WO2015060246A1 - Bouchon pour un forage de puits - Google Patents

Bouchon pour un forage de puits Download PDF

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Publication number
WO2015060246A1
WO2015060246A1 PCT/JP2014/077831 JP2014077831W WO2015060246A1 WO 2015060246 A1 WO2015060246 A1 WO 2015060246A1 JP 2014077831 W JP2014077831 W JP 2014077831W WO 2015060246 A1 WO2015060246 A1 WO 2015060246A1
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WO
WIPO (PCT)
Prior art keywords
plug
mandrel
well
peripheral surface
outer peripheral
Prior art date
Application number
PCT/JP2014/077831
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English (en)
Japanese (ja)
Inventor
大倉正之
▲高▼橋健夫
Original Assignee
株式会社クレハ
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社クレハ filed Critical 株式会社クレハ
Priority to JP2015543843A priority Critical patent/JP5955469B2/ja
Priority to CA2927080A priority patent/CA2927080C/fr
Priority to US15/028,227 priority patent/US20160237774A1/en
Publication of WO2015060246A1 publication Critical patent/WO2015060246A1/fr

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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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/10—Sealing or packing boreholes or wells in the borehole
    • E21B33/12—Packers; Plugs
    • 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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/10—Sealing or packing boreholes or wells in the borehole
    • E21B33/12—Packers; Plugs
    • E21B33/128—Packers; Plugs with a member expanded radially by axial pressure
    • 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
    • E21B33/00—Sealing or packing boreholes or wells
    • E21B33/10—Sealing or packing boreholes or wells in the borehole
    • E21B33/12—Packers; Plugs
    • E21B33/129—Packers; Plugs with mechanical slips for hooking into the casing
    • E21B33/1291—Packers; Plugs with mechanical slips for hooking into the casing anchor set by wedge or cam in combination with frictional effect, using so-called drag-blocks
    • 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
    • E21B43/26—Methods for stimulating production by forming crevices or fractures

Definitions

  • the present invention relates to a well drilling plug and a well drilling method used in well drilling performed to produce hydrocarbon resources such as oil or natural gas.
  • Hydrocarbon resources such as oil or natural gas have been mined and produced through wells (oil wells or gas wells, sometimes called “wells”) that have porous and permeable underground layers. With the increase in energy consumption, the wells have been deepened, and there are records of excavation exceeding 9000m in the world, and there are also deep wells exceeding 6000m in Japan.
  • the acid treatment and the crushing method are known as a stimulation method (Patent Document 1).
  • Acid treatment increases the permeability of the production layer by injecting a mixture of strong acids such as hydrochloric acid and hydrogen fluoride into the production layer and dissolving the rock reaction components (carbonates, clay minerals, silicates, etc.)
  • strong acids such as hydrochloric acid and hydrogen fluoride
  • rock reaction components carbonates, clay minerals, silicates, etc.
  • various problems associated with the use of strong acids have been pointed out, and an increase in cost has been pointed out including various countermeasures.
  • fracturing method also referred to as “fracturing method” or “hydraulic fracturing method”
  • the hydraulic fracturing method is a method in which a production layer is cracked by a fluid pressure such as water pressure (hereinafter sometimes simply referred to as “water pressure”).
  • a fluid pressure such as water pressure (hereinafter sometimes simply referred to as “water pressure”).
  • water pressure a fluid pressure
  • a vertical hole is excavated, followed by a vertical hole.
  • these well holes which means holes to form wells, sometimes referred to as “down holes”.
  • Fracturing fluid is fed into the tank at a high pressure, and cracks (fractures) are generated by water pressure in deep underground production layers (layers that produce hydrocarbon resources such as oil or natural gas), and hydrocarbon resources are collected through the fractures.
  • It is a production layer stimulation method for.
  • the hydraulic fracturing method has attracted attention for its effectiveness in the development of unconventional resources such as so-called shale oil (oil aged in shale) and shale gas.
  • Cracks (fractures) formed by fluid pressure such as water pressure are immediately closed by formation pressure when water pressure disappears.
  • the propellant is contained in the fracturing fluid (that is, the well treatment fluid used for fracturing), and the proppant is fed into the well hole and the proppant is introduced into the crack (fracture).
  • the proppant to be contained in the fracturing fluid an inorganic or organic material is used.
  • Silica, alumina and other inorganic particles are used, and sand particles such as 20/40 mesh sand are widely used.
  • the well treatment fluid such as fracturing fluid
  • various types of water base, oil base and emulsion are used.
  • the well treatment fluid is required to have a function capable of transporting proppant to a place where fractures are generated in the well hole. Therefore, the well treatment fluid usually has a predetermined viscosity and good dispersibility of proppant. Ease of processing and low environmental impact are required.
  • the fracturing fluid may contain a channelant for the purpose of forming a channel through which shale oil, shale gas, etc. can pass between the proppants. Therefore, in addition to proppant, various additives such as a channelant, a gelling agent, a scale inhibitor, an acid for dissolving rocks, and a friction reducing agent are used in the well treatment fluid.
  • fracturing fluid to create cracks (fractures) due to water pressure in deep underground production layers (layers that produce hydrocarbon resources such as oil or natural gas such as shale gas)
  • the predetermined section is partially blocked while sequentially closing from the tip of the well hole, and the blockage is blocked.
  • Fracturing fluid is fed into the compartment at high pressure to cause cracks in the production layer.
  • fracturing is performed by closing the next predetermined section (usually, a section before the preceding section, that is, a section on the ground side). Thereafter, this process is repeated until the necessary sealing and fracturing are completed.
  • the production layer may be stimulated again by fracturing the desired section of the well hole that has already been formed. In that case as well, operations for blocking and fracturing the well hole may be repeated. Further, in order to finish the well, the well hole may be closed to shut off the fluid from the lower part, and after the upper part is finished, the closing may be released.
  • Patent Documents 2 to 4 disclose blocking of a well hole.
  • well drilling plugs also referred to as “flac plugs”, “bridge plugs” or “packers” that can be fixed are disclosed.
  • Patent Document 2 discloses a downhole plug for well excavation (hereinafter, simply referred to as “plug”), specifically, a mandrel (main body) having a hollow portion in the axial direction, On the outer peripheral surface orthogonal to the axial direction of the mandrel, along the axial direction, a ring or an annular member (annular member), a first conical member (slip) and a slip, elastomer or rubber are formed.
  • a plug comprising a malleable element, a second conical member and slip, and an anti-rotation mechanism.
  • the blocking of the well hole by the downhole plug for well drilling is as follows.
  • the mandrel has a hollow portion in the axial direction, and a well or the like can be sealed by setting a ball or the like on the hollow portion.
  • metal materials aluminum, steel, stainless steel, etc.
