Production of methane from abundant hydrate deposits

Abstract

Methods of dissociating and recovering methane from solid hydrate deposits are provided. A method for recovering methane from a methane hydrate includes at least applying electromagnetic radiation to the methane hydrate to dissociate the methane-water bond. Further provided is an apparatus for dissociating methane from a methane hydrate. The apparatus includes at least: an electromagnetic spectrum power source; a probe connected to the electromagnetic spectrum power source; an antenna connected to the distal end of the probe is capable of focusing a radiated beam into a target area of a methane hydrate; and a control system in communication with and capable of controlling the electromagnetic spectrum power source, the probe, and the antenna.

Claims

1. A method for dissociating methane from hydrate deposits, comprising controlling an electromagnetic spectrum power source using a control system; generating electromagnetic radiation by said electromagnetic spectrum power source, said electromagnetic radiation at a controlled and chosen frequency, said chosen frequency in a range of about 18 to less than 23 THz; applying said electromagnetic radiation to a hydrate deposit upon direction of said control system; and dissociating methane from said hydrate deposit with the applied electromagnetic radiation; wherein said electromagnetic spectrum power source is within a caisson or within a suction pile.

2. The method of claim 1, wherein said hydrate deposit is located beneath the ocean's floor.

3. The method of claim 1, wherein said hydrate deposit is located in a well bore.

4. The method of claim 1, wherein said hydrate deposit is located in a flow line.

5. The method of claim 1, wherein said electromagnetic spectrum power source is within the caisson.

6. The method of claim 1, wherein said electromagnetic spectrum power source is within the suction pile.

7. A method for recovering from a methane hydrate, comprising controlling an electromagnetic spectrum power source using a control system; generating electromagnetic radiation by said electromagnetic spectrum power source, said electromagnetic radiation at a controlled and chosen frequency, said chosen frequency in a range of about 18 to less than 23 THz; applying said electromagnetic radiation to the methane hydrate upon direction of said control system; dissociating the methane hydrate into methane and water with the applied electromagnetic radiation; and recovering the methane; wherein said electromagnetic spectrum power source is within a caisson or within a suction pile.

8. The method of claim 7, wherein said electromagnetic spectrum power source is a CO.sub.2 laser.

9. A method for recovering methane from a methane hydrate located beneath an ocean floor, comprising: enclosing the methane hydrate in a caisson or in a suction pile; providing a control system that controls an electromagnetic spectrum power source; controlling said electromagnetic spectrum power source using said control system; generating electromagnetic radiation by said electromagnetic spectrum power source, said electromagnetic radiation at a controlled and chosen frequency, said chosen frequency in a range of about 18 to less than 23 THz; applying said electromagnetic radiation to the methane hydrate upon direction of said control system; disassociating the methane hydrate into methane and water with the applied electromagnetic radiation; and recovering the methane from the water; wherein said electromagnetic spectrum power source is within the caisson or within the suction pile.

10. The method of claim 9, wherein said electromagnetic spectrum power source is a CO.sub.2 laser.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the followed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:

(2) FIG. 1 is a schematic diagram showing the major components according to one embodiment, namely, the dissociation of hydrate deposits located on the ocean's floor.

(3) FIG. 2 is a schematic diagram showing the use of multiple major components according to a further embodiment.

(4) FIG. 3 is an overall process flow diagram, using an example embodiment to produce methane from hydrate deposits located on the ocean's floor.

DETAILED DESCRIPTION OF SEVERAL EXAMPLE EMBODIMENTS

(5) According to example embodiments, electromagnetic radiation is applied to the clathrate to dissociate the methane-water bond within the clathrate using the principle of electromagnetic resonance (EMR). According to further example embodiments, frequencies in the infrared region are used, which allows for the highly selective and efficient use of energy for dissociation without the wasted methane or environmental repercussions of existing thermal, pressure, and chemical methods of dissociation. In still further embodiments, methane extracted from hydrate using the application of electromagnetic radiation decreases U.S. greenhouse gas emissions by about 50%.

(6) According to example embodiments, a computer simulation based on a model optimizes the spectra and energy usage needed for specific methane hydrate reservoir characteristics and properties.

(7) By controlling and customizing spectra, it is possible to (1) dissociate methane hydrate; (2) maximize propagation within the reservoir; (3) minimize energy usage; and (4) maximize energy transfer efficiency.

(8) An example embodiment uses electromagnetic wave ablation to dissociate methane hydrate into its constituent compounds, methane and water. The process is essentially one of energy transfer by the use of electromagnetic radiation. In example embodiments, the process involves the selective transfer of energy to specific methane hydrates at the molecular level.

(9) According to example embodiments, the excitation from a specific wave spectra and resonance frequency breaks down the clathrate's ice cage at a low power level. In still further embodiments, the absorption band of electromagnetic radiation propagates through the ice or other media and reaches only the precise methane hydrates identified for dissociation. According to example embodiments, the dissociation takes place in a caisson, thus avoiding environmental impact. Once dissociated from the clathrate, the resulting methane is then separated, transported, and processed in the ordinary manner using technologies presently known in the art.

