Patent Grant
8312924
The present invention is directed to methods and apparatus to inject high energy density substances into subterranean environments where they react. More specifically, this invention is directed to methods and apparatus to inject high energy density fluids like reactive mono-propellants and other hypergolic fluids into subterranean environments through wellbores into the earth.
When a fluid, such as oil and natural gas, is being produced from a subterranean reservoir through a wellbore the reservoir's ability to produce such fluids is often enhanced by processes that inject fluids and solids from the surface through a wellbore into subterranean reservoirs. There is one field of work that uses these fluids and is known to those familiar with the art of oil and gas production as stimulation fluids or hydraulic fracturing fluid, and the process involving these fluids is often referred to as hydraulic fracturing job or stimulation job. It is commonly believed that fracturing the subterranean rock in the reservoir will enhance hydrocarbon production from the well. This is accomplished by pumping the fluids at very high pressures that are greater than the fracture pressure of the subterranean reservoir, thus cracking the rock.
In early days explosives like nitroglycerin were dropped in wells to break up, crack, or otherwise stimulate the subterranean rock to produce fluids. These explosives had the limitation of only cracking the rock near the wellbore. Therefore, the idea of extending the fractures and cracks in the rocks far afield from the wellbore was developed using the injection of high pressure hydraulic fracturing fluids. The fluids injected as stimulation or fracture fluids are often mixed at surface with a variety of chemicals and solids prior to injection. Many fluid types are used including freshwater, saltwater, nitrogen, carbon dioxide, hydrogen peroxide, monopropellants, hydrogen fluoride, acids, bases, surfactants, alcohols, diesel, propane, liquid natural gas, with many combinations of these fluids and many more fluids. Some of these fluids are blended with solids like sand, bauxite, ceramic proppants, propellants, proppants, and/or catalysts and the fluid and solids are pumped as a slurry into the wellbore and reservoir rocks.
There are further chemicals and fluids mixed at the surface and injected with stimulation processes like acid stimulation jobs or steam injection stimulations to improve the reservoir's ability to produce back the injected stimulation fluids to surface and enhance the reservoir production of hydrocarbon fluids. This is because the stimulation fluids remaining in the rock matrix of the subterranean reservoir or the chemicals transported by the fluids reduce the reservoirs ability to produce commercial hydrocarbon fluids. Additionally, those familiar with the art of stimulation or fracture technology in the oil and gas industry often mix at surface viscosifier agents and/or cross-linkers to the stimulation fluid, enhancing the fluid's ability to transport solids into the reservoirs. What is needed is a method and apparatus to add large amounts of heat generated inside the well during well stimulation as opposed to generating heat at surface and transporting the heat down the well.
Further, current industry practice of adding to stimulation fluids chemicals such as hydroxypropyl guars, polyacryl imides, and cellulose gelling agents reduces the hydraulic friction between the fluids being pumped and the well conduits that transport the fluids from surface to the subterranean reservoir. These are often referred to as friction reducer chemicals. As the oil and gas industry continues to find more gas and oil in lower permeability rocks, and in ever lower pressured “resource plays,” like shale gas and coal bed methane, shale oil, and tar sands, it becomes ever more important to find substances to pump into the reservoir rock to enhance the hydrocarbon production by reducing the detrimental effects of the chemicals added for friction reduction.
Moreover, there is a problem with these methods when the fluids, particularly water, are produced back from the wells because they must be treated to re-use in subsequent wells or safely and environmentally disposed. There are many detrimental issues with this produced back fluid. For example, while flowing back from the subterranean environment, injected fluids containing friction reduction chemicals, gelling agents, scale inhibitors surfactants, crosslinkers, and hydrogen sulfide gas often contain bacteria that feed on the gels and poly acrylimdes and thus are not suitable for surface disposal or re-injection into subsequent wells during a subsequent stimulation, enhanced oil recovery method, or hydraulic fracture treatment. In the case of hydrogen sulfide gas production while flowing fluids from the wells, the ability to neutralize and treat this gas in the wellbore system would be a great improvement over the current art of flowing to facilities where the hydrogen sulfide (H2S) gas is stripped out with various ammine solutions. Moreover, the lack of water resources in areas of large hydrocarbon recovery restricts the use of water as a treatment fluid.