  • fibers, wood, composite materials, plastics and the like are widely exemplified, and preferably a composite material containing a reinforcing material such as carbon fiber, in particular, It is described that it is a composite material containing a polymer such as an epoxy resin or a phenol resin, and that the mandrel is formed of aluminum or a composite material.
  • a material that decomposes by temperature, pressure, pH (acid, base) or the like can be used for the ball or the like in addition to the materials described above.
  • Patent Document 3 discloses a packer assembly for well excavation in which each packer is detachably connected to an adjacent packer.
  • a mandrel having a hollow portion in the axial direction, an outer peripheral surface orthogonal to the axial direction of the mandrel, along the axial direction, slip, slip wedge (slip wedge), elastic packer element And a packer with an extrusion limiter and the like.
  • Oil such as shale oil or natural gas such as shale gas (hereinafter collectively referred to as “oil and natural gas” or These may need to be removed when production such as “oil and / or natural gas” is initiated.
  • Plugs are usually not designed to be recovered after removal from clogging, so they can be removed by crushing, drilling or other methods of breaking or breaking into pieces, but crushing, drilling, etc. Needed a lot of money and time. There are also specially designed plugs that can be recovered after use (retrievable plug), but since the plugs are deep underground, recovering all of them requires a lot of money and time. Was.
  • Patent Document 4 discloses a disposable downhole tool (which means a downhole plug or the like) or a member thereof containing a degradable material that decomposes when exposed to an environment in a well.
  • degradable materials degradable polymers such as aliphatic polyesters such as polylactic acid are disclosed.
  • Patent Document 4 discloses a cylindrical body part (tubular body element) having a flow hole in the axial direction and an outer peripheral surface orthogonal to the axial direction of the cylindrical body part along the axial direction.
  • a combination of a packer element assembly consisting of an upper sealing element, a central sealing element and a lower sealing element, and a slip and a mechanical slip body is described. Further, it is disclosed that a flow of only one direction of fluid is allowed by setting a ball in the flow hole of the cylindrical main body part.
  • Patent Document 4 does not disclose whether the downhole tool or its member uses a material containing a degradable material.
  • downhole tools and downhole tool members that are plugs for well excavation are required to have sufficient resistance to high loads that are applied during transfer, maintenance of well closure, and closure during fracturing.
  • a load of about 45 kN (corresponding to about 10,000 pound weight) or more is applied in order to close a well hole and maintain the blockage during fracturing. Therefore, for example, the downhole tool and the downhole tool member which are plugs for well excavation reach a normal temperature of 66 ° C. (corresponding to about 150 ° F.), and in some cases, the temperature may exceed 100 ° C.
  • the downhole tool that is a plug for well excavation or a part or all of the member by disassembling after the completion of fracturing.
  • the well drilling plug is damaged in the environment of the well until the operations associated with fracturing are completed. It must be capable of having no required mechanical properties (tensile properties and / or compressive properties).
  • the problem of the present invention is that the mining conditions such as deepening are becoming more severe and diverse, and the load of the heavy load applied to the bent portion is reduced, so that the transfer in the well is ensured.
  • An object of the present invention is to provide a well drilling plug that can close and fracture a hole, reduce the cost of well drilling, and shorten the process by facilitating removal and securing of a flow path. Furthermore, the subject of this invention is providing the well drilling method which uses this plug for well drilling.
  • a well drilling plug comprising a mandrel and a member attached on an outer peripheral surface perpendicular to the axial direction of the mandrel is transferred within the well.
  • a high stress concentration occurs in the bent portion of the mandrel or the member, and as a result of further research, by controlling the shape of the bent portion in the mandrel or the member.
  • a well drilling plug comprising a mandrel and a member attached on an outer peripheral surface perpendicular to the axial direction of the mandrel, the mandrel or the member At least one A well drilling plug is provided, which is formed of a degradable material and has a curvature radius of 0.5 to 50 mm at a bent portion thereof.
  • At least one member selected from the group consisting of a slip, a wedge, a pair of ring-shaped fixing members, and a ring-shaped rubber member capable of expanding the diameter is attached to the outer peripheral surface orthogonal to the axial direction of the mandrel.
  • the pair of ring-shaped fixing members can fix an expandable ring-shaped rubber member attached on the outer peripheral surface orthogonal to the axial direction of the mandrel in a compressed state
  • Plug for well drilling (4) The well drilling plug according to (2) or (3), wherein a combination of at least one slip and a wedge is placed between a pair of ring-shaped fixing members.
  • the aliphatic polyester is polyglycolic acid.
  • the mandrel formed of a degradable material has a male screw structure on the outer peripheral surface, and one of the pair of ring-shaped fixing members has a female screw structure facing the male screw structure on the inner peripheral surface, and
  • One of the pair of ring-shaped fixing members is a plug for well excavation according to any one of (1) to (18), wherein the plug is fixed so that it cannot slide in the axial direction of the mandrel.
  • a well drilling method is provided in which part or all of a well drilling plug is disassembled.
  • a well drilling plug comprising a mandrel and a member attached on an outer peripheral surface perpendicular to the axial direction of the mandrel, wherein the mandrel or at least one of the members is disassembled.
  • the plug for well drilling is characterized by the fact that it is formed from a conductive material and the curvature radius of the bent part is 0.5 to 50 mm. Under such circumstances, it is possible to reduce the load of a large load applied to the bent portion, reliably perform transfer in the well, close the well hole, and fracturing, and to remove and flow This makes it possible to provide a well drilling plug that can reduce the cost of well drilling and shorten the process.
  • the well drilling method is characterized by the fact that mining conditions such as deepening are becoming increasingly severe and diverse, reducing the load of heavy loads on the bent part, Well drilling that can reduce the cost of well drilling and shorten the process by making it possible to reliably transfer the inside of the well, close the well hole and fracturing, and facilitate the removal and securing of the flow path. An effect is provided that a method is provided.
  • FIG. 1B is a schematic front cross-sectional view showing a state in which the diameter of an annular rubber member capable of expanding the diameter of the well excavation plug of FIG. It is a typical front view of the mandrel which has a flange part.
  • the present invention is a well drilling plug comprising a mandrel and a member mounted on an outer peripheral surface perpendicular to the axial direction of the mandrel, wherein the mandrel or at least one of the members is formed of a degradable material, and Further, the present invention relates to a well excavation plug characterized in that the radius of curvature of the bent portion is 0.5 to 50 mm.
  • a description will be given with reference to FIGS. 1A and 1B.
  • the plug for well excavation of this invention is a plug for well excavation provided with the mandrel and the member attached on the outer peripheral surface orthogonal to the axial direction of a mandrel.
  • the mandrel 1 provided in the plug for well excavation of the present invention is usually also referred to as a “core metal”, has a substantially circular cross section, and is sufficiently long with respect to the diameter of the cross section. It is a member that basically ensures the strength of the well drilling plug.
