Collecting unit for drilling cuttings

Abstract

The invention relates to a cuttings collector for obtaining cuttings from a subterranean wellbore, comprising at least: a) a cuttings collector rod provided with a double helix tool serving as a transfer screw having two conveying paths, b) an outer wall surrounding one of the two conveying paths, and a lower wall surrounding the other of the two conveying paths, c) the upper end of the drill cuttings collector rod is provided with a top sleeve having an opening and closing arrangement such that the collected drill cuttings can be directed into the desired conveying path.

Description

Technical Field

[0001] The present invention relates to removing drill cuttings during drilling operations and, more particularly, to a system and cuttings collector for collecting drill cuttings for analysis. Background Art

[0002] The present invention relates to a system for collecting drill cuttings for analysis. The drill cuttings consist mainly of fine particles and can provide valuable information about the rock when analyzed. The drill cuttings are transported out of the borehole along with the drilling fluid / mud.

[0003] In the analysis of drill cuttings, the mining industry needs to determine exactly where the cuttings were extracted. This will provide a better basis for decisions regarding the specification of the amount of explosives to be used, as well as production planning. Currently there is no precise method for determining the extraction location of a particular drill cutting sample. Drill cuttings are collected after drilling.

[0004] Norwegian patent application No. 20171943 (corresponding to US Pat. No. 2020 / 0300049A1) discloses a downhole tool for cleaning a well, the downhole tool comprising a rotatable device for taking out and removing material from the well. The downhole tool also comprises a storage portion for the removed material and a drive device for rotating the device for removing and removing material.

[0005] Patent US 2,557,925 discloses a universal sampler for extracting samples from a drill hole, the sampler comprising a drill bit and a conveying screw for conveying drill cuttings from the drill bit to the inner hole 34. The sample will fill the space between the conveying screw and the side wall surrounding the conveying screw.

[0006] The object of the present invention is to provide a unit for collecting drill cuttings to solve the problem of accurately obtaining data from a drill hole. Summary of the invention

[0007] According to the present invention, the above mentioned problems are solved by providing a cuttings collector which may form a replaceable part of a drill string used in drilling operations.

[0008] Specifically, the present invention provides a cuttings collector for obtaining cuttings from an underground wellbore, the cuttings collector comprising at least:

[0009] a. a cuttings collector bar provided with a first cutter and a second cutter, the first cutter and the second cutter together forming a double helical cutter, the double helical cutter serving as a conveying screw having a first conveying path and a second conveying path,

[0010] b. an outer wall extending between the first tool and the second tool over the entire length of the two tools so as to form an outer wall of the first conveying path,

[0011] c. the conveying path having an outer wall extending between the first tool and the second tool is provided with a lower wall which closes the first conveying path at its lower end,

[0012] d. the cuttings collector bar is provided at an upper end with a top sleeve having an open and closed arrangement, the top sleeve opening a first conveying path in a first position and the top sleeve closing the first conveying path in a second position, the first conveying path forming a cuttings collector chamber closed at the upper and lower ends when the top sleeve is in the closed position,

[0013] e. the outer wall of the cuttings collector chamber is provided with one or more filters for draining liquid from the cuttings collected in the cuttings collector chamber when the top sleeve is in the first position, and

[0014] f. An internal drilling mud passage extending along the entire axial length of the cuttings collector.

[0015] The second position of the top sleeve may provide an opening to the second conveying path so that drill cuttings may be discharged along the second conveying path.

[0016] The top sleeve may comprise a fixed portion having an opening and a rotatable portion which is rotatable about the cuttings collector rod, the rotation being achieved by engagement of a gear edge with a pinion driven by the drive means.

[0017] The top sleeve may also include a rotatable top sleeve having an opening, which can be rotated around the drill cuttings collector rod, and the drill cuttings collector chamber may be provided with an opening at the upper section, which is shaped and sized to match the opening of the optionally rotatable top sleeve, so that when the opening in the top sleeve is aligned with the opening in the drill cuttings collector chamber, the top sleeve is in a first position and drill cuttings can be collected in the drill cuttings chamber.

