EP0232268B1 - Device for controlling the locking of a sampling tube - Google Patents

Abstract

The eclipsable double fixed lock is pushed towards its lower position by the hydraulic pressure of the injection pump pushed boring liquid. Thus, an hydraulic seal is made between the interior tube and the exterior tube of the bore, when the liquid pressure exceeds a predetermined value. - The lock also allows the fluid to circulate when the pressure is less than the predetermined value, but above the recall force necessary to open the liquid flow regulation valve.

Description

The present invention relates to a device for controlling the locking of a cable sounder corer for a wet well, comprising an outer tube through which slides an inner tube consisting of a hooking head and a cylindrical body provided a hydraulic seal with the outer tube, a valve for adjusting the pressure of the drilling fluid and locking means with respect to the outer tube, consisting of a latch holder, a slide unlocking secured to the hooking head and a pin which releases, outside an annular blocking groove, the tabs of the aforementioned lock, under the effect of a traction by means of the operating cable and the fishing piece on the hanging head.

It also relates to a method for controlling the locking of a cable borehole sampler, using the device described above. According to this process, the drilling liquid is freely launched at the bottom of a wet well, possibly injected by means of a pump, in order to accelerate the descent and save time, and we rise to the surface after 'coring operation, using a recovery piece and a cable, an inner tube.

From FR-A-2 359 273, there is known a cable corer comprising a valve for adjusting the flow of drilling fluid, making it possible to detect from the surface, the precise moment of locking of the corer in the coring position, in a hole wet or dry.

The adjustable control valve comprises a spherical valve in a body formed by a sleeve constituting the head of the inner tube. The spherical obturator is applied elastically against an annular seat by a return spring bearing lowerly on an adjustment washer displaceable axially in the body.

In this known core drilling device, the operator has, in the adjustable control valve, for deep drilling, a particularly simple, quick and effective means of knowing when and if the inner tube is in the correct position for drilling and coring. For this purpose, it suffices to follow the pressure indicated at the pump without stopping any motor.

In fact, when the inner tube is locked in the outer tube, an annular rim rests on a suspension ring, at the level of the shutter and forms a seal. As a result, the water can no longer circulate between the inner tube and the outer tube at the level in question and this water is stopped by the shutter applied against the annular seat. Therefore, the water pressure indicated on the pressure gauge of the injection pump gradually increases to stabilize at a value corresponding to the return force of the spring, force which is previously known by the adjustment of this spring, before the introduction of the core barrel into the drilled hole. Thus, the evolution of the water pressure at the injection pump makes it easy to realize whether the inner tube is in the lower locked position and suspended from the suspension tube of the outer tube, before rotating the tube. outside in the drilled hole.

During soundings carried out at a great depth, that is to say greater than about 1000 m, it is difficult to deduce with certainty, from the evolution of the water pressure at the injection pump, if the lockout did take place.

Rather, reference is made to an indication on the pump pressure gauge of a sudden but fleeting increase in pressure above the predetermined valve adjustment pressure, due to the sudden stop of the liquid column causing the core barrel in his descent. It is difficult to observe on the pressure gauge of the injection pump, the impromptu water hammer linked to the precise moment of locking.

The descent of the core barrel, in free diving, despite the favorable contribution of the liquid drilling column driving it, requires more than twenty minutes and requires sustained and uninterrupted attention from the operator during the entire interval of time.

The present invention aims to remedy the above-mentioned drawback and proposes a device for controlling the locking of a cable sounder corer for a wet well, comprising an outer tube through which slides an inner tube consisting of a hooking head. and a cylindrical body provided with a hydraulic seal with the outer tube, a valve for adjusting the pressure of the drilling fluid and means for locking relative to the outer tube, consisting of a holder bolt, an unlocking slide secured to the hooking head and a pin which, outside of an annular blocking groove, releases the tabs of the above-mentioned bolt, under the effect of a traction by means of the cable maneuver and the fishing piece on the hooking head, characterized in that it comprises an eclipsable bistable lock, which, when pushed to a lower position by hydraulic pressure by means of the liquid injection pump drilling, has ssures the hydraulic seal of the inner tube with the outer tube, when said pressure of the drilling fluid exceeds a predetermined value and allows the circulation of the drilling fluid when the pressure decreases to a value below said value, while remaining greater than the return force required to open the drilling fluid pressure regulating valve.

