GAS EMISSIONS ABATEMENT SYSTEMS AND METHODS FOR REPURPOSING OF GAS STREAMS

Abstract

Systems and methods are provided for utilization in gas recovery conversion to truncate greenhouse emissions that result from gas flaring and venting in production operations. The disclosed stimulates responsible production versus unremitting flaring or venting that further burgeon emissions intensity. Industry lacks incentives and alternatives where common practice is to flare, vent to facilitate oil production. Flaring, venting augment methane emissions contrary to regulations. Seeking compliance but counter to national interests, producers can opt to shut-in or defer production. The systems and methods herein achieve exemplary processing, conditioning, compression, and storage of repurposed value-added gas streams to abate methane and other emissions intensity. The systems, methods and sequencing result in portable, scalable, autonomously operable well site configuration that repurposes surfacing gas volumes, and revalues reserves that would have otherwise been flared, vented, or abandoned. Abatement of methane and greenhouse gas emissions and their deleterious effects embedded in current hydrocarbons production.

Claims

1. A gas processing system comprising: a gas upcycle system for processing a fugitive gas into a usable processed gas comprising: a fugitive emission source configured to supply a fugitive feed gas; a gas processing system module coupled to the fugitive emission source; a compression and power management module coupled to the gas processing system module; a storage and treatment module coupled to the gas processing system module and the compression and power management module for storing the usable processed gas; and a safety and control systems module.

2. The gas processing system of claim 1 wherein the gas processing system module is configured to remove a plurality of condensates and contaminants from the fugitive feed gas and to transfer the plurality of condensates and contaminants to the storage and treatment module and wherein the gas processing system module is configured to produce the usable processed gas and is further configured to transfer the usable processed gas to the compression and power management module.

3. The gas processing system of claim 2 wherein the gas processing system module comprises any of a separator unit, an hydrogen sulfide removal unit, a carbon dioxide removal unit and a water removal unit configured to remove the plurality of condensates and contaminants from the fugitive feed gas.

4. The gas processing system of claim 2 wherein the compression and power management module is comprised of at least one compressor unit configured to receive the usable processed gas and the at least one compressor unit is further configured to remove a liquid from the usable processed gas and to produce a compressed processed gas.

5. The gas processing system of claim 4 wherein the compression and power management module is configured to deliver the liquid and the compressed processed gas to the storage and treatment module.

6. The gas processing system of claim 5 wherein the storage and treatment module is comprised of a compressed gas storage unit configured to receive the compressed processed gas and a condensates storage unit configured to receive the liquid.

7. The gas processing system of claim 6 wherein the storage and treatment module is further comprised of a chemical injection unit coupled to any of the compressed gas storage unit and the condensates storage unit.

8. The gas processing system of claim 6 wherein the safety and control systems module is comprised of any of an electrical generator unit, an electrical substation unit and a safety and control unit and wherein any of the electrical generator unit, the electrical substation unit and the safety and control unit are configured to receive the compressed processed gas and to generate electrical power and to deliver the electrical power to any of the gas processing system module, the compression and power management module, the storage and treatment module and the safety and control systems module.

9. (canceled)

10. (canceled)

11. (canceled)

12. The gas processing system of claim 3 wherein the hydrogen sulfide removal unit comprises an iron sponge, the carbon dioxide removal unit comprises a molecular sieve, and the gas processing system module further comprises a filter.

13. (canceled)

14. The gas processing system of claim 4 wherein the compression and power management module is comprised of a multi-stage compressor unit comprised of a plurality of compressors configured to progressively boost a pressure of the compressed processed gas to a final pressure.

15. The gas processing system of claim 14 further comprising a plurality of cooling units coupled to a respective one of the plurality of compressors.

16. (canceled)

17. The gas processing system of claim 1 wherein the fugitive source emission source is any of a waste gas flow and a fugitive emission flow.

18. The gas processing system of claim 17 wherein the fugitive emission source is from any of an oil production facility, a gas production facility, a pipeline, a chemical process, a manufacturing process and an industrial process.

19. The gas processing system of claim 18 wherein the fugitive feed gas from the fugitive emission source is comprised of a green house gas.

20. (canceled)

21. The gas processing system of claim 3 wherein the fugitive feed gas includes an acid and wherein the gas processing system module is configured to sweeten the fugitive feed gas.

22. The gas processing system of claim 21 wherein the gas processing system module is configured to sweeten the fugitive feed gas using any of a batch process, amines, oxidation, molecular sieves, physical solvents, potassium carbonate and membranes.

23. The gas processing system of claim 7 wherein the storage and chemical treatment system module is configured to remove a plurality of contaminants from the compressed processed gas.

24. The gas processing system of claim 7 wherein the storage and chemical treatment system module further comprises a storage tank, a pipeline and a tanker.

25. The gas processing system of claim 6 wherein the compressed processed gas comprises a commercial grade natural gas.

26-76. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] So that the manner in which the above-recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, can be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0026] FIG. 1 is a block diagram of a gas upcycle system in accordance with the present disclosure;

[0027] FIG. 2 is a block diagram of gas processing module of a gas upcycle system in accordance with the present disclosure;

[0028] FIG. 3 is a block diagram a compression and power management module of a gas upcycle system in accordance with the present disclosure;

[0029] FIG. 4 is a block diagram of a storage and treatment module of a gas upcycle system in accordance with the present disclosure;

[0030] FIG. 5 is a block diagram of a safety and control systems module of a gas upcycle system in accordance with the present disclosure;

[0031] FIG. 6 is a schematic representation of a simplified process of activities of a gas upcycle system in accordance with the present disclosure;

[0032] FIG. 7 is a schematic diagram of the simulation scheme of an implementation of an upcycle well appliance in accordance with the present disclosure;

[0033] FIG. 8A is an isometric view of an implementation of a mobile upcycle well appliance in accordance with the present disclosure;

[0034] FIG. 8B is an isometric view of an implementation of a compressed gas storage unit in accordance with the present disclosure;

[0035] FIG. 9 is a graphical representation of a phase envelope for a simulation case an upcycle well appliance in accordance with the present disclosure;

[0036] FIG. 10 is a graphical representation of a phase envelope for a simulation case an upcycle well appliance in accordance with the present disclosure;

[0037] FIG. 11 is a graphical representation of a phase envelope for a simulation case an upcycle well appliance in accordance with the present disclosure;

[0038] FIG. 12 is a graphical representation of a phase envelope for a simulation case an upcycle well appliance in accordance with the present disclosure;

[0039] FIG. 13 is a graphical representation of a phase envelope for a simulation case an upcycle well appliance in accordance with the present disclosure;

[0040] FIG. 14 is gas sweeting process guide chart of the prior art;

[0041] FIG. 15 is schematic diagram of a piping scheme of an implementation of an upcycle well appliance in accordance with the present disclosure; and

[0042] FIG. 16 is a graphical representation of the pressure profile of the piping scheme of FIG. 15 in accordance with the present disclosure.