  • the mandrel 1 provided in the plug for well drilling of the present invention has a cross-sectional diameter appropriately selected according to the size of the well bore (by slightly smaller than the borehole inner diameter,
  • the diameter of the annular rubber member 5 that can be expanded is such that the borehole can be closed by expanding the diameter, etc.).
  • the diameter is, for example, about 5 to 20 times, but is not limited thereto.
  • the diameter of the cross section of the mandrel 1 is in the range of about 5 to 30 cm.
  • the mandrel 1 provided in the plug for well excavation of the present invention may be solid, but from the viewpoint of securing the flow path at the initial stage of fracturing, reducing the weight of the mandrel, controlling the decomposition speed of the mandrel, etc.
  • the hollow mandrel has at least a portion of a hollow portion along the axial direction (that is, the hollow portion may penetrate the mandrel 1 along the axial direction or the mandrel 1 along the axial direction). And may not penetrate.)
  • the mandrel 1 has a hollow portion along the axial direction.
  • the cross-sectional shape of the mandrel 1 defines the diameter (outer diameter) of the mandrel 1 and the outer diameter of the hollow portion (corresponding to the inner diameter of the mandrel 1). It is an annular shape formed by two concentric circles.
  • the ratio of the diameters of the two concentric circles that is, the ratio of the outer diameter of the hollow portion to the diameter of the mandrel 1 is preferably 0.7 or less. Since the size of this ratio is in conflict with the size of the ratio of the thickness of the hollow mandrel 1 to the diameter of the mandrel 1, determining the upper limit of the ratio determines the preferable lower limit of the thickness of the hollow mandrel.
  • the ratio of the outer diameter of the hollow portion to the diameter of the mandrel 1 is more preferably 0.6 or less, and even more preferably 0.5 or less.
  • the diameter of the mandrel 1 and / or the outer diameter of the hollow portion may be uniform along the axial direction of the mandrel 1 or may vary along the axial direction. That is, by changing the outer diameter of the mandrel 1 along the axial direction, a convex part, a step part, a flange part, a concave part (groove part) on the outer peripheral surface of the mandrel 1 and a screw part (usually a male screw structure). Or a bent portion such as a meshing portion of a ratchet mechanism which will be described later.
  • the outer diameter of the hollow portion (the inner diameter of the hollow mandrel 1) changes along the axial direction
  • a convex portion, a step portion, a groove portion, and a screw portion (a male screw structure or a female screw) are formed on the inner peripheral surface of the mandrel 1. It is good also as what has bending parts, such as a structure. Further, the bent portion may have a tapered portion.
  • the convex portion, stepped portion, flange portion and concave portion (groove portion) on the outer peripheral surface and / or inner peripheral surface of the mandrel 1 can also be used as a support part when the well drilling plug is transferred in the well. Moreover, it can also utilize as a site
  • the outer peripheral surface of the mandrel 1 is allowed to move in one direction along the axial direction of the mandrel in cooperation with the inner peripheral surface of the member attached on the outer peripheral surface orthogonal to the axial direction of the mandrel 1.
  • a plurality of meshing portions that restrict movement in the opposite direction may be formed to constitute a ring-shaped ratchet mechanism that is orthogonal to the axial direction of the mandrel.
  • the material forming the mandrel 1 provided in the plug for well excavation of the present invention is not particularly limited, and a material conventionally used as a material forming the mandrel provided in the plug for well excavation may be used. it can.
  • metal materials aluminum, steel, stainless steel, etc.
  • fibers wood, composite materials and resins
  • composite materials containing reinforcing materials such as carbon fibers, particularly epoxy resins.
  • composite materials containing polymers such as phenol resins.
  • the plug for well excavation of the present invention is a plug for well excavation that can reduce the cost of well drilling and shorten the process by facilitating the removal and securing the flow path after fracturing. Therefore, the mandrel 1 is preferably formed from a degradable material.
  • the degradable material may be a biodegradable or hydrolyzable degradable material, or any other method. Degradable materials that can be chemically degraded can be used.
  • a material that is physically decomposed such as broken or collapsed by applying a large mechanical force such as a metal material such as aluminum that has been widely used as a mandrel provided in a well drilling plug, is provided by the present invention.
  • a metal material such as aluminum that has been widely used as a mandrel provided in a well drilling plug
  • This does not correspond to the degradable material forming the mandrel 1 provided in the plug for well drilling.
  • the strength of the original resin is reduced due to a decrease in the degree of polymerization and the like, resulting in brittleness.
  • the material that easily disintegrates and loses its shape corresponds to the degradable material.
  • the mandrel 1 when the mandrel 1 is formed from a degradable material, it is preferably a hydrolyzable material that is decomposed by water at a predetermined temperature or more as described in detail later.
  • the degradable material is more preferably an aliphatic polyester, and further preferably polyglycolic acid (hereinafter sometimes referred to as “PGA”). That is, a well drilling plug in which the mandrel 1 is formed of PGA is desirable.
  • the decomposable material may contain a reinforcing material, or may contain other compounding components.
  • the radius of curvature of the bent portion of the mandrel 1 can be 0.5 to 50 mm.
  • the plug for well drilling according to the present invention is bent under the condition that the radius of curvature of the bent portion in the mandrel 1 is in the above range, so that the mining conditions such as deepening become increasingly severe and diverse.
  • the plug for well excavation of the present invention is a plug for well excavation comprising a mandrel and a member attached on the outer peripheral surface orthogonal to the axial direction of the mandrel. is there. That is, in the well drilling plug, the outer peripheral surface of the mandrel is usually used for the purpose of efficiently and surely transporting the plug, blocking the well hole, and fracturing, and further improving the handling property. Various members are mounted on the top.
  • these various members include a member attached on the outer peripheral surface perpendicular to the axial direction of the mandrel, a member attached on the outer peripheral surface along the axial direction of the mandrel, and other directions along the axial direction of the mandrel.
  • at least one of a mandrel or a member attached to an outer peripheral surface perpendicular to the axial direction of the mandrel (hereinafter, also referred to as “an outer peripheral surface attaching member”) is formed of a degradable material,
  • the radius of curvature of the bent portion may be 0.5 to 50 mm.
  • the plug for well excavation according to the present invention has the above-described characteristics with respect to the mounting member on the outer peripheral surface, so that the mining conditions such as an increase in depth become increasingly severe and diverse, and the plug is applied to the bent portion.
  • Expenses for well drilling by reducing the load of heavy loads, reliably transferring in the well, blocking and fracturing the well, and making it easy to remove and secure the flow path It is a plug for well drilling that can reduce or shorten the process.
