MX2007008798A

MX2007008798A - Down hole physical upgrading of heavy crude oils by selective energy absorption.

Info

Publication number: MX2007008798A
Application number: MX2007008798A
Authority: MX
Inventors: Raymond S Kasevich
Original assignee: Ksn En Llc
Priority date: 2005-01-19
Filing date: 2006-01-19
Publication date: 2008-03-10
Also published as: WO2006078946A3; WO2006078946A2; CN101142372A; US20060180304A1; CA2595293A1; EP1871984A2; AR053537A1

Abstract

The present invention utilizes the ability of electromagnetic energy at the appropriate frequency to selectively deposit thermal energy in the heavy oil for precise control of cracking temperature throughout a given volume of material. Selective electromagnetic energy absorption in the heavy crude oil provides energy efficient transfer of heat at the molecular level and thereby insures precise temperature control throughout the treatment volume. This allows for optimization of the visbreaking process using electromagnetic energy.

Description

PHYSICAL ELEVATION OF OIL WELL FUNDS DENSIVE RAWS BY ENERGY ABSORPTION SELECTIVE Field of the Invention The present invention relates generally to the use of electromagnetic energy to subject the dense crude oil to mild thermal cracking conditions, thereby allowing the viscosity, pour point and specific gravity of the oil to be decreased and made easier. to recover and manage. More particularly, the present invention relates to methods for applying electromagnetic energy to dense oils in the reservoir, to promote lifting in situ and facilitate recovery. The present invention also relates to systems for applying electromagnetic energy to dense oils in situ. BACKGROUND OF THE INVENTION Dense crude oil presents problems in the recovery and production of oil. Raw API low gravity oils and crude oils that have a higher pour point, present production problems both inside and outside the tank. The extraction and refining of these oils is difficult and expensive. In particular, it is difficult to pump the dense crude oil or move it through pipes. Nowadays, several methods are used to reduce the disadvantages of dense crude oil. For example, the oil industry reduces surface handling problems by combining dense crude oil with light oils and liquid propane gas to make them easier to handle in pipelines and storage facilities. However, this method has drawbacks since it does not help in the initial recovery of the oil, and it is expensive. A process called "visromption" or mild thermal breakdown, can also be used to reduce the viscosity of dense crude oil. "Visromption" is a petroleum refinery process to increase the pumping capacity of dense crude oils. It is usually achieved by heating the dense crude oil in an oven. The process is characterized by slight decomposition, minimum coke formation and the retention of the cracked product in the existence of original feeding. The resulting mixture has viscosity, pour point and specific gravity values that are lower than the original oil. However, as currently applied, visromption can not be used in oils in situ. The present invention applies new contexts of visromption and for new purposes, and proposes improved methods for the application of visromption. In the present invention, the visromption is achieved using electromagnetic energy to heat the dense crude oil, instead of heating it in a furnace. In addition, the present invention is suitable for use in oil treatment in situ. Said treatment allows the elevation of the oil in the tank and helps to recover it. Brief Description of the Invention The present invention utilizes the electromagnetic energy capacity at the frequency suitable to selectively deposit thermal energy in the dense oil for precise control of the cracking temperature, through a determined volume of material. The absorption of selective electromagnetic energy in dense crude oil provides energy-efficient heat transfer at the molecular level, and thus ensures accurate temperature control throughout the treatment volume. This allows the optimization of the visromption process using electromagnetic energy. The proper selection of frequency power duration results in the rapid breaking down of dense hydrocarbons to any desired side, by absorption of electromagnetic energy. When the desired degree of desquamation is reached, the hot oil matrix provides a set of significantly different electrical properties that can be measured on the surface during the "electromagnetic visbreaking process". (EVP) ensures the temperature and control of p, precise absence of the bottom of the well. This proposed EVP provides efficient energy absorption and thermal stripping control of dense oils for in situ lifting. The application of low power (a few tenths of kilowatts) of electromagnetic energy for the formation of visrompimiento, will provide a slight decomposition of the dense oil, a minimum formation of coke and the retention of the product cracked in the original existence. The resulting mixture has viscosity, pour point and specific gravity values which are lower than those of the original oil. The present invention is promising for various applications. It can be used to raise dense crude oil in situ. It can also help in the recovery of dense crude oil from the deposits. In addition, the present invention can be used to more efficiently recover oil shale hydrocarbons, such as that found in the western part of the United States. In one embodiment of the present invention, a system may be provided for use in the treatment of dense underground crude oil. The system may comprise a bore in an area where there is crude oil in the earth, an electromagnetic energy applicator placed within the bore in the vicinity of the dense crude oil to be treated, a wire attached to the electromagnetic energy applicator to supply energy electromagnetic to the applicator, an electromagnetic energy generator adhered to the cable to generate electromagnetic energy that will be supplied to the applicator, and a product return line that runs along the perforation, the product return line being comprised of a distal end placed in the vicinity of the electromagnetic energy applicator through which oil or other products can be recovered and a proximal end at or near the surface of the earth. In another embodiment of the present invention, a method for treating dense crude underground oil is provided. The method comprises the steps of placing an electromagnetic energy applicator in a bore in the vicinity of dense crude oil, generating electromagnetic energy, applying electromagnetic energy to the dense crude oil with the applicator to achieve thermal cracking, and recovering the dense crude oil to through a product return pipe. Although multiple modalities are described, still other embodiments of the present invention may be appreciated by those skilled in the art, from the detailed description which follows, which shows and describes illustrative embodiments of the present invention. As can be appreciated, the present invention has the capacity and modifications in several obvious aspects, and without departing from the spirit and scope thereof. Accordingly, the drawings and the detailed description will be considered as illustrative by nature and not restrictive. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a simple piercing radiation type applicator. Figure 2 is an approach view of a part of the applicator system. Figure 3 is a perspective view of a part of another configuration of a simple piercing applicator. Figure 4 is a perspective view of a well head for use with the applicator system. Figure 5 illustrates a sample of the absorption data from experiments in the application of electromagnetic energy to large oil molecules in oil shales. Detailed Description of the Invention A variety of different types of bottomhole electromagnetic structures can be used to apply electromagnetic energy to the dense crude oil in situ. The right structure for any particular application depends on a variety of factors, including depth, uniformity of heating and minimization of the degree of coke and production of unsaturated hydrocarbons.