In a particular embodiment, said lock consists of a slide ring which can slide outwardly along a cylindrical body integral with the attachment head, said cover comprising a keeper having two uneven converging arms, playing the role of runners, in which is guided and made prisoner in turn, a lug secured to the above cylindrical body which occupies, under the action of a spring acting on the base of the ring and bearing against a nut for adjusting the cylindrical body when the injection of drilling fluid is interrupted, an upper rest position in which a lateral orifice of the above-mentioned ring is closed by the cylindrical body.

The invention also relates to a method for controlling the locking of a cable borehole sampler, using the device described above.

This process is essentially characterized in that the above-mentioned ring first occupies, during the descent of the core barrel, under the action of the hydraulic pressure of the drilling fluid, a stable intermediate position, in which the lateral orifice is closed. by the cylindrical body, so as to prevent the circulation of the drilling fluid towards the drill bit, whatever the hydraulic pressure applied and accelerate the descent of the inner tube as a function of the flow of drilling fluids injected.

When the pressure of the drilling fluid is then increased, the ring whose segment forms an annular sealing piston around the cylindrical body, moves against a spring acting on the base of the drawer ring and taking support against an adjusting nut of the cylindrical body towards a lower position of rest in which the lug is at the top of the strike and occupies a position which makes it possible to release, at the same time as the eclipsable lock, the passage of the drilling liquid.

Other particularities and details of the invention will appear during the following detailed description referring to the attached drawings which illustrate an embodiment of the invention, given by way of nonlimiting example.

• - les figures 1, 2 et 3 sont des coupes de tronçons successifs d'un appareil carottier, muni d'un dispositif de contrôle du verrouillage selon l'invention ;
• - la figure 4 montre une coupe du dispositif de contrôle du verrouillage en position intermédiaire, telle que prévu pour la descente du carottier ;
• - la figure 5 est une vue analogue à celles des figures 4, du dispositif de contrôle au cours d'un test de verrouillage ;
• - la figure 6 est une vue analogue à celles des figures 4 à 5, du dispositif de contrôle au cours d'une opération de carottage ;
• - la figure 7 est une vue en coupe transversale suivant la ligne VI-VI' du dispositif montré à la figure 6;
• - les figures 8 à 16 illustrent les évolutions successives du liquide de forage dans l'appareil carottier montré à figures 1 à 3.

In these drawings:

• - Figures 1, 2 and 3 are sections of successive sections of a core barrel device, provided with a locking control device according to the invention;
• - Figure 4 shows a section of the locking control device in the intermediate position, as provided for the descent of the corer;
• - Figure 5 is a view similar to those of Figures 4, of the control device during a locking test;
• - Figure 6 is a view similar to those of Figures 4 to 5, of the control device during a coring operation;
• - Figure 7 is a cross-sectional view along line VI-VI 'of the device shown in Figure 6;
• FIGS. 8 to 16 illustrate the successive changes in the drilling fluid in the core barrel device shown in FIGS. 1 to 3.

In these various figures, the same reference notations designate identical or equivalent elements.

Figures 1 to 3 illustrate a first embodiment of the device for placing the inner tube of a core barrel device according to the invention.

As illustrated in FIG. 1, a double cable core barrel, designated as a whole by the reference notation 1, comprises an external tube 1, provided below with a probing ring 2 and an internal tube 3 which can be slid axially in the external tube 1 and equipped at its base with a carrot extractor sleeve 4. The inner tube 3 is freely launched into the outer tube 1. In the coring position, the inner tube 3 is suspended in the outer tube 1 by an annular flange 5 s '' pressing a suspension ring 5 'of the outer tube 1.

It comprises a tubular latch holder 6 and a hooking head 7 having at its top a frustoconical hook 8 and a cone - guide 9 arranged below the hook 8. The hooking head 7 is connected by a diametric pin 10 to an unlocking slide 11 which has a diametrical slot 12 and two elongated openings 13 diametrically opposite. The unlocking slide 11 carries an unlocking pin 14 extending perpendicularly through the slot 12 below the openings 13. The unlocking pin 11 can slide relative to the latch holder 6. It also carries a safety pin 20 intended to avoid any untimely unlocking during the drilling operation.

