METHOD AND SYSTEM FOR MANAGING DRILLING WASTE

Description

BACKGROUND

In the resource recovery and fluid sequestration industries, disposal of drilling waste can present a significant challenge, marked by high costs and environmental concerns. Desired is a cost-effective and environmentally friendly process for managing drilling waste.

SUMMARY

Disclosed herein is a process for managing drilling waste, including pyrolyzing at least a portion of the drilling waste in a pyrolysis reactor to produce a stream including solid carbon and a gaseous pyrolysis product stream; and using heat present in at least a portion of the gaseous pyrolysis product stream to form electrical energy using an organic Rankine cycle, increase a temperature of a stream through heat exchange, or a combination thereof.

Also disclosed herein is a system for managing drilling waste, including a pyrolysis reactor to produce a stream comprising solid carbon and a gaseous pyrolysis product stream from at least a portion of the drilling waste; and an organic Rankine cycle system to convert heat in at least a portion of the gaseous pyrolysis product stream to electrical energy, a heat exchanger to increase a temperature of a stream, or a combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic view of a system supporting a process disclosed herein.

FIG. 2 is a schematic view of a system supporting a process disclosed herein.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

As used herein, the phrase “drilling waste” can include, for example, a water-based mud, an oil-based mud, drilling solids, barite, calcium carbonate, magnesium oxide, a polymer, a surfactant, a clay, a lime, a starch, a mineral oil, a synthetic oil, a paraffin oil, a biocide, a salt/brine, a shale inhibitor, a diesel, an emulsifier, an acid precursor, an acid (e.g., an organic acid), a chelant, an oxidizer, an enzyme, ethylene glycol monobutyl ether, a dispersant, a mono-ethanolamine, a tri-ethanolamine, a lubricant, a microplastic, a plastic, an asphaltene, graphene/graphite, a crude oil, or a combination thereof. A majority of the waste stream can include, for example, an oil or water.

Referring to FIG. 1, a process for managing drilling waste 10 can include treating the drilling waste 10 in a thermomechanical cuttings cleaner 100 to produce a first stream 12 including solids and a vapor stream 14. At least a portion of the vapor stream 14 is separated to produce a second stream 16 including solids and a hydrocarbon stream 18. At least a portion of the hydrocarbon stream 18 is pyrolyzed in a pyrolysis reactor 200 to produce a stream 20 including solid carbon and a gaseous pyrolysis product stream 22. The thermomechanical cuttings cleaner 100 is optional and at least a portion of the drilling waste 10 can be supplied to the pyrolysis reactor 200 to produce a stream 20 including solid carbon and a gaseous pyrolysis product stream 22 rather than the hydrocarbon stream 18 being supplied to the pyrolysis reactor 200 to produce a stream 20 including solid carbon and a gaseous pyrolysis product stream 22.

The pyrolysis product stream 22 can have a temperature of, for example, 100 to 800° C. Heat present in the gaseous pyrolysis product stream 22 can be used to (i) form electrical energy 24, e.g., electricity, using an organic Rankine cycle in an organic Rankine cycle system 250; (ii) increase a temperature of a stream through heat exchange; or (iii) a combination thereof.

The process can be an integrated process in which heat present in at least a portion of the gaseous pyrolysis product stream is used to increase a temperature of the hydrocarbon stream 18 fed to the pyrolysis reactor 200. The process can be an integrated process in which heat present in at least a portion of the gaseous pyrolysis product stream is used to form electrical energy using an organic Rankine cycle; at least a portion of the electrical energy 24 is supplied to the optional thermomechanical cuttings cleaner 100 when present, for example, through a thermomechanical cuttings cleaner line; at least a portion of the electrical energy 24 is converted to thermal energy 28, for example, in a converter, and at least a portion of the thermal energy 28 is supplied to the pyrolysis reactor 200, for example, through a pyrolysis reactor line; or a combination thereof. Prior to entering the organic Rankine cycle system 250, at least a portion of the gaseous pyrolysis product stream 22 can be passed through a filter 650 to reduce an amount of or eliminate solids in the gaseous pyrolysis product stream 22.