Before the current invention, methods to enhance production of hydrocarbons from wells used by those familiar with the art of treating stimulation fluids mixed friction reducers, gelling agents, cross linkers, and/or surfactants into water at surface prior to injecting the fluid and chemicals down a well casing or tubing. These chemicals are typically batch mixed into the stimulation fluids to be injected at the surface into large holding tanks, known as frac tanks, or the chemicals are added “on the fly” at surface to the stimulation or fracture fluid by injecting them into the discharge of a large centrifugal pump at the surface. The mixed fluid is then pumped through high pressure pumps and injected into the well and the reservoir at very high pressures and normally high injection rates thereby exceeding the fracture pressure of the reservoir rock. Hence the stimulation or rock fracturing is largely done with hydraulic forces.
This process, often referred to as “hydraulic fracturing,” is thought to crack or break the subterranean rock in the reservoir giving the reservoir more conductivity for the production of reservoir fluids like oil and gas. The objective is to put as much energy out away from the wellbore into the formation rock well beyond the wellbore to crack rock far field from the wellbore thereby improving the fluid conduction path from the far afield rock to the wellbore. Using current methods the hydraulic energy is highest at the wellbore where the stimulation or fracture chemicals enter into the well, and the energy available to crack and stimulate becomes progressively less as the stimulation and fracture fluids travel out beyond the wellbore. The typical method of treating heavy oil, tar sands, and depleted light oil reservoirs is to heat fresh water into steam and inject the steam into the wellbore once again concentrating most of the energy injected into the reservoir rock to near the wellbore. This stimulation or enhanced oil recovery method requires large amounts of fresh water, and the process loses considerable amounts of the heat energy in the transportation of the steam from surface to the subterranean environment.
A still further method of fracturing or stimulating subterranean rock reservoirs or stimulating subterranean reservoirs has been the dropping of explosives into the wells or injecting liquid and solid propellants, like nitroglycerin, dynamite and high grades of hydrogen peroxide, directly into reservoir rock. Hydrogen peroxide is known to decompose into hot water and oxygen in many reservoir rocks where the rocks act as a catalyst for the decomposition and no oxygen is required. The problem with this method is the very rapid and uncontrolled decomposition rate of hydrogen peroxide near the wellbore and the unpredictability of the reactivity of the reservoir rock as a catalyst.
It is desirable to use fluids with large chemical energy storage that do not require an oxygen environment to combust or decompose so that more chemical energy is available in the subterranean environment and may be placed far underground and far afield from the wellbore out into the reservoir to stimulate the subterranean reservoir with energy other than solely hydraulic energy, like heat and the expanding products of the fluids combustion and decomposition in the presence of catalyst, ignitors, and geothermal temperatures.
When a fluid, such as oil and natural gas, is being produced from a subterranean reservoir the reservoir energy depletes with time. It has been found that by the injection of certain fluids from the surface such as, nitrogen, water, steam, carbon dioxide, flue gas, air, and combinations of these fluids into a depleted or mature hydrocarbon reservoir the production of hydrocarbons from the depleted reservoir can be enhanced. There is one field of work that uses these fluids and is known to those familiar with the art of oil and gas production as Enhanced Oil Recovery, EOR. It is also known that the injection of heat can greatly enhance the injected fluid's ability to recover hydrocarbons from the depleted or mature reservoirs. This is particularly the case in “steam floods” and “steam assisted gravity drainage methods”, known as SAGD to those in the field of EOR, which uses injected steam from the surface but suffer from the heat loss as the steam is injected from surface and heat is lost along the length of the well and the surface pipe infrastructure in a field thereby delivering less heat energy to the subterranean reservoir. What is needed is a method to generate heat in-situ.