(10) According to example embodiments, the resonant frequencies for the breakup of isolated methane from the hydrate cage are in the infrared region of the electromagnetic spectrum. According to further embodiments, the frequency range can be between about 18 THz and about 35 THz, wherein the higher frequencies are accessible via a CO2 laser. In one such embodiment, the frequency range can be between 23-30 THz. In another embodiment, the frequency range can be between 18-23 THz. In another embodiment, the frequency range can be between 30-35 THz. The magnitude necessary to free methane can be dependent on the particular frequency used and its proximity to a resonant frequency. For example, in one embodiment, the magnitude can be less for frequencies in the 23-30 THz range than in the 18-23 THz or 30-35 THz range. By employing a CO2 laser, it is possible to twitch the oxygen atoms in the cage.

(11) According to example embodiments, the major components of an ablation apparatus include: (A) an electromagnetic spectrum power source with selectable points in the spectrum, (B) a probe/transmission line, (C) an antenna at the distal end of a probe, focusing the radiated beam into the targeted area, and (D) a proprietary control design.

(12) In further example embodiments, electromagnetic energy is delivered via a delivery probe to a precise location. The source generates power at a controlled level of a chosen frequency. Unlike the prior art, example embodiments are controllable and focused on the gaseous methane release, with an energy input directly proportional to the size of the release.

(13) In still other example embodiments, the antenna focuses the radiated beam so that most of the energy is deposited within the targeted area. By suitable choice of the power delivered, pulse duration, frequency, and antenna design (which affects the width of the radiated beam), efficient use of energy is achieved. In other embodiments, for safety, the control system of the apparatus provides for automatic shutoff in the event of an inappropriate power level, excessive reflected power, unsuitable pulse duration, or heating beyond prescribed limits.

(14) According to further example embodiments, energy requirements are minute in comparison to heat, chemical or pressure manipulation methods of dissociating methane hydrates. Unlike the indiscriminate application of heat, example embodiments allow precise control of the dissociation process, thereby preventing release of methane to the atmosphere and damage to the seabed structure. Furthermore, example embodiments do not leave any residual chemicals that can damage the water table.

(15) The overall process flow scheme and major equipment is shown in FIGS. 1 through 3.

(16) Turning now to FIG. 1, in an example embodiment, a Spar Buoy 100 (thirteen of which are currently installed in the Gulf of Mexico) or a similar type deep-water facility 100 houses the production equipment 102. The production zone comprising clathrates 103 at or beneath the sea bottom 105 are encased in caissons or suction piles 104 that connect to shore and the facility 100 via pipelines 106. An electromagnetic spectrum power source (not shown) is placed inside of the caisson or suction pile 104. A control umbilical 107 is used to regulate and power the electromagnetic spectrum power source and the subsea control module 108 below the sea surface 101, remotely from the Spar Buoy 100.

(17) Because example embodiments allow for dissociation at the seabed point of extraction, existing industry infrastructure and technology can be leveraged to develop and commercialize the resulting methane as fuel or convert it into liquid phase for other applications.

(18) Turning now to FIG. 2, according to example embodiments, following the dissociation of methane from the clathrate 102 in the production caisson 201, the dissociated methane and water are transported in subsea pipelines 202 and separated and processed in the ordinary manner using known technologies 203. In further example embodiments, multiple caissons 201 are used, and the subsea pipelines 202 from each are joined prior to the dissociated methane and water entering the production process 203. In still further embodiments, a hydrate inhibitor 204 is injected in the subsea pipelines 202 to prevent the formation of hydrates in the subsea pipelines 202. The processed methane exits the production process 203 through a product pipeline 205 for distribution.

(19) Turning now to FIG. 3, an overall process flow scheme 300 is disclosed. According to example embodiments, the electromagnetic resonance process in a caisson 301 occurs in multiple locations, for example, in 20 production wells 302 at a production rate of 100 mmscfd. However, fewer or more production wells are contemplated for a given application and location. Following the dissociation of the methane, the methane/water mixture enters a separation process 303, followed by a compression step 304. The processed methane is then dehydrated 305. The methane is used directly for power generation and utilities 306, or may alternatively or additionally be further processed for pipeline compression and export metering 307. The produced methane is tied into existing pipelines 308 for exportation.

(20) In other example embodiments, the disclosed technology is used to enhance drilling safety. In one embodiment, the technology is used as a tool for efficient clearing of well bores, platform installations, and well sites. These mid-depth hydrate deposits are unstable, exposing the equipment and workforce to imminent dangers.

(21) In still further embodiments, the technology is applied to deep water flow lines in conjunction with pigging systems for unblocking pipelines.

(22) In another example embodiment, the disclosed technology is used in conjunction with leak containment systems, to avoid blockage due to the formation of hydrates.

(23) The foregoing specification is provided only for illustrative purposes, and is not intended to describe all possible aspects of the present invention. While the invention has herein been shown and described in detail with respect to several exemplary embodiments, those of ordinary skill in the art will appreciate that minor changes to the description, and various other modifications, omissions and additions may also be made without departing from the spirit or scope thereof.