[0018] The upper end of the cuttings collector rod may be provided with a threaded tool joint pin of length l1 or h1 configured for engagement with a drill bit.

[0019] The cuttings collector may also include a wear ring that can be mounted around the upper threaded tool joint pin of the cuttings collector rod. The wear ring may have a maximum diameter OD that is greater than the diameter of the top sleeve and the cuttings collector rod. In a variation of the invention, the wear ring may provide a sliding surface for the top sleeve and the diameter of the wear ring corresponds to the maximum diameter of the cuttings collector.

[0020] The cuttings collector may also include one of the following:

[0021] a. Lower tool joint box, and

[0022] b. Lower threaded tool connector pin.

[0023] According to one aspect of the invention, the cuttings collector may be configured to form a replaceable component of a drill string.

[0024] The present invention also provides a method for obtaining drill cuttings from an underground wellbore, the method comprising at least the following steps:

[0025] a. providing a cuttings collector bar provided with a first cutter and a second cutter, the first cutter and the second cutter together forming a single double helical cutter, the single double helical cutter serving as a conveying screw having a first conveying path and a second conveying path,

[0026] b. providing an outer wall extending between the first tool and the second tool for the entire length of the two tools so as to form an outer wall of the first conveying path,

[0027] c. providing a lower wall which closes the first conveying path at the lower end of the first conveying path,

[0028] d. providing a top sleeve configured to be arranged at the upper end of a cuttings collector rod, said top sleeve being provided with an opening and closing arrangement, said top sleeve opening a first conveying path in a first position, and said top sleeve closing the first conveying path in a second position, said first conveying path forming a cuttings collector chamber closed at the upper and lower ends when the top sleeve is in the closed position,

[0029] e. providing one or more filters arranged on the outer wall of the cuttings collector chamber for draining liquid from cuttings collected in the cuttings collector chamber when the top sleeve is in the first position, and

[0030] f. Providing an internal drilling mud passage that extends the entire axial length of the cuttings collector.

[0031] Further advantages and details of the invention will become apparent from the dependent patent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be more readily understood by reference to the accompanying drawings, in which:

[0033] Figure 1 A cuttings collector for collecting cuttings is shown,

[0034] Figure 2 An opening and closing assembly for opening and closing a cuttings collector chamber of a cuttings collector is shown,

[0035] Figure 3An upper section of a cuttings collector is shown comprising a wear ring and a rotatable cover, the rotatable cover being shown in the figure as being provided with an opening leading to the cuttings collector portion of the cuttings collector,

[0036] Figure 4 showing a cross section of the lower section of the cuttings collector with the lower portion of the cuttings collector chamber,

[0037] Figure 5 showing a cross section of an upper section of a cuttings collector including an opening and closing assembly for opening and closing a cuttings collector chamber of the cuttings collector,

[0038] Figure 6 The upper section of the cuttings collector is shown, wherein the outer surrounding wall of the cuttings collector chamber has been omitted,

[0039] Figure 7 A cuttings collector is shown in which the outer surrounding wall of the cuttings collector chamber has been omitted,

[0040] Figure 8 An upper section of a cuttings collector is shown, wherein an opening in the outer wall of the cuttings collector chamber is provided with a filter,

[0041] Fig. 9 Details of the opening and closing mechanism for opening and closing the cuttings collector chamber inlet are shown,

[0042] Fig.10 A cuttings collector for collecting cuttings is shown,

[0043] Fig.11 shows an upper section of a cuttings collector having a rotatable sleeve provided with an inlet opening to a cuttings collector chamber,

[0044] Fig.12a A rotatable top sleeve of a cuttings collector chamber is shown, the top sleeve having an opening capable of closing and opening the inlet of the cuttings collector chamber, the top sleeve may be shaped as a frustoconical shape,

[0045] Figure 12b Shows the Fig.12a Rotatable top sleeve for viewing from different angles;

[0046] Fig.13 The lower housing portion of the cuttings collector is shown.

