Cable core drill head AND CORRECTOR

Abstract

Cable corer head AND CORE DRIVER The invention relates to a cable corer head (100), for obtaining soil, rock or similar cores of diameter between about 92 mm and about 120 mm comprising an upper part (110) provided with latches (15) and a lower part (120). The invention is characterized in that the upper part (110) of the core drill head (100) comprises a position indicator system (200) having a stop shoulder (1), an upper body (2) and a lower body (5), the upper body (2) comprising a ball (3), a housing (2b) for the ball (3), a ring (4) made of a deformable material having an inner diameter slightly greater than the diameter of the ball (3), and one or more water passages (2a), the lower body (5) comprising a housing (2c) for receiving the ball (3), when the latter has passed through the ring (4) under a water pressure brought through the water passages (2a).Figure from the summary: Fig. 2.

Description

Title of the invention: Cable core drill head AND CORRECTOR FIELD OF INVENTION

[0001] The present invention relates to a cable coring head, as well as a coring tool equipped with such a head. EARLIER ART

[0002] In the field of core drilling, it is common to have to operate a core drill at the bottom of a borehole. The core drill is the tool used to extract a core sample of rock, soil, or similar material from the bottom of the borehole.

[0003] The core barrels referred to in the invention according to the present invention are cable core barrels. To lower such core barrels to the bottom of a borehole and / or to raise them from the bottom of the borehole, these core barrels are held in place by a handling cable. This handling cable is connected to a drive unit, winch or similar, which allows them to be maneuvered downwards and / or upwards, in particular by winding the cable around a pulley.

[0004] An example of a prior art wireline core drill is the core drill marketed since 2021 by TECHNIDRILL™ under the reference TCS146. To date, this core drill is the largest in the range of wireline core drills marketed by TECHNIDRILL™. It allows for the production of 102 mm cores.

[0005] The cable corers according to the present invention are corers such as the TCS146 corer, for obtaining large diameter cores, in practice between about 92 mm and about 120 mm.

[0006] For core drilling, a very large quantity of water is continuously supplied from the surface. More specifically, the water is supplied to the cutting tool of the core drill, called the core bit. However, a large quantity of water is not always available at the drilling site. Furthermore, the consumption of large quantities of water poses environmental problems.

[0007] To limit water consumption, operators of cable corers should be informed on the surface, as soon as possible, if possible immediately, of the time when the corer is in place at the bottom of the well, to carry out coring, and / or of the time when the corer is full, the cores completely filling the inner tube of the corer.

[0008] Admittedly, means exist for informing surface operators of the position of cable core barrels and / or the filling of the inner tube of the core barrels, but only for core barrels intended for obtaining small-diameter cores, significantly less than 92 mm. It is not obvious how to adapt such systems to core barrels with cable of much larger dimensions, requiring a greater consumption of water, with different component parts. Summary of the invention

[0009] In view of the aforementioned prior art, an objective technical problem that the invention proposes to solve is to modify cable corers intended for obtaining large diameter cores, between about 92 mm and about 120 mm, by means which allow surface operators to determine simply and as soon as possible when the corer is in position at the bottom of the well to carry out coring, and / or which allow these operators to determine simply and as soon as possible when the corer is said to be full, i.e. that the coring operations are finished, and that it is then necessary to bring the corer back to the surface for the recovery of the cores taken from the bottom of the well.

[0010] The solution of the invention to this problem relates first to a cable-operated core drill head for obtaining soil, rock, or similar cores with a diameter between approximately 92 mm and approximately 120 mm, comprising an upper part equipped with latches and a lower part, characterized in that the upper part of the core drill head comprises a position indicator system including

[0011] a stopping shoulder, an upper body and a lower body,

[0012] the upper body comprising a ball, a housing for the ball, a ring made of a deformable material having an inner diameter slightly larger than the diameter of the ball, and one or more water passages,

[0013] the lower body comprising a ball receiving housing, when the ball has passed through the ring under water pressure brought through the water passages.

