Patent ID: 12258837

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.

The inventors hereof have determined that maintaining seals within a preferred operating range with regard to temperature can dramatically improve the sealing performance obtained. This can be accomplished by supplying a temperature controller in thermal communication with the seal. The temperature controller may be a heater or a cooler and in some cases may be either in the same device depending upon input. For example, a thermoelectric device may be used as a cooler with a first polarity and as a heater with a reversed polarity. Alternatively, a Ranque-Hilsch vortex tube may be used as a heater or a cooler depending upon which exit flow is used on the target component. The temperature controllers as disclosed herein comprise both discrete heaters and coolers that are in thermal communication or comprise the seal material itself with doping in all of or in a part of the seal material. The doping contemplated comprises materials in the seal that respond to inputs to create the temperature changes desired. It is to be understood that for all embodiments requiring the application of an electrical current, that current may be supplied locally or may be supplied from a more distant source such as from the surface from which a borehole extends.

Referring toFIG.1, a seal tool10comprises seal12such as a packer disposed upon a mandrel14. The seal12comprises a seal material16that is primarily of a commonly known type such as rubber, thermoplastic, swell rubber, shape memory material, etc. but also comprises one or more dopants18to ensure that the seal material16will be at least magnetically permeable and/or electrically conductive and in embodiments will also be thermally conductive. In these embodiments the temperature control material15is actually the doped seal material16itself. Different doping based embodiments are illustrated collectively inFIG.1where the stipple pattern is intended to be dopant of the various types noted below. In other embodiments discussed in connection with other figures hereinbelow, the temperature controller may be a separate material or even device that is in thermal communication with the seal12. Still referring toFIG.1, one or more of the dopants discussed may be incorporated in the seal material16. Magnetic conductivity is promoted by the inclusion of iron, cobalt, nickel, magnetite, ferrite or other materials known to exhibit magnetic permeability. Doping of magnetically permeable material may be in a range of from about 10 weight percent to about 60 weight percent of the total weight of the seal material16. For electrical conductivity, dopants such as carbon black, carbon fiber, graphite, carbon nanotubes, copper powder, aluminum powder or steel powder or other materials known to exhibit electrical conductivity may be used. Weight percentages of these components may be from 0.5 weight percent to 15 weight percent in various embodiments. To enhance thermal conductivity, dopants such as glass fiber, silica, silicon carbide, boron nitride and alumina or other materials known to exhibit thermal conductivity may be used in ranges of 5 weight percent to 30 weight percent of the total weight of the seal material. Electrically conductive dopants or fillers such as carbon black or graphite can improve thermal conductivity of a sealing material as well. It is to be appreciated that some combinations of dopants may have competing effects. For example, while glass fiber and other inorganics will increase thermal conductivity, they will undermine magnetic permeability. Hence for various operational cases, the desired effect from adding a particular dopant must be balanced against the overall effects that are being targeted.

With the material16of the seal12, or some portion thereof, doped (temperature control material)15and configured in a way that at least the portion that is doped, if not the entire element of the seal, is electrically insulated from surrounding conductive material, the doped portion can act as an inductor (electrical conductivity also desirable to support eddy currents that generate heat) or can act as a resistor.FIG.1schematically represents both of these embodiments. Accordingly, in these embodiments, the portion itself will respond to an electric current by generating inductive heating or resistive heating, respectively. Where there is also a thermally conductive condition in the seal material16(due to a thermally conductive dopant added thereto or due to the material16simply being inherently thermally conductive), that heat will propagate throughout the seal12. Such embodiments can maintain a seal12of seal tool10in a proper temperature range even in the face of operations such as injection of cooling fluid into the borehole and flowing the seal tool10.

For an inductive heating embodiment, an alternating current is supplied to the seal12through, for example, a conductor20. Due to the magnetic permeability and eddy currents that form in the material15of this embodiment of seal12, Joule heating of the seal12occurs. If iron is one of the doping materials, hysteresis losses may also provide a heating effect in the seal material12.

For a resistive heating embodiment, illustrated inFIG.2(where additional components of the system are identified including a frustocone11and slip13), there needn't be magnetically permeable dopant but rather only electrically conductive dopant18need be included. Thermally conductive dopants18may also be included in some resistive embodiments. To heat the seal12, a current is supplied to the seal12through power terminals22and24. Current flowing through the seal material16that is sufficiently doped with material15finds both electrical conductivity and resistance to flow consequently causing the generation of heat. This heat will naturally propagate through the seal12but will do so more quickly and evenly in the event the particular embodiment includes thermally conductive dopants as well.

Referring toFIG.3, another alternate embodiment is disclosed. In this embodiment, the seal material16need not contain magnetically permeable or electrically conductive dopants but may still contain thermally conductive dopants18. The embodiment does contain a temperature controller30comprising an internal resistance wire26. The wire26may be embedded in the seal material16. Power terminals22and24are included to supply the current pathway through the wire26.

In other embodiments, a coil may be disposed adjacent the seal material16.FIGS.4-9illustrate variations on the placement thereof and it is to be appreciated that each of the coil elements depicted may be a resistor or may be an inductor. The drawings are meant to be generic to both. For generic purpose, temperature controller30is a discreet unit. Controller30is included in each ofFIGS.4-9but in different positions or as a plurality of controllers30. There may also be a plate32that acts as a thermally conductive spreader located adjacent the controllers30or within which the controllers30are disposed. The plate32may be of a metallic material or could be another material, but in any event is thermally conductive. In each case, the application of current to the controller30will produce heat by resistance (direct current or alternating current) or through induction (alternating current) heating or hysteresis heating. That heat is spread either naturally through the seal12or with assistance from a plate32and/or from a thermally conductive dopant in the seal.