  • the mounting member on the outer peripheral surface is not particularly limited as long as it is a member conventionally used in a plug for well excavation, and includes a slip, a wedge, a pair of ring-shaped fixing members, and an annular rubber capable of expanding the diameter.
  • Preferred is at least one selected from the group consisting of members. These members are referred to as members in the sense that they include attachment members for attaching the respective members to the mandrel.
  • slip and wedge Combinations of slips 2a, 2b and wedges 3a, 3b (in FIGS. 1A and 1B, combinations of slip 2a and wedge 3a, and combinations of slip 2b and wedge 3b, combinations of two slips and wedges
  • the combination of the slip and the wedge provided in the well drilling plug may be one or plural.
  • Such plugs are well known per se.
  • slips 2a and 2b formed of a material such as a metal, an inorganic material, and a resin are slidably placed on the upper surfaces of the slopes of wedges 3a and 3b formed of a material such as a resin composite material, and the wedge
  • the slips 2a and 2b ride on the upper surfaces of the slopes of the wedges 3a and 3b and move outwardly perpendicular to the axial direction of the mandrel 1.
  • the outermost peripheral surface orthogonal to the axial direction of the mandrel 1 of the slips 2a and 2b is in contact with the inner wall H of the well hole to fix the plug and the inner wall H of the well hole.
  • the slips 2a and 2b have one or more protrusions on the abutting portion with the inner wall H of the well hole in order to further ensure the blockage (seal) of the space between the plug and the well hole.
  • a bent portion such as a stepped portion, a groove portion, or a rough surface (notched) may be provided.
  • slips 2a and 2b may be divided in advance into a predetermined number in the circumferential direction orthogonal to the axial direction of the mandrel 1, or may be divided into a predetermined number as shown in FIG. Instead, it may have a cut that ends in the middle from one end along the axial direction to the other end.
  • the combination of at least one slip 2a, 2b and wedge 3a, 3b is made up of a pair of ring-shaped fixing members 4a, 4b so that the axial force of the mandrel 1 can be applied to the wedges 3a, 3b. It is preferred to be in between. That is, the pair of ring-shaped fixing members 4a and 4b are configured to be able to slide along the axial direction of the mandrel 1 on the outer peripheral surface of the mandrel 1 and to change the mutual interval. The axial force of the mandrel 1 can be applied to the wedges 3a and 3b by directly or indirectly contacting the end portions along the axial direction of the wedges 3a and 3b.
  • each of the pair of ring-shaped fixing members 4a and 4b are not particularly limited as long as they can fulfill the above-described functions.
  • the axial force of the mandrel 1 is applied to the wedges 3a and 3b.
  • each end surface of the pair of ring-shaped fixing members 4a, 4b on the side in contact with the wedges 3a, 3b is planar.
  • Each ring-shaped fixing member of the pair of ring-shaped fixing members 4a and 4b is preferably an annular member that completely surrounds the outer peripheral surface of the mandrel 1, but may have a cut or a deformed portion in the circumferential direction.
  • a ring having a shape separated in the circumferential direction
  • a ring may be formed if desired.
  • Each of the ring-shaped fixing members of the pair of ring-shaped fixing members 4a and 4b has a wide ring shape (the axial length of the mandrel 1 is large) by placing a plurality of rings adjacent to each other in the axial direction. It can also be a fixing member.
  • the pair of ring-shaped fixing members 4a and 4b may have the same or similar composition, shape, and structure, or may have different compositions, shapes, and structures.
  • each ring-shaped fixing member may have a different length and outer diameter in the axial direction of the mandrel 1.
  • one ring-shaped fixing member of the pair of ring-shaped fixing members 4a and 4b can be configured to be unable to slide with respect to the mandrel 1 as desired.
  • the other ring-shaped fixing member of the pair of ring-shaped fixing members 4a, 4b slides on the outer peripheral surface of the mandrel 1, whereby each of the pair of ring-shaped fixing members 4a, 4b is fixed in a ring shape.
  • the members abut on the end portions along the axial direction of the wedges 3a and 3b, respectively.
  • the configuration in which one ring-shaped fixing member of the pair of ring-shaped fixing members 4a and 4b cannot slide with respect to the mandrel 1 as desired is not particularly limited.
  • the mandrel 1 and one ring-shaped fixing member of the pair of ring-shaped fixing members 4a and 4b are integrally formed (in this case, the ring-shaped fixing member is the mandrel 1).
  • a clutch structure such as a dog clutch or a fitting structure shall be used (in this case, sliding with respect to the mandrel 1)
  • a mandrel formed of a degradable material has a male screw structure on the outer peripheral surface, and one of the pair of ring-shaped fixing members faces the male screw structure.
  • a structure is provided on the inner peripheral surface, and one of the pair of ring-shaped fixing members is fixed in a state where it cannot slide in the axial direction of the mandrel. Door can be.
  • a well drilling plug in which the mandrel 1 and one ring-shaped fixing member of the pair of ring-shaped fixing members 4a and 4b are integrally formed, a well drilling plug formed by integral molding, or A well drilling plug formed by machining is provided.
  • the well excavation plug may include a plurality of pairs of the ring-shaped fixing members 4a and 4b.
  • a combination of the slips 2a, 2b and the wedges 3a, 3b and / or one or more of the diameter-expandable annular rubber members 5 which will be described in detail later are separately or combined to form a plurality of pairs. It can also be placed at a position between the ring-shaped fixing members 4a and 4b.
  • the well excavation plug is on the outer peripheral surface perpendicular to the axial direction of the mandrel 1 and at least one annular rubber member 5 capable of expanding the diameter at a position between the pair of ring-shaped fixing members 4a, 4b.
  • the pair of ring-shaped fixing members 4a and 4b described above fix the annular rubber member 5 whose diameter can be expanded, which is mounted on the outer peripheral surface orthogonal to the axial direction of the mandrel 1, in a compressed state. It can be.
  • the ring-shaped rubber member 5 capable of expanding the diameter transmits the axial force of the mandrel 1 on the outer peripheral surface of the mandrel 1 by directly or indirectly contacting the pair of ring-shaped fixing members 4a and 4b.
  • the mandrel 1 is compressed in the axial direction, and the diameter in the direction orthogonal to the axial direction of the mandrel 1 is increased as the axial distance is reduced (reduced diameter).
  • the annular rubber member 5 is expanded in diameter so that the outer portion in the direction orthogonal to the axial direction contacts the inner wall H of the well hole and the inner portion in the direction orthogonal to the axial direction is the outer periphery of the mandrel 1.
  • the ring-shaped rubber member 5 capable of expanding the diameter is fixed in a compressed state by a pair of ring-shaped fixing members 4a and 4b, and is maintained in contact with the inner wall H of the well hole while fracturing is performed. And has a function of maintaining a seal between the plug and the well hole.
  • the diameter-expandable annular rubber member 5 has the above-described function, there is no limitation on its material, shape and structure.