DETAILED DESCRIPTION

[0043] In the following detailed description of the embodiments, reference is made to the accompanying drawings, which form a part hereof, and within which are shown by way of illustration specific embodiments by which the examples described herein can be practiced. It is to be understood that other embodiments can be utilized and structural changes can be made without departing from the scope of the disclosure.

[0044] One subject of the present systems and methods that process, condition, compress and store natural gas from oil production activities is to repurpose production gas flow and waste gas flows such as those described above away from normalized combustion or venting applications as well as other fugitive emission flow.

[0045] The systems and methods disclosed herein are particularly suitable for the recovery and repurposing of a gas feed source of an oil production facility as well as other fugitive emission sources with a view for processing and storage wasted gases to comply with high quality standards and conditions. Typically, associated gas produced during oil extraction will be combusted or vented. Flaring is long known as a wasteful practice that releases CO2 and hazardous air pollution components; experience also suggests that flaring, can also be a major methane source either by becoming unlit and release unabated natural gas into the atmosphere, or by unwanted and incomplete combustion events. Fugitive emissions are leaks and other irregular releases of gases or vapors from a pressurized containment-such as appliances, storage tanks, pipelines, wells, or other pieces of equipment-mostly associated with oil and gas extraction, transport and refining activities. In addition to the economic cost of lost commodities, fugitive emissions contribute to local air pollution and may cause further environmental harm. It should be further noted that the systems and methods disclosed herein are suitable for use with on-shore wells, off shore wells, risers, production stacks and flares. In addition, systems and methods of the present disclosure is equally suitable for other applications such as industrial process applications including power plants, cement plants, gas plants, manufacturing process plants, petrochemical plants and the like.

[0046] Components of the gas stream or of its resulting combustion such as hydrogen sulfide (H2S) water or Carbon dioxide (CO2) can be removed from the produced gas with a view to upgrade it to commercial quality and make the resulting grades of quality acceptable to pipeline transportation or commercial fuel standards using implementations disclosed herein. Such commercial quality gases can include commercial grade natural gas.

[0047] The systems and methods disclosed herein be used to unlock sequestered deposits of natural gas efficiently, productively, and economically with the urgency required for a large swath of the oil and gas production landscape. Implementations are disclosed that can intake a stream of produced or manufactured gas from a gas production facility that add value to this intake stream and contribute to a net zero outcome while substantially reducing methane emissions by repurposing gas flows. Implementations are disclosed that can handle a larger range of both chemical and physical conditions found in different production gases facilities. Also disclosed are systems that are modular and scalable and can be used on a wide range of produced gas compositions (leaner to richer gas in more environments and production scenarios) and a wide range of field production conditions with varying pressures and temperatures. The modular and scalable systems disclosed herein can range from small-sized to fit on a truck (FIG. 8A)to large industrial sized facilities. Production gas is separated into sub-streams early in the treatment and handling phases and can produce multiple finished product grades that meet market specification requirements. Implementations disclosed produce high quality gas product grades of differing characteristics, the number of processes and the complexity involved in manufacturing gas value-added products. Such implementations include the ability to handle such sub-streams and finished products and are configured to store them separately for delivery to market.

[0048] In accordance with the foregoing objectives and others, the following disclosure is made herein to outline exemplary systems and methods that processes, conditions, compresses and stores natural gas from oil production activities to repurposing gas flows away from normalized combustion or venting applications.

[0049] Referring to FIG. 1, there is shown a schematic of an embodiment of a gas upcycle system in the form of an upcycle well appliance (UWA) 20 of the present disclosure which comprises the modules consisting of gas processing system 1000, compression and power management system module 2000, storage and chemical treatment system 3000, safety, control and utilities system module 4000 and, third party systems 5000. The UWA takes gas from a gas source such as a production well (not shown) into gas processing system 1000 which is then passed to compression and power management system 2000. the compressed gas is then passed to storage and chemical treatment system 3000 and safety and control system 4000. The compressed and processed gas is then delivered to third party system 5000. The various modules will be disclosed in more detail herein after.

[0050] Now with reference to FIG. 2, there is shown a schematic of gas processing system 1000 module of FIG. 1. Gas processing system 1000 is comprised of a gas/liquid separator 1100, a hydrogen sulfide removal unit 1200, a carbon dioxide removal unit 1300 and a water removal unit 1400. Feed gas that is supplied from a feed gas source is passed through gas/liquid separator 1100 to minimize any liquid entrainment within the gas prior to any further gas processing. Liquids collected by gas/liquid separator 1100 are routed to condensates storage unit 3200 (FIG. 4) of storage and chemical treatment system module 3000. The gas moves from gas/liquid separator 1100 to hydrogen sulfide removal unit 1200 wherein hydrogen sulfide is removed from the gas and are routed to condensates storage unit 3200 of storage and chemical treatment system module 3000. The gas from hydrogen sulfide removal unit 1200 moves to carbon dioxide removal unit 1300 and a water removal unit 1400 wherein the carbon dioxide and water are respectively removed and which are routed to condensates storage unit 3200 of storage and chemical treatment system module 3000. It should be appreciated by those skilled in the art that the units of storage and chemical treatment system module 3000 remove the various contaminants present in the gas via chemical and mechanical means. It should be noted that gas/liquid separator 1100, hydrogen sulfide removal unit 1200, carbon dioxide removal unit 1300 and water removal unit 1400 are scalable to accommodate different feed gas compositions. Additional contaminants, if present in the gas feed, can be removed by adding an appropriate removal unit shown in the figure as spare unit 1500.

[0051] Next with reference to FIG. 3, there is shown compression and power management system module 2000 of FIG. 1. After processing has been completed in gas processing system module 1000, the gas stream is routed to compression and power management system module 2000. Compression and power management system module 2000 can be comprised of a plurality of compressor units 2100. The plurality of compressor units 2100 can act as compressor stages to raise the pressure of the gas stream gas processing system module 1000 to a predetermined desired pressure wherein the compressed gas is routed to storage unit 3100 of storage and chemical treatment system module 3000. Any liquids that are produced during the compression stages by the plurality of compressor units 2100 can be collected and routed to condensates storage unit 3200 of storage and chemical treatment system module 3000.

[0052] Next with reference to FIG. 4, there is shown a schematic of storage and chemical treatment system module 3000 of FIG. 1 comprised of compressed gas storage unit 3100, condensates storage unit 3200 and chemical injection unit 3300. In practice storage and chemical treatment system module 3000 is configured to store gas and liquid streams in a view to arrange their commercial lifting as finished grades. As disclosed herein above, compressed gas from compression and power management system module 2000 are routed to compressed gas storage unit 3100 which are in turn routed to safety, control and utilities system module 4000 as will be disclosed in more detail herein after. Condensates from gas processing system module 1000 and from compression and power management system module 2000 are routed to condensates storage unit 3200. In certain embodiments, chemical injection unit 3300 can be used to treat gasses in compressed gas storage unit 3100 and/or to treat condensates in condensates storage unit 3200. of FIG. 1. Also disclosed herein as part of compressed gas storage unit 3100 are light weigh carbon reinforced cylinders. It should be appreciated by those skilled in the art that such a fit-for-purpose light weigh carbon reinforced cylinder enables the safe and cost effective transportation of the compressed processed gas 709 (FIG. 7) from remote locations of UWA 20. After processing has been completed other processes also include other liquids collected and recovered in the operation of the different units in Section 1000 to be routed to condensates storage unit 3200. It should be further appreciated that compressed gas storage unit 3100 can include a pipeline, a truck (FIG. 8A), a tanker and other storage and transportation systems and methods.

