DK3059384T3

DK3059384T3 - Device and method for extracting core samples from sediment formations

Info

Publication number: DK3059384T3
Application number: DK16155791.3T
Authority: DK
Inventors: Volker Herwig; Daniel Bartminn
Original assignee: Innogy Se
Priority date: 2015-02-17
Filing date: 2016-02-16
Publication date: 2018-09-10
Also published as: EP3059384B1; ES2686099T3; EP3059384A1; DE102015202836A1; LT3059384T; PL3059384T3

Description

DEVICE AND METHOD FOR TAKING CORE SAMPLES FROM SEDIMENT FORMATIONS

The invention relates to a device and a method for taking core samples from sedimentary formations with a carrier tool and with a sample-receiving housing mounted on the support tool that defines the sample-receiving space and which comprises a cutting geometry or a cutting shoe on a leading end.

What are termed core cutters are known for removing soil samples from a footing, said core cutters comprising a rod linkage as a carrier tool and a thin-walled steel cylinder attached to the rod linkage, which is driven into the footing with a leading cutting shoe. In this way, a soil sample to be removed penetrates into the hollow space enclosed by the steel cylinder. If the steel cylinder withdrawn, what is termed the core sample or probe sample is in the hollow space enclosed by the steel cylinder and remains there due to the cohesiveness of the withdrawn sediment. The steel cylinder is detachably mounted on the support tool, for example on a rod linkage. Immediately after removing the probe sample from the footing, the steel cylinder is separated from the carrier tool and closed air-tight with one or more rubber caps.

Furthermore, devices for removing core samples from earth formations are known, which are fixed, for example at the leading end of a drilling rod linkage. Such a device for the removal of core samples from earth formations through which has been drilled a cylindrical borehole is known, for example, from DE 1814449 A1.

At the foundation of offshore wind farms and offshore oil production facilities or even at the foundation of onshore footings in which metal foundation structures are driven into the footing, bacterial anaerobic corrosion of the metal structures located in the footing can occur. Bacterial anaerobic corrosion is an oxidation of metals indirectly induced by bacteria. In particular, in a moist environment and the presence of sulphur bacteria in the footing, partial decomposition of structures introduced into the footing can occur. This problem often arises when single pipes, steel bulkheads, oil tanks, or piles from foundation structures are laid in the ground in the seabed subsoil.

For the purpose of footing investigation, it would be useful and desirable to be able to carry out an air- and pressure-tight sampling so that the removed sample can reliably be tested for the bacterial composition thereof.

Such a pressure- and air-tight sampling of sedimentary formations is also desirable and advantageous from other perspectives.

As mentioned at the outset, up to the present soil samples are removed with what are termed core cutters, wherein attention is generally paid during the removal so that the core sample is intact and representative of the structure removed. As a rule, an exclusion of air from the sample container immediately after the sampling is also ensured so that the sample reaches a laboratory in an essentially undisturbed state. A known method for soil sample removal is described, for example, in DIN 4021. This method, however, suffers from the disadvantage that an isolation of the sample according to the original environment thereof is thus possible only with difficulty because the air-and pressure-tight isolation of the sample is ensured only after the removal from the relevant sediment formation. A device and a method for the removal of core samples from sedimentary formations is known, for example, from US 2012/0073875 A1. An air-tight isolation of the sample obtained cannot be produced with the device.

The documents US 3,383,131, EP 1 154 076 A1, US 2005/013327 A1, US 4,646,843, US 3,952,817, US 3,807,234, and US 1,655,64 can be taken as further prior art.

The object of the invention is thus to provide a device and a method for the removal of core samples from sedimentary formations which takes this problem into account.

The object is achieved with a device according to the subordinate device claims and a method according to claim 9. Advantageous embodiments of the invention arise from the respective dependent claims.

One aspect of the invention relates to a device for the removal of core samples from sedimentary formations with a carrier tool and with a sample-receiving housing mounted on the support tool which defines a sample-receiving space and which comprises a cutting geometry or a cutting shoe at a leading end, wherein the sample-receiving housing comprises a closure with which a substantially air-tight closure of the sample-receiving space in situ can be produced.

