EP3059384A1 - Device and method for taking core samples from sediment formations - Google Patents

Abstract

The invention relates to a device and a method for removing core samples from sediment formations with a carrier tool (1) and with a sample receiving housing (10) attached to the carrier tool (1) which delimits a sample receiving space (9) and which has a cutting geometry (11) or a cutting shoe at a leading end, wherein the sample receiving housing (10) comprises a closure, with which a substantially airtight seal of the sample receiving space (9) can be produced in situ.

Description

The invention relates to a device and a method for removing core samples from sediment formations with a carrier tool and with a sample receiving housing attached to the carrier tool, which delimits a sample receiving space and which comprises a cutting geometry or a cutting shoe at a leading end.

So-called piercing cylinders are known for taking soil samples from a ground, which comprise a linkage and a thin-walled steel cylinder attached to the linkage, which is driven into the ground with a leading cutting shoe. The soil sample to be taken penetrates into the cavity enclosed by the steel cylinder. If the steel cylinder is pulled, the so-called core sample or probe sample is located in the cavity enclosed by the steel cylinder and remains there due to the binding of the pulled sediment. The steel cylinder is detachably attached to the carrier tool, for example to a linkage. Immediately after removal of the probe sample from the ground, the steel cylinder is separated from the carrier tool and sealed airtight with one or more rubber caps.

Furthermore, devices for removing core samples from earth formations are known, which are fastened, for example, to the leading end of a drill pipe. Such a device for taking core samples of earth formations that are intersected by a cylindrical hole is, for example, from DE 1814449 A1 known.

In the founding of offshore wind farms or offshore oil production facilities or in the founding of onshore structures where metal foundations are driven into the ground, it can lead to bacterial anaerobic corrosion of the metal structures located in the ground. Bacterial anaerobic corrosion is a bacteria indirectly induced oxidation of metals. Especially in humid environments and in the presence of sulfur bacteria in the ground, it may happen that the structures introduced into the ground do partially decompose. This problem often occurs in buried pipes, steel sheet piling, oil tanks or piles of foundations in the seabed.

For the purposes of a subsoil investigation, it would therefore be useful and desirable to be able to carry out an air-tight and pressure-tight sampling, so that the sample taken can be reliably examined for their bacterial composition.

Such a pressure and airtight sampling of sediment formations is also desirable and advantageous from other points of view.

As already mentioned, so far soil samples are taken with so-called piercing cylinders, wherein care is taken in the removal principle that the core sample is intact and representative of the extracted microstructure. Also, an air seal of the sample container immediately after the sampling usually ensures that the sample passes into a laboratory substantially undisturbed.

A known method for soil sampling is described for example in DIN 4021. However, this method suffers from the disadvantage that it is hardly possible to isolate the sample according to its original environment because the air-tight and pressure-tight closure of the sample is only ensured after removal from the relevant sediment formation.

The invention is therefore based on the object to provide an apparatus and a method for removing core samples from sediment formations, which take this problem into account.

The object is achieved with a device according to claim 1 and with a method according to claim 13. Advantageous embodiments of the invention will become apparent from the dependent claims.

One aspect of the invention relates to an apparatus for removing core samples from sediment formations with a carrier tool and having a sample receiving housing attached to the carrier tool defining a sample receiving space and having a cutting geometry or cutting shoe at a leading end, the sample receiving housing comprising a closure in which a substantially airtight closure of the sample receiving space can be produced in situ.

According to the invention, it is therefore provided to close off the sample receiving housing with a closure such that it can be closed in situ, that is to say still within the sediment formation from which a core sample is to be drawn. As a result, one is essentially airtight and pressure-tight Completion of the core sample within the sample receiving space is possible before the core sample is drawn.

This is based on the knowledge that otherwise, when pulling the core sample with a downwardly open steel cylinder or with a downwardly open core tube inevitably a structural change would take place. Under certain circumstances, a shift of layer boundaries and consistency limits of the sediment of the sample can not be prevented. With the device according to the invention, it is reliably prevented that the core sample is exposed to a different ambient environment during the drawing, which does not correspond to the surrounding environment of the relevant sediment formation.

With a device according to the present invention, a core sample or probe sample can be obtained in a pressure-tight and airtight manner at the exploration location. The intended sample may thus be salvaged, with the exception of temperature, according to the surrounding environment prevailing at the exploration location, and then stored accordingly.

In the context of the invention, a carrier tool can be understood to mean a drill pipe, a guide rod or another type of linkage, via which the sample receiving housing can be brought into the sediment formation to be sampled.

