FR2864989A1 - DRILLING TOOL WITH RETENTION DEVICE - Google Patents

Abstract

Embodiments of the invention include a lateral coring tool (101) that includes a tool body, a hollow core shaft (803) extendable from the tool body, and a forming cutter ( 805) disposed at a distal end of the hollow core shaft (803). The coring tool comprises a retaining element (802) constituted for example by a piston disposed near a distal end of the internal shaft. An inner sleeve (807) may be disposed within the hollow core shaft (803).

Description

DRILLING TOOL WITH RETENTION DEVICE

  BACKGROUND OF THE INVENTION Wells are, as a rule, drilled in the ground to extract natural deposits of oil and gas, as well as other desirable materials that are trapped in geological formations in the Earth's crust. A well is drilled into the ground and directed to the targeted geological location from a drilling rig on the surface of the earth.

  After reaching a formation of interest, drillers often look for training and its grades by taking examples of rock formation and analyzing rock samples. Typically, a sample is cored from the formation using a core drill, and the sample obtained using this method is generally referred to as carrot. After transporting the core to the surface, it can be analyzed to evaluate, among other things, the storage capacity of the reservoir (porosity) and the flow potential (permeability) of the material that makes up the formation; the chemical and mineral composition of the fluids and mineral deposits contained in the pores of the formation; and the irreducible water content of the formation material. The information obtained from the analysis of a sample is used to design and implement the well and the production facilities.

    Conventional coring, or axial coring, involves the removal of a core from the bottom of the well. Typically, this is achieved after the withdrawal of the drill string or its release from the well, and a rotating core drill with a hollow interior for receiving the core is lowered into the well on the end of the drill string. drilling. Some drill bits include a core drill bit near the center of the bit, and a core can be removed without the need to trigger the drill string. A carrot obtained by conventional coring is taken along the path of the well; that is, the core is taken along the axis of the borehole from the rock below the bit.

  A typical axial core has a diameter of 10 to 15 centimeters (-4 to 6 inches) and a length of up to 30 meters (100 feet). The rotary motion is typically generated at the surface, and the coring ring is driven into the formation by the weight of the drill string that extends to the surface. The core breaks from the formation by simply pulling up on the coring crown that contains the sample.

  In contrast, in a lateral coring, a core is removed from the side wall of a drill hole drilled. Lateral coring is typically performed after removal of the drill string from the borehole. A stem coring tool that includes a coring ring is lowered into the borehole, and a small core is removed from the side wall of the borehole.

  In the lateral coring, the drill string can not be used to rotate the coring crown, nor provide the weight required to drive the crown into the formation. On the contrary, the coring tool must generate both the rotary movement of the coring ring and the axial force necessary to drive the coring ring into the formation.

  In the lateral coring, the available space is limited by the diameter of the borehole. There must be enough space to remove and store a sample. Because of this, a typical side carrot has a diameter of about 2.5 cm (-1 inch) and a length of less than about 5 cm (-2 inches). The small size of the sample does not allow sufficient frictional forces between the coring crown and the core to remove the core by simply removing the coring crown. On the contrary, the coring ring is typically tilted to cause fracture of the core and its breaking formation.

  An additional problem that may be encountered is that, due to the short length of a side core, it may be difficult to retain the core in the coring crown. Thus, a coring ring may also include mechanisms for retaining a core in the coring corona even after fracture or rupture of the sample since formation.

  Lateral coring is advantageous in wells where the exact depth of the target area is not well known. Logging tools, including coring tools, can be lowered into the borehole to evaluate the formations through which the borehole passes. Multiple cores can be sampled at different depths in the borehole so that information can be acquired around formations at different depths.

  FIG. 1 shows an example of a lateral coring tool 101 which is suspended in a borehole 113 by a wire rope 107, as described in US Pat. No. 6,412,575, which is assigned to the assignee of the present invention. A sample may be taken using a coring ring 103 extending from the coring tool 101 into the formation 105. The coring tool 101 may be wedged into the borehole by one or more support arms 111. An example of a commercially available coring tool is further disclosed in US Pat. Nos. 4,714,119 and 5,667,025, both assigned to the assignee of the present invention.