According to the invention it is thus provided to isolate the sample-receiving housing with a closure such that this closure can be closed in situ, that is, still within the sediment formation from which a core sample is to be withdrawn. In this way, an essentially airtight and pressure-tight isolation of the core sample within the sample-receiving space is possible before the core sample is withdrawn.

This is based on the finding that alternatively, a structural change would inevitably take place when withdrawing the core sample with a steel cylinder open from the bottom or a core tube open from the bottom. Under certain circumstances, even a shift of layer boundaries and consistency limits of the sediment in the sample cannot be avoided. With the device according to the invention, exposure of the core sample during withdrawal to another environment which does not match the surrounding environment of the respective sediment formation is reliably prevented.

With a device according to the present invention, a core sample or probe sample can be obtained in a pressure- and air-tight manner at the exploration location. Thus, the provided sample can be retrieved according to the ambient environment prevailing at the exploration location, except for the temperature, and then stored accordingly.

For the purposes of the invention, a drilling rod linkage, a guide rod linkage, ora different kind of rod linkage can be understood as a carrier tool, via which the sample-receiving housing can be brought into the sediment formation to be sampled.

For the purposes of the present invention, a steel cylinder can be provided as a samplereceiving housing which in the leading end in the feed direction is opened at least up to the feed in the sediment formation to be sampled.

For the purposes of the present invention, a cutting geometry or a cutting shear is understood as a peripheral edge or a peripheral rim of an opening of the sample-receiving housing.

In a particularly advantageous variant of the device according to the invention, it is provided that the closure comprises a closing body shaped as a spherical half shell 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 encloses a core sample in the second closed position. This half-shell closure or hemispherical closure can comprise a single half shell which is displaced by a rotation about a virtual centre of the sphere from a first open position to a second closed position.

Alternatively, the closure can comprise two closure bodies shaped as quarter shells which are displaceable in opposite directions to each other and thus perform an opening movement and a closing movement.

The closure body advantageously has the form of a sample tray so that through displacement from the first opened position to the second closed position it cuts out or removes a part of the core sample from the sediment formation.

If the closure comprises two closure bodies shaped as quarter shells, this quarter-shell closure body also advantageously forms a type of sample spoon.

In an advantageous embodiment of the device according to the invention, it is provided that the displacement of the closure body can be actuated by spring force. 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 way, a spring acting on the closure body can be pre-tensioned by the driving of the carrier element in the footing to be sampled, whereas a tensile force applied to the carrier element effects a relaxation of the spring, preferably having the form of a compression spring, whereby a displacement of the closure body into the second closed position is effected.

In a particularly expedient design of the device according to the invention, it is provided that the sample-receiving space housing has a spring-loaded bottom plate, which is peripherally sealed off against a boundary wad of the sample-receiving space and which forms a cavity to enclose the core sample with the closure body.

In an alternative variant of the device according to the invention, the closure comprises a closure plate with a plurality of lamellar closure bodies which define an approximately circular closure opening with variable diameter. The closure bodies form an iris diaphragm, which can be brought from a first opened in a second closed position by a rotation of parts of the sample-receiving housing. Preferably, the closure has the form of a dual-iris lamellar closure, wherein a leading first tier of the closure plate can be used to separate out the core sample or the probe sample from the sediment formation. A second tier of the closure plate can be used exclusively for the sealing of the sample-receiving space. Of course, the closure can also have the form of a single tier.

Between the first and second tier of the closure plate, an interstitial space can be provided as a sluice which is can be filled with a casting compound.

Similar to the operation of a camera shutter, a lamellar closure is integrated into a cover cap of the sample-receiving housing. The closure plate is open during the process of the sample-receiving housing penetrating into the footing. Before the core sample is subsequently retrieved, the closure plate is closed. The lamellar closure bodies that are loaded under pressure during retrieval of the core sample through the sample body in the closed state represent a pressure- and air-tight isolation of the core sample.

The pressure- and air-tight 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 closure plate can be initiated by a rotational movement of the carrier tool. For example, a cover cap of the sample-receiving housing can be formed to be rotatable to a boundary wall of the sample-receiving housing.

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

Alternatively, it can be provided that the closure is formed as a flap closure with at least two mutually sealing closure flaps.

As already mentioned above, it is convenient when the sample-receiving housing is formed as preferably releasable on the sample-receiving container mounted on the carrier tool, for example, in the form of a cylinder.

