Classifications

• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/25—Methods for stimulating production
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/003—Vibrating earth formations
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/028—Electrical or electro-magnetic connections
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
  • E21B17/02—Couplings; joints
  • E21B17/04—Couplings; joints between rod or the like and bit or between rod and rod or the like
  • E21B17/042—Threaded

Definitions

• the present invention belongs to the field of well stimulation.
• well stimulation is meant to generate a shock wave in a natural well or borehole.
• well stimulation can be used to improve the production of an underground resource extraction well (oil, natural gas, water, etc.), to carry out a seismological study (for example by carrying out measurements by means of a surface sensor), to perform underground rock fracturing, etc.
• Such a tool comprises a first electrode and a second electrode, electrically insulated from each other, extending substantially from one end to the other of said tool. Said first and second electrodes of the tool form at one end of said tool a stimulation head.
• the stimulation head generally comprises a chamber for receiving a fluid into which said first and second electrodes open. Examples of embodiments of such a tool are known:
• Patent US4479680 which describes a tool implemented to perform fracturing of underground rock.
• the tool In well stimulation operations, the tool is inserted into said well with the stimulation head down, and is lowered to the point where the stimulation is to be performed. Once the stimulation point is reached, pulses of electric current of high intensity (which may exceed a hundred kilo-amperes) are sent into the first electrode. A current arc is then formed, in the chamber of the head of stimulation, between the first electrode and the second electrode (generally connected to the electrical ground). Said current arc makes it possible to form a shock wave that will stimulate the well. For example, such a shock wave can make it possible to unclog an extraction well.
• Such a tool has a length generally between three and twenty meters, and is also very heavy, of the order of several hundred kilograms.
• such a tool is generally in the form of several sections to be assembled end to end. Each section then comprises a first electrode and a second electrode electrically insulated from each other.
• the first electrode of the tool is thus formed by the connection of the first electrodes of said sections, and the second electrode of the tool is formed by the connection of the second electrodes of said sections.
• the present invention has the main objective of providing a solution that allows a connection of the sections of a tool that is faster and simpler than the solutions of the prior art.
• the present invention also aims to provide a solution that allows, in some embodiments, a mechanical coupling between the sections which is both robust (resistant to a load of several hundred kilograms) and waterproof (resistant at a pressure of the order of several hundred bars at a temperature above one hundred degrees Celsius).
• the present invention also aims to propose a solution that allows, in some embodiments, an electrical coupling that is both robust (resistant to very high voltages - several tens of kilovolts - and very strong currents - several tens of kilo-amperes) and effective in order to limit the losses of electrical energy, the degradation of electrical contacts and electrical rampage by skin effect.
• the invention relates to an electrical device for stimulating a well, said device comprising several sections, said sections being adapted to be assembled end to end so as to form a tool comprising a first electrode formed by first electrodes of said sections and a second electrode formed by second electrodes of said sections, said second electrode being a peripheral electrode electrically isolated from said first electrode, and said first electrode and second electrode of the tool forming at one end of said tool a head stimulation.
• an end of a body of a first section comprises a peripheral ring rotatable relative to said body of said first section and immobile in translation relative to said body of said first section, said peripheral ring having a thread adapted to cooperate with threading the second electrode of an end of a second section to assemble said second section on said first section.
• the second electrode of the first section comprises an extension between the peripheral ring and a termination of the end of said first section. If it is the threading of the second electrode of the second section which is an external thread, then the second electrode of the second section comprises an extension between the threading and a termination of the end of said second section.
• the first section and / or the second section comprise means, called “electrical contact means", adapted to establish an electrical contact between the second electrodes of the first section and the second section at a contact zone of the extension. when the second section is assembled on the first section.
• the assembly of the second section on the first section will also be easier. Indeed, once the threading of the second section engaged with the thread of the peripheral ring, it will be sufficient to achieve the assembly of rotating said peripheral ring while maintaining a body of the second section immobile in rotation with respect to the body of the first section.