As a sample receiving housing in the context of the present invention, a steel cylinder may be provided whose leading end in the feed direction is open at least until the feed into the sediment formation to be sampled.

Under a cutting geometry or a cutting thrust within the meaning of the present invention, a circumferential edge or a peripheral edge of an opening of the sample receiving housing to understand.

In a particularly expedient variant of the device according to the invention it is provided that the closure comprises a spherical, half-shell-shaped closure body which is displaceable between a first open position and a second closed position, which forms a concave bottom of the sample receiving space in the first open position and which encloses a core sample in the second closed position. This half-shell closure or hemispherical closure may comprise a single half-shell which, upon rotation about a virtual sphere center, is displaced from a first open position to a second closed position.

Alternatively, the closure may comprise two quarter-shell-shaped closure bodies which are displaceable in opposite directions to one another and thus perform an opening movement and a closing movement.

The closure body is expediently designed as a sample spoon, so that it cuts out or removes part of the core sample from the sediment formation upon displacement from the first open position into the second closed position.

If the closure comprises two quarter-shell-shaped closure body, these quarter-shell closure body expediently also each form a kind of sample spoon.

In an advantageous embodiment of the device according to the invention it is provided that the closure body is displaceable spring-actuated. For example, the closure body can be displaced from the first open position to the second closed position by a tensile force applied to the carrier element. In this case, a force acting on the closure body spring can be biased by the driving of the support member in the soil to be sampled, whereas a tensile force applied to the carrier element causes relaxation of the spring preferably designed as a compression spring, which then causes a displacement of the closure body in the second closed position becomes.

In a particularly expedient embodiment of the device according to the invention, it is provided that the sample receiving chamber housing has a spring-mounted bottom plate, which is sealed at the edge against a Umfassungswad the sample receiving space and forms a cavity with the closure body to enclose the core sample.

In an alternative variant of the device according to the invention, the closure comprises a closure panel having a multiplicity of lamellar closure bodies which define an approximately circular closure opening with a variable diameter. The closure bodies form an iris diaphragm, which can be moved from a first open to a second closed position by a rotation of parts of the sample receiving housing. Preferably, the closure is designed as a double iris lamella closure, wherein a leading first stage of the shutter can serve to separate the core sample or the probe sample from the sediment formation. A second stage of the shutter can only seal the sample receiving space serve. Of course, the closure can also be designed in one stage.

Between the first and second stages of the shutter, a gap may be provided as a lock, which can be filled with a potting compound.

Similar to the functioning of a camera shutter, a lamellar shutter is integrated in a cover of the sample receiving housing. During the penetration of the sample receiving housing into the ground, the shutter is open. Before the core sample is subsequently recovered, the shutter is closed. The lamellar closure bodies, which are subjected to pressure during the recovery of the core sample by the sample body in the closed state, constitute a pressure and airtight closure of the core sample.

The pressure and airtight seal can be achieved by a special surface structure and / or surface texture of the lamellar closure body, for example by interlocking lip seals between the lamellar closure bodies.

The opening and closing movement of the shutter can be initiated via a rotational movement of the carrier tool. For example, a cover of the sample receiving housing can be rotatably formed to a surrounding wall of the sample receiving housing.

The sample receiving housing may be formed, for example, as a cylinder or cylindrical container.

Alternatively, it can be provided that the closure is designed as a flap closure with at least two sealing flaps closing against one another.

As already mentioned above, it is expedient for the sample receiving housing to be designed as a sample receiving container preferably detachably attached to the carrier tool, for example in the form of a cylinder.

Conveniently, the sample receiving housing is provided with a Vergussmassenanschluss which communicates with the sample receiving space and over which the sample receiving space is sealed with a potting compound. As potting compound is for example a paraffin or other viscous sealant in question.

The sample receiving housing or the sample receiving space is expediently provided at its trailing in the feed direction end with at least one vent, so that the air can escape within the sample receiving space during insertion. By means of the potting compound, which may be formed for example as paraffin or other sealant, the sample receiving space can be sealed in situ.

A Vergussmassenreservoir may be provided on or in the carrier tool, which is connected to the sample receiving space and which can be pressurized, for example, after driving the sample receiving housing into the sediment formation to be sampled so that the sealing compound seals the sample receiving space or penetrates into it.

In a variant of the device according to the invention it is provided that the closure comprises a drive which is selected from a group comprising electrical, pneumatic, hydraulic or mechanical drives. The drive is preferably used to relocate the closure body or bodies.