This latch holder houses a latch 15 consisting of two locking lugs 16 and 17 flat, parallel and housed in the diametrical slot 12. The lugs 16 and 17 pivot together around a diametrical pivot 18 which passes through the corresponding elongated openings 13 mentioned above and whose ends are fixed to the tubular latch holder 6. The latch holder 6 has two unlocking recesses 19, diametrically opposite and located opposite the diametrical slot 12. On its outer face, the latch holder 6 has a circumferential hooking groove 21 near its upper end 22 which is also chamfered. The lock holder 6 is made integral with the remaining lower part of the inner tube 3 by a pin 23. The slide 11 can slide slightly relative to the lock holder 6 in particular thanks to the possibility of sliding of the pivot 18 in the elongated openings 13 mentioned above.

The lugs 16 and 17 of the latch 15 are constantly biased by a spring 24, to be spaced from one another and removed together from the longitudinal axis common to the inner tube 3 and the outer tube 1.

A space is provided between the outer tube 1 and the inner tube 3 for supplying the lower core area with cooling water which not only allows the evacuation of calories, but also that of sounding debris.

The water passage channel included in the inner tube 3 has an adjustable valve 26 for controlling the pressure of the water supplied under the action of an injection pump not shown, installed on the surface.

The adjustment of the above-mentioned valve 26 is carried out using an adjustment screw 27 with a hexagonal head 28 mounted in the cylindrical body 33 and makes it possible to move axially in height inside the inner tube 3, a washer 29 so as to more or less compress the return spring 30 and thus adjust the return force of said spring 30.

The return force of the spring 30 is adjusted as a function of the conditions of the coring operations, so as to allow the opening of the valve 26 as soon as a predetermined water pressure selectively in full knowledge of the exact conditions of the coring operations, in particular the depth of drilling is reached.

According to a feature of the invention, the locking control device comprises a bistable retractable lock 3, which, when pushed to a lower position by hydraulic pressure greater than the setting value of the spring 30, by means of the pump for injecting the drilling liquid, ensures the hydraulic tightness of the cylindrical body 33 with the outer tube 1 and allows the arrival of the drilling liquid in a chamber delimited by the drawer ring 32 of the bistable retractable lock 31.

Then, the thrust of the drilling fluid is maintained at a value less than the setting force of the spring 38 but greater than the return force of the spring 30 necessary for the opening of the valve for adjusting the pressure of the drilling fluid.

In a particular embodiment of the device according to the invention, said latch 31 consists of a drawer ring 32 which can be slid outside along a cylindrical body 33 secured to the hooking head 7, said drawer ring 32 comprising a keeper 34 having two converging arms 35, 36 unequal, playing the role of slides, in which is guided and made in turn prisoner, a lug 37 secured to the above-mentioned cylindrical body 33, capable of occupying three extreme positions, corresponding to the operations descent, lock indication and drilling.

The aforesaid drawer ring 32 first occupies, during the descent of the inner tube of the core barrel, under the action of the hydraulic pressure of the drilling fluid on a segment 32 ', a stable intermediate position, in which each lateral orifice 40 is closed by the cylindrical body 33, so as to prevent the circulation of the drilling liquid towards the drill bit 2, whatever the hydraulic pressure applied (FIG. 4).

When the pressure of the drilling fluid is then increased, the ring 32, the segment 32 'of which forms a sealing piston around the cylindrical body 33, provided with a seal 33', moves against the spring 38 acting on the base of the ring-drawer 32 and bearing against an adjusting nut 39 of the cylindrical body 33 towards a lower rest position in which each lateral port 40 above is closed (Figure 5).

The circulation of drilling fluid to the drill bit 2 is prevented, regardless of the hydraulic pressure supplied by the injection pump.