[0047] Fig.14a A cuttings collector is shown,

[0048] Fig.14b A cuttings collector is shown,

[0049] Fig.14c A cuttings collector is shown,

[0050] Fig.14d An exploded view of the cuttings collector is shown,

[0051] Fig.14e Showing details of the cuttings collector,

[0052] Fig.15a shows a cross section of a cuttings collector,

[0053] Fig.15b shows a cross section of a cuttings collector, and

[0054] FIG. 15C shows a cross section of a cuttings collector including a wear ring. DETAILED DESCRIPTION

[0055] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[0056] The purpose of a cuttings collector is to obtain cuttings / samples from a wellbore so that parameters of the wellbore can be correlated to a specific sample. Of particular interest is determining the location from which the cuttings sample was extracted. Currently, cuttings are collected without any means of assigning the cuttings to a specific location.

[0057] The idea of ​​the present invention is to provide a cuttings collector (hereinafter referred to as a cuttings collector 10, 100 in the form of a joint configured for insertion into a drill string) which is mounted directly or almost directly behind a drill bit. Both ends of the cuttings collector are provided with a connection portion, generally in the form of a thread, so that the front end / upper end can be connected to a drill bit or a connector, while the rear end / lower end can be connected to a subsequent drill rod. The cuttings collector comprises a cuttings collector rod, which is provided with an internal axial drilling liquid / mud supply channel. The drilling liquid helps to transport the cuttings to the drilling opening outside the drill string in a direction opposite to the drilling direction. The surface of the cuttings collector rod is provided with a double helix structure, which acts as a conveying screw with two conveying paths. An outer wall is provided around the cutter of the feed screw so that a cuttings collector chamber is formed. The cuttings collector is also provided with an opening and closing arrangement, which can allow the cuttings to enter the cuttings collector chamber or be discharged from the borehole along the conveying path of the cuttings collector rod.

[0058] The solution of a double helix providing two conveying paths is not only suitable for conveying the cuttings outwards and away from the drill bit, but also provides a balanced solution when the cuttings collector rotates, since the cuttings will coil along the cuttings collector rod and the centre of mass will coincide with the axis of rotation of the cuttings collector. A conveying path that is axial with respect to the cuttings collector rod will cause the cuttings collector to be unbalanced during rotation, since the centre of mass will not coincide with the axis of rotation of the cuttings collector.

[0059] The drilling mud supplied through the internal passage of the cuttings collector has sufficient pressure to carry the cuttings into the cuttings collector chamber in a direction opposite to the drilling direction, or to carry the cuttings out along the cuttings collector and further along the drill string and out of the borehole.

[0060] Solutions involving cuttings collectors rely on the operator having access to the drill bit's position data at all times. When the distance between the drill bit and the opening of the cuttings collector chamber is known, the source location of the collected cuttings can be well determined.

[0061] In industrial drilling, LWD and MWD systems are commonly used. LWD and MWD systems transmit production data to operators in real time or substantially real time. The data includes the position of the drill bit.

[0062] One embodiment of the present invention

[0063] The cuttings collector will now be described in more detail with reference to the accompanying drawings.

[0064] Figure 1 An exemplary cuttings collector 10 is shown, which, as can be seen, is divided into four sections 11, 12, 13 and 14. The length of the upper section is 11, which is shown as an upper threaded tool joint pin 11. The upper tool joint pin can be configured for direct threaded connection with a drill bit (not shown). The upper tool joint pin 11 can also be connected to other components of the drill string, such as stabilizers, reamer, etc.

[0065] The correlation between the parameters collected by the LWD and MWD systems and the source location of the drill cuttings will be best when the distance between the drill bit and the cuttings collector 10 is small. Therefore, the cuttings collector 10 is usually installed close to the drill bit.

[0066] The figure shows a replaceable wear ring 16 adjacent to the upper tool joint pin 11. The length of the wear ring 16 is l2, see Figure 1 .