• the electrical contact means thus arranged on the first section and / or the second section, protect the bearings, the joints and the threads of the peripheral ring and the second section. Indeed, because of the electric current levels considered, the flow of electric current through the threads could cause seizing or welding of said threads between them.
• the end of the section which carries the external thread must necessarily be engaged in the end of the other section, which is then in the form of a sleeve with an internal thread. Therefore, the extension of the second electrode of the section which carries the external thread is closer to the electrically insulating material, which separates said second electrode from the first electrode than the second electrode from the other section.
• the electric current tends to flow, in the second electrode of the tool, closer to said electrically insulating material. It is therefore understood that, by skin effect, the current will tend to circulate mainly by the electrical contact means, so that the flow of electric current through the threads will be limited.
• the electric well stimulation device comprises one or more of the following characteristics, taken individually or in any technically possible combination.
• the contact zone is a peripheral zone of the extension.
• Such arrangements make it possible to ensure a greater electrical contact surface between the respective second electrodes of the first section and the second section, while maximizing the distance between the electrical contact means and the first electrode.
• the extension comprises a peripheral sealing gasket arranged between the contact zone of said extension and the external thread.
• peripheral seal makes it possible to seal the mechanical coupling, and thus to avoid the formation of current micro-arcs.
• Such an arrangement of the peripheral seal is furthermore advantageous in that it makes it possible to protect said peripheral sealing gasket. Indeed, as has been described for the threads, the electric current, by skin effect, will tend to circulate mainly by the electrical contact means, so that the electric current that could be subjected to said peripheral sealing gasket will be limit.
• the electrical contact means comprise an electrically conductive peripheral seal, a toric spring and / or an electrically conductive foil.
• first section and the second section comprise respective means, called “rotational locking means", adapted to cooperate to immobilize in rotation a body of the second section relative to the body of the first section when the assembling said second section on said first section.
• the means for locking in rotation of at least one section are not geometrically adapted to cooperate with the means for locking in rotation of at least one other section. .
• peripheral ring and / or the body of the first section comprise a recess forming a bearing surface adapted to cooperate with gripping means.
• the recess is in the form of a blind hole or a flat.
• the first section comprises another peripheral ring movable in rotation and immobile in translation relative to the body of said first section, said other peripheral ring comprising a thread adapted to cooperate with a thread of the second electrode of a third section for assembling said third section on said first section.
• FIGS. 1 to 3 views before assembly, after assembly and in half-section after assembly of an electrical device for stimulating wells
• FIGS. 4 and 5 sectional views of a first section and a second section of an electrical device for stimulating wells according to a particular embodiment, before assembly and after assembly,
• FIG. 7 is a sectional view of a first section, a second section and a third section of an electrical stimulation device according to a particular embodiment, after assembly,
• FIG. 8 a sectional view of an alternative embodiment of the electrical stimulation device of Figure 7.
• FIGS 1, 2 and 3 show schematically an electrical device 10 for stimulating wells.
• well stimulation generally means generating a shock wave in a natural well or borehole.
• Such well stimulation can be implemented to improve the production of an underground resource extraction well, to carry out a seismological study, to perform underground rock fracturing, and so on.
• the electrical stimulation device 10 comprises several sections 11 adapted to be assembled end to end.
• FIG. 2 represents said electrical stimulation device 10 after assembly of said sections 11 so as to obtain a tool 10a.
• FIG. 3 schematically represents a half-sectional view of the tool 10a of FIG.
• electrical stimulation device refers to all the sections 1 1, whether assembled or not, while the term “tool” refers to the object obtained by assembling the sections. 1 1. Consequently, all the sections 1 1 assembled together may be indifferently designated in the following description by “electrical stimulation device” or "tool”.
• the tool 10a comprises a first electrode 12 and a second electrode 13. Said first electrode 12 and said second electrode 13 are electrically insulated from each other, throughout the body of the body. 10a tool, by a layer 14 electrically insulating.