  • the annular rubber member 5 having a reverse U-shaped cross section in the circumferential direction orthogonal to the axial direction of the mandrel 1 is used, the U-shaped tip portion is compressed in the axial direction of the mandrel 1.
  • the diameter can be increased toward the apex of the inverted U shape.
  • the ring-shaped rubber member 5 capable of expanding the diameter abuts against the inner wall H of the well hole when the diameter is expanded and closes (seal) the space between the plug and the well hole.
  • the axial length of the mandrel 1 is preferably 10 to 70%, more preferably 15 to 65% with respect to the length of the mandrel 1.
  • the well excavation plug of the present invention has a sufficient sealing function and can also function to assist the fixing of the well hole and the plug after sealing.
  • the well drilling plug can be provided with a plurality of annular rubber members 5 that can be expanded in diameter, whereby the space between the plug and the well hole can be closed (sealed) at a plurality of positions.
  • the function of assisting in fixing the well hole and the plug can be more reliably performed.
  • the well drilling plug includes a plurality of annular rubber members 5 capable of expanding the diameter
  • the composition, shape or structure of the plurality of annular rubber members 5 capable of expanding the diameter the position of the mandrel 1 in the axial direction, and a pair of The relative positional relationship with the ring-shaped fixing members 4a and 4b can be selected as appropriate.
  • the ring-shaped rubber member 5 capable of expanding the diameter is required not to lose the sealing function even in contact with a further high pressure or fracturing fluid accompanying fracturing in a high temperature and high pressure environment in a deep underground. Therefore, a rubber material excellent in heat resistance, oil resistance and water resistance is usually preferable, and for example, nitrile rubber, hydrogenated nitrile rubber, acrylic rubber and the like are often used. Further, the ring-shaped rubber member 5 capable of expanding the diameter may be, for example, rubber having a structure formed of a plurality of rubber members such as laminated rubber, or may have a structure in which other members are laminated.
  • the inner wall H of the well hole may be provided with one or more bent portions such as a convex portion, a step portion, a groove portion, and a rough surface (notched).
  • the material forming the outer peripheral surface mounting member provided in the plug for well excavation of the present invention is not particularly limited, and a material conventionally used as a material for forming the member provided in the plug for well excavation is used.
  • a material conventionally used as a material for forming the member provided in the plug for well excavation is used.
  • metal materials aluminum, steel, stainless steel, etc.
  • fibers, wood, composite materials and resins can be mentioned.
  • composite materials containing reinforcing materials such as carbon fibers, particularly epoxy resins.
  • composite materials containing polymers such as phenol resins.
  • the plug for well excavation of the present invention is a plug for well excavation that can reduce the cost of well drilling and shorten the process by facilitating the removal and securing the flow path after fracturing.
  • at least one of the outer peripheral surface mounting members is formed of a degradable material.
  • the degradable material in the plug for well excavation of the present invention, as the degradable material forming at least one of the mounting members on the outer peripheral surface, the degradable material having biodegradability and hydrolyzability as described in the mandrel above.
  • degradable materials that can be chemically decomposed by some other method can be used.
  • the well excavation plug of the present invention when at least one of the outer peripheral surface mounting members is formed from a degradable material, a large load is applied to the bent portion of the outer peripheral surface mounting member formed from the degradable material.
  • the radius of curvature of the bent portion of the mounting member on the outer peripheral surface shall be 0.5 to 50 mm from the viewpoint of reducing the load on the well and reliably carrying out the transfer in the well, blocking the well hole, and fracturing. Can do.
  • the plug for well excavation of the present invention is such that the curvature radius of the bent portion of the mounting member on the outer peripheral surface is in the above range, so that the mining conditions such as deepening are becoming more severe and diverse.
  • the transition portion (where the outer diameter of the mounting member on the outer peripheral surface gradually changes to form the bent portion) becomes longer. In some cases, a bent portion having a desired shape and position cannot be formed.
  • the plug for well excavation provided with the mandrel of the present invention and the outer peripheral surface mounting member has at least one of the mandrel or the outer peripheral surface mounting member formed of a degradable material, and the curvature of the bent portion.
  • the radius is 0.5 to 50 mm.
  • the decomposable material will be described in detail below.
  • the degradable material forming at least one of the mandrel or the outer peripheral mounting member of the present invention is, for example, biodegradable that is degraded by microorganisms in the soil in which the fracturing fluid is used, or in the fracturing fluid
  • it is a hydrolyzable material that decomposes with water at a predetermined temperature or higher.
  • materials that physically break down such as destruction and collapse by applying a large mechanical force such as metal materials such as aluminum, which have been widely used in well drilling plugs, are degradable.
  • metal materials such as aluminum, which have been widely used in well drilling plugs
  • the strength of the original resin decreased due to a decrease in the degree of polymerization, etc., resulting in brittleness.
  • a material that easily collapses and loses its shape by applying an appropriate force corresponds to the degradable material.
  • the decomposable material forming at least one of the mandrel or the outer peripheral surface mounting member of the present invention is required to have a desired strength in a high-temperature and high-pressure environment in a deep underground and at the same time be excellent in decomposability. Therefore, a degradable resin is preferable.
  • the degradable resin means a resin that can be chemically decomposed by biodegradability, hydrolyzability, and other methods as described above.
  • Examples of the degradable resin include aliphatic polyesters such as polylactic acid, polyglycolic acid, poly- ⁇ -caprolactone, and polyvinyl alcohol (such as partially saponified polyvinyl alcohol having a saponification degree of about 80 to 95 mol%).
  • the degradable material is preferably an aliphatic polyester.
  • Decomposable resins can be used alone or in combination of two or more by blending or the like.
  • the mounting member on the outer peripheral surface formed of a decomposable material is an annular rubber member capable of expanding the diameter
  • examples of the decomposable material include aliphatic polyester rubber, polyurethane rubber, natural rubber, polyisoprene.
  • Decomposable rubbers such as acrylic rubber, aliphatic polyester rubber, polyester-based thermoplastic elastomer, and polyamide-based thermoplastic elastomer can be used.
  • the aliphatic polyester includes, for example, homopolymerization or copolymerization of oxycarboxylic acid and / or lactone, esterification reaction of aliphatic dicarboxylic acid and aliphatic diol, aliphatic dicarboxylic acid, aliphatic diol, oxycarboxylic acid and An aliphatic polyester obtained by copolymerization with lactone and / or one that dissolves rapidly in water at a temperature of about 20 to 100 ° C. is preferable.
  • Examples of the oxycarboxylic acid include glycolic acid, lactic acid, malic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxypentanoic acid, hydroxycaproic acid, hydroxyheptanoic acid, hydroxyoctanoic acid, and other aliphatic hydroxycarboxylic acids having 2 to 8 carbon atoms. Is mentioned.