It has been found that by the injection of certain fluids like air, natural gas, oxygen, and combinations of these fluids into a depleted or mature hydrocarbon reservoir the production of hydrocarbons from the depleted reservoir can be enhanced by igniting the oil, natural gas, coal, tar sand, shale oil, shale gas, or kerogen located in-situ in the reservoir. The field of work that uses these burning fluids is known to those familiar with the art of oil and gas production as Fire Flooding or In-Situ retorting. It is known that the placement of heat in-situ can greatly enhance the fuel in-situ to ignite. This is particularly the case in tar sands and shale oil reservoirs. What is needed is a method to generate heat in-situ in the reservoir as far from the wellbore as possible with ignitable fluids or with fluids that will assist in the ignition of the in-situ reservoir fluids.
Additionally, enhanced oil recovery projects, in-situ retorting of shale oil, fire floods, and fracture and stimulation treatments are often performed in parts of the world that have high ambient surface temperatures, where the use of explosive and reactive fluids like hydrogen peroxide becomes more dangerous as these fluids become more reactive as their temperature increases at surface. Likewise, enhanced oil recovery projects, in-situ retorting, fire floods, fracture, and stimulation treatments are often performed in parts of the world that have low surface temperatures, such that the reactive fluids like hydrogen peroxide might freeze, rendering them unpumpable. Currently, when using water as the work fluid this cold condition is easily resolved by heating the working fluid, e.g. water, with heat exchangers for stimulation or EOR projects. The methods to maintain the temperatures on the surface of highly reactive mono-propellants for example is not currently available. What is needed are methods and apparatus to allow for the temperature control of high energy density fluids to allow them to be injected safely at well sites into wells.
For example currently, a hot oiler truck comes to the well that is to be stimulated with water fracture based fluids and, by burning propane on the truck's heat exchangers and passing the working fluid to be pumped into the well, the truck heats up the working fluid on the truck such that heated fluid passes through heat exchangers on the truck and at the same time passes the working fluid, usually water, to be used for the stimulation treatment over the truck's heat exchanger and then re-circulates the fracture treatment water back to a heated holding tank. In this way the fracture treatment water is heated in cold weather such that it can be pumped and does not get solid on the surface. However, this heating method of pumping the fluids into a heat exchanger on a truck that is burning propane is exceedingly dangerous when the fluids to be pumped are mono-propellants like hydrogen peroxide or hydrazine.
A still further need to transmit large amount of energy beyond the wellbore in an interval is known to those familiar with the art of enhanced oil recovery, EOR, and in-situ retorting of hydrocarbons. This need to get energy out into the subterranean reservoirs beyond the wellbore can also be extended to the new and evolving field of enhanced gas recovery, EGR, and fluid sequestering like CO2. In both EOR and EGR, there is a need to get energy down wellbores and out into the reservoir. Indeed, the method of horizontal wells for steam flooding was developed to allow the steam energy to contact larger portions of the subterranean reservoir.
A still further method of enhanced oil recovery, or indeed subterranean in-situ retorting of oil is to place large heaters in the earth to heat hydrocarbons and kerogens such that they can be produced from the subterranean intervals. Subterranean heaters, however, cannot heat large areas of the subterranean reservoir far afield from the wellbore because the heater is located in wellbore and the earth is a great heat sink. To improve the heating of the subterranean reservoir, one must drill either a large number of heater wells and add exceeding large amounts of heat in these wells from surface or drill very expensive and long horizontal wells in which heaters are placed. In all cases the desire is to get energy, and in the case of enhanced oil and gas recovery, heat energy large distances from the wellbore. In the case of oil shale, the immense amount of heat needed to remove the oil from the shale is not cost effective, hence a method is needed to ignite and to feed oxygen to the oil shale, using the in-situ generated heat from the combustion of some of the oil shale or kerogen to heat the oil shale reservoir. However, getting oxygen to the oil shale is not easy due to the shale's low inherent permeability which makes the injection of oxygen into the rock away from the wellbore very difficult. What is needed is a fluid that can heat the rock, ignite in the rock, and deliver oxygen to the rock while assisting in the burning of in-situ fluids.