Alternatively it can be provided that the closure can be actuated via a gear which converts a feed movement of the carrier tool into a displacement movement of a closure body, which converts an axial movement or rotational movement of the carrier tool into a displacement movement of a closure body.

A further aspect of the invention relates to a method for removing core samples from sediment formations with a device comprising a carrier tool and a sample receiving housing attached to the carrier tool which delimits a sample receiving space and which comprises a cutting geometry or a cutting shoe at a leading end, wherein the sample receiving space with a Closure is substantially hermetically sealable, the method comprising driving the sample receiving housing into an undisturbed sediment formation, such that the core sample to be removed is at least partially enclosed by the sample receiving space, wherein in a subsequent process step, the sample receiving space is closed and sealed in situ, and then the sample receiving housing is pulled over the carrier tool.

Preferably, the sample receiving space is sealed or sealed in situ with a potting compound before the core sample is drawn.

The method according to the invention is preferably carried out using a device having one or more of the features described above, and ideally in an arrangement which corresponds to the geometric boundary conditions of the standardized and known sampling devices.

In particular, with respect to the diameter of the drawn specimens, it is advantageous to comply with the known dimensions according to standardization. Therefore, the invention preferably comprises the devices described above arranged vertically.

The invention will be explained below with reference to an embodiment shown in the drawings.

Figur 1

eine Vorrichtung zum Entnehmen von Kernproben gemäß Stand der Technik,

Figuren 2a, 2b

eine Vorrichtung gemäß der Erfindung, die stark vereinfacht ist, wobei Figur 2a das Probenaufnahmegehäuse der Vorrichtung gemäß der Erfindung in geöffnetem Zustand und Figur 2b das Probenaufnahmegehäuse der Vorrichtung gemäß der Erfindung in geschlossenem Zustand zeigt,

Figuren 3a, 3b

ein zweites Ausführungsbeispiel der Vorrichtung gemäß der Erfindung, wobei Figur 3a eine teilweise geschnittene Seitenansicht und Figur 3b eine Unteransicht zeigt, und

Figuren 4a, 4b

ein drittes Ausführungsbeispiel der Vorrichtung gemäß der Erfindung veranschaulicht, wobei Figur 4a die Probenaufnahme mit geschlossenem Verschluss zeigt.

Show it:

FIG. 1

a device for taking out core samples according to the prior art,

FIGS. 2a, 2b

a device according to the invention, which is greatly simplified, wherein FIG. 2a the sample receiving housing of the device according to the invention in the open state and FIG. 2b shows the sample receiving housing of the device according to the invention in the closed state,

FIGS. 3a, 3b

A second embodiment of the device according to the invention, wherein FIG. 3a a partially sectioned side view and FIG. 3b shows a bottom view, and

FIGS. 4a, 4b

illustrates a third embodiment of the device according to the invention, wherein FIG. 4a shows the sample holder with closed closure.

It is first referred to FIG. 1 , which shows a device for taking out core samples according to the prior art.

In all drawings the same components are designated by the same reference numerals.

In the FIG. 1 Device shown comprises a carrier tool 1 in the form of a linkage, which is arranged displaceably in a guide hood 2. The guide hood 2 comprises a guide plate 3, with which the device can be set up on a building ground 4.

Within the guide hood 2, a piercing cylinder 5 is arranged at the leading end of the carrier tool 1. The piercing cylinder 5 is formed as open on its leading side, thin-walled steel cylinder. An anvil 6 is fastened to the end of the carrier tool 1 or the carrier rod remote from the piercing cylinder 5, on which case a drop weight 8 guided on a percussion linkage 7 can act. About the guided on the striker 7 case weight 8, the carrier tool 1 is driven with the piercing cylinder 5 in the ground 4. The sample receiving space 9 enclosed by the piercing cylinder is filled with the probe sample or with the core sample. If the piercing cylinder 5 is pulled, the core sample is located in the sample receiving space 9 surrounded by the piercing cylinder 5.

When the piercing cylinder 5 is pulled, it is not ensured that the layer boundaries and the consistency limits of the core sample are preserved. In the sample receiving space 9 about trapped air can escape via a vent not shown.

Reference is now made to the FIGS. 2a to 4b showing several variants of a device according to the invention.

FIG. 2a shows a carrier tool 1 with a mounted on the leading end of the carrier tool 1 sample receiving housing 10 in the form of an open cylinder which surrounds the sample receiving space 9 and which is provided at its leading end with a circumferential cutting geometry 11.

