Method for Introducing an Inductor Loop Into a Rock Formation

Abstract

An induction device and method for introducing an inductor loop into a rock formation to heating an oil reservoir in the rock formation to extract oil extraction, wherein a first inductor bore is chilled for introducing a first inductor arm, a second inductor bore is drilled for introducing a second inductor arm, at least one intersecting bore is drilled to create a first area of intersection with the first inductor bore and a second area of intersection with the second inductor bore, the first inductor arm is introduced into the first inductor bore and the second inductor arm is introduced into the second inductor bore, and at least one connecting arm is introduced into the intersecting bore for electrically conductive connection to the two inductor arms in the two areas of intersection so as to form the inductor loop.

Claims

1.-10. (canceled)

11. A method for introducing an inductor loop into a rock formation to heat an oil reservoir in the rock formation to extract oil, the method comprising: drilling a first inductor bore for introducing a first inductor arm; drilling a second inductor bore for introducing a second inductor arm; drilling at least one intersecting bore to create a first region of intersection with the first inductor bore and a second region of intersection with the second inductor bore; introducing the first inductor arm into the first inductor bore and the second inductor arm into the second inductor bore; and introducing at least one connecting arm into the intersecting bore for electrically conductive connection to the two inductor arms in the two regions of intersection so as to form the inductor loop.

12. The method as claimed in claim 11, wherein the first inductor bore and the second inductor bore are drilled through a shared inductor bore opening.

13. The method as claimed in claim 11, wherein the inductor bores have at least one redirection point.

14. The method as claimed in claim 11, wherein the intersecting bore has at least one redirection point.

15. The method as claimed in claim 11, wherein a locating means is arranged at a bore end of at least one of the first and second inductor bores to detect said bore end when drilling the intersecting bore.

16. The method as claimed in claim 11, wherein the intersecting bore is closed off.

17. The method as claimed in claim 11, wherein the inductor bores within the oil reservoir are drilled at uniform or essentially uniform separating distances of more than approximately 50 m.

18. The method as claimed in claim 11, further comprising: introducing an electrically conductive fluid into at least one of the two regions of intersection to create the electrically conductive connection of the connecting arm and the adjacent inductor arm.

19. The method as claimed in claim 18, further comprising: introducing at least one transverse bore into the regions of intersection of the intersecting bore to introduce the electrically conductive fluid.

20. The method as claimed in claim 13, wherein the inductor bores have one redirection point

21. The method as claimed in claim 14, wherein the at least one redirection point is drilled sectionally along a curved path.

22. The method as claimed in claim 16, wherein the intersecting bore is filled in adjacent to the at least one connecting arm to closed off said intersecting bore.

23. An induction device for heating an oil reservoir in a rock formation to extract oil, comprising: a first inductor arm in a first inductor bore; a second inductor arm in a second inductor bore; and at least one connecting arm arranged in an intersecting bore which forms regions of intersection with the first and second inductor bores; wherein the connecting arm connects the first and second inductor arms together in an electrically conductive manner.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Further features, advantages and details of the invention are derived from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. In this case, the features cited in the claims and in the description may be essential to the invention either individually or in any desired combination, in which:

[0052] FIG. 1 schematically shows a first step of a method in accordance with the invention;

[0053] FIG. 2 schematically shows a second step of a method in accordance with the invention;

[0054] FIG. 3 schematically shows a third step of a method in accordance with the invention;

[0055] FIG. 4 schematically shows a further embodiment of an induction device in accordance with the invention;

[0056] FIG. 5 schematically shows a representation of the action of a locating means in accordance with the invention;

[0057] FIG. 6 schematically shows a possibility for a region of intersection in accordance with the invention;

[0058] FIG. 7 schematically shows a further possibility for a region of intersection in accordance with the invention;

[0059] FIG. 8 schematically shows a possibility for the use of an electrically conductive fluid in accordance with the invention;

[0060] FIG. 9 schematically shows a geometric arrangement of the individual bores in accordance with the invention;

[0061] FIG. 10 schematically shows a further possibility for the arrangement of the individual bores in accordance with the invention;

