disclosure as described herein are contemplated as would normally occur to one skilled in the art to which the disclosure relates. It will be apparent to those skilled in the relevant art that some features that are not relevant to the present disclosure may not be shown in the drawings for the sake of clarity.
At the outset, for ease of reference, certain terms used in this application and their meanings as used in this context are set forth. To the extent a term used herein is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in at least one printed publication or issued patent. Further, the present techniques are not limited by the usage of the terms shown below, as all equivalents, synonyms, new developments, and terms or techniques that serve the same or a similar purpose are considered to be within the scope of the present claims.
As one of ordinary skill would appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name only. The figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. When referring to the Figures described herein, the same reference numerals may be referenced in multiple figures for the sake of simplicity. In the following description and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus, should be interpreted to mean “including, but not limited to.”
The articles “the,” “a” and “an” are not necessarily limited to mean only one, but rather are inclusive and open ended so as to include, optionally, multiple such elements.
As utilized herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. It should be understood by those of skill in the art who review this disclosure that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numeral ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and are considered to be within the scope of the disclosure. Nevertheless, an element is “substantially perpendicular” to a reference element when the element is oriented at an angle of between 80 degrees and 100 degrees to the reference element.
The term “acid gas” and “sour gas” refers to any gas that dissolves in water to produce an acidic solution. Non-limiting examples of acid gases include hydrogen sulfide (H2S), carbon dioxide (CO2), or sulfur dioxide (SO2), or mixtures thereof.
The term “heat exchanger” refers to a device designed to efficiently transfer or “exchange” heat from one matter to another. Exemplary heat exchanger types include a co-current or counter-current heat exchanger, an indirect heat exchanger (e.g. spiral wound heat exchanger, plate-fin heat exchanger such as a brazed aluminum plate fin type, shell-and-tube heat exchanger, etc.), direct contact heat exchanger, or some combination of these, and so on.
The “major axis” of an element refers to a line of symmetry parallel to the predominant linear dimension of the element. In other words, an element is longest in a direction of its major axis than along any other axis perpendicular or substantially perpendicular thereto.
The term “piperack” refers to a structural system that supports pipes, conduits tubes, and the like.
Although the phrases “gas stream,” “vapor stream,” and “liquid stream,” refer to situations where a gas, vapor, and liquid is mainly present in the stream, respectively, there may be other phases also present within the stream. For example, a gas may also be present in a “liquid stream.” In some instances, the terms “gas stream” and “vapor stream” may be used interchangeably.
The disclosure relates to a system and method for the standardized design and construction of a hydrocarbon processing plant, such as an LNG train. In an aspect, a significant number of connections between modules and/or processing units may be eliminated by integrating process equipment and piperack components in multipurpose modules that are connected to other distinct abutting modules. Additionally, ambient cooled heat exchangers, such as air fin coolers, can be located in the multipurpose modules. This is in contrast to the traditional LNG train design where (1) all process units and modules are arranged around a central piperack and (2) ambient cooled heat exchangers rejecting heat from the process units are located in or on the central piperack.
The LNG train 300 may also include acid gas removal (AGR) equipment or components that remove CO2 and H2S molecules from the feed gas 314 down to the very low levels required to prevent freezing in the downstream refrigeration and liquefaction units. As shown in
Another aspect is shown in the LNG train 400 of
Equipment that performs the dehydration process may be modularized and integrated with a piperack section or module to form a multipurpose dehydration/HHC module 418. The multipurpose dehydration/HHC module 418 may be located at the appropriate location for LNG processing, which as shown in
Piping connections from the piperack 412 and the multipurpose AGR module 416 connecting to other downstream processing units or piperack modules in the LNG train are routed through the multipurpose dehydration/HHC module 418. All or substantially all ambient cooled heat exchangers used in the dehydration and HHC processes, such as a regeneration gas cooler, are located on or in the multipurpose dehydration/HHC module. This solution eliminates multiple connections between the multipurpose dehydration/HHC module 418 and the piperack 412 that were required in known LNG layout configurations as previously described.
A multipurpose AGR module 516 is disposed along the major axis 502 of the LNG train 500. The multipurpose AGR module 516 has a major axis 506. In an aspect, the major axis 506 is parallel to, and/or co-incident with, the major axes 502, 504. The multipurpose AGR module 516 includes heat exchanger units 540 that provide some or all of the required cooling for the AGR equipment or components thereon. The heat exchanger units 540 may be ambient heat exchanger units, and may be ambient air fin heat exchanger units. While the heat exchanger units 540 may be disposed along the major axis 506 and therefore are at least parallel to the disposition of the heat exchanger units 534 associated with the central piperack 512, the heat exchanger units may be designed and configured to provide a heat exchange function only for the equipment or components in the multipurpose AGR module 516, and therefore may not be considered to be part of the heat exchanger units 534, which are designed to provide a heat exchange function for other processing units of the LNG train 500.
A multipurpose dehydration/HHC module 518 is also disposed along the major axis 502 of the LNG train 500. The multipurpose dehydration/HHC module 518 has a major axis 508. The multipurpose dehydration/HHC module 518 includes ambient air fin heat exchangers 542 that provide some or all of the required cooling for the dehydration/HHC equipment or components thereon. The heat exchanger units 542 may be ambient heat exchanger units, and may be ambient air fin heat exchanger units. While the heat exchanger units 542 may be disposed along the major axis 508 and therefore are at least parallel to the disposition of the heat exchanger units 534 associated with the central piperack 512, the heat exchanger units 542 may be designed and configured to provide a heat exchange function only for the equipment or components in the multipurpose dehydration/HHC module 518, and therefore may not be considered to be part of the heat exchanger units 534, which are designed to provide a heat exchange function for other processing units of the LNG train 500.