Referring toFIG.10, another embodiment of a seal tool10with a temperature controller30is illustrated. In this embodiment, the controller30is adjacent or embedded within the seal material16and constitutes its own device. The device is a thermoelectric device34such as a Peltier device, and hence may be caused to produce or remove heat at will based upon polarity of current supplied thereto. This embodiment can heat or cool the seal12depending upon what is needed to ensure that the seal stays within a preferred temperature range to enhance its sealing capability.

Referring toFIGS.11and12, the temperature controller30comprises a Ranque-Hilsch vortex tube40or alternatively referred to herein as a vortex device40is illustrated within tool10to act as the temperature control material. Vortex tubes are well known in their own right. Such tubes accept an input of compressed fluid into a spin chamber. At an end of the tube is a cone that splits the heated flow from the cooled flow. The heated flow exits and the cooled flow rebounds to exit an opposite end of the tube. In the context of the invention, the vortex tube or device40is made a part of the tool10as disclosed herein.FIG.11illustrates a configuration where the seal12is heated andFIG.12illustrates a configuration where the seal12is cooled. InFIG.11, a hot fluid output path42is disposed in thermal communication with the seal12to keep seal12warm and in the optimal sealing temperature range despite the pumping of fluids that would otherwise cool the seal12. As illustrated, path42is helically disposed in the mandrel14of the tool10, although other path shapes could be substituted where a good thermal efficiency is achieved such as back and forth loops that are circumferentially, perimetrically or longitudinally aligned relative to a longitudinal extent of the tool10. The cold fluid path46from device40is routed away from the seal12. Inlet48of the device40may be fed by a pump, a control line, etc. as desired where a clean fluid (gas or liquid) is to be supplied to the device40. Alternatively, wellbore fluid may also be used to supply the device40. As illustrated, there is a restriction41in the inside diameter flow path43of the mandrel14. There also may be in embodiments, a nozzle, an object seat, etc. Any restriction at this location will create a differential pressure thereacross enabling fluid pressure at inlet48to be raised, by for example pumps at the surface, to supply the device40with a working fluid.

As illustrated inFIG.12, it is the cold fluid that is used to manage the seal12. In this case, a cold fluid path50is routed to be in thermal communication with the seal12. As inFIG.11, the path50may be helical or similar (as described above) and restrictions to flow are the same as discussed with regard toFIG.11. In this embodiment the hot fluid path52exits the device40in a direction away from the seal12. This arrangement assists in maintaining the seal12in an optimal temperature range despite the pumping of hot fluids.

In either ofFIG.11or12, the working fluid, whether that be a clean gas or liquid supplied or a wellbore fluid, may be dumped back to the flow path43or may be dumped to an annulus in some embodiments. Also, and particularly in the case of supplied clean fluid, the fluid may be recycled back to a reservoir for that fluid at surface or another location by, for example, connecting control lines to the paths42/46/50/52and extending those control lines to the desired destination of the recycled fluid.

Referring toFIG.13, a borehole system60is illustrated. The system60comprises a borehole62in a subsurface formation64. A string66is disposed within the borehole62. The seal tool10with temperature control material as disclosed herein is disposed within or as a part of the string66.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1: A seal includes a seal body and a temperature controller in thermal communication with the seal material.

Embodiment 2: The seal as in any prior embodiment wherein the temperature controller is disposed adjacent the seal material.

Embodiment 3: The seal as in any prior embodiment wherein the temperature controller is embedded in the seal material.

Embodiment 4: The seal as in any prior embodiment wherein the temperature controller is an inductor.

Embodiment 5: The seal as in any prior embodiment wherein the temperature controller is a conductor.

Embodiment 6: The seal as in any prior embodiment wherein the temperature controller is a thermoelectric device.

Embodiment 7: The seal as in any prior embodiment wherein the temperature controller is a Ranque-Hilsch vortex tube.

Embodiment 8: The seal as in any prior embodiment wherein a hot flow path of the vortex tube is directed into thermal communication with the seal material.

Embodiment 9: The seal as in any prior embodiment wherein a cold flow path of the vortex tube is directed into thermal communication with the seal material.

Embodiment 10: The seal as in any prior embodiment further including a plate in contact with the seal material.

Embodiment 11: The seal as in any prior embodiment wherein the plate contains the temperature controller.

Embodiment 12: The seal as in any prior embodiment further including a thermally conductive dopant incorporated into the seal material.

Embodiment 13: A method for controlling temperature of a seal including applying an energy source to the temperature controller as in any prior embodiment, and generating a temperature difference in the temperature controller.

Embodiment 14: The method as in any prior embodiment wherein the applying is applying an electric current.

Embodiment 15: The method as in any prior embodiment wherein the current is alternating current.

Embodiment 16: The method as in any prior embodiment wherein the current is direct current.

Embodiment 17: The method as in any prior embodiment wherein the applying is applying compressed gas.

Embodiment 18: The method as in any prior embodiment wherein the generating is cooling.

Embodiment 19: The method as in any prior embodiment wherein the generating is heating.

Embodiment 20: A borehole system includes a borehole in a subsurface formation, a string in the borehole, and a seal tool as in any prior embodiment, disposed within or as part of the string.

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” includes 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.