[0053] Safety, control and utilities system module 4000 further comprises both all the safety and control systems of the methods and systems proposed as well as the utilities supporting its operation.

[0054] The methods and systems disclosed herein can be self-sufficient for operation purposes, and as such, UWA 20 can be configured to generate is own power.

[0055] Alternatively, power external to UWA 20 can be sourced from the local grid. Referring now to FIG. 5, there is shown a schematic of safety, control and utilities system module 4000. With respect to power generation for autonomous consumption, electrical generation unit 4100 can be comprised of a gas powered electrical generator unit which can receive gas from compressed gas storage unit 3100 for generating electrical power. With respect to externally powered embodiments of UWA 20, electrical substation unit 4200 is configured to be connected, for example to an external power source such as an external utility grid, a solar power infrastructure and battery backup systems.

[0056] To ensure the safe and reliable operation of the methods and systems of safety, control and utilities system module 4000 includes safety and control unit 4300 which comprises the requisite safety and controls managements systems and houses the requirements for localized intervention for operation and control including processors, computer storage, communications, software and associated systems. safety and control unit 4300 is further configured to control the operational intervention procedures which may be required at the location of UWA 20. Also included in safety and control unit 4300, is the network capability to transmit and receive selected information from an external source (such as third party systems module 5000, FIG. 1) The amount and configuration of network communications can be adjusted to meet a user's requirements.

[0057] Third party systems module 5000 is configured to be adapted for the requirements of third parties related to the operation of UWA 20 and includes the configurations required to accomplish operational and controls tasks remotely Such configurations can include wireless and Wi-Fi enable devices and applications.

[0058] The operation of UWA 20 can be conceptualized as process, activities, function sections and operational areas. As an example, and with reference to FIG. 6, there is shown simplified process activities of UWA 20 which comprises: [0059] Collecting feed gas from a feed gas source for conditioning; [0060] Conditioning gas and liquids ready for safe handling at storage; and [0061] Storage of different finished products generated including testing, certification, and chemical additive considerations for further segregation for market quality readiness of the products.

[0062] Similarly, the functional sections comprise: [0063] Feed reception and handling section which includes facilities to receive the gas feed and initiate its separation, treatment, and handling in preparation for the subsequent function; [0064] Segregation and collection section which includes the processing required to separate the relevant components of the feed gas and their treatment towards finished grades where gas is compressed, and liquids are collected; and [0065] Storage and disposal section comprised of components and systems to store finished grades and complete any additional treatment required to facilitate their delivery to market.

[0066] Further, the operational areas comprise: [0067] Separation area which is configured to receive the raw natural gas stream from the feed gas for subsequent processing in a front end. Separation of any free-flowing liquids the natural gas feed stream occurs here and could result in being sent to the liquid collection area described below. The separation area further includes routing the separated gas to the next stage of processing; [0068] H2S removal area includes the stripping of pollutants such as hydrogen sulfide from the gas utilizing molecular sieves or catalytic solutions; [0069] Water & CO2 removal area includes the removal of nontoxic pollutants from the gas such as water and carbon dioxide using molecular sieve beds; [0070] Compression area includes compressors to increase the pressure of the processed gas in preparation for storage processed gas comprised lighter hydrocarbon gases; [0071] Liquids collection area includes systems fort the liquefaction of the heavier components of the gas. The liquids recovered during the different processing stages are collected and consolidated in this area; [0072] Chemical injection area includes various injection systems and equipment that may be required to add treatment to the compressed gas or the collected liquid. Examples of such chemical additions may be H2S scavengers, odorization, or any other additives necessary for compliance and safety per market standards; [0073] Storage area which is comprised various vessels required to store the various finished product grades of UWA 20. Quantity sizing considerations of the various storage vessels are configured to meet both market lifting volumes and offtake profiles per operational requirements of each installation; [0074] Safety, instrumentation and control area includes all the equipment and controls necessary to ensure the safe, reliable, and environmentally conscious operations of all operational areas of UWA 20; [0075] Utilities area is configured to accommodate the interoperability required of each individual installation of a UWA 20 and their respective locations.

[0076] It should be appreciated by those skilled in the art that the systems and methods disclosed herein enable the repurposing and processing of gases destined to be flared or vented as part of prior art production operation practices. As disclosed herein above, the methods and systems are comprised of multiple modules and sequencing of conditioning elements where the result is a revalued variety of gas products for offtake to market. Products result from conversion of flows through the sequence of methods and systems that offset methane and other green house gas emissions and permit re-classification of gas reserves previously understood to be unusable but recoverable in nature.

[0077] As disclosed herein above, after UWA 20 is coupled to the outlet of a wellhead production facility the process conversion can autonomous wherein the UWA utilizes processed gas from the feed gas source to power the UWA. The work of the methods and systems can be divided into multiple stages, including as noted above in the simplified process activities of FIG. 6. The stages of UWA 20 can be further detailed as: [0078] a) Gas conditioning stage wherein liquid hydrocarbons are separated from the feed gas using a gas/liquid separator, H2S removed using a solid media scrubber, and H2O and CO2 adsorbed by a molecular sieve. It is important to note that after this gas conditioning stage the conditioned gas will meet pipeline gas quality standards. [0079] b) Gas compression stage which can comprise a multi-stage positive displacement gas compressor configured to increase the near atmospheric temperature of the produced gas stream to a desired pressure level for storage by progressively boosting the gas at each stage. [0080] c) The storing stage comprises the storage of the processed and compressed gas in approved containers and its dispensing and commercialization for use as fuel or similar specified commercial products.

[0081] Now referring to FIG. 8A, there is shown an implementation of a mobile gas upcycle system 800 comprised of motorized vehicle comprised of a truck 801 and an unpowered vehicle comprised of a trailer 802 including UWA 20 mounted on the trailer. Similar to that disclosed herein above, UWA 20 includes gas processing module 1000, Compression and power module 2000. storage and chemical treatment module 3000 and safety and control module 4000. In operation mobile gas upcycle system 800 can be driven to a well site (or other area of interest) from which feed gas is to be extracted. Once mobile gas upcycle system 800 is positioned adjacent to the area of interest stabilizers 803 can be lowered to releasable fix the mobile gas upcycle system in place. Gas processing module can be coupled to the feed gas source and the feed gas can be processed as disclosed herein above. Once the feed gas is processed and routed to compressed gas storage unit 3100 (FIGS. 4, 8B) of chemical treatment module 3000 mobile gas upcycle system 800 can be driven away or another compressed gas storage unit can be fitted to trailer 802, as will be disclosed in more detail with reference to FIG. 8B, and the process can continue.