Conveniently, the sample-receiving housing is provided with a casting compound connection which communicates with the sample-receiving space and through which the sample-receiving space is sealable with a casting compound. The casting compound can, for example, be a paraffin or another viscous sealant.

The sample-receiving housing or the sample-receiving space is advantageously provided at trailing end thereof in the feed direction with at least one vent opening so that the air within the sample-receiving space can escape during the insertion. The sample-receiving space can be sealed up in situ by means of the casting compound which, for example, can have the form of paraffin or another sealant.

On or in the carrier tool can be provided a casting compound reservoir which is connected to the sample-receiving space, and which can thus be put under pressure, for example, after advancing the sample-receiving housing into the sediment formation to be sampled, such that the casting compound seals up the sample-receiving space or penetrates thereinto.

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 preferably serves to displace the closure body or closure bodies.

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

Another aspect of the invention relates to a method for removing core samples from sedimentary formations with a device comprising a carrier tool and a sample-receiving housing mounted on the carrier tool which defines a sample-receiving space and which comprises a cutting geometry or a cutting shoe at a leading end, wherein the samplereceiving space can be closed off in a substantially air-tight manner by a closure, wherein the method comprises driving the sample-receiving container into an undisturbed sediment formation in such a way that the core sample to be removed is enclosed at least partially by the sample-receiving space, wherein in a following method step, the samplereceiving space is closed and sealed in situ by a casting compound and then the samplereceiving housing is withdrawn via the carrier tool.

Preferably, the sample-receiving space is closed off or sealed up in situ with a casting compound before the core sample is withdrawn.

The method according to the invention is preferably carried out using a device with one or more of the features described above, and ideally in an arrangement corresponding to the geometrical boundary conditions of the standard and well-known sampling devices. In particular, with respect to the diameter of the withdrawn test body, it is advantageous to comply with the known dimensions according to standards. Therefore, the invention comprises the above-described devices, preferably arranged vertically.

The invention is explained below on the basis of an exemplary embodiment shown in the drawings.

Brief description of the drawings:

Figure 1 shows a device for the removal of core samples according to the prior art,

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

Figures 3a, 3b show a second embodiment of the device according to the invention, wherein 3a shows a partially sectional side view, and 3b shows a bottom view, and

Figures 4a, 4b illustrate a third embodiment of the device in accordance with the invention, wherein 4a shows the sample receiver with a closed closure.

Reference is first made to Figure 1, which shows a device for the removal of core samples according to the prior art.

In all of the drawings, the same components are denoted by the same reference numerals.

The device illustrated in Figure 1 comprises a carrier tool 1 in the form of a rod linkage, which is slidably arranged in a guide cover 2. The guide hood 2 comprises a guide plate 3 with which the device can be set up on a footing 4. A core cutter 5 is arranged at the leading end of the carrier tool 1 inside the guide cover 2. The core cutter 5 is formed as a thin-walled steel cylinder that is open on its leading side. An anvil 6 is attached at the end of the carrier tool 1 or the carrier rod distal to the core cutter 5, on which a drop weight 8 directed by a strike rod linkage 7 can act. The carrier tool 1 with the core cutter 5 is driven into the footing 4 via the drop weight 8 guided by the strike rod linkage 7. The sample-receiving space 9 enclosed by the core cutter is then filled with the probe sample or the core sample. When the core cutter 5 is withdrawn, the core sample is located in the sample-receiving space 9 enclosed by the core cutter 5. It is not assured that the layer boundaries and consistency limits of the core sample will be retained during withdrawal of the core cutter 5. In the sample-receiving space 9, approximately enclosed air can escape via a vent opening, not shown.

Reference is now made to Figures 2a through 4b which show several variants of a device according to the invention.

Figure 2a shows a carrier tool 1 with a sample-receiving housing 10 in the form of an open cylinder mounted on the leading end of the carrier tool 1, which sample-receiving housing encloses the sample-receiving space 9 and is provided with a peripheral cutting geometry 11 at the leading end thereof.