What is needed is a method to transmit large amounts of energy beyond the wellbore in a subterranean interval being stimulated to enhance oil or gas production. A further need is to accomplish this far field from the injection wellbore for enhancement effect in the subterranean reservoir with substances that will not reduce the permeability of the reservoir or otherwise inhibit the reservoir to produce fluids back to the wellbore and to the surface. A further need is to reduce the environmental damage done on the surface of the earth and sea by the flow back to surface of stimulation and fracture fluids containing chemicals and bacteria. A still further need is to have available methods and apparatuses to safely handle and control the rate of reaction of reactive fluids and solids such as propellants, catalyst, and fuels pumped into subterranean environments like reservoir rocks at outdoor well sites that may have cold and hot surface environments. Many wells are located in locations on the earth where the surface temperatures are below the sublimation temperatures of many reactive mono-propellant fluids like hydrogen peroxide or hydrazine. What is needed is a method to keep these reactive high energy density substances, like liquid propellants, from freezing at well sites with cold surface temperatures.
The present invention is directed to new methods and apparatuses to treat subterranean reservoirs through wellbores with reactive high energy density substances. This invention teaches methods and apparatuses that allow substances such as mono-propellants, oxidizers, catalysts, and fuels to be injected into subterranean environments to release large amounts of energy into the subterranean environment by controlling their temperature, thus allowing these fluids to be injected safely.
In one aspect of the present invention, surface vessels, conduits, and/or pumps are designed to perform a process that maintains the highly reactive substances and their transport fluids in a low reactive state by controlling their temperature while at surface.
In a further aspect of the present invention highly reactive high energy density substances are frozen into solid form and mixed into cold fluids to allow the solid substances to be delivered to a well site, pumped and transported as a slurry into the well and out into the reservoir with the transport fluids that keep the substances cold. The invention further teaches methods to blend the substances with fuels, oxidizers, mono-propellants, and catalysts at low temperatures to keep the blend in a low reaction state.
In another aspect of the present invention highly reactive high energy density fluids are heated, and monitored to maintain them in a liquid state on surface at a well site where cold surface environment temperatures are below the propellants freezing point, to allow the propellant to be pumped as a liquid into the well.
In a still further aspect of the present invention a method is presented to form solid reactive materials from liquid reactive materials using cold solids to seed the formation of the reactive fluids.
In a still further aspect of the present invention a method is presented to ignite highly reactive high energy density fluids in a down hole reaction chamber connected to a coiled tubing thereby directing said fluids to be pumped from an appropriately temperature controlled surface storage vessel, through surface lines, through a coiled tubing string disposed in a well through a wellhead sealing pack off elastomeric device with a reaction chamber on the coiled tubing distal end that atomizes high energy density fluid and ignites the fluid allowing the coiled tubing to articulate in the well bore the position of the reaction chamber while pumping the fluid from surface thereby releasing heat and or decomposition products from the reaction chamber into the subterranean environment.
In a still further aspect of the present invention a method is presented to provide energy to a subterranean environment by directing a reactive high energy density fluid from a surface storage vessel (that is optionally temperature controlled), through surface lines, through a conduit such as a coiled tubing string disposed in a wellbore, and into the wellbore where the fluid decomposes or reacts. In some embodiments, upon exiting the conduit, the fluid enters a down hole reaction chamber connected to the conduit. In the reaction chamber, the high energy density fluid is ignited, and may atomized to assist in ignition. The reaction chamber can have a one-way valve that allows the fluid and/or reaction/decomposition products to exit the chamber and enter the formation, but prevents flow in the reverse direction.
The method can include reciprocating the reaction chamber (such as by reciprocating the conduit) to release heat or reaction/decomposition products along a length of the wellbore. At or near the wellhead, the conduit can be directed through an appropriate pack off elastomeric device to provide a seal.