  • Examples of the lactone include lactones having 3 to 10 carbon atoms such as propiolactone, butyrolactone, valerolactone, and ⁇ -caprolactone.
  • aliphatic dicarboxylic acid examples include aliphatic saturated dicarboxylic acids having 2 to 8 carbon atoms such as oxalic acid, malonic acid, succinic acid, glutaric acid and adipic acid, and aliphatic acids having 4 to 8 carbon atoms such as maleic acid and fumaric acid. And unsaturated dicarboxylic acid.
  • Examples of the aliphatic diol include alkylene glycols having 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, butanediol, and hexanediol, and polyalkylene glycols having 2 to 4 carbon atoms such as polyethylene glycol, polypropylene glycol, and polybutylene glycol. Can be mentioned.
  • polyesters can be used alone or in combination of two or more. Moreover, as long as the property as a degradable resin is not lost, it can also be used combining the component which forms polyesters which are aromatic, such as terephthalic acid.
  • aliphatic polyesters that are particularly preferred degradable resins include polycarboxylic acid-based aliphatic polyesters such as polylactic acid (hereinafter sometimes referred to as “PLA”) and PGA; poly- ⁇ -caprolactone (hereinafter referred to as “PCL”). Lactone aliphatic polyesters such as polyethylene succinates and polybutylene succinates; diol / dicarboxylic acid aliphatic polyesters such as polyethylene succinates; copolymers thereof such as glycolic acid / lactic acid copolymers (hereinafter referred to as , "PGLA”), as well as mixtures thereof. Moreover, the aliphatic polyester which combines and uses aromatic components, such as a polyethylene adipate / terephthalate, can also be mentioned.
  • PHA polycarboxylic acid-based aliphatic polyesters
  • PCL poly- ⁇ -caprolactone
  • Lactone aliphatic polyesters such as polyethylene succinates and polybutylene
  • the aliphatic polyester is most preferably at least one selected from the group consisting of PGA, PLA and PGLA, and more preferably PGA.
  • the glycolic acid repeating unit is 50% by mass or more, preferably 75% by mass or more, more preferably 85% by mass or more, and still more preferably 90% by mass or more. It includes 95% by mass or more, most preferably 99% by mass or more, and particularly preferably 99.5% by mass or more of a copolymer.
  • a repeating unit of L-lactic acid or D-lactic acid is 50% by mass or more, preferably 75% by mass or more, more preferably 85% by mass.
  • a stereocomplex polylactic acid including a copolymer having 90% by mass or more, and obtained by mixing poly-L-lactic acid and poly-D-lactic acid may be used.
  • the ratio (mass ratio) of glycolic acid repeating units to lactic acid repeating units is 99: 1 to 1:99, preferably 90:10 to 10:90, more preferably 80:20 to 20:80. Copolymers can be used.
  • melt viscosity As the aliphatic polyester, preferably PGA, PLA or PGLA, those having a melt viscosity of usually 50 to 5000 Pa ⁇ s, preferably 150 to 3000 Pa ⁇ s, more preferably 300 to 1500 Pa ⁇ s can be used. The melt viscosity is measured at a temperature of 240 ° C. and a shear rate of 122 sec-1. If the melt viscosity is too small, the strength required for the mandrel provided in the well drilling plug may be insufficient.
  • melt viscosity is too large, for example, a high melting temperature is required to produce a mandrel, and the aliphatic polyester may be thermally deteriorated or the decomposability may be insufficient.
  • the melt viscosity is about 20 g of sample at a predetermined temperature (240 ° C.) using a capillograph (“Capillograph 1-C” manufactured by Toyo Seiki Seisakusyo Co., Ltd.) equipped with a capillary (diameter 1 mm ⁇ ⁇ length 10 mm). For 5 minutes, and then the measurement is performed under the condition of a shear rate of 122 sec ⁇ 1 .
  • PGA which is a particularly preferred aliphatic polyester, has a weight average molecular weight of 180,000 to 300,000, a temperature of 270 ° C., a shear rate, for example, from the viewpoint of moldability such that cracking is less likely to occur during molding by solidification extrusion molding.
  • PGA having a melt viscosity of 700 to 2000 Pa ⁇ s measured at 122 sec ⁇ 1 is more preferable.
  • PGA having a weight average molecular weight of 190,000 to 240000, a temperature of 270 ° C., and a melt viscosity measured at a shear rate of 122 sec ⁇ 1 is 800 to 1200 Pa ⁇ s.
  • the melt viscosity is measured according to the method described above (the measurement temperature is 270 ° C.).
  • the weight average molecular weight is obtained by dissolving 10 mg of PGA sample in hexafluoroisopropanol (HFIP) in which sodium trifluoroacetate is dissolved at a concentration of 5 mM to 10 mL, and then filtering with a membrane filter. 10 ⁇ l of the sample solution was measured by gel permeation chromatography (GPC) under the following conditions.
  • HFIP hexafluoroisopropanol
  • a degradable material preferably a degradable resin, more preferably an aliphatic polyester, and even more preferably PGA, is a resin material (degradable material is degradable), as long as it does not impair the object of the present invention.
  • a resin other additives such as other resins
  • a stabilizer e.g., a stabilizer
  • a decomposition accelerator or a decomposition inhibitor e.g., a a decomposition inhibitor
  • a reinforcing material may be contained or blended.
  • the degradable material preferably contains a reinforcing material.
  • the degradable material can be referred to as a composite material.
  • the degradable material is a degradable resin, it is a so-called reinforced resin.
  • the mandrel or outer peripheral surface mounting member formed from a reinforced resin is preferably formed from an aliphatic polyester containing a reinforcing material.
  • the reinforcing material As the reinforcing material, it is possible to use a material that has been conventionally used as a reinforcing material such as a resin material for the purpose of improving mechanical strength and heat resistance, such as a fibrous reinforcing material or a granular or powdered reinforcing material. Can be used.
  • the reinforcing material can be contained in an amount of usually 150 parts by mass or less, preferably 10 to 100 parts by mass with respect to 100 parts by mass of a degradable material such as a degradable resin.
  • fibrous reinforcing materials include glass fibers, carbon fibers, asbestos fibers, silica fibers, alumina fibers, zirconia fibers, boron nitride fibers, silicon nitride fibers, boron fibers, potassium titanate fibers, and the like; stainless steel, aluminum Metal fiber materials such as titanium, steel and brass; high melting point organic fiber materials such as aramid fiber, kenaf fiber, polyamide, fluororesin, polyester resin and acrylic resin; and the like.
  • fibrous reinforcing material short fibers having a length of 10 mm or less, more preferably 1 to 6 mm, and further preferably 1.5 to 4 mm are preferable, inorganic fibrous materials are preferably used, and glass fibers are particularly preferable. preferable.