[0082] Referring next to FIG. 8B, there is shown an implementation of compressed gas storage unit 3100 comprised of a non-powered vehicle in the form of trailer 805 and a plurality of storage tanks 806 securely positioned thereon. It should be appreciated by those skilled in the art that the compressed gas storage unit 3100 shown provides advantages from an operational and safety perspective. The plurality of tanks 806 can comprise US Department of Transportation type IV storage cylinders. Compressed gas storage unit 3100 provides a high capacity for storage and as fewer trips are necessitated to bring the compressed gas to a production or transfer facility thereby minimizing emissions from a truck (801, FIG. 8A) towing trailer 805. In operation, trailer 805 can be driven to a well site (or other area of interest) from which feed gas is to be extracted. Once compressed gas storage unit 3100 is placed adjacent to mobile gas upcycle system 800, stabilizers 807 can be lowered to releasable fix the compressed gas storage unit 3100 in place. Gas processing module 1000 can be coupled to the feed gas source and the feed gas can be processed as disclosed herein above and traveled to the plurality of storage cylinder 806 of compressed gas storage unit 3100.

Simulations

[0083] Simulations were run for the UWA 20 disclosed herein above to validate the inventiveness and efficacy of the UWA. Aspen HYSYS (HYSYS) was used as the simulator platform as it is a chemical process simulator currently developed by AspenTech used to mathematically model chemical processes, from unit operations to full chemical plants and refineries. As will be set forth in detail herein below, HYSYS was extremely useful in simulating the UWA 20 of the present disclosure. HYSYS is able to perform many of the core calculations of chemical engineering, including those concerned with mass balance, energy balance, vapor-liquid equilibrium, heat transfer, mass transfer, chemical kinetics, fractionation, and pressure drop. With reference to FIG. 7, there is shown a schematic diagram of the simulation scheme of an implementation of a UWA in the form of UWA 700 based on the process flow diagram set forth and disclosed in the various figures herein above. Consistent with the preceding disclosure, UWA 70 comprises an inlet of feed gas 701 from a well head being fed into separator 702 (separator unit 1001, FIG. 1) which separates condensate flow 703 from gas flow 704. Gas flow 704 is directed to iron sponge 705 (H2S removal) and molecular sieves 706 (water and CO2 removal) (both part of gas processing system module 1000, FIG. 1). It should be appreciated by those skilled in the art that molecular sieves 706 are inventively incorporated into UWA 700 as these components are incorporated into large industrial plants and heretofore were not generally considered viable for a smaller scale system. The processed gas stream 707 is routed to multi-stage compressor unit 708 (compression units 2100, FIG. 3). Multi-compressor system 708 is comprised of four stages of compression wherein each stage includes an input power, a mechanical compressor, a cooling system and a separator. The liquid output of the separators of multi-compressor system 708 are routed to condensate storage unit 3200 (FIG. 4) while the gas output from a lower stage is fed to the input of the compressor of the next stage. The final gas output 709 from the fourth stage of multi-compressor system 708 is presented at a final pressure and is routed to compressed gas storage unit 3100 (FIG. 3). Although final gas output 709 is shown as having progressed through all the stages of UWA 700, a less refined final gas output is contemplated by the current disclosure. For example, final gas output 709 can comprise a low pressure component of UWA 700 that can an offspec gas. UWA 700 can be comprised of selective modes to address multiple use cases with different final gas output 709 products that are not all finished end commoditized products but can include commercial grade natural gas. In addition, final gas output 709 can be used for reinjection purposes at a well site and can then be recaptured by UWA 700 for reprocessing after reinjection. Simulations were run on UWA 700 for various cases 1-5 wherein the inlet temperature and inlet temperature of feed gas 701 into separator 702 were the same. The gas stream composition and/or mass throughput of feed gas 701 were varied. The input feed gas 701 conditions for the simulation are summarized in Table 1 below. Further input conditions related to the effects of water and sulfur content were that H2O was at saturation condition and that the maximum H2S concentration in the feed gas was 300 ppm. In addition, the simulation conditions assume that all the feed gas sulfur content is removed by the iron sponge unit 705, and that all the water vapor and carbon dioxide are removed by the molecular sieve 706. Although UWA 700 is disclosed as having various components, fewer or more components are contemplated in the current disclosure depending on the source and type of gas stream presented to the UWA.

TABLE-US-00001 TABLE 1 Feed Gas Conditions Case 1 2 3 4 5 Normal Normal Normal Design (20% Min. flow rate flow rate flow rate above max) flow rate Inlet Temperature (F.) 90 90 90 90 90 Inlet Pressure (psia) 54.7 54.7 54.7 54.7 54.7 Molar Flow (lbmole/hr) 2.22 2.22 2.22 3.56 1.10 Mass Flow (lb/hr) 54.60 46.87 44.30 71.17 21.97 Gas Volume Flow (kscfd) 20.00 20.00 20.00 32.40 10.00 Comp Mole Frac (Methane) 0.6563 0.7705 0.8018 0.8022 0.8012 Comp Mole Frac (Ethane) 0.1353 0.1071 0.1185 0.1185 0.1184 Comp Mole Frac (Propane) 0.1019 0.0497 0.0320 0.0321 0.0320 Comp Mole Frac (i-Butane) 0.0097 0.0044 0.0056 0.0056 0.0056 Comp Mole Frac (n-Butane) 0.0372 0.0139 0.0056 0.0056 0.0056 Comp Mole Frac (i-Pentane) 0.0082 0.0030 0.0017 0.0017 0.0017 Comp Mole Frac (n-Pentane) 0.0086 0.0038 0.0014 0.0014 0.0014 Comp Mole Frac (n-Hexane) 0.0074 0.0038 0.0019 0.0019 0.0019 Comp Mole Frac (CO2) 0.0034 0.0224 0.0201 0.0201 0.0200 Comp Mole Frac (Nitrogen) 0.0221 0.0119 0.0019 0.0019 0.0019 Comp Mole Frac (H2S) 0.0003 0.0003 0.0003 0.0003 0.0003 Comp Mole Frac (H2O) 0.0095 0.0094 0.0093 0.0089 0.0101

Results

[0084] As disclosed herein above, simulations were performed using HYSYS for UWA 7000 for the conditions listed in Table 1 for cases 1-5. Table 2 shows the conditions and compositions of the gas stream for final gas output 709 being sent to compressed gas storage unit 3100.