The process can further include dehydrating at least a portion of a cooled pyrolysis product stream 26 produced by the organic Rankine cycle in dehydrator 300 to produce a stream 30 including hydrogen and a mixed stream 32. The process can further include pyrolyzing at least a portion of the mixed stream 32 in the pyrolysis reactor 200. The process can further include condensing at least a portion of the mixed stream 32 in a product condenser 350 to form a liquid product 34.

The pyrolysis can be conducted in the presence of a catalyst 36 and the stream 20 including solid carbon can further include catalyst. The process can further include separating the stream 20 including solid carbon and catalyst in catalyst separator 400 to produce a stream 38 including catalyst and a stream 40 including solid carbon. The catalyst separator 400 can be, for example, a filter or centrifuge. Catalyst in the stream 38 including catalyst can be reused in the pyrolysis reactor 200, for example, after regeneration of the catalyst.

The catalyst can include an inorganic material, a metal oxide, red mud, red clay, a natural ore, fly ash, hydroxyapatite, boron nitride, an alkali metal, an alkaline earth metal, a transition metal, a noble metal, a rare earth metal, a zeolite, a ceria-zirconia solid solution catalyst CeZrO_x, or a combination thereof. For example, the catalyst can include Ni, Raney Ni, Pt, Rh, Ni—Fe, Ni—Cu, Ni—Mn, Ni—Mo, Ni—Ca, Ni—Co, Ni—Co with CaO additive, or a combination thereof.

The catalyst can include ZSM-5 zeolite, HZSM-5, siliceous LTA zeolite, Hβ zeolite, β zeolite, HY zeolite, and Zeolite Y. The catalyst can include a modified ZSM-5 catalyst, in which aluminum or hydrogen is substituted with a different metal such as Bi, Ce, Co, Cu, Fe, Ga, Mo, Mn, Na, Ni, Pd, Pt, Rh, Ru, Sm, Sr, V, Zn or a combination thereof. For example, the catalyst can include a cobalt and nickel catalysts supported on ZSM-5, zeolite and bimetallic Mo—Co, Mo—Ni, Mn—Cu, Mn—Co, Mn—Ce, Mn—Sm, Ni—Sr, Ni—Zn, and V—Mo catalysts supported on ZSM-5. The catalyst can include modified HZSM-5 catalyst such as Ce/HZSM-5, Pt/HZSM-5, Ni/HZSM-5, Ni—Mg/HZSM-5, Ni—K/HZSM-5, Ni—Zn/HZSM-5, Ni—Cu/HZSM-5, Ni—Pb/HZSM-5, Ni—Ca—Co/HZSM-5, or a combination thereof.

The catalyst can include a metal fluoride catalyst such as AlF₃, CaF₂, or a combination thereof. The catalyst can include a metal salt such as KCl, CaCl₂, FeCl₃, AlCl₃, ZnCl₂, or a combination thereof. The catalyst can include a chalcogenide, including a sulfide, a selenide, or a telluride of transition and post-transition metals, including but not limited to MoS₂, TiS₂, WS₂, SnS₂, cobalt sulfide, molybdenum sulfide, and cobalt-molybdenum sulfide. The catalyst can include an alkali metal catalyst such as NaOH, KOH, LiOH, Na₂CO₃, NaAlO₂, KNO₃, K₂CO₃, or a combination thereof.

The catalyst can include a Cu—, Ni—, and Pd-containing silicoaluminophosphate, including but not limited to a SAPO-31 molecular sieve. The catalyst can include sulfur-impregnated NiMo/γ-Al₂O₃, Pt/H-ZSM-5, and Pd/SAPO-31 catalysts. The catalyst can include Pd and Ru catalysts on carbon support, Pd and Ru catalysts on zeolite support, Pt, Ni, Co—Mo, Ni—Ca, Ni—W, Ni—Co, and Ni—Mo on alumina support, Co on SiO₂ support (Co—SiO₂), nickel-impregnated ZrO₂ catalyst, nickel-impregnated CeO₂ catalyst, CeZrO_x-supported Ni catalyst, CeZrO_x-supported Cu catalyst, CuO supported on graphite carbon catalysts, iron-based catalysts supported on activated carbon, nickel-impregnated rice husk biochar catalysts, potassium-impregnated pumice, Fe doped TiO₂(Fe—TiO₂), or a combination thereof.