• Said first and second electrodes 12, 13 of the tool 10a form at an end of said tool 10a a stimulation head 15, which is considered to be known to those skilled in the art.
• Each section 1 1 comprises for example a portion of the first electrode 12, a portion of the electrically insulating layer 14 and a portion of the second electrode 13 of the tool 10a.
• the second electrode 13 is a peripheral electrode surrounding the electrically insulating layer 14, said electrically insulating layer 14 surrounding the first electrode 12 which constitutes a central core of the tool 10a.
• the tool 10a may comprise other elements that are not 1 to 3.
• one or more sections 1 1 of the tool 10a may each comprise an electric energy accumulator, an electrical protection device, etc.
• the present invention relates to an improvement made to the assembly means of at least two sections of the electrical stimulation device 10, hereinafter referred to respectively as the first section 11a and the second section 11b. It should be noted that this improvement is preferably implemented for the assembly means of all the sections 1 1 of said electrical stimulation device 10.
• one end of the body of the first section 11a has a peripheral ring 16.
• Said peripheral ring 16 is rotatable relative to said body of said first section 11a and is immobile in translation relative to said body of said first section 11a.
• said peripheral ring 16 comprises a thread adapted to cooperate with a thread 133 of one end of a body of the second section 1 1 b to assemble said second section 1 1 b on said first section 1 1 a.
• FIGS. 4 and 5 show schematically sectional views of an exemplary embodiment of the first and second sections 1 1 a, 1 1 b, respectively before assembly and after assembly.
• FIG. 6 schematically represents, in perspective, the first section 11 of FIGS. 4 and 5.
• the threading of the peripheral ring 16 of the first section 11a is an external thread, that is to say a thread arranged on the face of the peripheral ring 16. located on the opposite side to the first electrode 12 forming the central core of said first section 1 1 a.
• the second electrode 13 of the first section 11a has an extension 130 between the peripheral ring 16 and a termination 131 of the end of said first section 11a.
• the peripheral ring 16 is for example made by means of two half-rings 16a, 16b assembled between two peripheral stops 132a, 132b of the second electrode 13 of the first section 11a.
• the two half-rings 16a, 16b are assembled together by any suitable means, for example by means of screws 160. Because the peripheral ring 16 is arranged between the two abutments 132a, 132b of the second electrode 13 of the first section 1 1a, said peripheral ring 16, while being rotatable relative to said second electrode 13 of said first section 1 1a, is immobile in translation relative to said second electrode 13 of said first section 1 1 at.
• the second electrode 13 forms at the end of said second section 1 1 b a sleeve within which the extension 130 of the second electrode 13 of the first section 11 1 can penetrate.
• the threading 133 of the second section 1 1 b, made at said sleeve is an internal thread, that is to say a thread arranged on the face of said sleeve located on the side of the first electrode 12 forming the central core of the second section.
• the internal threading 133 of the second electrode 13 of the second section 11b is adapted to cooperate with the external threading of the peripheral ring 16 of the first section 11a to assemble said second section 11 b on said first section 1 1 a.
• the assembly of the second section 1 1b on the first section 1 1 a is simple to achieve. Indeed, once the thread 133 of the second section 1 1 b engaged with the threading of the peripheral ring 16, it will be sufficient to achieve the assembly to rotate said peripheral ring 16 by keeping the body of the second section 1 1 b stationary in rotation relative to the body of the first section 1 1 a.
• the peripheral ring 16 and / or the body of the first section 11a has a recess forming a bearing surface adapted to cooperate with gripping means.
• the peripheral ring 1 6 and the body of the first section 1 1 a both comprise such recesses, in order to be able to immobilize the body of the first section 1 1 a when the ring is rotated.
• ring 16 device More particularly, the peripheral ring 16 comprises in the example illustrated in Figure 6 blind holes 161, adapted to cooperate with a lug key, and the body of the first section 1 1a has flats 1 January 1. None precludes, according to other examples, to consider other forms of recesses.