TABLE-US-00002 TABLE 2 Simulations Results Case 1 2 3 4 5 Outlet Temperature (F.) 100 100 100 100 100 Outlet Pressure (psia) 4350.19 4350.19 4350.19 4350.19 4350.19 Mass Flow (lb/hr) 53.87 44.29 41.95 67.96 20.97 Comp Mole Frac (Methane) 0.6651 0.7960 0.8263 0.8263 0.8263 Comp Mole Frac (Ethane) 0.1371 0.1107 0.1221 0.1221 0.1221 Comp Mole Frac (Propane) 0.1033 0.0514 0.0330 0.0330 0.0330 Comp Mole Frac (i-Butane) 0.0098 0.0045 0.0057 0.0057 0.0057 Comp Mole Frac (n-Butane) 0.0377 0.0143 0.0057 0.0057 0.0057 Comp Mole Frac (i-Pentane) 0.0083 0.0031 0.0017 0.0017 0.0017 Comp Mole Frac (n-Pentane) 0.0087 0.0039 0.0014 0.0014 0.0014 Comp Mole Frac (n-Hexane) 0.0075 0.0039 0.0019 0.0019 0.0019 Comp Mole Frac (CO2) 0.0000 0.0000 0.0000 0.0000 0.0000 Comp Mole Frac (Nitrogen) 0.0224 0.0123 0.0019 0.0019 0.0019 Comp Mole Frac (H2S) 0.0000 0.0000 0.0000 0.0000 0.0000 Comp Mole Frac (H2O) 0.0000 0.0000 0.0000 0.0000 0.0000

[0085] As disclosed herein above, each of the four compression stages of multi-compressor system 708 includes an input power for both the mechanical compressors and the cooling units. The total energy requirements for multi-compressor system 708 for cases 1-5 are shown in Table 3:

TABLE-US-00003 TABLE 3 Energy Estimates Case 1 2 3 4 5 Compression Duty (Btu/hr) 14674.52 15164.98 15377.75 24911.95 7688.87 Cooling Duty (Btu/hr) 20187.82 19244.16 19173.02 31060.29 9586.51 Estimate Power (Hp) 13.70 13.52 13.58 22.00 6.79

[0086] Simulation runs shown in Table 2 above have shown the presence of condensate species (C3, C4 & C5+) in the gas stream to storage. Industrial experience shows the presence of such species is lesser in the gas stream to storage, and these components tend to be recovery during the different stages of compression as condensates. Condensate modelling accuracy is a well know phenomenon requiring detailed and additional simulation work to better estimate such occurrence. Additional sensitivities were run utilizing discrete changes to the compression operating conditions (e.g., increase of cooling duty and gas composition of the feed gas). These runs confirmed the condensate recovery.

[0087] In addition to the simulations for cases 1-5 summarized directly herein above, process simulation sensitivity analyses were performed for three different inlet natural gas compositions A, B, C. The purpose of process simulation sensitivity analyses is to confirm the likelihood of condensate formation (e.g., liquids) and, therefore, confirm the requirement for equipment, such as condensate storage unit 3200, to handle the recovery of such liquids and their disposal.

[0088] The properties of feed gas 701 used in the sensitivity analyses are summarized in Table 4 below.

TABLE-US-00004 TABLE 4 Raw Natural Gas Properties Case A B C Description Sample 3 from Sample 1 from Hypothetical Production Gas Production Gas Quality Document Quality Document Temperature ( F.) 90.00 90.00 90.00 Pressure (psia) 54.70 54.70 54.70 Molecular Weight 19.98 24.60 23.43 Actual Gas Flow (ft.sup.3/min) 3.91 3.89 3.89 Std Gas Flow (kscfd) 20.00 20.00 20.00 Actual Liquid Flow (ft.sup.3/h) 0.00 0.00 0.00 Actual Density (lb/ft.sup.3) 0.19 0.23 0.22 Composition (Molar %) Methane 79.92 65.43 75.58 Ethane 11.81 13.49 13.50 Propane 3.19 10.16 0.29 Ibutane 0.55 0.97 0.73 Butane 0.55 3.71 0.75 Ipentane 0.17 0.82 1.31 Pentane 0.14 0.86 2.34 Hexane 0.19 0.74 3.70 CO.sub.2 2.00 0.34 0.34 Nitrogen 0.19 2.20 0.19 H.sub.2S 0.00 0.00 0.00 H.sub.2O 1.28 1.28 1.28

[0089] As disclosed herein above, UWA 700 handling and processing consists of a liquid-gas separator section in separator 702, a gas sweeting (H2S removal) section comprising iron sponge 705, a subsequent water (H2O) and carbon dioxide (CO2) removal section comprising sieve 706, a multi-compressor system 708 with each compression stage comprising a reciprocating compressor, an air cooler and a liquid-gas separator vessel, and compressed gas storage unit 3100 comprising a high-pressure gas storage facility for final gas output 709.

Simulation Results for Case A

[0090] For Case A, feed gas 701 comprises a gas composition having 91.73% of C1-C2 and 4.79% of C3+ compounds, as is shown in Table 4. Processed gas stream 707 is assumed to be dry gas at the inlet to multi-compressor system 708, wherein the H2S, H2O and CO2 have been removed by iron sponge 705 and sieve 706. The composition of final gas output 709 comprises a 94.84% C1-C2 and 4.94% C3+ composition.

[0091] The properties and composition of processed gas stream 707 entering multi-compressor system 708 are shows in Table 5.

TABLE-US-00005 TABLE 5 Processed Gas Properties at Inlet of Multi-Compressor System Case A Compression Temperature 89.9 F. Pressure 43.56 psia Vapour Fraction 1.0000 Std Gas Flow 1 .35 MSCFD Actual Gas Flow 4.7 0 ft3/min Actual Liquid Flow 0.0000 ft3/hr Molecular Weight 1 .50 Mass Density 0.1453 lb/ft3 Master Comp Mole Frac (Methane) 0.8263 Master Comp Mole Frac (Ethane) 0.1221 Master Comp Mole Frac (Propane) 0.0330 Master Comp Mole Frac (i-Butane) 0.0057 Master Comp Mole Frac (n-Butane) 0.00 7 Master Comp Mole Frac (i-Pentane) 0.0017 Master Comp Mole Frac (n-Pentane) 0.0014 Master Comp Mole Frac (n-Hexane) 0.0018 Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.0019 Master Comp Mole Frac (K2S) 0.0000 Master Comp Mole Frac (H2O) 0.0000 indicates data missing or illegible when filed

[0092] Now referring to FIG. 8A FIG. 9, there is shown a graphical representation of a phase envelope 90 for the simulation of Case A plotting pressure versus temperature for UWA 700. The crycondentherm point 91, corresponding to the maximum temperature at which a liquid-vapor equilibrium exists, which for Case A is approximately 36 F. It should be appreciated by those skilled in the art that a temperature of 36 F. is below the expected operating conditions of UWA 700. The significance of such a condition is that for Case A, the product stream mixture of final gas output 709 will exhibit a vapor phase behavior at any pressure. As can be seen from phase envelope 900 for Case A, in order to separate and be able to extract the gas condensable liquids components it is necessary to lower the temperature below 36 F., without exceeding 1280 psia, the cricondenbar point 92, which comprises the maximum pressure at which a liquid-vapor equilibrium exist, so that the mixture is in the mixed phase region 93.