For example, the catalyst can include a nonacidic alumina silicate, a transition metal oxide including Fe, Mn, Ni, Co, Mo, Cu, V, or a combination thereof supported on a zeolite, or a combination thereof. The catalyst can include a solid acid catalyst, including but not limited to amorphous carbon bearing sulfonic acid groups, sulfonated graphene acid catalyst, fly ash treated with sulfuric acid, metal oxide sheets, or a combination thereof.

The pyrolysis reactor can include, for example, a fluidized bed, a circulating fluid bed, a vacuum pyrolizer, an ablative pyrolizer, or a combination thereof. The pyrolysis can include microwave plasma discharge to initiate pyrolysis. The catalyst can include, for example, an iron-based catalyst, a noble metal-like catalyst prepared by Mo₂N, W₂N, MoP, or WP supported on Hβ, HY, or HZSM-5 such as a Mo₂N/HZSM-5 catalyst. The catalyst can include a modified HZSM-5 catalyst such as Ti(SO₄)₂/HZSM-5 or Ti(SO₄)₂—Mo₂N/HZSM-5, a hybrid catalyst Co—SiO₂/Mo—Pd—Pt-HZSM-5, or a combination thereof. The catalyst can include an Al₂O₃—(Ni,Zn,Mg)Fe₂O₄ composite catalyst.

During startup of the pyrolysis reactor 200, air 42 in pyrolysis reactor 200 can be removed from the pyrolysis reactor 200 through a relief valve 450. For example, during startup, when present, the hydrocarbon stream 18 fed to the pyrolysis reactor 200, nitrogen 46, or a combination thereof can displace air 42 in the pyrolysis reactor 200, which is removed from the pyrolysis reactor 200 through the relief valve 450, which thereafter can be closed. Removal of air and oxygen can minimize or eliminate carbon dioxide formation during decomposition of hydrocarbons in the pyrolysis reactor 200. With the minimization or elimination of carbon dioxide formation during decomposition of hydrocarbons in the pyrolysis reactor 200, solid carbon can remain after decomposition of hydrocarbons in the pyrolysis reactor 200.

The disclosed process for managing drilling waste includes pyrolysis and organic Rankine cycle technology, heat exchange, or a combination thereof. The process and a system therefore can be implemented at a drilling site. With the process, waste management costs can be reduced and hydrogen can be produced.

Pyrolysis can produce zero carbon emissions. Use of the organic Rankine cycle, heat exchange, or a combination thereof in combination with pyrolysis can conserve energy through recovery and use and heat in the disclosed process and system that would otherwise be wasted. The process includes separating hydrocarbons from the drilling waste and pyrolyzing the separated hydrocarbons.

The optional thermomechanical cuttings cleaner can convert kinetic to thermal energy and produce the first stream 12 including solids and the vapor stream 14. Small particles, for example, having a diameter of 1 to 5 micrometers, can be separated from the vapor stream 14 exiting the optional thermomechanical cuttings cleaner 100. For example, separating the vapor stream 14 to produce the second stream 16 including solids and the hydrocarbon stream 18 can include subjecting at least a portion of the vapor stream 14 to centrifugal force. At least a portion the vapor stream 14 can be fed to an optional particle separator 150, for example, a cyclone, in which the vapor stream 14 is subjected to centrifugal force. Solids 44 recovered from the optional thermomechanical cuttings cleaner 100 and the optional particle separator 150 can be collected and at least a portion thereof can be carried to a single location, for example, using an optional screw conveyor 500.