The cutting geometry 11 is a circumferential, optionally sharpened rim which forms the opening 19 of the sample-receiving space 9 pointing in the feed direction of the device. The sample-receiving housing 10 further comprising a closure body 12 which in the exemplary embodiment according to Figures 2a and 2b is designed as a half-shell closure, that is, having a spherical, half-shell shape. The closure body 12 is rotatable about an imaginary centre point which defines the radius of the closure body 12, and indeed rotatable from the position shown in Figure 2a to the position shown in Figure 2b. Figure 2a shows the closure body 12 in the first opened position, and Figure 2b shows the closure body 12 in the second, closed position.

In the position shown in Figure 2a, the closure body 12 defines a bottom of the samplereceiving space 9. In the case of this exemplary embodiment, the closure body 12 forms a cavity 13 for receiving a core sample. The sample-receiving housing 10 has the form of a cylindrical container 14 which communicates via an opening formed as casting compound connection 15 with a casting compound reservoir 16 within the carrier tool 1. A paraffin is provided as a casting compound that can enter from the casting compound reservoir 16 via the opening 15 into the housing 14. The closure body located in the open position 12 seals the housing 14 against the escape of casting compound.

In the method according to the invention, it is initially provided that the sample-receiving housing 10 or the cylindrical container 14 advances via the carrier tool 1 into the sediment formation of the footing 4 to be sampled. In this way, the footing 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, moves into the second, closed position shown in Figure 2b, wherein the closure body 12 thereby removes the sediment from the sediment formation and encloses same in the cavity 13. The closure body 12 having moved into the second position shown in Figure 2b allows subsequent flow of the casting compound so that the casting compound completely seals off and seals up the sample-receiving housing 10.

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

The device according to the invention shown in Figures 3a and 3b likewise comprises a cylindrical container as a sample-receiving housing 10, which cylindrical container has a circumferential cutting geometry 11 which encloses a leading, circular opening 19 of the sample-receiving space 9, which component is a cover cap 17 that is rotatable relative to the housing 14. In the exemplary embodiment according to Figures 3a and 3b, the entire housing 14 forms the sample-receiving space 9 in the sense of the invention.

Into the cover cap 17 is integrated a closure plate 18 as a two-tier iris diaphragm, wherein said closure plate 18 comprises a plurality of lamellar closure bodies 12. Moreover, the cylindrical container 14 is also provided with a casting compound connection on the side thereof facing towards the carrier tool 1. Within the carrier tool 1 is provided a casting compound reservoir with a casting compound, for example, in the form of a paraffin. A rotation of the cover cap 17 relative to the housing 14 effects an opening and closing of the closure plate 18, wherein the closure plate 18 comprises a first tier 20 facing away from the sample-receiving space 9 and a second tier 21 facing towards the samplereceiving space 9, which first tier and second tier include a sluice 22 therebetween. The sluice 22 communicates via a channel 23 with a casting compound reservoir 16 within the carrier tool 1.

The sample-receiving housing 10 is driven on the carrier tool 1 with open closure plate 18 into the footing 4 so that the core sample is enclosed by the housing 14 or by the sample-receiving space 9. Then, the closure plate 18 is closed via a rotational movement of the carrier tool, wherein on the one hand, the sediment body or the core sample is separated, and on the other hand the sample-receiving space 9 is closed in a substantially pressure-tight manner. Then, the casting compound is introduced into the sluice 22 via the channel 23 so that the sample-receiving space 9 is sealed off and sealed up. Another variant of the device according to the invention is shown in Figures 4a and 4b. Within the housing 14 is likewise a closure body 12 arranged in the form of a spherical half-shell. As in the exemplary embodiment according to Figures 2a and 2b, the closure body 12 rotatably arranged about an imaginary centre point that defines the radius of curvature of the closure body 12 within the container 14 or within the sample-receiving space 9, and likewise forms a cavity 13 for receiving the core sample. In the first opened position of the closure body 12, which is shown in Figure 4a, the vertex of the convex side of the closure body 12 bears against a spring-mounted bottom plate 24 in the samplereceiving space 9.

The bottom plate 24 is supported via a compression spring 25 against a front wall 26 remote from the front opening of the housing 14. In addition, the bottom plate is peripherally sealed off against a boundary wall 27 of the sample-receiving space 9. During the advance of the carrier tool 1 into the footing 4, the sediment penetrates into the container 14 and into the cavity 13 of the closure body and displaces the closure body 12 with the bottom plate 24 in the direction of the front wall 26 of the housing 14, wherein the compression spring 25 is tensioned.