In another aspect, a method is provided for the in situ treatment of hydrogen sulfide, comprising pumping a reactant that reacts with hydrogen sulfide to produce desirable products such as elemental sulfur into a wellbore via a stainless steel (as opposed to carbon steel) conduit and reacting the reactant with the hydrogen sulfide to produce desirable products. In some embodiments, the reactant comprises hydrogen peroxide and the product comprises elemental sulfur.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art of hydrocarbon production enhancement from wells that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures and methods for carrying out well hydrocarbon production enhancement. For example the well production enhancement for enhanced oil recovery, in-situ processing of shale oil, coal, coal bed methane, shale gas, and tar sands, as well as other well enhancement fields, can use the methods and apparatuses of this invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which:
As used herein, “a” or “an” means one or more. Unless otherwise indicated, the singular contains the plural and the plural contains the singular.
In many aspects and embodiments, the present invention uses reactive high energy density substances that can deliver a relatively high amount of energy per unit weight. Examples of such substances include 10% hydrogen peroxide, 100% hydrogen peroxide, hydrazine mixtures, and other substances.
In the embodiment of
In one embodiment, heat exchanger fan 6 blows air across heat exchanger tubes 4 in heat exchanger 5, and is driven by prime mover 7. Other means of heat exchange are also in the scope of this invention. In one embodiment, the tank shroud 3 is filled with a suitable fluid, and heat exchanger tubes 4 are submersed in the reactive fluid. The reactive fluid is enclosed by shrouds filled with dilution fluids like water that allows for dilution of the reactive fluid in the event of a leak. In one embodiment, the fluid filling tank shroud 3 is water, and for convenience this disclosure may refer to water. Of course, other fluids can be used that provide either heat exchange or safety via dilution, or preferably, both. Heat exchanger 5, tank 1, inner tank 2, shroud 3, and tubes 4 are not limited to the geometries, orientations, or structure disclosed in the
The water in shroud 3 can be circulated from water tank 10 through pump 11 with the water returning from tank shroud 3 to water tank 10. In one embodiment, tank 1 can be instrumented with temperature monitoring sensors 8, and in one embodiment the sensors are optical fibers 8, disposed inside tubes 4 and tubes 9 located inside tank 1, both in tank shroud 3 and inside inner tank 2. Optical fibers 8 can be used as temperature sensors themselves and are preferably monitored with an Optical Time Domain Reflectometer machine (“OTDR”) 12 that launches light down the fibers and interprets the backscatter light back to the machine to give continual distributed temperature profiles from the optical fibers 8. This device is often referred to as an OTDR Distributive Temperature System (“OTDR DTS”). Additionally, the circulation of water from tank 10 through tank 1 in shroud 3 allows for an even heat to be maintained in the reactive fluid inside inner tank 2. Thus,
The embodiment of
Thus
The embodiment in
In one embodiment, pump 19 is enclosed in shroud 20, which may use fluid from tank 10 in a manner similar to other shrouds described above. Pump 19 is powered by any known means, but preferably by hydraulic power pack 21 and controlled remotely from a frac van 22 with hydraulic controls via hydraulic control line 23. Hydraulic control pack 21 is powered by prime mover 24 that is preferably monitored and controlled remotely from the frac van 22 by hydraulic control line 25. The use of hydraulic power increases safety when working with reactive fluids.
Injection pump 19 pressurizes the reactive fluid and the substances from tank 1 and injects them into (preferably shrouded) high pressure conduit 26 for injection into well 27 and out into subterranean reservoirs 28. In a manner similar to other shrouds described, shrouded high pressure conduit 26 can have water supplied from tank 10 via pump 11 and line 29, and water is returned to water tank 10 through line 34. In one embodiment, wellhead 30 is shrouded with wellhead shroud 20, which receives a fluid such as water from tank 10 through line 29A, and the fluid returns to tank 10 through line 31.
Thus
In one embodiment, the temperature of the reactive fluid is continually monitored in the well using at least one temperature sensor such as optical fiber 32 using the OTDR DTS machine 12. Thus,
In another embodiment shown in
In another embodiment a reactive fluid like hydrogen peroxide can transferred from tank 1 at a controlled temperature, and solids like sand, ceramics, bauxite, proppants, and/or catalyst, can be added from tank 33 through a pump 240 into blender vessel 36. Other reactive fluids and solids can be used as are known in the art. In embodiments where the temperature of the fluid in vessel 36 is desired to be cold, solids from tank 33 are preferably cool or cold. The solids and reactive fluid are mixed and injected into the well 27 and out into the reservoir 28. Thus, reactive fluids are delivered into the reservoir 28 at a low temperature, increasing the distance the reactive fluid can be placed beyond the wellbore, releasing energy into the far field of subterranean reservoir 28.