The cutting geometry 11 is designed as a circumferential, possibly sharpened edge of the opening 19 of the sample receiving space 9 pointing in the feed direction of the device.

The sample receiving housing 10 further comprises a closure body 12, which is formed in the embodiment according to Figures 2a and 2b as a half-shell closure, that is spherical, half-shell-shaped. The closure body 12 is rotatable about an imaginary center defining the radius of the closure body 12, from the in FIG. 2a position shown in the in FIG. 2b shown position. FIG. 2a shows the closure body 12 in the first open position, FIG. 2b shows the closure body 12 in the second, closed position.

In the in FIG. 2a the closure body 12 defines a bottom of the sample receiving space 9. The closure body 12 forms in the case of this embodiment a cavity 13 for receiving a core sample. The sample receiving housing 10 is designed as a cylindrical container 14, which communicates via an opening 15 designed as Vergussmassenanschluss with a Vergussmassenreservoir 16 within the carrier tool 1.

As potting a paraffin is provided that can enter from the Vergussmassenreservoir 16 via the opening 15 in the housing 14. The closure body 12 located in the open position seals the housing 14 against the escape of the potting compound.

In the method according to the invention, it is initially provided to advance the sample receiving housing 10 or the cylindrical container 14 via the carrier tool 1 into the sediment formation of the subsoil 4 to be sampled. In this case, the ground 4 or the sediment penetrates into the cavity 13 formed by the closure body 12. Then, the closure body 12, for example by means of an electric, pneumatic or hydraulic drive in the in FIG. 2b In the process, the closure body 12 releases sediment from the sediment formation and encloses it in the cavity 13. The second in FIG. 2b shown position moving closure body 12 allows a reflow of the potting compound, so that the potting compound completely seals the test receptacle housing 10 and sealed.

Reference is now made to the second embodiment of the invention, which in the FIGS. 3a and 3b is shown. The same components are provided there with the same reference numerals.

The in the FIGS. 3a and 3b The device according to the invention shown also comprises as a sample receiving housing 10, a cylindrical container having a circumferential cutting geometry 11 which surrounds a leading, circular opening 19 of the sample receiving space 9, which is part of a relative to the housing 14 rotatable end cap 17. In the embodiment according to FIGS. 3a and 3b the entire housing 14 forms the sample receiving space 9 in the sense of the invention.

In the end cap 17, a shutter 18 is integrated as a two-stage iris diaphragm, wherein the shutter 18 comprises a plurality of lamellar closure bodies 12. Incidentally, the cylindrical container 14 is also provided on its side facing the carrier tool 1 with a Vergussmassenanschluss. Within the carrier tool 1, a Vergussmassenreservoir with a potting compound, for example in the form of a paraffin, is provided. Rotation of the end cap 17 relative to the housing 14 causes opening and closing of the shutter 18, the shutter 18 comprising a first stage 20 facing away from the sample receiving space 9 and a second stage 21 facing the sample receiving space 9, enclosing a gate 22 between them , The lock 22 communicates via a channel 23 with a Vergussmassenreservoir 16 within the carrier tool. 1

The sample receiving housing 10 is driven on the carrier tool 1 with open shutter 18 in the ground 4, so that the core sample is enclosed by the housing 14 and the sample receiving space 9. Then, the shutter 18 is closed by means of a rotary movement of the carrier tool, on the one hand the sediment body or the core sample being separated, on the other hand the sample receiving chamber 9 is sealed substantially pressure-tight. Then, the sealing compound is introduced into the lock 22 via the channel 23, so that the sample receiving space 9 is sealed and sealed.

Another variant of the device according to the invention is in the FIGS. 4a and 4b shown.

Within the housing 14, a closure body 12 is also arranged in the form of a spherical half-shell. The closure body 12 is as in the embodiment according to FIGS. 2a and 2b about an imaginary center, which defines the radius of curvature of the closure body 12, rotatably disposed within the container 14 and within the sample receiving space 9 and also forms a cavity 13 for receiving the core sample. In the first open position of the closure body 12, the in FIG. 4a is shown, the apex of the convex side of the closure body 12 abuts against a resiliently mounted in the sample receiving space 9 bottom plate 24.

The bottom plate 24 is supported via a compression spring 25 against an end remote from the front opening of the housing 14 end wall 26. In addition, the bottom plate is sealed at the edge against a surrounding wall 27 of the sample receiving space 9.