[0067] The elongated central section of the cuttings collector 10 is Figure 1 13 in the figure. The central section includes a cuttings collector rod 13. The cuttings collector rod 13 is provided with a conveying screw having two conveying paths, one of which is provided with an outer wall 12. The conveying path provided with the outer wall 12 forms a cuttings collector chamber. The cuttings collector chamber is provided with an opening 14, and the opening 14 is equipped with one or more filter members to filter liquid from the cuttings stored in the cuttings collector chamber. The lower section of the cuttings collector 10 is shown as a threaded section 15 with a length of l4. The threaded section is shown as having an external thread. However, the section 15 can also be a box adapted to the drill rod socket.

[0068] Figure 2 The upper portion of the cuttings collector is shown, including the lower portion of the wear ring 16 and the upper portion of the cuttings collector 10 adjacent to the wear ring 16. The wear ring 16 has two upper cutters 27u and two lower cutters 27l. It also includes an upper fastener 28u and a lower fastener 28l, which are shown as bolts and nuts in the figure. As can be seen from the figure, the wear ring 16 includes two halves that can be assembled around the cuttings collector rod 13. In the figure, the bolts 28u, 28l are shown as being inserted through the protruding sections 27u and 27l, respectively. In addition to being configured for bolt insertion, the protruding sections can also protrude a sufficient distance to engage the wall of the drill hole so that the cuttings collector 10 will not get stuck in the drill hole. As mentioned above, the protruding cutters 27u, 27l can be used as reamer, and the wear ring 16 is replaceable.

[0069] It is conceivable to use other fasteners 28u, 281, such as a hinge solution that rotates about a vertical axis and has a latch opposite to the hinge axis.

[0070] exist Figure 2 For illustrative purposes, the wear ring 16, the top sleeve A, the drive device 21 including the pinion 22 are pulled away from l3 and l4, see Figure 1 .

[0071] The top sleeve A comprises a fixed part with an opening and a rotatable part 23. The rotatable part 23 can rotate around the cuttings collector rod 13, which rotation is achieved by the engagement of the gear edge 24 with the pinion 22. The pinion 22 is driven by the drive device 21. The rotatable part 23 is provided with an opening 25, which will move around the cuttings collector rod 13 when the rotatable part 23 is driven by the pinion 22.

[0072] Figure 3 The upper section of the cuttings collector 10 is shown, viewed obliquely from the threaded tool joint pin 11. The figure shows the wear ring 16 and the top sleeve A. A part of the top sleeve A may be a fixed integral part of the cuttings collector section 13.

[0073] The wear ring 16 shows that the distance between the limit points of the two upper cutters 27u and the distance between the limit points of the two lower cutters 27l form an OD. In order to prevent the cuttings collector 10 from getting stuck during drilling operations, the OD must be greater than or equal to Figure 1 The diameter d of the cuttings collector 10 in the region 13 is shown in FIG.

[0074] Figure 3Two upper cutters 27u and two lower cutters 27l are shown. However, it is not necessary to use four cutters. The configuration of the cutters is a matter of function and design, and it is conceivable to use only two cutters arranged diametrically opposite each other. The cutters can be used as expanders, so that the diameter of the drilled hole is slightly increased compared to the diameter of the drill bit.

[0075] Figure 3 Also shown is the opening and closing mechanism provided by the top sleeve A in combination with the drive device 21 and the pinion 22. The drive device 21 and the pinion 22 are not shown. Figure 3 . The fixed part of the top sleeve A has an opening 25 leading to the cuttings collector chamber and an opening leading to a portion of the cuttings collector 10 for discharging cuttings along one of the conveying paths. Alternatively, the opening in the fixed part of the top sleeve A can extend above the cuttings collector chamber and the conveying path for discharging cuttings. By rotating the upper cover 23 provided with the opening, it can be controlled whether the opening in the rotatable upper cover is aligned with the opening of the cuttings collector chamber or the opening of the conveying path for discharging cuttings.