• first section 11a and the second section 11b have respective means, called “rotational locking means", adapted to cooperate to immobilize in rotation the body of the second section 1 1b by relative to the body of the first section 1 1 a during the assembly of said second section 1 1 b on said first section 1 1 a.
• rotational locking means adapted to cooperate to immobilize in rotation the body of the second section 1 1b by relative to the body of the first section 1 1 a during the assembly of said second section 1 1 b on said first section 1 1 a.
• rotational locking means further facilitates the assembly of the second section 1 1b on the first section 1 1 a. Indeed, once the rotational locking means of the second section 1 1 b engaged with the rotational locking means of the first section 1 1 a, it is sufficient to achieve the assembly to rotate the ring 16 peripheral to the body first section 1 1 a.
• the rotational locking means are, for the first section 1 1 a, in the form of a key 1 10.
• said locking means in FIG. rotation are for example in the form of a groove (not shown in the figures) in which said key can slide during the assembly of the second section 1 1 b on the first section 1 1 a.
• the end of the second electrode 13 of the second section 11b surrounds the extension 130 of the second electrode 13 of the first section 11a and a portion of the peripheral ring 16 of said first section 11a.
• the electrical contact between the first electrode 12 of the first section 11a and the first electrode 12 of the second section 11b may be established using any suitable means known to those skilled in the art.
• the end of the first electrode 12 of the first section 11 has formed a sleeve 121 adapted to receive an extension 120 of the first electrode 12 of the second section 11b.
• the extension 120 of the first electrode 12 of the second section is devoid of a layer of electrically insulating material, and means are provided inside the sleeve 121 of the first electrode 12 of the first section 1 1 a to establish the electrical contact between the first electrodes.
• the electrical contact means of the sleeve 121 are of the multicontact type, for example a sleeve comprising shape memory, a coil spring or foils.
• the electrical contact between the second electrode 13 of the first section 1 1 a and the second electrode 13 of the second section 1 1 b is for example established via the ring 16 peripheral, the latter being optionally made of electrically material driver.
• the second electrode 13 of the first section 11a comprises means, called “electrical contact means", adapted to establish an electrical contact with the second electrode 13 of the second section at a contact zone of the extension 130 of the second electrode 13 of the first section 1 1 a.
• said electrical contact means are in the form of an electrically conductive peripheral seal 134.
• electrical contact means for example an electrically conductive foil arranged at the periphery of the extension 130 of the second electrode 13 of the first section 1 1 a.
• the electrical contact means could be carried by the second electrode 13 of the second section 1 1 b, or at the same time by the first section 1 1 a and the second section 1 1 b.
• the electric current which by skin effect tends to flow in the second electrode 13 closer to the electrically insulating layer 14, will tend to bypass the ring 16 device.
• the electric current flows from the first electrode 12 of the first section 1 1a to the first electrode 12 of the second section 1 1 b, then flows back from the second electrode 13 of the second section 1 1b to the second electrode 13 of the first section 1 1 a, we see that the shortest path allowing the electric current to pass as close to the electrically insulating layer 14 is to go through the contact zone of the extension 130 of the first section 1 1 a . In doing so, the electric current will tend to bypass the peripheral ring 16.
• the extension 130 of the second electrode 13 of the first section 11a has two joints 135 sealing devices.
• said seals 135 peripheral sealing are arranged between the contact zone of said extension 130 and the peripheral ring 16. In this way, and as indicated above, the electric current will tend to circumvent said seals 135 peripheral sealing, and the risk that they are damaged by the flow of electric current are reduced.
• FIG. 7 schematically represents an alternative embodiment of the first section 1 1 a illustrated by FIGS. 4 to 6.
• said first section 1 1 a (represented with a gray filling in FIG. 7) comprises two peripheral rings. arranged at opposite ends of said first section 11a.