  • Granular or powdery reinforcing materials include mica, silica, talc, alumina, kaolin, calcium sulfate, calcium carbonate, titanium oxide, ferrite, clay, glass powder, zinc oxide, nickel carbonate, iron oxide, quartz powder, magnesium carbonate, Barium sulfate or the like can be used.
  • the reinforcing materials can be used alone or in combination of two or more.
  • the reinforcing material may be treated with a sizing agent or a surface treatment agent as necessary.
  • the mandrel or outer peripheral surface mounting member formed from a degradable material may be formed of a composite material of a degradable material and a metal or an inorganic material.
  • a base material made of a degradable material such as a degradable resin such as PGA is provided with a recess such as a recess having a predetermined shape, and a metal (metal piece or the like) having a shape matching the shape of the recess or Examples include those in which an inorganic substance is inserted and fixed with an adhesive, or a metal piece or an inorganic substance and a base material are wound and fixed so as to maintain a fixed state.
  • the radius of curvature of the bent portion In the well drilling plug including the mandrel of the present invention and the outer peripheral surface mounting member, at least one of the mandrel or the outer peripheral surface mounting member is formed of a degradable material, and the bent portion thereof
  • the curvature radius is 0.5 to 50 mm. That is, the radius of curvature of the bent portion of the mandrel formed from the degradable material or the mounting member on the outer peripheral surface is 0.5 to 50 mm.
  • the radius of curvature of at least one bent portion of the mandrel or the outer peripheral surface mounting member formed from the degradable material will be described in detail.
  • the mandrel provided in the plug for well excavation, or an outer peripheral mounting member such as a slip, a wedge, a pair of ring-shaped fixing members, an annular rubber member capable of expanding the diameter, etc.
  • bent portions such as convex portions, step portions, flange portions, and groove portions are provided. Further, these bent portions allow movement of the mandrel in one direction along the axial direction of the mandrel on the outer peripheral surface of the mandrel and the inner peripheral surface of the mounting member on the outer peripheral surface, and restrict movement in the opposite direction.
  • a ring-shaped ratchet mechanism that forms a plurality of meshing portions and is orthogonal to the axial direction of the mandrel can be configured.
  • the outer peripheral surface mounting member, the mounting member for mounting the outer peripheral surface mounting member to the mandrel, or the mandrel may be provided with a screw portion (male screw structure or female screw structure). Needless to say, there are threads and bent portions of the screw bottom. Therefore, the well excavation plug of the present invention has a mandrel formed from a degradable material or a curvature radius of a bent portion such as a convex portion, a step portion, a flange portion, a groove portion, a screw thread, and a screw bottom in an outer peripheral surface mounting member. Is 0.5 to 50 mm. Further, the mandrel formed of the decomposable material may include a meshing portion of a ratchet mechanism on the outer peripheral surface, and the curvature radius of the meshing portion may be 0.5 to 50 mm.
  • the well excavation plug including the mandrel and the outer peripheral surface mounting member of the present invention allows the mandrel and the outer peripheral surface mounting member to jointly close the well and enable fracturing. Therefore, the mandrel and the mounting member on the outer peripheral surface provided in the plug for well drilling are subjected to a heavy load applied to the bent portion under the increasingly severe and diverse mining conditions such as deepening.
  • the required mechanical properties tensile properties and / or compression
  • a pressure of about several tons is applied to the closed space, and a tension pressure and / or a compression pressure corresponding to a high pressure is applied to the mounting member on the outer peripheral surface.
  • stress concentration occurs at convex portions, stepped portions, groove portions, screw threads and screw bottoms, and bent portions such as flange portions and meshing portions of the ratchet mechanism, and a greater tensile pressure and / or compressive pressure is applied.
  • the well drilling plug of the present invention has at least a part of the mandrel or the outer peripheral surface mounting member. Formed from degradable material. Compared with metal materials such as aluminum, which are conventionally used as materials for forming well drilling plugs, degradable materials such as degradable resins such as aliphatic polyester have mechanical properties under the environment in the wells. Often small. However, in the present invention, since the radius of curvature of the bent portion of the mandrel formed from the degradable material or the mounting member on the outer peripheral surface is 0.5 to 50 mm, it is necessary to prevent damage in the environment of the well.
  • the curvature radius of the bent portion of the mandrel or outer peripheral surface mounting member formed from a degradable material is the minimum in the bent portion when the bent portion is composed of a plurality of curved surfaces having different curvature radii. Means the radius of curvature.
  • the radius of curvature of the bent portion of the mandrel formed from the degradable material or the mounting member on the outer peripheral surface is preferably 1 to 40 mm, more preferably 3 to 36 mm, The range is preferably 5 to 32 mm.
  • the mandrel formed from the degradable material or the mounting member on the outer peripheral surface formed from the degradable material has a plurality of bent portions, all the bent portions
  • the radius of curvature may be 0.5 to 50 mm, but the radius of curvature of the bent portion to which a larger load is applied in the transfer in the well, blockage of the well hole, and fracturing is within the above range. There may be.
  • the bent part of the mandrel formed from the degradable material or the mounting member on the outer peripheral surface is at least selected from the group consisting of a convex part, a step part, a flange part, a meshing part of a ratchet mechanism, a groove part, a screw thread, and a screw bottom.
  • the height of the tapered portion is 1 mm or more, more preferably because the load of a large load may be reduced.
  • the range is 2 to 50 mm, more preferably 3 to 45 mm, and particularly preferably 5 to 40 mm.
  • a taper part means the length in alignment with the mandrel axial direction of the part except the part which has the minimum curvature radius in the bending part in the mandrel formed from a degradable material, or an outer peripheral surface attachment member.
  • FIG. 2 is a schematic view of a specific example of a mandrel having a flange portion (thickness (A): 30 mm) as a bent portion formed from PGA which is a degradable resin.
  • a round bar-like flange part having a large diameter is connected to a round bar-like (pipe-like) mandrel via a taper part having a radius of curvature Rmm and a height Tmm of the taper part.
  • the upper end of the upper round bar is fixed, and a load of 45 kN is applied to the flange portion (corresponding to the tensile force caused by the pressure applied during fracturing).
  • Table 1 shows the results of measuring the tensile stress (unit: MPa) applied to the flange portion while changing the radius of curvature R (unit: mm) and the height T (unit: mm) of the tapered portion.
  • the mandrel having this flange portion can be used in a high-temperature environment at a high depth. It was inferred that the pressure applied to the well drilling plug would not cause damage.
  • the taper part height is 10 or 20 mm. 3 and no. Since the maximum stress applied to the flange portion of 4 is even smaller at 31 MPa or less, the mandrel having this flange portion reliably ensures the pressure received by the well drilling plug even in a higher temperature environment at a higher depth. It was inferred that it could resist.