[0076] Figure 4 A cross section of the lower section of a cuttings collector 10 is shown. In the figure, the lower section comprises a lower pin 15, which is adapted to engage a drill rod or a casing. A drilling mud supply channel 44 is shown as an inner part of the cuttings collector rod. The cuttings collector chamber is delimited internally by the inner wall 43 of the cuttings collector rod 13 and externally by the wall 12 shown. The tool defining the conveying path of the cuttings collector chamber ends at a horizontal barrier 41, so that the cuttings collector chamber can only be opened at the upper end, i.e. in the top sleeve A. In order to separate liquid from the cuttings collected in the cuttings collector chamber, the wall 12 is provided with a filter, which discharges the fluid and leaves the cuttings in the cuttings collector chamber for analysis.

[0077] Figure 5 A cross section of the upper part of the cuttings collector 10 is shown. A drilling mud channel 44 extends axially through the part of the cuttings collector 10 shown. The figure shows that the top sleeve A has a rotatable part 23, which is provided with a gear edge 24. The pinion 22 and the drive 21 are also shown. A collar 26 is also shown protruding from the cuttings collector rod so that the wear ring 16 will not move in the axial direction.

[0078] Figure 6 The upper portion of the cuttings collector 10 is shown with the outer wall 12 removed to show access to the cuttings collector chamber and the conveying path for discharging the cuttings. Two spiral cutters 61a and 61b are shown with a distance 63 between them.

[0079] The distance between the cutters 61a and 61b defines the conveying path. The cuttings collector chamber is defined by the inside edge of the first cutter 61a, which is wound on the cuttings collector rod 13 like a spiral cutter / helical structure, and the inside edge of the second cutter 61b, which is wound on the cuttings collector rod 13 like a spiral cutter. The cuttings collector rod is not tapered, and the distance between the first cutter 61a and the second cutter 61b is consistent from the top to the bottom of the cuttings collector 10. The upper tool joint pin 11 includes the top of the cuttings collector 10. The cuttings collector chamber 63 is further defined by the outer wall 12 (not shown) of the cuttings collector rod 13 and the outer wall (not shown) of the cuttings collector chamber 42. Figure 6 Also shown is a single inlet chamber 62 for collected drill cuttings which then enter the cuttings collector chamber.

[0080] Figure 7 The cuttings collector chamber 63 is shown extending a vertical length l3, see Figure 1 and Figure 7 This section of the cuttings collector 10 is also characterized in that the cuttings collector rod is provided with an open outer spiral structure. This includes a portion inside the vertical interval 13 that is not covered by the outer wall 12 of the cuttings collector. This portion provides a continuous path for the cuttings collector, which will act as a conveying screw for cuttings that are not allowed to enter the cuttings collector chamber 63.

[0081] Figure 8 The upper section of the cuttings collector 10 is shown comprising the uppermost portion of the cuttings collector chamber 63, which is defined by a "closed end" A having an opening / closing mechanism 21, 22, 23, 24, 25, see Figure 2 and Figure 3 The “closed end” A may be a top sleeve that may be disengaged from the remainder of the cuttings collector chamber 63 . Figure 2 The top sleeve A in FIG. 1 is shown with an internal gear edge 24, which is mounted on a rotatable part of the top sleeve 23, which can rotate around the cuttings collector rod 13 so that the opening / closing function can be achieved. A pinion 22 is shown as being engaged with the gear edge 24. The pinion can be rotated by a drive device 21. The drive device 21 can be an electric motor. The electric motor can be a stepper motor. When the pinion rotates, the rotatable part of the top sleeve 23 will rotate. The fixed part of the top sleeve A is provided with an opening 25. When the rotatable part of the top sleeve 23 rotates on the top of the opening 25, a complete or partial closure of the top sleeve A is achieved.

[0082] When a sample is to be collected, the opening / closing mechanism can be controlled by increasing the rotational speed of the drill. Collecting the sample is performed at the normal rotational speed of the drill.