In another embodiment a reactive fluid is transferred from tank 1 at a controlled temperature, and very cold solids can be added from tank 33 into blender vessel 36. The solids preferably have a temperature lower than the freezing point of the reactive fluid from tank 1, thereby causing the reactive fluid to freeze around and in the solids. The solids thusly coated with reactive fluid are pumped out of blending vessel 36 into well 27 and into the subterranean reservoirs 28. Thus, reactive fluids are delivered into the reservoir 28 at a low temperature, greatly increasing the distance the reactive fluid can be placed beyond the wellbore, releasing energy into the far field of subterranean reservoir 28.
For example, the fluid in blender vessel 36 is kept cool by adding cold fluids, such as, cryogenic fluids, liquid nitrogen, methanol, or water, from tank 38 through pump 39 to the shroud of vessel 36. Heat can be removed from mixing vessel 36 in heat exchanger 5. Likewise, if the surface environmental temperatures are lower than the reactive fluids freezing point, blender 36 can be heated via a shroud or other heat exchanging system, which receives fluid such as hot water from tank 38. Hot oiler truck 13 can heat the water in tank 38 using the propane burners and a heat exchanger on hot oiler truck 13. If desired, the slurry leaving blender vessel 36 can be further temperature controlled before well injection by adding or removing heat via a heat exchange fluid in tank 37, which can be controlled in any known manner, preferably with hot oiler truck 13 when heat, QIN, is required.
Once the injected fluid and solid warms up in the subterranean reservoir 28 and releases energy, Qout, e.g., by igniting, the in-situ energized fluid in the reservoir can be flowed back to the well surface through a line to a surface tank. This high temperature reaction in the reservoir and the reaction products will combine and further enhance the in-situ hydrocarbons' ability to flow from the well.
In
Now directing your attention to the
In another embodiment, at least one hypergolic component is pumped down a wellbore. In yet another embodiment, at least two hypergolic components are separately pumped down a wellbore released such that they will mix in the wellbore. For example, a first reactive substance such as hydrogen peroxide is pumped from the surface into the wellbore and reservoir using one conduit, and a second substance that will spontaneously ignite with the first substance, such as ammonia, is pumped from the surface into the wellbore and reservoir using a separate conduit. The two substances will mix in the wellbore and subterranean formation forming a hypergolic fluid. The substances may, in some embodiments, be temperature, pressure controlled, and/or shrouded as described in any one of the above embodiments.
In any of the embodiments, the containers and conduits can be made from any material known in the art, such as stainless steel. The containers and/or conduits can, if desired, be passivated, coated with films, chemical films, or metal oxides, and/or otherwise treated to enhance the overall process. If a surface is passivated, it is desirable to test the surface for passivation at various times. In some embodiments, pressure monitoring and/or testing is desired for certain containers and/or conduits.
In another embodiment, a method provides energy to a subterranean environment by directing a reactive high energy density fluid from a surface source (such as a temperature controlled vessel), through surface lines, through a conduit (such as a coiled tubing) disposed in a wellbore, and into the wellbore where the fluid decomposes, ignites, or reacts to form products that comprise elemental oxygen. The energy of this reaction heats the surrounding formation. In addition, the elemental oxygen product reacts with in situ hydrocarbons to propagate additional reactions into the formation, which can generate heat, decompose heavy hydrocarbons and kerogen into lighter hydrocarbons, and increase the productivity of the well.
In an another aspect of the present invention, acoustical and/or seismic energy is transmitted from the surface to the reaction chamber. This energy is used to ignite an explosive in the reaction chamber. In an alternate and/or specific example, acoustical energy is used to heat at least one element in the reaction chamber.