[0014] Advantageously, - the ball is a calibrated spherical ball with a diameter between approximately 20 mm and approximately 25 mm; - the water passage(s) have diameters smaller than the diameter of the ball; - the lower body is provided with at least one orifice allowing the passage of a tool to enable an operator to push the ball through the ring into the housing; - the head further comprises a sealing system including an inner tube assembled on a support and one or more seals which, in the compressed state, block a water passage inside an outer tube of the core drilling head; - the sealing system further comprises a spring; and - the head comprises an inner tube, a bearing box, a support flange, one or more support washers, a box shaft and a safety nut.

[0015] The solution of the invention has as its second object a cable corer equipped with a corer head as defined above. BRIEF DESCRIPTION OF THE FIGURES

[0016] The invention will be better understood upon reading the following non-limiting description, drawn up with reference to the accompanying drawings, in which:

[0017] [Fig-1] [Fig.1] is an overview of a core drill head according to the invention, in which are not represented the inner tube of the corer, nor all the external parts of said head, namely in particular the sleeves, the suspension ring, outer tube;

[0018] [Fig.2] [Fig.2] is a cross-sectional view of the position indicator system contained in a cable core drill head according to the invention; and

[0019] [Fig.3] [Fig.3] is a cross-sectional view of the head of [Fig.1], in which a coring head closure system according to the invention is shown in particular. DETAILED DESCRIPTION OF THE INVENTION

[0020] A wireline corer is a tool for retrieving core samples taken from the bottom of a borehole, which is generally equipped with: an electric or thermal motor, which provides the power needed to operate a drilling system; a cable drum, which is mounted on the corer and allows the drill cable to be stored and wound when in operation; a drill cable, which is attached to the corer on one side and to a lifting device on the other; a drill rod, namely a set of hollow metal tubes which are assembled to form a column, and which are attached to the lower part of the drill cable and serve to transmit the rotation and thrust force to the drill end, these rods being able to be added or removed as drilling progresses to reach the desired depth;a core drill head located at the lower end of the drill rods, which includes various cutting tools, such as drill bits, core bits or cores, used to penetrate the soil or rock and collect samples; a lifting system, which allows the drill head to be lowered and raised in the borehole, this system being operated manually or by a motorized device; an operator control device controlling the movement of the wireline core drill, this device being generally a control console equipped with buttons, levers or even a touch screen to monitor and adjust various parameters such as rotation speed, thrust pressure, water pressure and drilling depth.

[0021] The present invention relates to a cable corer head, namely the essential component of the cable corer which enables the collection of soil or rock samples at different depths.

[0022] The wireline core drill head according to the invention comprises a drill head body, generally made of robust and resistant steel, which houses all the internal components of the drill head and provides the necessary structure to withstand the drilling forces; Clamping jaws, located at the lower end of the drill head, which are designed to hold cutting tools, such as drill bits or treble bits, firmly in place during drilling; cutting tools, attached to the clamping jaws, which allow the head to penetrate the soil or rock to collect samples; a blow-off tube, located in the center of the drill head, which allows drilling debris to be removed from the borehole; a guide cone is located at the upper end of the drill head and serves to guide the cutting tool when it is lowered into the borehole; and means for connection to the lifting system.

[0023] The present invention relates exclusively to a cable core drill head 100 for obtaining cores with a diameter between approximately 92 mm and approximately 120 mm, namely cores of relatively large diameter in the field of coring.

[0024] It should be noted that, in practice, wireline corers have different, standardized dimensions. Depending on their dimensions, the corers are generally designated B, N, H, P, and S. Type B wireline corers are intended for core drilling with a diameter of approximately 36.4 mm (core diameter), in shallow boreholes with borehole diameters of around 59.7 mm, and for geotechnical applications where relatively small samples are required. Type N wireline corers are intended for core drilling with a diameter of approximately 47.6 mm, in moderately deep geotechnical and mining boreholes with borehole diameters of around 75.3 mm. Type H core drills are intended for core drilling with a diameter of approximately 63.5 mm, in deeper boreholes and in harder geological formations, with hole diameters of around 95.6 mm.Type P core drills are designed for drilling cores with a diameter of approximately 85 mm in geological exploration boreholes where medium-sized samples are required, with borehole diameters of around 122.1 mm. Type S core drills are designed for drilling cores with a diameter of approximately 102 mm in deep boreholes in various geological formations, extracting relatively large samples with borehole diameters of around 146 mm.