Figure 1 is a perspective view of a simple piercing radiation type applicator. The applicator system 10 is placed inside the perforation 12. The perforation 12 is supported by boxing 14. The applicator system 10 is subsequently used to apply electromagnetic energy to the dense crude oil in the vicinity of the perforation 12. The applicator structure 20 is a line retort. As a reference point, a typical applicator 20 can be approximately 70 feet (convert) in length. In a typical configuration the applicator 20 can be positioned from 100 to 600 feet below the ground in the borehole 12. Radio frequency ("RF") power is supplied to the applicator 20 through an RF generator (not shown). The RF generator is connected to the applicator 20 through a part of flexible coaxial cable 30. In turn, the flexible coaxial cable 30 is connected to a part of the rigid coaxial cable 32. The coaxial cable may or may not be supported by ceramic beads , which are desirable at higher temperatures. By means of this, the RF generator supplies RF energy to the applicator 20, which in turn applies RF energy to the target volume to achieve visromption. This allows the in situ elevation of the dense crude oil and helps its recovery. The recovery of the oil and related product is achieved by means of the production line 40. This non-metallic pipeline runs from the production area of the perforation 12 through the perforation to the surface 16. A surface, the production line 40 it is connected through a product return line to a storage or processing facility (not shown). The production line 40 provides a firm mounting base for the RF hardware of the applicator system 10. The coaxial cables 30 and 32 can be adhered directly to the production line 40 using the connectors 42. The applicator 20 also adheres to the production line 40. Figure 2 is an approach view of a part of the applicator system. The structure of the applicator 20, the rigid coaxial cable 32, and the production line 40 are all placed inside the perforation 12. Typical dimensions for said systems are shown in Figure 2. The ceramic support beads 34 support the cable rigid coaxial 32. In addition, the ceramic pressure window 36 is placed on top of the applicator 20. Figure 3 is a perspective view of a portion of another configuration of a simple piercing applicator. In this configuration, a bipolar feed is used. The coaxial feed 38 surrounds the production line 40. The ceramic window 36 is placed on the bottom of the coaxial feed 38. Although specific examples of structures of the applicator are provided, it will be understood that other settings known in the art can also be used. . Uniform heating can be achieved using antenna formation techniques, such as that described in U.S. Patent No. 5,065,819. Said techniques can be used to minimize the coke processing conditions in the perforation of the applicator and to avoid excessive electrode voltage gradients in high powers. The formations reduce the excessive voltage gradients in the perforation by means of mutual coupling. The ability to separately measure the reflected power of each applicator perforation containing the radiator and the mutual impedance coupling between any pair of applicator perforations, ensures precise control of the temperature of the heated volume. Other variations are possible, including non-radiation structures such as those proposed in the Bridges and associates publication, "RF Heating of Utah Tar Stands," Final Report, IIT Research Institute. However, such structures are sensitive to breakage with high voltage and require extensive drilling, which is not economical. A special well head can be used in conjunction with the applicator system 10. Properly designed, the reservoir head can be used to provide a safe and efficient supply of RF energy to the applicator.