Simulation Results for Case B

[0093] For Case B, feed gas 701 comprises a 78.92% C1-C2 and 17.26% C3+ composition, of which 10.16% correspond to propane, as is shown in Table 6. After removal H2S, H2O and CO2, processed gas stream 707 at the inlet to multi-compressor system 708, the processed gas comprises an 80.21% C1-C2 and 17.53% C3+ composition.

[0094] The properties and composition of processed gas stream 707 entering multi-compressor system 708 are shows in Table 6.

TABLE-US-00006 TABLE 6 Processed Gas Properties at Inlet of Multi-Compressor System Case B Compression Temperature 8 .91 F. Pressure 43.55 psia Vapour Fraction 1.0000 Std Gas Flow 18.86 MSCFD Actual Gas Flow 4.818 ft3/min Actual Liquid Flow 0.0000 ft3/hr Molecular Weight 24.62 Mass Density 0.1844 lb/ft3 Master Comp Mole Frac (Methane) 0.6850 Master Comp Mole Frac (Ethane) 0.1371 Master Comp Mole Frac (Propane) 0.1033 Master Comp Mole Frac (i-Butane) 0.00 Master Comp Mole Frac (n-Butane) 0.0377 Master Comp Mole Frac (i-Pentane) 0.0083 Master Comp Mole Frac (n-Pentane) 0.0087 Master Comp Mole Frac (n-Hexane) 0.007 Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.0224 Master Comp Mole Frac (H2S) 0.0000 Master Comp Mole Frac (H2O) 0.0000 indicates data missing or illegible when filed

[0095] Referring now to FIG. 10 there is shown a graphical representation of a phase envelope 100 for the simulation of Case A plotting pressure versus temperature for UWA 700. It can be seen that for Case B, the crycondentherm point 101 corresponds to 123 F., which is at or above the expected operating conditions of UWA 700. It should be noted that intercooling temperature 102 of about 110 F., the pressure range for mixed phase is between about 500 psia and about 1400 psia (horizontal lines 103, 104 respectively). It should be appreciated by those skilled in the art that such conditions prevent liquids condensation in the first stages of multi-compressor system 708.

[0096] As can be seen from Table 6, Case B comprises a feed gas 701 having a heavier hydrocarbon composition. The results of the simulation for Case B confirms that the occurrence of a liquid stream is favored by the heavier hydrocarbon presence in feed gas 701. These results are to be expected because the heavier hydrocarbons expand the phase envelope to reach a higher crycondentherm point 101 and a wider pressure range within the dome at lower pressures at the desired operating temperature than in Case A above.

Simulation Results for Case C

[0097] Case C comprises a feed gas 701 which is a relatively leaner gas, with conditions and compositions for the feed gas entering multi-compressor system 708 shown Table 7.

TABLE-US-00007 TABLE 7 Processed Gas Properties at Inlet of Multi-Compressor System Case C Compression Temperature 8 .91 F. Pressure 43. psia Vapour Fraction 1.0000 Std Gas Flow 1 MSCFD Actual Gas Flow 4.824 ft3/min Actual Liquid Flow 0.0000 ft3/hr Molecular Weight 23.43 Mass Density 0.1753 lb/ft3 Master Comp Mole Frac (Methane) 0.7682 Master Comp Mole Frac (Ethane) 0.1372 Master Comp Mole Frac (Propane) 0.002 Master Comp Mole Frac (i-Butane) 0.0074 Master Comp Mole Frac (n-Butane) 0.00 Master Comp Mole Frac (i-Pentane) 0.0133 Master Comp Mole Frac (n-Pentane 0.0238 Master Comp Mole Frac (n Hexane) 0.0 Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.001 Master Comp Mole Frac (H2S) 0.0000 Master Comp Mole Frac (H2O) 0.0000 indicates data missing or illegible when filed

[0098] For Case C, feed gas 701 comprises a composition of 89.08% of C1-C2 and 9.12% of C3+ compounds. After removal of H2S, H2O and CO2, the gas mixture of processed gas stream 707 comprises a 90.54% C1-C2 and 9.26% C3+ composition, as is shown in Table 7.

[0099] Referring now to FIG. 11 there is shown a graphical representation of a phase envelope 110 for the simulation of Case C plotting pressure versus temperature for UWA 700. It can be seen that for Case C, the crycondentherm point 111 corresponds to approximately 177 F., which includes greater area under the curve within which to set temperature operating conditions and a greater range of operability in the mixed phase zone, with pressures from about 151 psia to about 2097 psia (horizontal lines 113, 114 respectively). It should be appreciated by those skilled in the art that such conditions allow for better use of the first stages of multi-compressor system 708 and for separating liquids.

[0100] In the first stage of compression multi-compressor system 708, and after the cooling process using the respective cooling units, a small fraction of liquids can obtained, which liquids are comprised mostly of C5-C6 (88.14%). The properties and composition of the liquids from the first stage for Case C are summarized in Table 8 below.

TABLE-US-00008 TABLE 8 Liquids from Compression Stage 1 for Case C Liq1 Temperature 110.0 F. Pressure 174.2 psia Vapour Fraction 0.0000 Std Gas Flow 0.20 MSCFD Actual Gas Flow <empty> ft3/min Actual Liquid Flow 4.587e002 ft3/hr Molecular Weight 7 Mass Density 38.44 lb/ft3 Master Comp Mole Frac (Methane) 0.0458 Master Comp Mole Frac (Ethane) 0 0372 Master Comp Mole Frac (Propane) 0.0024 Master Comp Mole Frac (i-Butane) 0.0139 Master Comp Mole Frac (n-Butane) 0.01 2 Master Comp Mole Frac (i-Pentane) 0.0735 Master Comp Mole Frac (n-Pentane) 0.1 0 Master Comp Mole Frac (n-Hexane) 0. Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.0000 Master Comp Mole Frac (H2S) 0.0000 Master Comp Mole Frac (H2O) 0.0000 indicates data missing or illegible when filed

[0101] The effect of such liquid exiting the first stage of multi-compressor system 708 can best be seen with reference to FIG. 12 which is a graphical representation of a phase envelope 120 for the simulation of Case C plotting pressure versus temperature for UWA 700 for the second stage of the multi-compressor system.

[0102] The crycondentherm point 121 at maximum liquid-vapor equilibrium temperature has decreased to 165 F., and the pressure range in the mixed phase zone 122, at the operating temperature 123, is now between about 190 psia and about 2000 psia (horizontal lines 124, 125 respectively). It should be appreciated by those skilled in the art that such conditions allow the liquids extraction to continue in the second stage of compression of multi-compressor system 708, from which a liquids stream with the properties and composition disclosed in the Table 9 can be extracted.