[0025] The cable core drill heads according to the present invention are S-type cable core drill heads, intended to carry out core drillings of diameter between approximately 92 and approximately 120 mm, in particular core drillings of approximately 102 mm.

[0026] In [Fig.1], a cable corer head 100 according to the invention is shown, without the inner tube of the corer and without all the external parts of said head, namely in particular the sleeves, the suspension ring, the outer tube.

[0027] The cable core drill head according to the invention includes a system indicating the position of the core drill at the bottom of the hole, this system being referenced 200 in [Fig.2].

[0028] The position indicator system 200 comprises a stop shoulder 1, an upper body 2 provided with a housing allowing the movement of a spherical ball 3, a or several inclined water passages 2a, for example four in number, a ring 4 made of a deformable material, in particular plastic, and a lower body 5, which receives the ball 3 when it passes through the ring 4.

[0029] The ball 3 is calibrated with a diameter between approximately 20 mm and approximately 25 mm, for example equal to 0.87” (22.10 mm). The inner diameter of the passage of the ring 4 is slightly smaller than the diameter of the ball 3. Thus, when the diameter of the ball 3 is 0.87”, the diameter of the ring is, in an example, 0.86” (21.84 mm).

[0030] The position indicator system 200 operates during the descent of the entire inner part of the core barrel and when the stopping shoulder 1 comes to rest against a suspension ring (not shown), which is located in the outer part of the core barrel. The water, which is continuously supplied to the inside of the rods during coring, can then no longer pass through the annular part of the core barrel. The water is thus forced to pass through the four inclined passages 2a, which have diameters smaller than the diameter of the ball 3. The water then exerts an increasing pressure on the ball until the ring 4 deforms, given its deformable plastic design, to allow the ball 3 to pass through and permit the flow of water to the core barrel for its proper operation.

[0031] On the surface, the operator is informed of the increase in water pressure, then of the sudden drop in water pressure thanks to the pressure gauge of the cable corer.

[0032] During the raising of the inner part of the cable corer, when the inner tube of the corer is full of samples and out of the hole, the driller replaces the ball 3 by making it pass back through the plastic ring 4 with a tool such as a large screwdriver, by passing this tool through one of the two orifices 5a of the lower body 5 of the system 200.

[0033] Advantageously, the cable coring head 100 according to the invention further comprises a sealing system 300. This system 300 is shown in [Fig.3].

[0034] It includes an inner tube support 7, a bearing box 8, a support flange 9, two support washers 10, one or more plugs, for example two, made of plastic, for example of rubber, these plugs having different hardnesses depending on the nature of the soil, a box shaft 12, a compression spring 13, and a safety nut 14.

[0035] This system operates when the inner tube of the corer is full of soil samples, i.e., when the core is complete. The inner tube 6 is assembled, for example screwed, onto the support 7, and the core presses against the face 7a of this support 7, which has the effect of pushing the assembly onto the upper part of the head 100, which is locked by the latches 15 and the locking sleeve (not shown). Under the pressure of the core, the two rubber stoppers 11 are compressed against the inside of the outer tube and block the passage of water.

[0036] At the surface, the operator is alerted to the sudden increase in water pressure by the drilling rig's pressure gauge. He stops the core drilling descent and shuts off the water pump. This ensures the safe positioning of the inner core barrel, secures the core within the inner tube, and protects the entire core barrel, preventing over-drilling and conserving water.

[0037] During the initial ascent of the core barrel, using a retrieval clamp and the drill's winch cable, the spring 13 decompresses to allow the two rubber obturators to return to their original diameter so as not to rub against the walls of the drill rods. The system automatically returns to the coring position without any intervention from the driller upon exiting the hole.