[0083] Fig. 9 The opening / closing mechanism of the top sleeve A is shown in more detail. The upper part B in the figure shows the fixed part of the top sleeve comprising two openings 25a and 25b. The openings 25a and 25b can be a single opening 25. In addition, the opening 25 or 25a and 25b can form a relatively large part or even cover a complete 360° sector.

[0084] Fig. 9 The lower portion C in Figure 2 shows the rotatable portion 23 of the top sleeve. The opening 94 defines an opening that may be arranged to allow drill cuttings to enter a cuttings collector chamber or to exit a conveying path for discharging drill cuttings from a borehole.

[0085] Second embodiment

[0086] Fig.10 A second embodiment of a cuttings collector is shown. The principle of using a conveying screw to convey cuttings into or out of the wellbore is the same as the first embodiment of the cuttings collector 10 discussed above. The second embodiment shows a cuttings collector 100 in which the top sleeve comprising a horizontal surface with an opening is replaced by a top sleeve 106 which is substantially shaped as a frustum of a cone. The top sleeve 106 is provided with an opening which can be aligned with an opening to the cuttings collector chamber or to a conveying path for discharging cuttings. The combined aligned openings are in Figure 10 to Figure 1 5 is shown with reference numeral 125.

[0087] Fig.10 The cuttings collector 100 shown in FIG. 1 is divided into four sections, including an upper section h1 which forms a tool joint pin 101 of the cuttings collector corresponding to the tool joint pin of the drill pipe. The intermediate area between h1 and h2 is not assigned any reference numeral. The cuttings collector 100 also includes a top sleeve having an axial length l2 discussed above.

[0088] Adjacent to l2 is section h3 of the cuttings collector comprising the cuttings collector chamber. At the bottom of the cuttings collector is shown a box 105 of length h4. The box 105 is adapted to engage with a drill pipe socket.

[0089] The cuttings collector 100 is shown having an enclosure wall 102 that extends through a middle section h3 of the cuttings collector 100 .

[0090] The filters 104 of the cuttings collector 100 differ from the filters of the illustrated cuttings collector 10 in that they have a significantly smaller surface area.

[0091] The cuttings collector 100 is shown as having a diameter w.

[0092] Fig.11The upper portion of the cuttings collector 100 is shown in more detail. A section is cut away from the figure to reveal a drive 121 operable to rotate the top sleeve 106 about a vertical axis. This will be discussed in more detail with reference to other figures. The top sleeve 106 is shown as having a maximum diameter D.

[0093] The design of the top sleeve 106 would not be suitable as a "reamer". In addition, the top sleeve 106 protruding beyond the diameter w may cause wear to the transmission between the drive and the internal gear edge (not shown) of the top sleeve 106. Therefore, the cuttings collector 100 can be provided with a wear ring 1516, as shown in Figure 15C and discussed in the description of Figure 15C. Unless otherwise specified, the second embodiment of the cuttings collector 100 is provided with a wear ring 1516, as shown in Figure 15C.

[0094] Fig.12a The top sleeve is shown separated from the cuttings collector 100, and is shown with a gear edge 124. In this figure, the gear edge is shown as being located at the upper portion of the top sleeve 106, which in the present case is not tapered. The remainder of the top sleeve 106 forms a frustoconical shape. The top sleeve 106 is shown with an opening 104. The opening 104 can be aligned with an opening in the cuttings collector 100 that allows access to the cuttings collector chamber or to a conveying path for discharging cuttings.

[0095] To prevent the cuttings collector 100 from getting stuck in the wellbore and / or to prevent the top sleeve 106 from engaging the wall of the wellbore, a wear ring 16 may be mounted to the cuttings collector, such as Figure 2 , Figure 3 and Figures 5 to 8 As shown in , or alternatively and as shown in FIG. 15C , a wear ring 1516 may be installed.

[0096] Figure 12b The top sleeve 106 is shown viewed from different angles.

[0097] Fig.13 The lower portion of the cuttings collector 100 is shown. Two filters are shown for filtering liquid from the cuttings collector chamber so that the cuttings in the cuttings collector chamber do not contain excessive liquid. The lower portion of the cuttings collector 100 includes an opening 131 for conveying mud / cuttings from a conveying path for discharging cuttings (i.e., a path that does not form a cuttings collector chamber).