TABLE-US-00009 TABLE 9 Liquids From Compression Stage 2 for Case C Liq2 Temperature 110.0 F. Pressure psia Vapour Fraction 0.0000 Std Gas Flow 1.0 MSCFD Actual Gas Flow <empty> ft3/min Actual Liquid Flow 0.20 ft3/hr Molecular Weight 60.78 Mass Density 34.82 lb/ft3 Master Comp Mole Frac (Methane) 0.1883 Master Comp Mole Frac (Ethane) 0.1167 Master Comp Mole Frac (Propane) 0.005 Master Comp Mole Frac (i-Butane) 0.02 4 Master Comp Mole Frac (n-Butane) 0.0330 Master Comp Mole Frac (i-Pentane) 0.0888 Master Comp Mole Frac (n-Pentane) 0.17 4 Master Comp Mole Frac (n-Hexane) 0.3 43 Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.0002 Master Comp Mole Frac (H2O) 0.0000 Master Comp Mole Frac (H2S) 0.0000 indicates data missing or illegible when filed

[0103] As can be appreciated by those skilled in the art, after extraction of the liquid phase following the second stage of compression of multi-compressor system 708, the phase envelope of the mixture will be changed. Such changes can best be seen with reference to FIG. 13 which is a graphical representation of a phase envelope 130 for the simulation of Case C for the gas stream entering the third stage of multi-compressor system 708. As can be seen, the crycondentherm point 131 has decreased to just over 111 F., limiting liquid extraction at this third stage to the set operating conditions. In addition, if we look at the C1-C2 fractions in the liquids of first and second stages (Tables 8, 9), it can be seen that the molar fraction of these components increases at each stage of compression, so condensation up to this point is more prevalent. The third and fourth stages of compression of multi-compressor system 708 comprise a dry gas composition for compression to be feed to compressed gas storage unit 3100. The properties and composition of the final gas output 709 from multi-compressor system 708 for Case C are summarized in Table 10 below.

TABLE-US-00010 TABLE 10 Final Gas Output to Storage Properties ToStorage Temperature 110.0 F. Pressure psia Vapour Fraction 1.0000 Std Gas Flow 18.40 MSCFD Actual Gas Flow 4.473e002 ft3/min Actual Liquid Flow 0.0000 ft3/hr Molecular Weight 20. Mass Density 1 .58 lb/ft3 Master Comp Mole Frac (Methane) 0.8101 Master Comp Mole Frac (Ethane) 0.1395 Master Comp Mole Frac (Propane) 0.0027 Master Comp Mole Frac (i-Butane) 0.0 2 Master Comp Mole Frac (n-Butane) 0.00 0 Master Comp Mole Frac (i-Pentane) 0.00 Master Comp Mole Frac (n-Pentane) 0.01 Master Comp Mole Frac (n Hexane) 0.0118 Master Comp Mole Frac (CO2) 0.0000 Master Comp Mole Frac (Nitrogen) 0.0020 Master Comp Mole Frac (H2S) 0.0000 Master Comp Mole Frac (H2O) 0.0000 indicates data missing or illegible when filed

Feed Gas Sweetening

[0104] As disclosed herein before, it is advantageous to the condition the feed gas 701 prior to entering multi-compressor system 708 of UWA 700. Several alternatives for sour or acid natural gas processing (e.g., removal of hydrogen sulfide) are enabled for use with implementations of the UWA disclosed herein and be classified according to the type of application, feed gas 701 properties, requirements, and product specifications. Although many factors are considered in the gas sweetening process selection, (e.g., operating temperature and pressure, environmental and other regulations, available facilities, capital and operating costs) the prior art guide 140 selected as part of the present disclosure shown with reference to FIG. 14.

[0105] Considering the operating conditions for UWA 700 of the present disclosure wherein the operating conditions of feed gas 701 comprise a typical acid content (H2S) is to be below 300 ppm and only traces to none are targeted in final gas output 709, the better options to process the UWA feed gas are those shown in the lower left corner 141 of FIG. 14 above, namely (a) amines, (b) batch process, (c) direct oxidation and (d) molecular sieves but can also include physical solvents, membranes, amines and potassium carbonate as shown in the chart

[0106] Generally, batch processes (b) are usually more economical if the sulfur content of feed gas 701 is known to be below 20 lbs/day. With the UWA gas feed 701 prevalent in many gas wells and can be up to 27 thousands of standard cubic feet per day (kscfd), batch processes are the preferred alternative for the unit design.

[0107] Examples of some commercially available batch processes are Chemsweet, Sulfa-Check or an iron sponge such as SULFATREAT. Chemsweet and Sulfa-Check are sludge processes (operating similar to Amines) and are therefore more complex to use operationally. These batch processes can require additional equipment (e.g. chemical and water storage tanks, mixing equipment, gas-liquid separators, pumps, provide agitation, etc.).

[0108] An alternative H2S sweeting process is commonly referred as iron sponge (705, FIG. 7) which comprises an iron oxide which reacts with hydrogen sulfide forming iron sulfide and water. This batch process can be a much simpler design and it possesses desired features for UWA 700, namely 1) lesser/lower operational complexities; 2) smaller footprint; 3) scalable; and 4) more favorable cost economics when compared to the sludge type alternatives.

Feed Gas Dehydration and Carbon Dioxide Removal

[0109] It should be appreciated by those skilled in the art that there are mainly three types of dehydration processes available for use with implementations of a UWA 700 for feed gas 701 dehydration: 1) absorption by hygroscopic liquids or solids; 2) adsorption by solid desiccants; and 3) condensation by cooling or compression.

[0110] Condensation processes are by their very nature energy intensive and require higher investment and costs which are unnecessary and undesirable if from the outset these can be avoided from a technical selection perspective. Typically, absorption represents a higher percentage of operational burden that requires larger equipment footprints such as contact towers, that generate higher operating costs, process and operational complexity among other conditions.

[0111] The commercial processes of adsorption by solid desiccants are composed of three (3) types of beds: 1) silica-based adsorbents; 2) alumina-based adsorbents; and 3) molecular sieves. The equipment and process complexity of the processes described tend to be relatively uniform and similar in each case. In many technical cases, adsorbents can be exchanged using the same contact tower and auxiliary equipment generating a desirable condition and convenience for field operations.

[0112] Silica and alumina-based beds normally require lower (less) temperature requirements for regeneration. This translates into less dry gas use and lower energy consumption which are favorable conditions. In the case of molecular sieves, favorable conditions include the satisfactory achievements of lower water dewpoints compounded by other desirable conditions whereby carbon dioxide and hydrogen sulfide can be removed simultaneously generation favorable outcomes.

[0113] Molecular sieves are fit for purpose and of practical implementation matching the best conditions sought by the current design considerations. Absorption by molecular sieves are the definitive selection for this design that will achieve the removal of carbon dioxide and water most effectively. Further, molecular sieves are undoubtedly the most effective desiccant and adsorbent for drying natural gas for this design. Molecular sieves have high resistance to contamination and their strong crushing properties increase cyclic times that provide an extended product life, all desirable considerations that will permit best possible technical outcomes of the selections. Other favorable competitive advantage of the implementation of molecular sieves is their capability to be regenerated, all the while reducing the overall quantity (amount) required for the design while adding cost benefits that make their inclusion in the design and field operation economically favorable by this study.