Another aspect is shown in the LNG train 600 of
Another aspect is shown in the LNG train 700, which is similar to LNG trains 500 and 600. LNG train 700 includes a multipurpose AGR module 716 having a major axis 706, and a multipurpose dehydration/HHC module 718 having a major axis 708. The multipurpose AGR module 716 is positioned so that its major axis 706 is perpendicular or substantially perpendicular to the major axis 704 of the piperack. Rows of heat exchanger units 740 associated therewith are aligned with major axis 706. The multipurpose dehydration/HHC module 718 is positioned so that its major axis 708 is parallel and/or co-incident with the major axis 704 of the central piperack 712. The multipurpose dehydration/HHC module 718 may be positioned such that rows of heat exchanger units 742 associated therewith are aligned with one of the parallel lines 734a, 734b of the heat exchangers 734 associated with the central piperack 712.
In another aspect, the function performed by a multipurpose module may include the mechanical refrigeration of the natural gas stream, which may be accomplished in part by rejecting heat to an ambient (i.e., to the environment at the operating site) using one or more air and/or water- cooled heat exchangers. The mechanical refrigeration may be accomplished in part by a refrigerant comprising propane and/or propylene. Alternatively or additionally, the mechanical refrigeration may be accomplished in part by a mixed refrigerant comprising methane, ethane and/or ethylene, propane and/or propylene, and/or butane.
The disclosed aspects discuss one or more multipurpose modules that are assembled at a manufacturing site that is separate from or distant from the operating site of a hydrocarbon processing facility (such as an LNG plant), transported to the operating site, and connected to parts of the hydrocarbon processing facility. As discussed herein, it may not be feasible to assemble all parts or components of a multipurpose module at a manufacturing site. According to disclosed aspects, a multipurpose module may include components built or assembled on or adjacent the multipurpose module but transported to the operating site separate from the multipurpose module. Such components may be considered to be part of the multipurpose module because the components perform part of the function associated with the remaining components on the multipurpose module. Additionally, while the disclosed aspects have been described as being part of an LNG plant, the aspects may be advantageously used in the construction of other hydrocarbon processing plants.
Another aspect uses refrigerant driver and compressor string modules that include the interstage and discharge coolers for refrigerant compressors. The compressor discharge streams are cooled directly by air cooled heat exchangers installed on the top of the compression string module or by a recirculating or once-through water cooling system with heat exchangers installed within the compression modules. This disclosed aspect can be deployed with either electric motor, gas turbine or steam compressor drivers. The benefits of the disclosed aspects include a decrease in the size of the central piperack and the footprint of the LNG train, a decrease in the number of process streams (e.g. compressor discharge streams) requiring site piping connections to the central piperack, and the cost savings associated with these benefits. Additional benefits are realized by schedule and logistics synergies associated with the reconfigured layout and the opportunity to conduct more pre-commissioning of the refrigerant driver and compressor systems in the fabrication yard. In one example, it is estimated that modularizing the compressors as disclosed herein eliminates approximately 20% of the required man-hours for construction of a single LNG train. With LNG processing plants having three or more LNG trains, the savings in construction costs can be significant. Furthermore, locating air fin coolers on top of the compressor modules has the potential of removing two piperack modules and may eliminate as much as 60 large-bore connections that would otherwise be required to be completed at the assembly site. Additionally, approximately 25% of the high reliability welds (i.e., “golden welds”) are eliminated as well. The cost savings associated with the reduced number of connections and welds is anticipated to be significant.
The steps depicted in
Disclosed aspects may be used in hydrocarbon management activities. As used herein, “hydrocarbon management” or “managing hydrocarbons” includes hydrocarbon extraction, hydrocarbon production, hydrocarbon exploration, identifying potential hydrocarbon resources, identifying well locations, determining well injection and/or extraction rates, identifying reservoir connectivity, acquiring, disposing of and/ or abandoning hydrocarbon resources, reviewing prior hydrocarbon management decisions, and any other hydrocarbon-related acts or activities. The term “hydrocarbon management” is also used for the injection or storage of hydrocarbons or CO2, for example the sequestration of CO2, such as reservoir evaluation, development planning, and reservoir management. The disclosed methodologies and techniques may be used in extracting hydrocarbons from a subsurface region and/or processing the hydrocarbons. Hydrocarbons and contaminants may be extracted from a reservoir and processed. The hydrocarbons and contaminants may be processed, for example, in the LNG plant or other processing plant as described herein. Other hydrocarbon extraction activities and, more generally, other hydrocarbon management activities, may be performed according to known principles.
It should be understood that the numerous changes, modifications, and alternatives to the preceding disclosure can be made without departing from the scope of the disclosure. The preceding description, therefore, is not meant to limit the scope of the disclosure. Rather, the scope of the disclosure is to be determined only by the appended claims and their equivalents. It is also contemplated that structures and features in the present examples can be altered, rearranged, substituted, deleted, duplicated, combined, or added to each other.
This application claims the priority benefit of U.S. Patent Application 62/237,838 filed Oct. 6, 2015 entitled MODULARLIZATION OF A HYDROCARBON PROCESSING PLANT, the entirety of which is incorporated by reference herein.
Number | Date | Country | |
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62237838 | Oct 2015 | US |