[0098] The lower section of the cuttings collector 100 includes a box tool joint 144 that is threaded to mate with a pin tool joint of a drill pipe.

[0099] Fig.14aThe cuttings collector 100 is shown to include an upper tool joint pin 101 having an axial passage 144 for supplying drilling mud to the drilling operation. Fig.14a Further shown is the top sleeve 106 having an opening 125 , ie, the opening in the top sleeve 106 aligns with an opening to one of the conveying paths of the cuttings collector 100 .

[0100] The lower section of the cuttings collector is denoted by reference numeral 105 .

[0101] Fig.14b is a perspective view of the cuttings collector 100 viewed obliquely from the pin 101. The axial drilling mud supply passage 144 is clearly visible.

[0102] Fig.14c 1 is a perspective view of a cuttings collector 100, wherein the top sleeve 106 and the cover have been omitted. The cover covers the compartment 1427 for the drive device 121. The drive device is omitted in the figure.

[0103] Note that two openings 146 are shown, one opening leading to a cuttings collector chamber and the other opening leading to a conveying path for removing cuttings from the wellbore.

[0104] Fig.14d An exploded view of the cuttings collector 100 is shown. As shown in the figure, the filter 104 of the cuttings collector may be provided with a grill 1425 to protect the filter 104.

[0105] Fig.14e A cross-section of the cuttings collector 100 is shown, in which the top sleeve 106 has been omitted. The compartment 1427 for the drive 121 is clearly visible, and it can be seen that the drive is connected to the pinion 122 via the shaft 1426. The pinion is arranged to be able to engage with the gear edge 124. The opening 146 in the sample chamber is clearly visible.

[0106] Fig.15a A cross section of a cuttings collector 100 is shown. It can be seen that the drilling mud supply passage 144 extends the length of the cuttings collector. In this figure, the opening in the top sleeve 106 is aligned with one of the openings in the body of the cuttings collector. The figure shows a spiral cutter extending from the top sleeve to the lower section of the cuttings collector.

[0107] Fig.15b There is shown a cross section of a cuttings collector 100. The figure clearly shows the internal conveying path provided by the two spiral cutters which extend from the top sleeve down to the lower section of the cuttings collector.

[0108] 15C shows a cross section of the upper section of the cuttings collector 100. As can be seen from the figure, the cuttings collector 100 has a maximum outer diameter D, which is provided by the wear ring 1516.

[0109] The wear ring can have a variety of embodiments. The figure shows the form of an inner wear ring sleeve 1516B configured to surround the upper portion of the inner core of the drill cuttings collector 100. The wear ring sleeve 1516B is shown as having an outer wear layer 1516A. The wear ring sleeve 1516B and the wear layer 1516A together form the wear ring 1516 of the drill cuttings collector 100.

[0110] In one embodiment, the wear ring 1516 may be formed as a unitary structure.

[0111] The wear ring 1516 may be replaceable, or alternatively, the wear layer 1516B may be replaceable.

[0112]

[0113]

[0114]

[0115]

[0116]

Claims

1. A cuttings collector (10, 100) for obtaining cuttings from an underground wellbore, comprising at least: a) a cuttings collector bar (13) provided with a first cutter (61a) and a second cutter (61b), the first cutter and the second cutter together forming a double helical cutter, the double helical cutter serving as a conveying screw having a first conveying path and a second conveying path, b) an outer wall (12) extending between the first tool (61a) and the second tool (61b) over the entire length of both the first tool and the second tool so as to form the outer wall (12) of the first conveying path, c) the conveying path having the outer wall (12) extending between the first tool (61a) and the second tool (61b) is provided with a lower wall (41) which closes the first conveying path at its lower end, d) the cuttings collector bar (13) is provided at an upper end with a top sleeve (A, B, C) having an opening and closing arrangement (25, 25a, 25b), the top sleeve (A, B, C) opening the first conveying path in a first position and the top sleeve closing the first conveying path in a second position, the first conveying path forming a cuttings collector chamber (63) closed at the upper and lower ends when the top sleeve (A, B, C) is in the closed position, e) the outer wall (12) of the cuttings collector chamber (63) is provided with one or more filters (14) for draining liquid from the cuttings collected in the cuttings collector chamber (63) when the top sleeve (A, B, C) is in the first position, and f) An internal drilling mud passage extending along the entire axial length of the cuttings collector.

