EA040627B1 - PROCESS FOR DECOMPOSITION OF HYDROCARBON GAS IN THE RESERVOIR TO PRODUCE HYDROGEN WITHOUT GREENHOUSE GAS EMISSIONS - Google Patents

Description

Field of invention

The present invention relates to a process for the decomposition of hydrocarbon gas in a reservoir and the production of hydrogen. Horizontal and deviated wells with multi-stage hydraulic fracturing with fillers equipped with downhole tractors are used for hydrogen production using electromagnetic microwave heating, plasma pyrolysis and catalytic cracking of hydrocarbons.

Introduction

Significant natural gas reserves in the world accumulate in tight reservoirs, shale, depleted non-commercial gas fields.

The process of decomposition of hydrocarbon gas into hydrogen and carbon in the reservoir opens up access to a huge source of clean energy. Decomposition of natural gas at high temperature makes it possible to obtain hydrogen without the formation and emission of greenhouse gases.

Cracking of methane at temperatures above 1000°C is an endothermic reaction

CH ₄ - "C + 2H ₂ ΔΗ \u003d +75 kJ / mol

In the presence of catalysts, cracking reactions can proceed at lower temperatures, in the range of 500-600°C.

Microwave heating occurs under the influence of electromagnetic waves and due to heat transfer. Microwaves are non-ionizing electromagnetic radiation with a wavelength of 1 mm - 1 m and a frequency of 300 MHz - 3000 GHz. Fluctuations in electric and magnetic fields propagate in the form of electromagnetic radiation. Molecules of water and many other substances are electric dipoles. They have a partial positive charge on one end and a partial negative charge on the other. The time-varying electromagnetic field of the microwaves causes the dipole molecules to rotate and oscillate to align themselves accordingly. Rotating molecules hit other molecules and set them in motion, intermolecular friction thus dissipates energy, increases the temperature in solids and liquids. Materials exposed to electromagnetic radiation heat up.

Maxwell's equations describe both electric and magnetic fields and their relationship to electric charges, currents, and field changes. Faraday's law of induction and Ampère's law with Maxwell's extension:

VxE = -dB/dt

V x H \u003d - dD / dt + J where E is the electric field strength, V / m;

B - magnetic flux density, also called magnetic induction, T or V / m ² .

H - magnetic field strength, A/m;

D - electrical induction, C/m ² ;

J - electric current density, A / m ² .

The dielectric properties of materials are usually expressed using the relative permittivity ε ₀ ε _Γ .

D \u003d EoEg E where ε ₀ is the absolute permittivity of vacuum or the dielectric constant, ε _Γ is the relative permittivity.

Microwave energy is attenuated as it propagates through a dielectric material. The absorbed microwave energy provides electromagnetic heating of saturated reservoir rocks, which makes it possible to achieve the necessary temperature conditions for the pyrolysis of hydrocarbons and the decomposition of methane.

Invention

This invention relates to a method for producing hydrogen in hydrocarbon deposits due to the decomposition of methane in the process of plasma pyrolysis and catalytic cracking in the reservoir as a result of microwave electromagnetic exposure using horizontal and inclined wells with multi-stage hydraulic fracturing with fillers.

A horizontal or deviated well 2 and a vertical production well 3 were drilled in a natural gas field 1 (FIG. 1). A mobile electromagnetic microwave generator 4 is installed at the wellhead 2. Cable lines 5 are installed in the well to direct microwave radiation into the formation through waveguide antennas 6 in the horizontal section of the well 2. Microwave generation tubes or thrones can also be installed in the well. The temperature in the zone containing the hydrocarbon gas rises when the microwave energy is adsorbed by dielectric heating. Methane pyrolysis reactions occur in the bottomhole zone of the well in the horizontal section of well 2, which is heated in the process of electromagnetic irradiation. Well 2 may be a horizontal well with multistage hydraulic fracturing with filler equipped with downhole tractors to move the electromagnetic waveguide antenna along the horizontal wellbore. Downhole tractors are usually

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Claims (3)

part of the downhole equipment assembly and are placed in the well by standard tripping operations. Metal catalyst particles can be pumped into fractures along with proppant to allow catalytic cracking reactions to decompose methane into hydrogen 7 and carbon 8 at lower temperatures (500-600°C). The produced solid carbon 8 will accumulate in the bottomhole zone, fractures and in the horizontal wellbore. Power lines 9 (E-lines) are used to transmit electricity and electromagnetic waves to the downhole assembly in well 2 (FIG. 2). The layout of the equipment in the horizontal section of the well includes waveguide antennas 10, a downhole downhole tractor 11, a compensator and an emergency disconnect device 12, an electric motor 13 for driving a downhole tractor. The fractures 14 in the well may be filled with proppant and catalyst metal particles. Nickel particles or nickel in combination with aluminum can be used as active catalysts in the process of catalytic cracking of methane in fractures and in the bottomhole zone of a well. Cobalt and iron can also be used as a catalyst for the catalytic cracking of methane. The process of plasma pyrolysis with the formation of hydrogen 7 and carbon 8 occurs in the area of waveguide antennas in fractures, the bottomhole zone and in the wellbore. The resulting solid carbon will gradually fill the wellbore. The downhole tractor 11 is used to move the waveguide antenna along the horizontal section of the wellbore 2 as solid carbon is formed (FIG. 3). In a subsequent step in the process, the carbon may be leached to the surface to be used to produce carbon products such as graphene and/or activated carbon. In the process described above, hydrogen produced from methane coming from the formation into perforations and/or fractures in well 2 can be recovered from the reaction zones via wellbore 2. Hydrogen generated in the formation and gravity segregated up the formation can be recovered using a special production well 3 from the roof of the geological structure of the field (Fig. 1). This invention, using microwave plasma technology, allows for a cost-effective, modular, small-scale process for the decomposition of methane in the reservoir and the production of hydrogen. The process of decomposition of natural gas in the formation of the field is a method of decarbonization of hydrocarbon fuels for the transition to a hydrogen economy with cleaner and cheaper carbon products. CLAIM 1. A method for producing hydrogen in hydrocarbon fields using microwave directional waveguide antennas moved by downhole tractors along horizontal or inclined sections of a wellbore used to generate hydrogen as a result of microwave heating, plasma pyrolysis and catalytic cracking of gas drained into the well through an artificially created system fractures filled with catalyst particles together with proppant proppant. 2. The method according to claim 1, which uses mobile or land-based stationary electromagnetic wave generators, cable transmission lines in the well, downhole waveguide antennas or tubes for generating microwaves in the well, multi-stage hydraulic fracturing with filler to create a fracture system. 3. The method of claim 1, wherein carbon products such as graphene and activated carbon produced by the hydrocarbon plasma pyrolysis process can also be recovered at the surface at low cost. -