• the first section January 1 has, at an end opposite the end of the peripheral ring 16 described with reference to Figures 4 to 6, another ring 17 device.
• Said peripheral ring 17 is movable in rotation and immobile in translation relative to the body of the first section 1 1 a.
• said peripheral ring 17 comprises a thread adapted to cooperate with a thread of one end of a body of a third section 1 1 c to assemble said third section 1 1 c on said first section 1 1 a.
• the threading of the peripheral ring 17 of the first section 11a is an external thread.
• the second electrode 13 of the first section 11a has an extension 136 between the peripheral ring 17 and a termination 137 of the end of said first section 11a.
• the second electrode 13 forms at the end of said third section 1 1 c a sleeve within which the extension 136 of the second electrode 13 of the first section 1 1 has can penetrate.
• the threading of the third section 1 1c, made on the second electrode at said sleeve is an internal thread, that is to say a thread arranged on the face of said sleeve on the side of the first electrode 12 forming the central core of the third section 1 1 c.
• the internal threading of the second electrode 13 of the third section 1 1c is adapted to cooperate with the external thread of the peripheral ring 17 of the first section 1 1 a to assemble said third section 1 1 c on said first section 1 1 a.
• peripheral ring 16 and the extension 130 can also be applied to the peripheral ring 17 and the extension 136 of the second electrode 13 of the first section 11a.
• the first section 11a is devoid of electrically insulating layer 14 and first electrode 12.
• the electrically insulating layers 14 and the first respective electrodes 12 of the second section 11 b and the third section 1 1 c extend inside the first section 1 1 a, and cooperate therein so as to ensure both the electrical continuity of the first electrode 12 and the electrical insulation between said first electrode 12 of the tool 10a and the second electrode 13 of the first section 1 1 a.
• FIG. 8 schematically represents an alternative embodiment of the first section 11a of FIG. 7, in which the said first section 11a comprises a part of the electrically insulating layer 14 and a portion of the first electrode 12 of the tool 10a.
• the first electrode 12 of the first section 1 1 has formed two opposite sleeves, respectively 121 and 123, adapted to receive respective extensions 120 and 122 of the first electrode of the second section 1 1 b and the first electrode of the third section 1 1 C.
• Such provisions are advantageous in that they allow to have identical ends for the second section 1 1b and the third section 1 1 c, which facilitates their production and their interior layout.
• the electrical stimulation device 10 has been described by considering a peripheral ring 16 having an external thread.
• the peripheral ring 16 is then in the form of a sleeve inside which can penetrate the end of the second section 1 1 b.
• one and / or the other of said two peripheral rings may comprise an internal thread adapted to cooperate with an external thread made on the periphery of the second electrode 1 3 of another section.
• the electrical stimulation device 10 may comprise only two sections 11, but it may also comprise more.
• said electrical stimulation device comprises at least three sections, the means for locking in rotation of at least one section are not geometrically adapted to cooperate with the rotational locking means of at least three sections. another stretch.
• Such arrangements make it possible to use said rotational locking means as polarizers.
• Such a keying function may be advantageous especially in the case where the sections comprise accumulators of electrical energy and / or electrical protection devices.
• the position of the sections relative to each other may be essential, and may be provided by the rotational locking means further providing a keying function.
• the keying function can be obtained by considering different number keys of different sizes, different positions, etc. from one section to another.

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• General Life Sciences & Earth Sciences (AREA)
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• 2012
  • 2012-12-07 FR FR1261804A patent/FR2999221B1/fr not_active Expired - Fee Related
• 2013
  • 2013-12-06 WO PCT/EP2013/075792 patent/WO2014086969A2/fr active Application Filing
  • 2013-12-06 US US14/650,301 patent/US9732601B2/en active Active
  • 2013-12-06 CA CA2895323A patent/CA2895323C/fr active Active
  • 2013-12-06 EP EP13815403.4A patent/EP2929132B1/de active Active

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