As used herein, the term “pyrolysis” refers to the thermal decomposition of hydrocarbons at elevated temperatures, for example, 250 to 1500° C., and at a pressure in a range of 0.1 to 1 millipascals (mPa). Thermal energy 28 is used to decompose hydrocarbons in the hydrocarbon stream 18.

In heating source 600, electrical energy 24 can be converted into thermal energy 28 used to heat the hydrocarbons to decomposition temperatures in the pyrolysis reactor 200. Supplemental energy 550, for example, solar energy, wind energy, energy stored in a battery, or a combination thereof, can also be used to power the optional thermomechanical cuttings cleaner 100 and pyrolysis reactor 200.

Use of a catalyst in the pyrolysis reactor 200 can lower the decomposition temperature of hydrocarbons in the hydrocarbon stream 18. Use of a catalyst in the pyrolysis reactor 200 can also lower power requirements of pyrolysis reactor 200.

Hydrogen in stream 30 is valuable as a clean fuel. Stream 30 can be stored and transported off site to be purified for further use, sale, or a combination thereof.

A process for managing drilling waste includes pyrolyzing the drilling waste in a pyrolysis reactor to produce a stream including solid carbon and a gaseous pyrolysis product stream; and using heat present in the gaseous pyrolysis product stream to form electrical energy using an organic Rankine cycle, increase a temperature of a stream, or a combination thereof. In an integrated process, the process can include converting heat present in at least a portion of the gaseous pyrolysis product stream to electrical energy using an organic Rankine cycle and the process can further include converting at least a portion of the electrical energy to thermal energy and supplying at least a portion of the thermal energy to the pyrolysis reactor.

Referring to FIG. 2, in boiler 251 of an organic Rankine cycle system, heat in the gaseous pyrolysis product stream 22 exiting the pyrolysis reactor 200 can be used to vaporize working fluid in liquid form in the organic Rankine cycle system. Transfer of heat from the gaseous pyrolysis product stream 22 to the vaporize working fluid in liquid form in the organic Rankine cycle system also produces a cooled pyrolysis product stream 26 that exits the reboiler. The vaporized working fluid then passes through a turbine 252, which produces the electrical energy 24. After passing through the turbine 252, the vaporized working fluid is returned to liquid form in working fluid condenser 253. Flow of the working fluid through the organic Rankine cycle system, for example, from the working fluid condenser 253 to the boiler 251, is maintained by pump 254.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1. A process for managing drilling waste, comprising: pyrolyzing at least a portion of the drilling waste in a pyrolysis reactor to produce a stream comprising solid carbon and a gaseous pyrolysis product stream; and using heat present in at least a portion of the gaseous pyrolysis product stream to form electrical energy using an organic Rankine cycle, increase a temperature of a stream through heat exchange, or a combination thereof.

Embodiment 2. The process as recited in embodiment 1 comprising using heat present in at least a portion of the gaseous pyrolysis product stream to increase a temperature of the drilling waste fed to the pyrolysis reactor.

Embodiment 3. The process as recited in embodiment 1 wherein the process comprises using heat present in at least a portion of the gaseous pyrolysis product stream to form electrical energy using the organic Rankine cycle, converting at least a portion of the electrical energy to thermal energy, and supplying at least a portion of the thermal energy to the pyrolysis reactor.

Embodiment 4. The process as recited in embodiment 1 wherein the process comprises using heat present in at least a portion of the gaseous pyrolysis product stream to form electrical energy using the organic Rankine cycle, the process further comprises, prior to pyrolyzing at least the portion of the drilling waste in the pyrolysis reactor: treating at least a portion of the drilling waste in a thermomechanical cuttings cleaner to produce a first stream comprising solids and a vapor stream; and separating at least a portion of the vapor stream to produce a second stream comprising solids and a hydrocarbon stream, pyrolyzing at least the portion of the drilling waste in the pyrolysis reactor comprises pyrolyzing at least a portion of the hydrocarbon stream in the pyrolysis reactor, and the process further comprises supplying at least a portion of the electrical energy to the thermomechanical cuttings cleaner.