If the carrier tool 1 is then withdrawn, 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 off against the bottom plate 24.

As with the previous exemplary embodiments, it can be provided that a casting compound is introduced from the casting compound reservoir 16 in the container 14 via the opening 15 in the front wall 26 of the container 14, and the container 14 is sealed up.

After removal of the carrier tool 1 from the sediment formation or from the footing, the container 14 is released from the carrier tool 1 and is disposed of accordingly.

List of reference symbols 1) Carrier tool 2) Guide cover 3) Guide plate 4) Footing 5) Core cutter 6) Anvil 7) Strike rod linkage 8) Drop weight 9) sample-receiving space 10) Sample-receiving housing 11) Cutting geometry 12) Closure body 13) Cavity 14) Container 15) Opening 16) Casting compound reservoir 17) Cover cap 18) Closure plate 19) Opening 20) First tier of the closure plate 21) Second tier of the closure plate 22) Sluice 23) Channel 24) Bottom plate 25) Compression spring 26) Front wall 27) Boundary wall

Claims

Device and method for extracting core samples from sediment formations

An apparatus for sampling core samples from sediment formations with a holding tool (1) as well as with a sampling housing (10) disposed on the holding tool (1) defining a sampling space (9) and comprising a cutting geometry (11) or a drill shoe at a leading end, wherein the sample housing (10) comprises a closure such that the closure comprises a spherical, semi-bowl-shaped closure body (12), characterized in that the closure body can be displaced between a first open position and a second closed position, the first open position forms a concave bottom of the sample compartment (9) and in the second closed position a core sample encloses that the sample compartment (9) is provided with a bottom plate (24) which is resiliently sealed to the edge side thereof. at least one enclosing wall (27) in the sampling room (9), which together with the closure body (12) forms a cavity (13) for enclosing core samples, so that an airtight closure can be formed of the sample collection room.

Device according to claim 2, characterized in that the closure body (12) is designed as a test case which, in a movement from the first position to the second position, extracts the core sample from the sediment formation.

A device for sampling core samples from sediment formations with a holding tool (1) as well as with a sampling housing (10) disposed on the holding tool (1) defining a sampling space (9) and comprising a cutting geometry (11) or a drill shoe at a leading end, wherein the sample housing (10) comprises a closure, characterized in that the closure is formed as a flap closure with two closure caps (12) closing with a sealing effect relative to each other with which an airtight can be formed closing the sampling room (9).

Device according to one of claims 1 to 3, characterized in that the sample housing (10) is formed as a container (14), which is preferably detachably mounted on the holding tool (1).

Apparatus for sampling core samples from sediment formations with a holding tool (1) as well as with a sampling housing (10) disposed on the holding tool (1) defining a sampling space (9) and comprising a cutting geometry (11) or a drilling shoe at a leading end, wherein the sample housing (10) comprises a closure, characterized in that the closure can form an airtight closure of the sample collection space (9) and that the sample collection housing (10) is provided with a molding mass connection which is connected with the sampling room (9) and through which the sampling room (9) can be sealed with a casting material.

Device according to claim 5, in which the sample collection housing (10) is formed as a container (14) which is preferably detachably arranged on the holding tool (1), characterized in that the holding tool (1) comprises a casting mass reservoir (16) which is connected to the sampling room (9).

Device according to one of claims 1 to 6, characterized in that the closure comprises a drive mechanism selected from a group comprising electric, pneumatic, hydraulic or mechanical drives.

Device according to one of claims 1 to 7, characterized in that the closure can be actuated via a drive which converts an axial or rotational movement of the holding tool (1) to a displacement movement of a closure body (12).

A method for sampling core samples from sediment formations with a device comprising a holding tool (1), as well as with a sampling housing (10) disposed on the holding tool (1) defining a sampling space (9) and comprising a cutting geometry (11) or a drilling shoe at a leading end, wherein the sample housing (9) can be closed substantially airtight with a closure, the method comprising introducing the sample container into an undisturbed sediment formation in such a way that the core sample to be sampled, at least partially enclosed by the sampling compartment (9), the sample compartment compartment (9) being closed in situ with a casting mass in a subsequent process step, after which the sampling housing (10) is pulled over the holding tool (1).

Method according to claim 9, characterized in that it is carried out using a device with the features of one of claims 1 to 8.