  FIG. 2 represents a perspective view of an existing coring device 201 taking a core 207 from a formation 203. A coring ring 205 is connected to the coring device 201, which may include a motor to extend the crown. 205 and communicate a rotational movement to the coring ring 205. The coring ring 205 extends into the formation 203 and a core 207 is captured in the inside of the coring ring 205. It should be noted that the coring device 201 would typically be disposed in a coring tool (e.g., 101 in FIG. 1) for downhole use. The coring ring 205 would extend from the device 201 and the tool (for example 101 in FIG. 1) and in the formation 203.

  Rotary core tools typically use a cylindrical cored crown with a forming cutter at a distal end of the coring crown. The coring ring is turned and forced against the wall of the borehole. When the core drill enters the formation, the hollow interior of the crown receives the core. A rotating coring ring extends from the tool using a mechanical connecting shaft. The shaft is typically connected to a motor that imparts rotary motion to the coring ring and forces the ring against the wall of the formation. The rotary core tools are generally wedged against the opposite wall of the borehole by a support arm. The cutting edge of the rotating coring ring is usually embedded with tungsten carbide, diamonds or other hard materials for cutting into the formation.

  FIG. 3 shows an example of a conventional rotary core drill 301 that can be used with a lateral coring tool, such as the coring tool 101 of FIG. 1. A similar coring crown is described in US Pat. 371 221 which is assigned to the assignee of the present invention. The coring crown 301 comprises a shaft 303 which has a hollow interior 305. A forming cutter 307 for drilling is located at one end of the shaft 303. When the coring tool 301 enters a formation (not shown) and a core (not shown) can be received in the hollow interior 305 of the crown 301. After receipt of a sample in the hollow interior 305, the core typically comes off the formation by moving or rocking the drilling system. The coring ring 301 is then removed from the formation with the core retained in the hollow interior 305 of the coring ring 301. Other known forming cutters for a rotating coring ring can be used. Examples of such forming cutters are described in co-pending US Patent Application No. 09 / 832,606 assigned to the assignee of the present invention.

  While existing core tools are useful, there is a need for a coring tool that will more effectively ensure that a good core can be recovered for analysis.

  SUMMARY OF THE INVENTION In one or more embodiments, the invention relates to a lateral coring tool that includes a tool body, an expandable hollow core shaft from the body of the tool, a forming cutter. disposed at a distal end of the hollow core shaft, and a retaining member segmented into a plurality of petals and disposed in the hollow core shaft. In some embodiments, the plurality of petals comprises three petals.

  In some embodiments, the invention relates to a method for removing a core that includes extending a coring crown into a formation, receiving the core in an inner sleeve having a segmented retention member in a plurality petals near a distal end of the inner sleeve, and removal of the core coring from the formation.

  In some other embodiments, the invention relates to a lateral coring tool that includes a body of the tool, a hollow core shaft expandable from the body of the tool, a forming cutter disposed at a distal end of the tool hollow core shaft, and an inner sleeve disposed within the hollow core shaft, and at least one retention mechanism selected from the group consisting of a piston and a check valve, wherein the piston is disposed in the inner sleeve and movable relative to the inner sleeve, and the non-return valve is disposed in the inner sleeve.

  In some embodiments, the invention relates to a method for removing a core which comprises extending a coring ring into a formation, receiving the core in an inner sleeve having a piston disposed therein such that so that the piston is movable relative to the inner sleeve, and the removal of the core coring of the formation.

  In some embodiments, the invention relates to a lateral coring tool that includes a body of the tool, a hollow core shaft expandable from the body of the tool, a forming cutter disposed at a distal end of the tool hollow core shaft, and an inner sleeve disposed within the hollow core shaft. The inner sleeve may include a bladder configured to apply radial pressure to a core when the bladder is selectively filled with fluid.

  In some embodiments, the invention relates to a lateral coring tool that includes a tool body, a hollow core shaft expandable from the body of the tool, a forming cutout disposed at a distal end of the tool hollow core shaft, and a resilient retaining member disposed near the distal end of the core tool and having an opening at its center.

  Other aspects and advantages of the invention will emerge more clearly on reading the following description and the appended claims.