A permanent increase in pressure can be easily detected on the surface by the pressure gauge. It indicates that the inner tube 3 of the core barrel rests in a sealed manner by an annular flange 5 on the suspension ring 5 'of the outer tube 1 and that the drawer ring 32 is pushed back into the sealed lower position.

By interrupting the injection of the drilling liquid, the spring 38 is allowed to move the ring 32 towards an upper so-called drilling rest position, in which the lug 37 is located at the foot of the strike 34 and the lateral orifice 40 is arranged in front of a window 40 ′ of the cylindrical body 33 and allows the circulation of drilling liquid towards the drilling ring 2 as soon as the pressure is sufficient to overcome the return force of the spring 30 of the adjustment valve 26 ( figure 6).

A sequential description of the process using the device described above is illustrated by the following figures.

Figures 8 to 10 show where the drilling fluid moves in the core drilling device, during the descent of the latter into the borehole. The drilling fluid is injected using the injection pump into the drill string.

The displacement of the column of drilling liquid downwards helps to accelerate the descent of the inner tube 3 of the core barrel in the drill string.

During the descent of the inner tube of the core barrel, the pressure adjustment valve 26 is closed since the ball bears tightly on its seat.

Arrived in the drilling position, the inner tube 3 of the core barrel comes to rest in a sealed manner on the suspension ring 5 'and the locking of the inner core barrel is effected by spacing of the tabs 16, 17 of the bolt 15.

Since the drilling liquid is injected by a positive displacement pump, the tightness of the outer tube 1 with the inner tube 3 causes a pressure build-up which, when it reaches the valve pressure of an overload not shown mounted on the pump, will cause the opening to indicate tangibly, safely and permanently, that there is locking.

The progression of the drilling liquid in the chamber delimited by the drawer ring 32 of the bistable eclipsable latch 31 is illustrated in FIGS. 11 to 13. FIG. 12 shows how the column of drilling liquid is stopped by the bistable eclipsing latch 31.

To bring the bistable lock into the drilling position, in which each lateral orifice 40 is located opposite a window 40 'of the cylindrical body 33, the operator, while letting the pump run, discharges the drilling fluid to the open air by a valve with two outlets.

By thus removing the pressure in the drill string, the return spring 35 is allowed to push the ring 32 towards the upper so-called drilling position. The drilling fluid is thus allowed to flow between the inner tube and the outer tube of the core barrel towards the drill bit.

The progression of the drilling fluid towards the drill bit 2 is illustrated in FIGS. 11 to 16.

The recovery of the inner tube 3 of the core barrel device is carried out in a known manner by lowering an overshot into the outer tube 1, using a cable.

Under the effect of a traction by means of the cable and the fishing piece or overshot on the hooking head, the unlocking pin 14 releases from the annular blocking groove, the tabs 16, 17 of the above-mentioned lock 15 .

The locking control device according to the invention signals in a precise, lasting and verifiable manner, the locking of the inner tube, which makes it possible to ensure that it has been carried out normally, while known systems provide this indication. fleetingly.

As soon as the locking has taken place, the pressure gauge indicates a value higher than the reference pressure. A possible increase in pressure can be read on the pump pressure gauge. On the other hand, by interrupting the injection of drilling liquid, the eclipsable lock is released and the passage of the drilling liquid to the drilling ring 2 is released.

Having an adjustable valve 26 and having a small annular space between the outer tube and the wall of the hole will, as in known systems, allow drilling with low flow rates of injection fluid, which allows to reduce the loss of carrot by erosion, while maintaining a correct evacuation of sediments.

As described in FR-A-2 359 273, a deflector sleeve 41 ′ is fixed to the lower part of the tube 11 carrying locks, onto which a solid shaft 41 is screwed. The shaft 41 carries around it and from top to bottom, a retaining ring 42, support washers 43, expansion rings 44 between them, a first ball bearing 45, a spacer sleeve 46, a second ball bearing 47, spring washers 48 and another retaining ring 49. The mechanical elements 43 to 48 surrounding the shaft 41 are clamped between the two retaining stops 42 and 49 by a self-locking nut 50, screwed sure

the threaded lower end of the shaft 41. On the other hand, the bracing sleeve 46 has a threaded part on which a support 51 of the inner tube is screwed. The tapped lower part of the support 51 carries a tube 3 receptacle of the carrot, threaded above and below. The lower part of the receptacle tube 3 is in turn screwed into the extractor sleeve 4, which is provided below with an extractor spring 52.