[0062] FIG. 11 schematically shows a further possibility for the arrangement of the individual bores in accordance with the invention;

[0063] FIG. 12 schematically shows a further possibility for the arrangement of the individual bores in accordance with the invention; and

[0064] FIG. 13 is a flowchart of the method in accordance with the invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0065] FIGS. 1 to 3 describe a method in accordance with the invention. Two inductor bores 120 and 130 are introduced separately via two inductor bore openings 160, here. After a first vertical course, the two inductor bores 120 and 130 are redirected via a redirection point 170 into horizontal planes at different heights in the oil reservoir 110 in the rock formation 100. In this case, the two inductor bores 120 and 130 are blind holes, each having a bore end 122 and 132. The separating distance A within the oil reservoir 110 is preferably constant and configured so as to be greater than approximately 50 m.

[0066] After drilling the inductor bores 120 and 130, at least one and in this exemplary embodiment exactly one intersecting bore 140 is made. This takes place purely vertically here, because the two inductor bores 120 and 130 are arranged at different heights in a vertically aligned plane. In this case, the intersecting bore 140 creates regions of intersection 150 in the region of the respective bore ends 122 and 132.

[0067] After all of the bores 120, 130 and 140 have been created, the two inductor arms 20 and 30 are introduced into the two inductor bores 120 and 130. A connecting arm 40 is now arranged at the respective bore ends 122 and 132, closing the inductor loop 90 and thereby forming the induction device 10. Here, on the surface of the rock formation 100, it is of course also possible to create a control unit that provides the inductor loop 90 with the corresponding injection of current for the heating process.

[0068] FIG. 4 shows an embodiment that differs from the embodiment shown in FIGS. 1 to 3, in which the two inductor arms 20 and 30 are not at different heights, but extend side-by-side at a separating distance from each other at an identical height within the oil reservoir 110. The intersecting bore 140 must therefore likewise be redirected by a redirection point 170. The other features of this embodiment correspond to the embodiment from FIGS. 1 to 3.

[0069] FIG. 5 illustrates the boring process for the intersecting bore 140. In this embodiment, a locating means 50 that provides signals in, e.g., magnetic or radiative form, is situated at the bore end 122 of the first inductor bore 120. The drill head 200, that creates the intersecting bore 140, has a detection device 210 for receiving these signals. By virtue of this “tracer process”, it is highly probable that a situation as shown in FIG. 6 can be achieved. Here, the region of intersection 150 between the intersecting bore 140 and the inductor bore 120 is formed as an overlapping region of intersection 150. It is now possible to effect a mechanical contact at this point for the electrically conductive connection between the connecting arm 40 and the respective inductor arm 20 or 30.

[0070] FIGS. 7 and 8 show a situation which can be achieved, e.g., without a locating means 50. Here, region of intersection 150 is formed as a convergence or minimal separating distance between the intersecting bore 140 and the inductor bore 120. This minimal separating distance is preferably smaller than or equal to approximately 1 m. Consequently, the rock formation 100 itself can therefore form the electrically conductive connection in this region of intersection 150. In order to ensure that the conductivity is not impeded by rock types having poor electrical conductivity, an electrically conductive fluid 60 can be introduced using transverse bores 142, for example. In this case, electrically conductive liquid can be used, particularly in the form of a suspension of electrically conductive particles.

[0071] FIGS. 9 to 12 illustrate different geometries for the arrangement of the individual bores 120, 130 and 140. FIG. 9 shows an embodiment having radial distribution of three first inductor arms 120 and three second inductor arms 130 in total. In order to connect the respective arms 120 and 130 to form a respective inductor loop 90, provision is made here for an intersecting bore 140 that follows a circular path 152 after the redirection point 170. FIG. 10 illustrates an embodiment in which two inductor arms 120 and 130 spread apart after the redirection point 170. In a similar manner to that shown in FIG. 4, distribution on a shared horizontal plane is possible in this type of configuration. Here, though, a shared inductor bore opening 160 has been used, as in the case of FIGS. 9 and 11, such that the inductor arms 120 and 130 run through a shared bore in the vertical section.