In some embodiments, upon exiting the conduit, the fluid enters a down hole reaction chamber connected to the conduit. In the reaction chamber, the high energy density fluid is ignited, and atomized to aid the ignition. The reaction chamber can have a one-way valve that allows the fluid and/or reaction/decomposition products to exit the chamber and enter the formation, but prevents flow in the reverse direction. In some cases, the method includes reciprocating the reaction chamber (such as by moving the conduit) to release heat or reaction/decomposition products along a length of the wellbore. At or near the wellhead, the conduit is directed through an appropriate pack off elastomeric device to provide a seal.
In another embodiment, a method is provided for the in situ treatment of hydrogen sulfide. Hydrogen sulfide is a dangerous chemical with many undesirable qualities. Hydrogen peroxide reacts with hydrogen sulfide to produce elemental sulfur and other products. Moreover, hydrogen peroxide reacts with or interacts with many materials found in oxides of metals and subterranean minerals, with a very reactive catalyst being iron oxide. Hence the injection or transport of hydrogen peroxide into wells with iron or carbon steel tubulars, frac lines, or well heads is highly dangerous, and becomes exceedingly dangerous as the percentage of active hydrogen peroxide is increased.
In some embodiments, the current method uses a stainless steel (as opposed to carbon steel) conduit to carry substances, such as hydrogen peroxide, that react with hydrogen sulfide to produce desirable products, such as elemental sulfur. The reactant is delivered into a wellbore via a stainless steel conduit, where it reacts with the hydrogen sulfide to produce desirable products. Thus, as fluids are produced back, they contain less (or no) harmful hydrogen sulfide, which increases safety and saves time and money because the need to treat the hydrogen sulfide is reduced or eliminated. In any or all of the embodiments, the conduit is a continuous conduit, meaning that it is not made up from repeated threaded joints.
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
This application claims priority to U.S. Provisional Patent Application No. 61/045,062, filed on Apr. 15, 2008, which is incorporated by reference herein in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2859587 | Scott et al. | Nov 1958 | A |
| 3246697 | Natland | Apr 1966 | A |
| 3367123 | Schambra | Feb 1968 | A |
| 3551349 | Kallfass | Dec 1970 | A |
| 3630281 | Fast et al. | Dec 1971 | A |
| 3777816 | Meier | Dec 1973 | A |
| 3842910 | Zingg et al. | Oct 1974 | A |
| 3858655 | Engle et al. | Jan 1975 | A |
| 3880236 | Durning et al. | Apr 1975 | A |
| 4593763 | Burke | Jun 1986 | A |
| 4641710 | Klinger | Feb 1987 | A |
| 4805726 | Taylor et al. | Feb 1989 | A |
| 4867238 | Bayless et al. | Sep 1989 | A |
| 4909981 | Garabedian | Mar 1990 | A |
| 5163511 | Amundson et al. | Nov 1992 | A |
| 5322019 | Hyland | Jun 1994 | A |
| 5433271 | Vinegar et al. | Jul 1995 | A |
| 5733521 | Minamikawa et al. | Mar 1998 | A |
| 5851505 | Nishide et al. | Dec 1998 | A |
| 5875850 | Burge et al. | Mar 1999 | A |
| 5928621 | Ledon et al. | Jul 1999 | A |
| 6001324 | Ledon et al. | Dec 1999 | A |
| 6054109 | Saito et al. | Apr 2000 | A |
| 6296829 | Devos et al. | Oct 2001 | B1 |
| 6447744 | Haas et al. | Sep 2002 | B1 |
| 6676712 | Creutz et al. | Jan 2004 | B2 |
| 6780206 | Nordhoff et al. | Aug 2004 | B2 |
| 7185702 | Blauch et al. | Mar 2007 | B2 |
| 7874350 | Pfefferle | Jan 2011 | B2 |
| 20030221579 | Grattan | Dec 2003 | A1 |
| 20060289166 | Stromquist et al. | Dec 2006 | A1 |
| 20070062704 | Smith | Mar 2007 | A1 |
| 20070199696 | Walford | Aug 2007 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20090308613 A1 | Dec 2009 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61045062 | Apr 2008 | US |