Brief Description of the drawings

  Other characteristics and advantages of the invention will emerge more clearly on reading the following description, made with reference to the accompanying drawings, in which: FIG. 1 is a cross-section of a well with a coring tool of FIG. prior art suspended in the well; Figure 2 is a perspective view of a prior art coring device; Figure 3 is a perspective view of a prior art rotary core drill bit; Fig. 4A is a cross section of a coring ring according to an embodiment of the invention; Figure 4B is a cross-section of a core drill according to an embodiment of the invention; Figure 4C is a cross section in accordance with an embodiment of the invention; Fig. 5A is a cross-section of a core drill with a retainer according to an embodiment of the invention; Fig. 5B is a cross-section of a core drill with a retainer according to an embodiment of the invention; Figure 6A is a front view of a core drill retainer according to one embodiment of the invention; Figure 6B is a front view of a coring retaining member in accordance with one embodiment of the invention; Figure 6C is a front view of a coring retaining member in accordance with one embodiment of the invention; Figure 6D is a front view of a coring retaining member in accordance with one embodiment of the invention; Figure 7A is a cross-section of a coring retaining member in accordance with one embodiment of the invention; Fig. 7B is a cross-section of a coring retaining member according to an embodiment of the invention; Fig. 7C is a cross section of a coring retaining member according to an embodiment of the invention; Figure 7D is a cross-section of a coring retaining member in accordance with one embodiment of the invention; Figure 7E is a cross-section of a retaining element of the coring crown and the inner sleeve according to an embodiment of the invention; Figure 8A is a cross section of a coring ring with a piston according to an embodiment of the invention; Fig. 8B is a cross-section of a coring ring with a plunger according to an embodiment of the invention; Figure 9 is a cross-section of a coring ring with a pad according to an embodiment of the invention; Figure 10 is a cross-section of a coring crown with a sample retainer according to an embodiment of the invention.

detailed description

  In some embodiments, the invention relates to a coring ring with a retaining member that retains a core in a coring ring. In other embodiments, the invention includes a plunger or pad that allows a core to be received and retained in a coring tool. In other embodiments, the invention provides methods for retaining a core in a coring tool. The invention will now be described with reference to the accompanying drawings.

  Fig. 4A is a cross-section of a core ring 401 with a retainer element 411 according to an embodiment of the invention. Figure 4A shows only the coring crown 401, but it will be understood by those skilled in the art that the coring crown 401 is an integral part of a coring tool (not shown) which is used to collect cores from a formation. For example, the coring bit may be an integral part of a coring tool, such as the coring tool 101 in FIG.

  The coring crown 401 in FIG. 4A comprises a hollow shaft 403 with a forming cutter 405 disposed at a distal end of the shaft 403. The forming cutter 405, a forming cutter, is formed by a material for drilling in 402. The forming cutter 405 may be formed of a strong material which is covered with an extra hard material, such as polycrystalline diamond or tungsten carbide. In other embodiments, the forming cutter 405 may include other cutting devices through the soft formation, such as brushes. The term distal end is used to describe the end of the coring crown 401 that first comes into contact with the formation. The distal end is the end of the shaft 403 that is farthest from the center of the core tool (not shown) during core removal. This is the first part of the coring crown 401 to enter a formation.

  As shown in FIG. 4A, a core ring 401 may comprise an inner sleeve 407 which is disposed inside the hollow shaft 403. The inner sleeve 407 serves to receive a core (not shown in FIG. 4A) when It enters the coring crown 401. In some embodiments, the inner sleeve 407 is a non-rotating inner sleeve. A non-rotating inner sleeve is an inner sleeve which is free to rotate independently of the hollow shaft 403. Thus, when the core tool enters a formation 402, the friction between the inner sleeve and the core (e.g. Figures 4B and 4C) prevent the inner sleeve from rotating relative to the formation 402. In some other embodiments, a mechanical stop, such as a key (not shown) may prevent rotation of the inner sleeve. This reduces erosion of the core by eliminating friction between the core and the inner sleeve during sampling. Examples of coring sleeves are described in Co-pending US Patent Application No. 10 / 248,475, assigned to the assignee of the present invention.

  A retainer 411 is disposed at the distal end of the inner sleeve 407. The retainer 411, as will be seen, allows a core to enter the core ring 401 and the inner sleeve 407, and also retains the core 410 in the inner sleeve 407 after receiving the core 410 in the coring crown 401.

  Figure 4B shows a cross-section of a coring crown 401 in the process of receiving a core 410. When the forming cutter 405 enters the formation 402, a core 410 enters the coring crown 401.