Figure 4 is a perspective view of a well head for use with an applicator system. The weight of the downhole applicator (not shown) rests on a special bellows 46 that is located inside the wellhead. This ensures that any mechanical movements induced by heat from the downhole apparatus during the energy transfer, does not interrupt the power flow. An inlet opening 44 allows nitrogen to be introduced into the wellhead and borehole, further ensuring the safe application of RF energy. The insulators 45 are placed above the bellows 46, and an expansion joint of the central conductor is placed on top thereof. At the top of the well head, where the coaxial cable 30 runs and runs towards the RF generator 28, a coaxial line seal and a vertical alignment clamp 26 secure the cable to the wellhead. The return line of the product 41 brings the recovered product through the system to a storage or processing facility (not shown) and the water extraction line 43 allows the removal of water from the bore 12. The present invention also has application in oil shale fields, such as those found in the western part of the United States. The large oil molecules that come out in these oil shales have been heated in a series of experiments to evaluate the dielectric frequency response with temperature. In the response to simple low temperatures is directed by the water with cream until this water is eliminated as a vapor. After the water's vapor state, the minerals control the degree of energy absorption until temperatures of approximately 300 to 350 degrees Celsius are reached. In this temperature range, the electromagnetic energy begins to be absorbed preferentially by the dense oil. The triggering of this selective absorption is rapid and requires power control to ensure that excessive temperatures do not occur with significant coke generation. Figure 5 illustrates a sample of the absorption data of said experiments. Due to the selective energy absorption capacity at high temperatures of the dense oil, it is therefore possible to very carefully control the volume temperature of the crude oil from the bottom of the well heated by electromagnetic energy. The energy requirement is to minimize once the water with cream is removed by vaporization. It takes much less energy to reach breaking temperatures with electromagnetic energy than any other thermal medium to provide visbreaking. Kasevich has published a molecular material that is related to the specific heating of dense oil molecules. He discovered that comparing cable insulation oils with kerogen (oil) from oil shales, a statistical distribution of relaxation times in the kerogen dielectric, provided the best theoretical description of how electromagnetic energy is absorbed into the oil through dielectric properties. With higher temperatures and lower potential energy barriers within the molecular complex, rapid rise occurs and selective energy absorption occurs. In use, a user of one embodiment of the present invention may place an applicator system in a bore in an area in which dense crude oil exists. The user can place the applicator structure as it is in the bore in the target area for the application of RF energy. The user can connect the applicator structure to an RF generator through the coaxial cable. A production pipeline could run from the production area to the surface, and from there to a storage or processing facility. Subsequently, the user can apply RF energy using the RF generator for the applicator, thus applying the RF energy to the dense crude oil in situ. RF energy can be controlled to minimize coke processing and achieve the desired cracking and lifting of dense crude oil.

The resulting products can subsequently be recovered through the production pipeline and transferred to a storage or processing facility. Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes in shape and details can be made without departing from the spirit and scope of the present invention.

Claims

1. A system to be used in the treatment of dense underground crude oil, where the system comprises: a drilling in an area in which the crude oil exits in the ground; an electromagnetic energy applicator placed within the bore in the vicinity of the crude oil to be tested; a wire attached to the electromagnetic energy applicator to supply electromagnetic energy to the applicator; an electromagnetic energy generator due to the cable to generate electromagnetic energy that will be supplied to the applicator; and a polymer return pipe through the bore, wherein the return pipe of the product comprises: a distal end placed in the vicinity of the electromagnetic energy applicator through which the oil or other products can be recovered; and a near end at or near the surface of the earth. The system as described in claim 1, characterized in that the applicator is an antenna array. The system as described in claim 1, characterized in that the applicator is a solenoid antenna. 4. The system as described in claim 1, characterized in that the applicator is a helical antenna. The system as described in claim 1, characterized in that at least one of the cable and the applicator adhere to the product return line. The system as described in claim 1, characterized in that the product return line is connected to a storage or processing facility. The system as described in claim 1, characterized in that it further comprises: a wellhead on the surface of the borehole, wherein the well head comprises: bellows connected to the structure of the applicator in such a way that Bellows support the weight of the applicator. The system as described in claim 7, characterized in that it comprises a sealing opening for the introduction of gas to the wellhead and perforation. 9. The method for treating dense crude underground oil, wherein the method comprises the steps of: placing an electromagnetic energy applicator in a bore in the vicinity of the dense crude oil; generate electromagnetic energy; apply the electromagnetic energy to the dense crude oil with the applicator, to achieve a thermal breakdown, recover the dense crude oil through a return pipe of the product. The method as described in claim 9, characterized in that it comprises the steps of: controlling the electromagnetic energy applied to the dense crude oil, in order to raise the dense crude oil in situ. The method as described in claim 9, characterized in that the electromagnetic energy is applied to the dense crude oil in an oil shale.