2. The drill cuttings collector according to claim 1, wherein: The second position of the top sleeve (A, B, C) provides an opening to the second conveying path, allowing drill cuttings to be discharged along the second conveying path.

3. The drill cuttings collector according to claim 1 or 2, wherein: The top sleeve (A, B, C) comprises a rotatable part (23) and a fixed part with an opening, wherein the rotatable part (23) can rotate around the cuttings collector rod (13) and achieves the rotation by engaging a gear edge (24) with a pinion (22), which is driven by a drive device (21).

4. The drill cuttings collector according to claim 1 or 2, wherein: The top sleeve (A, B, C) comprises a rotatable top sleeve having an opening, the rotatable top sleeve being rotatable around the drill cuttings collector rod (13), and the drill cuttings collector chamber (63) being provided with an opening at an upper section, the opening being shaped and sized to match the opening of the rotatable top sleeve, so that when the opening in the rotatable top sleeve is aligned with the opening in the drill cuttings collector chamber (63), the top sleeve is in the first position and drill cuttings can be collected in the drill cuttings collector chamber (63).

5. A cuttings collector according to any one of the preceding claims, wherein: The cuttings collector rod (13) is provided with a threaded pin having a length of l1 or h1 at an upper end, and the threaded pin (11) is configured to engage with a drill bit.

6. The drill cuttings collector according to claims 1 to 3, wherein: The cuttings collector also includes a wear ring (16) which can be mounted around an upper threaded pin of the cuttings collector rod.

7. The drill cuttings collector according to claim 6, wherein: The wear ring (16) has a maximum diameter OD which is larger than the diameter of the top sleeve (A, B, C) and the cuttings collector rod.

8. The drill cuttings collector according to any one of claims 1 to 5, wherein: The cuttings collector further includes a wear ring which provides a sliding surface for the top sleeve and has a diameter corresponding to a maximum diameter of the cuttings collector.

9. A cuttings collector according to any one of the preceding claims, wherein: The drill cuttings collector also includes one of the following: a) the lower housing, and b) Lower threaded pin (15).

10. A cuttings collector according to any one of the preceding claims, wherein: The cuttings collector is configured to form a replaceable component of a drill string.

11. A method for obtaining drill cuttings from a subterranean wellbore, comprising at least the following steps: a) providing a cuttings collector bar (13) provided with a first cutter (61a) and a second cutter (61b), the first cutter and the second cutter together forming a double helical cutter, the double helical cutter acting as a conveying screw having a first conveying path and a second conveying path, b) providing an outer wall (12) extending between the first tool (61a) and the second tool (61b) over the entire length of both the first tool and the second tool so as to form an outer wall (12) of the first conveying path, c) providing a lower wall (41) which closes the first conveying path at its lower end, d) providing a top sleeve (A, B, C) configured to be arranged at the upper end of the cuttings collector bar (13), the top sleeve (A, B, C) being provided with an opening and closing arrangement (25, 25a, 25b), the top sleeve (A, B, C) opening the first conveying path in a first position and the top sleeve (A, B, C) closing the first conveying path in a second position, the first conveying path forming a cuttings collector chamber (63) closed at the upper and lower ends when the top sleeve (A, B, C) is in the closed position, e) providing one or more filters (14) mounted on the outer wall of the cuttings collector chamber for draining liquid from cuttings collected in the cuttings collector chamber when the top sleeve (A, B, C) is in the first position, and f) Providing an internal drilling mud passage extending the entire axial length of the cuttings collector.

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