  When the core 410 enters the inner sleeve 407, it spreads the petals 411a, 411b of the retainer 411 so that the core 410 can enter the coring crown 401. When the petals 411a, 411b move, they apply a radially inward force on the core 410 which serves to guide the core 410 and hold it in place.

  Figure 4C shows a cross-section of a core ring 401 which has received a core 410 in the inner sleeve 407 disposed within the hollow shaft 403 of the core ring 401.

  The core 410 is retained in the coring crown 401 by the petals 411a, 411b of the retainer (411 in Fig. 4A) in at least two ways. First, the petals 411a, 411b press inward on the core 410 to stabilize it and hold it in place. Secondly, when the core 401 retracts from the formation 402, the petals 411a, 411b will tend to close and grab the core 410. In the hard rock, the additional friction between the core 410 and the petals 411a, 411b will act as a bevel gripping member which retains the core 410 in the coring crown 401.

  In soft rock, the petals 411a, 411b can completely close and trap the core 410 in the coring crown 401. This may be advantageous because of the tendency of soft or soft formations to fall out of the coring crown. Rather than losing 1-1.3 cm (-3/4 inch to 1 inch) of the core of a loose formation, the petals 411a, 411b can close to retain carrot 410 in the corona. 401. The only carrot 410 that is lost is that part of the core that extends after the petals 511a, 511b. In some embodiments, the petals are about 0.6 cm (-1/4 inch) long, and about 0.6 cm (-1/4 inch) of core is lost in the petal closure. This helps in grasping and retaining soft forming cores that may simply fall out of the coring corona when the sample is taken using the conventional core drill.

  The retainer 411 shown in Figures 4A, 4B and 4C is preferably made of rubber, although it can be made of any material that is flexible and still has a memory. A material with a memory will remember its original position so that it will tend to return to its original position each time it has moved. In some embodiments, the material remains in the elastic deformation regime when it has been completely displaced by the core. Thus, when the petals of a retainer are pushed radially outward by a core, the petals are flexible enough to move away so that the core can easily enter the coring crown, but they also tendency to push radially inward to their original position. This tendency to return to the original position is that it creates the radial pressure against the core that will guide it into the coring crown and retain it during removal of the coring core from the formation.

  In some embodiments, a retainer may not be attached to a distal end of an inner sleeve. For example, FIG. 5A shows a core ring 501 with an inner sleeve 507 disposed within a hollow core shaft 503. A forming cutter 505 is disposed at the distal end of the hollow core shaft 503. The retaining member 511 is located near the midpoint along the axial length of the inner sleeve 507. In this position, a retaining member 511 provides guidance for a core (not shown) to be maintained near the axial center of the inner sleeve 507, while still providing the ability to retain the core in the coring ring 501 when the ring is removed from the formation (not shown). For example, in a hard formation, the retainer 511 may act as a beveled grip which retains the core (not shown) in the core 501.

  Figure 5B shows another embodiment of a coring ring with a retaining member 521 according to the invention. The core ring 521 includes a hollow core shaft 523 with a forming cutter 525 at the distal end. A retainer 531 is held in the central opening of the forming cutter by a ring 533 in the forming cutter. In this position, the retainer 531 may allow a core (not shown) to penetrate the core ring 521, and may also retain the core in the core 521 after receipt of the sample.

  It should be noted that a core drill according to the invention can have various combinations of described features. For example, it may comprise a retaining element located as shown in Figure 5A, but without an inner sleeve. In another example, a core ring may comprise a ring (e.g., ring 533 in FIG. 5B) that is not disposed near the distal end of the core ring. Those skilled in the art can imagine other embodiments of a coring crown that do not deviate from the scope of the invention.

  Fig. 6A shows a side view of a retainer 601 according to an embodiment of the invention. The retainer 601 has three petals 602a, 602b, 602c which are cut from the center of the retainer 601 to an outer petal circumference 605. In some embodiments, the petal circumference 605 is essentially the same size as the inside diameter of the forming cutter (for example, 505 in FIGS. 5A, 5B and 5C). This allows the core to fit well through the retainer. In other embodiments, the petal circumference 605 may be larger than the inside diameter of the forming cutter (e.g., 505 in FIGS. 5A, 5B and 5C).

  The petals 602a, 602b, 602c shown in Figure 6A are located adjacent one another. That is, the edges of a petal, 602a for example, are adjacent to the ridges of the other petals, 602b, 602c, for example.