  • the plug for well excavation of the present invention is a plug for well excavation provided with a mandrel and a mounting member on the outer peripheral surface, and at least one of the mandrel or the member is formed of a degradable material.
  • the well excavation plug is characterized in that the radius of curvature of the bent portion is 0.5 to 50 mm.
  • the well drilling plug of the present invention may further include other members that may be normally provided in a well drilling plug. For example, when the mandrel has a hollow portion along the axial direction, the ball is placed in the hollow portion and controls the flow of fluid (formed from a material such as metal or resin, and may be formed from a degradable material). Can be provided.
  • a well drilling plug mandrel, an outer peripheral mounting member, and a member for coupling or releasing the other member to or from each other member, for example, a rotation stop member, etc. be able to.
  • the plug for well excavation provided with the mandrel of the present invention and the mounting member on the outer peripheral surface may be all made of a degradable material.
  • the plug for well excavation of the present invention applies a mandrel axial force to a pair of ring-shaped fixing members in the axial direction of the mandrel.
  • Directional force is transmitted, and as a result, the diameter-expandable annular rubber member is compressed in the axial direction of the mandrel, and the axial distance is reduced (reduced diameter).
  • the member expands in the direction perpendicular to the axial direction of the mandrel.
  • the annular rubber member expands in diameter so that the outer portion in the direction orthogonal to the axial direction contacts the inner wall of the well hole and the inner portion in the direction orthogonal to the axial direction contacts the outer peripheral surface of the mandrel.
  • the space between the plug and the well hole can be closed (seal) (blocking of the well hole).
  • the slip rides on the upper surface of the slope of the wedge and moves outwardly perpendicular to the axial direction of the mandrel, and the outermost peripheral surface perpendicular to the axial direction of the mandrel of the slip contacts the inner wall of the wellbore.
  • the plug can be fixed in place in the wellbore.
  • fracturing can be performed in a state where the space between the plug and the well hole is closed (sealed).
  • the well drilling plug according to the present invention is usually used after completion of fracturing of predetermined sections, when drilling of the well is completed and the well is completed, and production of oil, natural gas, etc. is started.
  • at least one of a mandrel or an outer peripheral mounting member formed from a degradable material by biodegradation, hydrolysis, or chemical decomposition by some other method is optionally formed from the degradable material.
  • the mandrel can be easily decomposed and removed, and hydrocarbon resources can be mined efficiently.
  • the well drilling plug of the present invention conventionally, after completion of the well, a large number of well drilling plugs left in the well are removed, recovered, crushed, drilled or other methods, Many expenses and time required for destruction or fragmentation are not required, so that the cost of well drilling can be reduced and the process can be shortened.
  • the well drilling plug of the present invention is a well drilling plug including a mandrel and an outer peripheral surface mounting member, and at least one of the mandrel or the member is a degradable material.
  • the manufacturing method is not limited as long as the plug for well excavation, which is formed from the above and has a curvature radius of 0.5 to 50 mm, can be manufactured.
  • each member provided in the plug for well excavation is molded by injection molding, extrusion molding (including solid extrusion molding), centrifugal molding, compression molding, or other known molding methods, and each member obtained is After machining such as cutting or drilling as necessary, a well drilling plug can be obtained by a combination of methods known per se.
  • the well drilling plug of the present invention is a well drilling plug in which a mandrel formed from a degradable material and an outer peripheral surface mounting member formed from a degradable material are integrally formed, injection Formed from a decomposable material and a mandrel formed from a degradable material by integral molding by a molding method such as molding, extrusion molding (including solid extrusion molding), centrifugal molding, or by machining such as cutting. It is preferable to integrally form the mounting member on the outer peripheral surface.
  • the present invention is a well drilling plug comprising a mandrel and a member mounted on an outer peripheral surface perpendicular to the axial direction of the mandrel, wherein the mandrel or at least one of the members is formed of a degradable material, and
  • the well drilling plug is characterized by the curvature radius of the bent part being 0.5-50mm, and the mining conditions such as deepening are becoming increasingly severe and diverse. Therefore, it is possible to reduce the load of a large load applied to the bent portion, reliably transfer in the well, close the well hole and fracture, and facilitate the removal and securing of the flow path. Therefore, it is possible to provide a well drilling plug capable of reducing the cost of well drilling and shortening the process, so that the industrial applicability is high.
  • the present invention provides a well drilling machine wherein a part or all of a well drilling plug is disassembled after performing a well hole sealing process using the well drilling plug.
  • the well drilling method reduces the load of the heavy load on the bent part and makes sure that it is transported in the well well, while the mining conditions are becoming more severe and diverse, such as deepening. It is possible to provide a well drilling method capable of reducing the cost of well drilling and shortening the process by making it possible to close and fracture the well hole and facilitate the removal and securing of the flow path. So the industrial applicability is high.

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Abstract

L'invention concerne un bouchon pour un forage de puits, ledit bouchon comprenant un mandrin et un élément fixé à la face circonférentielle externe qui coupe le mandrin dans la direction axiale, le mandrin et/ou l'élément étant composés d'un matériau dégradable, de préférence de l'acide polyglycolique, et le rayon de courbure d'une partie pliée variant entre 0,5 et 50 mm. L'invention concerne également un procédé de creusement de puits caractérisé en ce que la totalité ou une partie du bouchon pour un forage de puits se dégrade après que le puits de forage est scellé à l'aide du bouchon pour le forage de puits.
PCT/JP2014/077831 2013-10-23 2014-10-20 Bouchon pour un forage de puits WO2015060246A1 (fr)

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JP2015543843A JP5955469B2 (ja) 2013-10-23 2014-10-20 坑井掘削用プラグ
CA2927080A CA2927080C (fr) 2013-10-23 2014-10-20 Bouchon pour un forage de puits
US15/028,227 US20160237774A1 (en) 2013-10-23 2014-10-20 Plug for well drilling

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JP2013220223 2013-10-23

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USRE46028E1 (en) 2003-05-15 2016-06-14 Kureha Corporation Method and apparatus for delayed flow or pressure change in wells
US9708878B2 (en) 2003-05-15 2017-07-18 Kureha Corporation Applications of degradable polymer for delayed mechanical changes in wells
US10280703B2 (en) 2003-05-15 2019-05-07 Kureha Corporation Applications of degradable polymer for delayed mechanical changes in wells
WO2017111159A1 (fr) * 2015-12-25 2017-06-29 株式会社クレハ Matériau profilé pour élément d'outil de fond de puits, élément d'outil de fond de puits, outil de fond de puits
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CA2927080C (fr) 2018-07-10
US20160237774A1 (en) 2016-08-18
CA2927080A1 (fr) 2015-04-30
JPWO2015060246A1 (ja) 2017-03-09

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