[0072] Returning to FIG. 9, the circular path 152 meets all of the ends of the plurality of inductor arms 120 and 130. However, provision is preferably made for inserting a plurality of connecting arms into the circular path, such that only two adjacent arms of inductor arms 120 and 130 are connected together in each case. The remaining sections of the circular path 152 do not contain any conductive sections. A respective connecting arm is therefore only a segment of a circle, specifically, e.g., a segment of a circle having an angle of approximately 60° in the example according to FIG. 9. Provision is preferably made for three conductive sections to be arranged in the circular path 152 in the example of FIG. 9. Between the conductive sections, the bore of the circular path 152 may remain empty or be filled by a nonconductive section.

[0073] FIG. 11 shows an embodiment in which the inductor arms 120 and 130 are distributed via redirection points 170 over different heights within the rock formation 100. Here, a shared inductor bore opening 160 can be used again. It is even sufficient here to make a single vertical bore as an intersecting bore 140. In the case of particularly far-reaching oil reservoirs 110, it is also possible to use an embodiment as per FIG. 12, which has a dedicated inductor bore opening 160 for each inductor bore 120 and 130, wherein a shared intersecting bore 140 provides the desired connection for the electrical conductivity that is required to close the inductor loops 90.

[0074] With regard to FIGS. 11 and 12, it should be noted that two adjacent inductor arms 120 and 130 are each conductively connected together. To this end, it is preferably possible to introduce a plurality of connecting arms into the intersecting bore 140, such that only two adjacent arms of inductor arms 120 and 130 are connected together in each case. The remaining sections of the intersecting bore 140 contain no conductive sections. A respective connecting arm is therefore merely a tubular conductor of limited length. According to the example in FIG. 11, two conductive sections are arranged in the intersecting bore 140. In FIG. 12, three conductive sections are arranged in the intersecting bore 140, each between a pair of two inductor arms 120, 130. Between the conductive sections, the bore of the intersecting bore 140 may remain empty or be filled by a nonconductive section.

[0075] In particular, the disclosed embodiments of invention have the advantage of making it easy to close a conductor loop that can be operated by a frequency converter during operation. The inductor arms 120, 130 in this case have means which, during operation, generate an electromagnetic field that extends into the oil reservoir and then acts inductively on the oil or on hydrocarbons in the oil reservoir. The electrically closed part of the conductor loop, which consists of the electrically conductive connecting arm in the intersecting bore, does not necessarily include means which generate a distinctive electromagnetic field in a particular manner. Indeed, this is unnecessary because the connecting arm is essentially provided for the purpose of completing the conductor loop. This results in a contiguous conductor loop consisting of two inductor arms 120, 130 and the connecting arm for connecting these two inductor arms 120, 130.

[0076] The foregoing explanation of the embodiments describes the present invention solely in the context of examples. It is naturally possible freely to combine individual features of the embodiments, where technically applicable, without thereby departing from the scope of the present invention.

[0077] FIG. 13 is a flowchart of a method for introducing an inductor loop (90) into a rock formation (100) to heat an oil reservoir (110) in the rock formation (100) to extract oil. The method comprises drilling a first inductor bore (120) for introducing a first inductor arm (20), as indicated in step 1310.

[0078] Next, a second inductor bore (130) is drilled for introducing a second inductor arm (30), as indicated in step 1320.

[0079] At least one intersecting bore (140) is now drilled to create a first region of intersection (150) with the first inductor bore (120) and a second region of intersection (150) with the second inductor bore (130), as indicated in step 1330.

[0080] Next, the first inductor arm (20) is introduced into the first inductor bore (120) and the second inductor arm (30) into the second inductor bore (130), as indicated in step 1340.

[0081] Next, at least one connecting arm (40) is introduced into the intersecting bore (140) for electrically conductive connection to the two inductor arms (20, 30) in the two regions of intersection (150) so as to form the inductor loop (90), as indicated in step 1350.

[0082] Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.