  In some embodiments, a retainer 601 includes slots or perforations 607. The slots 607 provide additional flexibility to the petals 602a, 602b, 602c when the retainer 601 is constructed from a rigid material or when there are only a small number of petals hardening each petal.

  Figure 6B shows an embodiment of a retainer 621 with the petals 622a, 622b, 622c which are not adjacent to each other. In this embodiment, the petals 622a, 622b, 622c are separated from each other by returning to the petal circumference 625.

  Figure 6C shows another embodiment of a retainer 631 according to the invention. Petals 637, 638, 639 overlap one another. For example, petal 637 has edge 637a that overlaps with edge 639b of petal 639. The other edge 637b of petal 637 is overlapped by edge 638a of petal 638. Similarly, petal 639 has the ridge 639a which overlaps ridge 638b of petal 638.

  Figure 6D shows another embodiment of a retainer 641 according to the invention. The retainer includes an aperture 646 at its center. Opening 646 is created because retaining member 641 extends inward only to an opening circumference 647. A core (not shown) can clear a path through opening 646 by moving the element The resilience of the retainer 641 will cause the retainer 641 to exert an inward force on the core when received.

  Figure 6D also shows other optional features of a retainer.

  For example, a retainer 641 with an opening 646 can not have petals. A carrot can simply move a solid retainer.

  In other embodiments, such as that illustrated in Figure 6D, the retainer 641 may include one or more petals 642a, 642b, 642c. The petals 642a, 642b, 642c may be individual petals, or the petals 642a, 642b, 642c may be perforated by perforations 643 extending between the opening circumference 647 to the petal circumference 645. Where carrot (not shown) is taken, the core will break the perforations 643, and the core can be received in the coring crown (not shown).

  In fact, it should be noted that the multitude of the above-described embodiments of a retainer may utilize radial perforations to segment the petal retainer. This would allow the retainer to serve as a cover that would prevent contaminants from entering the core before sampling and rupture of the perforations.

  It should be noted that the radial perforations are distinguished from the circumferential perforations that can be used to increase the flexibility of the retainer.

  Figs. 7A-7E show various embodiments of a retainer for use with a core drill according to the invention. Figure 7A shows a retaining member 711 with petals 711a, 711b which are bevelled inwardly. The petals 711a, 711b have a petal circumference that is essentially the same as the inner diameter of the forming cutter 705. A core will pass well through the petals 711a, 711b of the retainer 711.

  Figure 7B shows another embodiment of a retainer 721 where the petals 721a, 721b are bevelled outwardly. In this embodiment, when the petals 721a, 721b are displaced by a core (not shown), the pressure applied by the petals 721a, 721b will be slightly greater because they are moved further away from their original position.

  Figure 7C shows another embodiment of a retainer 731 according to the invention. The petals 731a, 731b of the retainer 731 are rounded and extruded into the inner sleeve 707. When a core (not shown) is received in the inner sleeve 707, the petals 731a, 731b will be moved inwardly. .

  Figure 7D shows another embodiment of a retainer 741 according to the invention. The petals 741a, 741b of the retainer 741 are rounded and extruded outwardly from the inner sleeve 707. When a core (not shown) is received in the inner sleeve 707, the petals 741a, 741b are going to be moved inward.

  Fig. 7E shows an embodiment of a retainer 751 that is similar to that shown in Fig. 7B. In Fig. 7E, the inner sleeve 757 has a notch 753 which provides space for the petals 751a, 751b in their displaced position. The inner diameter D2 of the inner sleeve 757 in the notch 753 is larger than the nominal diameter D1 of the inner sleeve 757. In the illustrated embodiment, the nominal diameter D1 of the inner sleeve 757 is substantially the same as the inner diameter of 705. When a core (not shown) passes into the inner sleeve 757, the petals 751a, 751b of the retainer 751 will be moved into the notch 753. The petals 751a, 751b, when they are moved in the notch 753, have essentially the same diameter as the nominal diameter D1 of the inner sleeve 757. This allows the core 701 to fit well at all points along the axis of the inner sleeve 757 , while still obtaining the advantages of a retainer according to the embodiments of the invention.

  The embodiment of an inner sleeve 757 shown in Figure 7E may be used with various embodiments of a retainer. For example, an inner sleeve 757 with a notch 753 may be used with any of the embodiments of a retainer shown in Figures 7A-7E.