[0114] The technical recommendation for Adsorption unit consists of at least two (2), potentially vessels filled with molecular sieves that will adsorb both the water and the carbon dioxide in the feed during the process adsorption period and subsequently regeneration using a heated stream of treated gas will occur in satisfactory manner.

[0115] It is important to highlight that here are several types of molecular sieves. Referential properties of the most widely used molecular sieves are shown in Table 1 below:

TABLE-US-00011 TABLE 41 Typical Properties of Molecular Sieves Nominal Pore Bulk Density Water Capacity Molecules Type Diameter () (lb/cu ft) * (%/wt.)** Adsorbed*** Typical Applications 3A 3 47 20 H.sub.2O, NH.sub.3 Dehydration of unsaturated hydrocarbons 4A 4 45 22 H.sub.2S, CO.sub.2, SO.sub.2, Static desiccant. Drying of C.sub.2H.sub.4, C.sub.2H.sub.6, C.sub.3H.sub.6 saturated hydrocarbons 5A 5 43 21.5 n-C.sub.4H.sub.9OH Separates n-paraffins from branched and cyclic hydrocarbons 13X 10 38 28.5 Di-n-propyl-amine Coadsorption of H.sub.2O, H.sub.2S and CO.sub.2 * For pellets **lb H2O/100 lb pellet adsorbent @25 C. ***Each listed compound plus all preceding

[0116] Typically, larger pore sizing equates to higher adsorption capacity. Both, Type 3A and 4A molecular sieves are very frequently utilized for the dehydration of natural gas. Definitively, Type 4A has been selected for this application given that it possesses the ability to absorb water (H2O) and carbon dioxide (CO2) with (a) a consistent adsorption speed, (b) higher degree of stability and (3) demonstrates a higher water retention capability over a Type 3A sieve per unit weight in use. For this reason, the recommendation is to proceed with Type 4A molecular sieves specification for this application as stated above.

Gas Compression and Storage

[0117] A multistage positive displacement compressor is recommended for selection in this application to bring the processed gas to the higher-pressure storage conditions as primary consideration.

[0118] For operational purposes, the multistage positive displacement compressor is expected to deliver the flexibility of supplying compressed gas within the range of 2500 up to 4000 psi.

[0119] Further, the compressor outlet pressure is expected to offer and provide allowances for the availability of different arrangements to connect to the different gas storage (e.g., Type IV) solutions. Storage would likely vary as per requirements and availability for the disposal route develop across the different commercial scenarios market landscape.

Hydraulic Considerations

[0120] As part of the enablement of the UWA 700 (FIG. 17) and for the purposes of the estimation of the piping diameter of the system, the conditions shall be a maximum gas velocity of 200 ft/s and maximum pressure drop of 0.15 psi per 100 ft of piping were assumed. With reference to FIG. 15, an arrangement 150 used for the piping diameter evaluation includes inlet pipe 151 for introducing the feed gas, separator 152, iron sponge 153, molecular sieve 154, filter 155 as well as first stage compressor 156. It should be appreciated by those skilled in the art that arrangement 150 is based on the processes and systems for a UWA disclosed herein above. The various components of arrangement 150 include an inlet and outlet for purposes of the evaluation (except for first stage compressor 156 which only includes an inlet for these purposes).

[0121] Pressure drop calculations for the different components of FIG. 15 depend on various different factors: (1) vessel dimensions, (2) flow properties, (3) operating conditions (4) vessel internals and loadings. On this latter point on internals and loadings, it is necessary to consider the presence of additional structural forms (e.g., plates, trays, supports) as well as any other material loadings (e.g., catalysts, molecular sieves) The latter apply for the iron sponge 153 and molecular sieve 154. For these specific vessels, considerations are also given to the loading characteristics such as (5) size, (6) distribution, (7) void fractions, (8) wear and (9) rearrangement due to aging effects.

[0122] For the pressure drop calculations of vessels containing solid loadings, a 1/16 extruded particle sizing was. The following operating conditions were used: feed gas flow 20% above maximum flow (27 kscfd) and a molecular weight of low methane feed concentration.

[0123] It is important to note the unusual smaller sizing and footprint of the UWA vessel services (e.g. sizing, configuration of iron sponge, molecular sieves) result in limited data existing in the prior art for the purposes of comparison and benchmarking of each individual process service (e.g. gas sweetening, molecular sieves). Heretofore there exists no similar arrangement of components, in terms of sizing and process throughput.

Results

[0124] The pressure profile across the different vessels is presented in Table 12 below:

TABLE-US-00012 TABLE 52 Design Pressure Drop Pressure Drop Equipment (psi) Separator 152 0.15 Iron Sponges 153 5 Molecular Sieves 154 5 Filter 155 1

[0125] Pressure drops for 1 and 1 diameter piping were evaluated at different gas flows rates (e.g., Minimum (10 kscfd), Normal (20 kscfd) and Maximum (30 kscfd) use cases) results are summarized in Table 13 below:

TABLE-US-00013 TABLE 13 Pipe Pressure Drop (psi/100 ft) Flow (kscfd) 1 1 10 0.04 0.004 20 0.14 0.015 32.4 0.35 0.04

[0126] The diameter set to meet the criteria as noted is set under design conditions of is the 1 inch piping.

[0127] With reference to FIG. 16, the pressure profile 160 across the UWA is shown in graphical form.

[0128] Through this verification process, the proposed arrangement 150 is confirmed to be both workable and to have sufficient capacity to accommodate requirements for a safe operation at both start of and end of run operating cycles for minimum, normal and maximum gas flow rate process throughputs.

[0129] Although the implementations is/are described herein with reference to specific embodiments, various modifications and changes can be made without departing from the scope of the present implementations, as presently set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of the present implementations. Any benefits, advantages, or solutions to problems that are described herein with regard to specific embodiments are not intended to be construed as a critical, required, or essential feature or element of any or all the claims.

[0130] Unless stated otherwise, terms such as first and second are used to arbitrarily distinguish between the elements such terms describe. Thus, these terms are not necessarily intended to indicate temporal or other prioritization of such elements. The terms coupled or operably coupled are defined as connected, although not necessarily directly, and not necessarily mechanically. The terms a and an are defined as one or more unless stated other The terms comprise (and any form of comprise, such as comprises and comprising), have (and any form of have, such as has and having), include (and any form of include, such as includes and including) and contain (and any form of contain, such as contains and containing) are open-ended linking verbs. As a result, a system, device, or apparatus that comprises, has, includes or contains one or more elements possesses those one or more elements but is not limited to possessing only those one or more elements. Similarly, a method or process that comprises, has, includes or contains one or more operations possesses those one or more operations but is not limited to possessing only those one or more operations.

[0131] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.