It is obvious that the invention is not exclusively limited to the modes and embodiments represented and that many modifications can be made in the form, the arrangement and the constitution of some of the elements involved in its realization provided that these modifications are not in contraction with the subject of the following claims.

Claims (6)

1. A device for controlling the locking of a cable-type boring sampling means for damp wells, comprising an external tube (1) through which there slides an internal tube (3) constituted by a coupling head (7) and a cylindrical body equipped with a hydraulic gasket (33') with the external tube (1), a valve (26) for adjusting the pressure of the drilling liquid and means (15) for locking relative to the external tube (1), constituted by a bolt holder (6), an unlocking slideway (11) which is rendered integral with the coupling head (7) and by a pin (14) which releases the tabs (16, 17) of the above-mentioned bolt (15) from an annular blocking groove by the effect of the traction of a manoeuvring cable and of the fishing member on the coupling head (7), characterised in that it comprises a bistable eclipsable bolt (31) which, when pushed towards a lower position by the hydraulic pressure of the pump injecting the drilling liquid provides the hydraulic seal between the internal tube (3) and the external tube (1), when said drilling liquid pressure exceeds a predetermined value and allows the circulation of drilling liquid when the pressure drops to a value below said value while remaining higher than the restoring force required for opening the valve (26) for adjusting the flow rate of drilling liquid.

2. A device according to Claim 1, characterised in that said bolt is constituted by a pull-ring (32) capable of sliding externally along a cylindrical body (33) intergal with the coupling head (7), said ring (32) comprising a slot (34) having two unequal converging arms (35, 36) acting as slide means in which a lug (37) integral with the above-mentioned cylindrical cody (33) is guided and, in turn, trapped, the lug (37) occupyingy the action of a spring (38) acting on the collar of the ring (32) and resting against an adjusting nut (39) of the cylindrical body (33) when the injection of drilling liquid is interrupted, an upper rest position in which a lateral orifice (40) of the above-mentioned ring (32) is blocked by the cylindrical body (33).

3. A method for controlling the locking of a cable-type boring sampling means using a device according to one of the characteristics of Claims 1 and 2, in which some drilling liquid is squirted freely to the bottom of a damp well, possibly by pump injection, in order to accelerate the descent and to save time, and in which an internal tube is raised to the surface after the sampling operation by means of a fishing member and a cable, characterised in that the above-mentioned ring firstly occupies, during the descent of the sampling means, by the action of the hydraulic pressure of the drilling fluid, a stable intermediate position in which the lateral orifice (40) is blocked by the cylindrical body (33) so as to prevent the circulation of the drilling liquid towards the annular bit (2) whatever the hydraulic pressure applied and to accelerate the descent of the internal tube (3) as a function of the flow rate of injected drilling liquid.

4. A method according to Claim 3, characterised in that the pressure of the drilling liquid is then increased so as to move the pull-ring (32) forming a sealing piston into the cylindrical body (33) towards a spring (38) acting on the collar of the ring (32) and resting against a nut (39) for adjusting the cylindrical body (33) towards a lower rest position in which the lug is located at the top of the slot (34) and in which the above-mentioned lateral orifice (40) is blocked.

5. A method according to Claim 3, characterised in that an interruption in the injection of drilling liquid permits the spring (38) to move the ring (32) towards an upper rest position in which the lug is located at the foot of the slot (34) and the lateral orifice (40) is situated opposite a window of the cylindrical body (33) and allows the circulation of drilling liquid towards the annular bit (2) once the pressure is sufficient to overcome the restoring force of the adjusting valve (26).

6. A method according to anyone of Claims 3 and 4, characterised in that the increase in pressure can easily be determined at the surface from the manometer and in that an adequate rate of flow of drilling liquid towards the annular bit (2) is provided by reducing the pressure below the restoring force of the spring (38) of the ring (32) while remaining higher than the restoring force (24) of the spring of the adjusting valve (26).

Images