  A retainer in accordance with any of the embodiments of the invention may be specifically designed for one use only, or it may be designed to capture and retain multiple cores. For example, some coring rings are designed so that the cores are stored in the inner sleeve.

  That is, the inner sleeve moves from the inside of the core ring into a storage area. In other embodiments, only the core moves in a storage device, and the inner sleeve is used to grasp another sample.

  As will be understood by those skilled in the art, Figs. 7A-7E show a cross-section of particular embodiments of a core drill and a retainer in accordance with the invention. As such, the figures represent only two petals in each embodiment. This is simply a function of a cross section, and this should not limit the invention. A retainer according to the invention may have any number of petals. Optionally, the retainer may be uniform, solid, tapered, or have one or more openings therethrough. Other configurations may be provided. The retainer may be adapted to tear and / or stretch as the core advances into the sleeve. The portions of the retainer that are stretched or torn may apply force to the core to grip the core. The retainer is preferably resilient so that it can retract substantially to its original configuration and close behind the core, thereby preventing portions of the core from emerging from the core sleeve.

  Figure 8A shows a cross-section of a coring ring 800 with an inner sleeve 807 having a piston 802 according to the invention. The piston 802 is axially movable relative to the inner sleeve 807. The piston 802 is initially positioned near the distal end of the inner sleeve 807. When a core is removed from the formation 810, the core will move the piston 802 by relative to the inner sleeve 807. The piston 802 may also include sealing devices 812 or bearings to allow easier movement of the piston 802 within the inner sleeve 807.

  In the illustrated embodiment, the inner sleeve 807 has a diameter that is substantially the same as the inner diameter of the forming cutter 805. In order to fit with the inner sleeve 807, the piston 802 has a diameter that is substantially the same as the inside diameter of the inner sleeve 807 so that the sealing devices of the piston 812 can form a barrier between the inner sleeve 807 and the piston 802.

  Fig. 8B shows a cross-section of the core ring 800 with a core 801 received within the core ring 800. The core 801 has moved the piston 802 to a position near the proximal end of the inner sleeve 807. The piston 802 moves when the core 801 is received in the coring ring 800. Thus, the piston 802 provides a support for the core 801. This can be advantageous in the soft formations, where the core of the formation s' would collapse when it enters the coring crown. The piston 802 can prevent the formation from collapsing.

  In addition, when the core ring 800 is removed from the formation 810, the piston 802 helps to hold the core in the inner sleeve 807. In some embodiments, the chamber 815 behind the piston 802 includes a check valve or other means (not shown) to allow air or fluid to be discharged from the chamber 815, but this will not allow reverse flow. Thus, a vacuum behind the piston 802 will prevent the piston 802 from going in the outer direction.

  In some embodiments, the chamber 815 behind the piston is completely ventilated. Nevertheless, the core 801 may not be able to move out of the inner sleeve 807 without also moving the piston 802. This may be caused by a vacuum created between the piston 802 and the core 801.

  The friction between the piston 802 and the inner sleeve 807 will create additional resistance to the movement of the core 801, which will help retain the core 801 in the coring crown 800.

  In addition, in addition to a simple piston 802, the inner sleeve 807 may also include a ratchet device or a locking device. Such a device would prevent the piston from going in the outer direction.

  Fig. 9 shows a cross-section of a coring ring 900 which comprises a pad for receiving and retaining the core 901 in the ring 900. A hollow outer shaft 903 enters a formation 910 using a forming cutter 905 disposed at the distal end of the shaft 903. A core 901 is received in an inner sleeve 917 which is disposed within the hollow shaft 903.

  The cavity (shown at 918) in the inner sleeve 917 behind the core 901 is filled with a fluid, such as water. The proximal end of the inner sleeve 917 includes a valve 921 for selectively allowing the fluid to pass between the sleeve 917 and the remainder of the tool. The valve 921 may be, for example, a check valve which allows the fluid to exit the cavity 918 when a core 901 moves in the inner sleeve 917. When the core ring 900 is removed from the formation, the valve 921 can be used to prevent the reverse flow of fluid in the cavity 918, and a vacuum is created behind the core 901 which holds the core 901 in the coring ring 900.

  In at least one embodiment, check valve 921 in FIG. 9 may be combined with core ring 800 in FIGS. 8A and 8B.