[0038] The cable core drill head according to the invention is compatible with the TCS146 cable core drills marketed by TECHNIDRILL™ which do not include the position indication 200 and sealing 300 systems. Compatibility with all components of the TCS146 range under the head is maintained.

[0039] Many parts are shared with those of smaller core drill sizes. This reduces the manufacturing costs of the head according to the invention, keeping it competitive, and makes it easier for users to obtain spare parts.

[0040] The indication system thus allows the operator to determine, during the descent of the core barrel into the hole, once the water pressure gauge rises and then drops sharply, that the core barrel is correctly positioned, properly locked, and therefore in the working position. During the ascent of the core barrel to the surface, and before reuse, the driller will replace the ball by driving it back through the ring using a tool.

[0041] The sealing system thus allows, once the inner tube of the core barrel is full of soil samples, the water passage to be blocked by deforming under the crushing pressure of the core. This results in an increase in water pressure on the drill rig's pressure gauge, indicating to the driller that the core barrel is full. The driller can then shut off the water and retrieve the inner tube. This secures the positioning of the inner core barrel, the sample (core) within the inner tube, and the entire core barrel, preventing over-drilling. It also saves time, as the driller is immediately alerted on the water pressure gauge and can therefore react more quickly.

[0042] The addition of a position indicator and rubber stoppers allows for significant water savings during coring, especially in fractured ground. As explained above, the driller has direct access to the water pressure gauge when the core barrel is in place or full. Therefore, they can immediately reduce the water flow and pressure using these systems. Incorporated into the new head, it is no longer necessary to wait for the water to overflow outside the hole and to bring up its corer not fully filled.

[0043] It should be noted that experiments were conducted to validate the invention. It was not initially obvious that the position indicator system would function on a large coring rig for extracting cores with diameters between approximately 92 mm and approximately 120 mm. Surprisingly, the diameter of the core sampler, between approximately 20 mm and approximately 25 mm, proved sufficient to ensure the position indicator system function. It was demonstrated that water savings ranged from 30% to 50% per core extraction, depending on the depth and soil type.

Claims

Demands

1. A wireline coring head (100) for obtaining soil, rock, or similar cores with a diameter between approximately 92 mm and approximately 120 mm, comprising an upper part (110) equipped with latches (15) and a lower part (120), characterized in that the upper part (110) of the coring head (100) comprises a position indicator system (200) having a stop shoulder (1), an upper body (2), and a lower body (5), the upper body (2) comprising a ball (3), a housing (2b) for the ball (3), a ring (4) made of a deformable material having an inner diameter slightly larger than the diameter of the ball (3), and one or more water passages (2a), the lower body (5) comprising a housing (2c) for receiving the ball (3) when the ball (3) has passed through the ring (4) under water pressure supplied through the water passages (2a).

2. Cable core drill head (100) according to claim 1, characterized in that the ball (3) is a calibrated spherical ball with a diameter between about 20 mm and about 25 mm.

3. Cable corer head (100) according to any one of the preceding claims, characterized in that the water passage(s) (2a) have diameters smaller than the diameter of the ball (3).

4. Cable core drill head (100) according to any one of the preceding claims, characterized in that the lower body (5) is provided with at least one orifice (5a) allowing the passage of a tool in order to enable an operator to push the ball (3) through the ring (4) into the housing (2b).

5. Cable coring head (100) according to any one of the preceding claims, characterized in that it further comprises a sealing system (300) including an inner tube (6) assembled on a support (7) and one or more seals (11) which, in the compressed state, obstruct a water passage inside an outer tube of the coring head (100).

6. Cable core drill head (100) according to claim 5, characterized in that the sealing system further comprises a spring (13).

7. Cable core drill head (100) according to claim 5 or 6, characterized in that it comprises an inner tube (7), a box (8) bearing, a support flange (9), one or more support washers (10), a gearbox shaft (12) and a safety nut (14).

8. Cable corer equipped with a corer head according to one of the preceding claims.

Images