When advancing the carrier tool 1 in the ground 4, the sediment penetrates into the container 14 and into the cavity 13 of the closure body and shifts the closure body 12 with the bottom plate 24 in the direction of the end wall 26 of the housing 14, wherein the compression spring 25 is tensioned.

If then the carrier tool 1 is pulled again, the return movement of the compression spring 25 initiates a rotational movement of the closure body 12, so that the closure body can enclose the core sample and can seal against the bottom plate 24.

As in the preceding exemplary embodiments, provision can be made for a potting compound to be introduced from the potting compound reservoir 16 into the container 14 via the opening 15 in the end wall 26 of the container 14, and the container 14 to be sealed.

After removal of the carrier tool 1 from the sediment formation or from the ground, the container 14 can be detached from the carrier tool 1 and deposited accordingly.

LIST OF REFERENCE NUMBERS

1)

carrier tool

2)

guidance hood

3)

guide plate

4)

Building

5)

sample ring

6)

Anvil

7)

shock linkage

8th)

drop weight

9)

Sample receiving space

10)

Samples containing case

11)

cutting geometry

12)

closure body

13)

cavity

14)

container

15)

opening

16)

Vergussmassenreservoir

17)

end cap

18)

shutter

19)

opening

20)

first stage of the shutter

21)

second stage of the shutter

22)

lock

23)

channel

24)

baseplate

25)

compression spring

26)

bulkhead

27)

containment

Claims (15)

Device for removing core samples from sediment formations with a carrier tool (1) and with a sample receiving housing (10) attached to the carrier tool (1) which delimits a sample receiving space (9) and which comprises a cutting geometry (11) or a cutting shoe at a leading end , characterized in that the sample receiving housing (10) comprises a closure, with which an airtight seal of the sample receiving space can be produced. Apparatus according to claim 1, characterized in that the closure comprises a spherical, half-shell-shaped closure body (12) which is displaceable between a first open position and a second closed position, which forms a concave bottom of the sample receiving space (9) in the first open position and enclosing a core sample in the second closed position. Apparatus according to claim 2, characterized in that the closure body (12) is designed as a sample spoon, which dissolves the core sample from the sediment formation in a movement from the first position to the second position. Device according to one of claims 1 to 3, characterized in that the closure body (12) is displaceable spring-actuated. Apparatus according to claim 4, characterized in that the sample receiving space (9) has a spring-mounted bottom plate (24), the edge against at least one Enclosed wall (27) of the sample receiving space (9) is sealed and forms with the closure body (12) has a cavity (13) for enclosing the core sample. Apparatus according to claim 1, characterized in that the closure comprises a shutter (18) having a plurality of lamellar closure bodies (12) defining an approximately circular shutter opening with a variable diameter. Apparatus according to claim 1, characterized in that the closure is designed as a flap closure with two sealingly closing closure caps (12) against each other. Device according to one of claims 1 to 7, characterized in that the sample receiving housing (10) as preferably releasably attached to the carrier tool (1) mounted container (14) is formed. Device according to one of claims 1 to 8, characterized in that the sample receiving container has a Vergussmassenanschluss which communicates with the sample receiving space (9) and over which the sample receiving space (9) is sealable with a potting compound. Apparatus according to claim 8 or 9, characterized in that the carrier tool (1) comprises a Vergussmassenreservoir (16) which is connected to the sample receiving space (9). Device according to one of claims 1 to 10, characterized in that the closure comprises a drive, which is selected from a group comprising electrical, pneumatic, hydraulic or mechanical drives. Device according to one of claims 1 to 10, characterized in that the closure is actuated by a transmission, which converts an axial movement or a rotational movement of the carrier tool (1) in a displacement movement of a closure body (12). A method for removing core samples from sediment formations with a device comprising a carrier tool (1) and a sample receiving housing (10) attached to the carrier tool which delimits a sample receiving space (9) and which comprises a cutting geometry (11) or a cutting shoe at a leading end, wherein the sample receiving chamber (9) is sealable with a closure substantially airtight, the method comprising driving the sample container into an undisturbed sediment formation, such that the core sample to be sampled is at least partially enclosed by the sample receiving space (9), wherein in one following process step, the sample receiving space (9) is sealed in situ and sealed and then the sample receiving housing (10) via the carrier tool (1) is pulled. A method according to claim 13, characterized in that the sample receiving space (9) is completed in situ with a potting compound. Method according to one of claims 13 or 14, characterized in that it is carried out using a device having the features of one of claims 1 to 12.

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