  In such an embodiment, the piston (802 in Figs. 8A and 8B) would force fluid through the check valve (921 in Fig. 9). The check valve (921 in Fig. 9) would prevent the reverse flow of fluid and vacuum behind the piston (802 in Figs. 8A and 8B) and thereby retain the core of the piston in place.

  Figure 10 shows a cross section of a coring ring 1001 according to another embodiment of the invention. A hollow shaft 1003 has a forming cutter 1005 at a distal end of the shaft 1003. A bladder 1007 is used as an inner sleeve in the core ring 1001 in Fig. 10. The bladder 1007, when deflated, provides enough space to accept a carrot. The bladder 1007 can then be inflated effectively by filling it with fluid. The fluid may be stored hydraulic fluid, or it may be drilling mud that is pumped into the bladder. The type of fluid used should not limit the invention.

  When the bladder 1007 is filled, it will compress inwardly and exert radial pressure on a core (not shown). The pressure will apply an overload on the carrot which will both stabilize and retain the carrot.

  Embodiments of the invention may have one or more of the following advantages. A coring crown with a retainer or other retainer in accordance with the invention will retain the core in the coring cored during removal of the core ring from the formation. This will prevent damage or loss of the core during this process.

  Advantageously, a coring ring may comprise a retaining element which will close completely when a sample is gripped in a soft or loose formation. When the retainer closes, the core will be completely enclosed in the coring crown and protected against further damage and loss.

  Advantageously, a coring ring that includes a non-rotating inner sleeve will not degrade the core through the friction between the core and the inner sleeve and the retainer. The inner sleeve and the retainer will not rotate relative to the formation and the core when grasped.

  Advantageously, embodiments of the invention that include a piston in the inner sleeve provide guiding of a core when received. The piston is moved by the core, and after complete reception of the core, the piston creates a vacuum behind the core which holds the core in the inner sleeve when the core is removed from the formation.

  Advantageously, embodiments of the invention that include a pad provide constant guidance to the core as it enters the core ring. After receiving it in the coring crown, the carrot is retained by a vacuum behind the core.

  While the invention has been described with respect to a limited number of embodiments, one skilled in the art having benefited from this description will note that other embodiments may be contemplated which do not depart from the present invention. scope of the invention as described herein. Accordingly, the scope of the invention would be limited only by the appended claims.

Claims (11)

  1. lateral coring tool (101), characterized in that it comprises: a body of the tool; a hollow core shaft (803) extendable from the body of the tool; a forming cutter (805) disposed at a distal end of the hollow core shaft; and an inner sleeve (807) disposed within the hollow core shaft.   The lateral coring tool (101) according to claim 1, characterized in that the inner sleeve comprises a bladder (1007) configured to apply radial pressure to a core when the bladder (1007) is selectively filled with a fluid.   The lateral coring tool (101) according to claim 1, characterized in that it further comprises at least one retaining mechanism selected from the group consisting of a piston (802) and a non-return valve, wherein the piston (802) is disposed in the inner sleeve (807) and movable relative to the inner sleeve (807), and the check valve is disposed in the inner sleeve (807).   4. Lateral coring tool (101) according to claim 3, characterized in that at least the retaining mechanism is the piston (802).   5. Lateral coring tool (101) according to claim 4, characterized in that it further comprises a sealing device disposed between the piston (802) and the inner sleeve (807).   The coring tool (101) according to claim 4, characterized in that an inner diameter of the inner sleeve (807) is substantially the same as the inner diameter of the forming cutter (805).   The lateral coring tool (101) according to claim 4, characterized in that it further comprises a check valve operably connected to the inner sleeve (807).   8. Lateral coring tool (101) according to claim 1, characterized in that it further comprises a resilient retaining element (100) disposed near a distal end of the coring tool and having an opening thereon. its center.   9. The lateral coring tool (101) according to claim 1, 3 or 8, characterized in that it further comprises a petal segmented retaining element (411) disposed near an opening at a distal end of the sleeve. internal.   10. A method of sampling a core, characterized in that it comprises: extending a coring ring (800) in a formation (810); receiving the core in an inner sleeve (807) having a piston (802) disposed therein so that the piston is movable relative to the inner sleeve; and removing the coring corona from the formation.   11. The method of claim 10, characterized in that it further comprises the selective filling of a bladder (1007) with a fluid in order to apply a radial pressure on the core.