Embodiment 5. The process as recited in embodiment 4 further comprising converting a portion of the electrical energy to thermal energy and supplying at least a portion of the thermal energy to the pyrolysis reactor.

Embodiment 6. The process as recited in embodiment 1 wherein the process comprises using heat present in at least a portion of the gaseous pyrolysis product stream to form electrical energy using the organic Rankine cycle, the organic Rankine cycle produces a cooled pyrolysis product stream, and the process further comprises dehydrating at least a portion of the cooled pyrolysis product stream to produce a stream comprising hydrogen and a mixed stream.

Embodiment 7. The process as recited in embodiment 6 further comprising pyrolyzing at least a portion of the mixed stream in the pyrolysis reactor.

Embodiment 8. The process as recited in embodiment 6 further comprising condensing at least a portion of the mixed stream to form a liquid product.

Embodiment 9. The process as recited in embodiment 1 wherein the pyrolysis reactor is conducted in the presence of a catalyst and the stream comprising solid carbon further comprises catalyst.

Embodiment 10. The process as recited in embodiment 9 further comprising separating at least a portion of the stream comprising solid carbon and catalyst to produce a stream comprising catalyst and a stream comprising solid carbon.

Embodiment 11. The process as recited in embodiment 10 further comprising reusing at least a portion of the catalyst in the stream comprising catalyst in the pyrolysis reactor.

Embodiment 12. The process as recited in embodiment 1 wherein pyrolyzing the hydrocarbon stream in the pyrolysis reactor comprises removing air in the reactor through a relief valve at a startup of the pyrolysis reactor.

Embodiment 13. The process as recited in embodiment 1 wherein separating the vapor stream to produce the second stream comprising solids and the hydrocarbon stream comprises subjecting at least a portion of the vapor stream to centrifugal force.

Embodiment 14. A system for managing drilling waste, comprising: a pyrolysis reactor to produce a stream comprising solid carbon and a gaseous pyrolysis product stream from at least a portion of the drilling waste; and an organic Rankine cycle system to convert heat in at least a portion of the gaseous pyrolysis product stream to electrical energy, a heat exchanger to increase a temperature of a stream, or a combination thereof.

Embodiment 15. The system as recited in embodiment 14 comprising the organic Rankine cycle system, wherein the system further comprises a converter for converting at least a portion of the electrical energy to thermal energy and a pyrolysis reactor line for supplying at least a portion of the thermal energy to the pyrolysis reactor.

Embodiment 16. The system as recited in embodiment 14 comprising the organic Rankine cycle system, wherein the system further comprises: thermomechanical cuttings cleaner to produce a first stream comprising solids and a vapor stream from at least a portion of the drilling waste; a particle separator to produce a second stream comprising solids and a hydrocarbon stream from at least a portion of the vapor stream; and a thermomechanical cuttings cleaner line for supplying at least a portion of the electrical energy to the thermomechanical cuttings cleaner.

Embodiment 17. The system as recited in embodiment 16 further comprising a converter for converting at least a portion of the electrical energy to thermal energy and a pyrolysis reactor line for supplying at least a portion of the thermal energy to the pyrolysis reactor.

Embodiment 18. The system as recited in embodiment 14 comprising the organic Rankine cycle system, wherein the system further comprises a dehydrator to dehydrate at least a portion of a cooled pyrolysis product stream produced by the organic Rankine cycle system to produce a stream comprising hydrogen and a mixed stream.

Embodiment 19. The system as recited in embodiment 18 further comprising a product condenser to condense at least a portion of the mixed stream to form a liquid product.

Embodiment 20. The system as recited in embodiment 14 further comprising a catalyst separator to separate at least a portion of the stream comprising solid carbon and catalyst to produce a stream comprising catalyst and a stream comprising solid carbon.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and/or “substantially” and/or “generally” can include a range of ±8% of a given value.

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a borehole, and/or equipment in the borehole, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited.