US3434551A - Buoyant coring apparatus - Google Patents

Description

March 25, 1959 A. M. ROSFELDER BUOYANT GORINGi APPARATUS Sheet Filed June 26, 1967 FIG.

FIG. 2.

March 25, 1969 A. M. ROSFELDER 3,434,551

BUOYANT comm APPARATUS Filed June 26, 1967 Sheet 2 of 2 g INVENTOR.

ANDRE M. ROSFELDER ATTORNEY.

US. Cl. 175-6 1t] Claims ABSTRACT OF THE DISCLOSURE The description discloses a buoyant rig for supporting coring operations of an underwater coring barrel. The buoyant rig includes a fioat and a bottom weighted stand which are interconnected by at least one guide wire. The core barrel slidably extends through the weighted stand and is positioned parallel to the guide wire and is slidable therealong by a guide means. When the core barrel is powered the barrel will be guided along the guide wire as it penetrates the ocean bottom. A gimbal connection between the core barrel and the stand for uneven ocean bottoms and the guide wire may be separated from the stand after a sample is obtained so that the float will raise the core barrel and the remaining rigging apparatus to the ocean surface.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

In deep sea coring operations it is highly impractical to attempt drilling from a surface ship because of the weight of the long driving elements which would be required between the ship and the coring barrel. One of the easiest methods of obtaining a deep sea core sample is to utilize a free corer such as that illustrated in the patent to Charlton et al., US. Patent No. 3,295,616, or that illustrated in a patent to Moore, US. Patent No. 3,078,931. While such free fall coring devices are simple to operate, the length of core sample obtainable therefrom is limited since the driving force for a such a corer is entirely dependent upon the submerged weight of the device.

In order to obtain long core samples from a deep sea environment it is necessary that the coring barrel be powered by a submerged power means and that some sort of rigging be set up on the ocean floor to support the core barrel during the driving operation. Conventional rigging has taken the form of tripods, quadripods, or other kinds of rigid frames. This type of rigging has been very difiicult to handle aboard an oceanographic vessel and also it is very difiicult to set up firmly on an uneven ocean bottom. In view of the increasing demand for deep sea core samples, there now exists an urgent need for a simpler rigging apparatus which can be easily handled.

The present invention provides a rigging apparatus which is not perplexed with the problems of material handling and set up on the ocean bottom. This has been accomplished essentially by a float and a bottom weight stand which are interconnected by one or two guide wires. The core barrel slidably extends through the weight stand and upon penetration into the ocean bottom the guide wire acts as a rail in guiding the downward movement. Such an arrangement avoids the complexities of conventional rigid framed rigs and is much simpler to handle from an oceanographic vessel. Of considerable importance is the ease with which such an arrangement can be set up on the ocean bottom. The weight stand provides the lowest possible center of gravity of the overall apparatus and will quickly assume a steadfast position on the ocean bottom. 70

On uneven bottoms the present invention may be easily adapted to obtain vertical core samples. This may be ac- 3,434,551 Patented Mar. 25, 1969 complished by a gimbal connection between the coring barrel and the weighted stand. The coring operation may also be facilitated by a piston which is slidably disposed Within the coring barrel and is attached by a wire to the float. This piston will cause a suction which facilitates entry of the bottom sediment into the coring barrel. The present invention also lends itself to a quick and easy retrieval of the coring barrel after a bottom sample has been obtained. This may be accomplished by a means for separating the guide wire from the weight stand whereupon the float will withdraw the coring barrel from the ocean bottom and raise the apparatus less the weight stand to the ocean surface.

An object of the present invention is to overcome all of the aforementioned problems of the prior art.

Another object is to provide a submerged power driven coring barrel and a simple and easy to use rigging apparatus for positioning the coring barrel on the ocean bottom.

A further object is to provide an underwater powered coring barrel and bottom rigging apparatus therefor which, after the core sample has been obtained, can be raised to the ocean surface without using at raising cable.

Still another object is to provide an underwater powered coring barrel and a bottom rigging apparatus which, upon coming to rest upon an uneven bottom, will vertically position and guide the coring barrel during its penetration of the ocean bottom.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a schematic side view, partly in cross section, showing a coring barrel positioned by a rigging apparatus on the ocean bottom;

FIG. 2 is an enlarged detail illustration of the connection of the coring barrel to the weighted stand;

FIG. 3 is a schematic side illustration, partly in cross section, showing another embodiment of my invention wherein a coring barrel is supported on the ocean bottom by a buoyant rigging apparatus; and

FIG. 4 is a schematic side view, partly in cross section, illustrating still another embodiment of my invention.

Referring now to the drawings wherein like reference numerals designate like or similar parts throughout the several views, there is shown in FIG. 1 a coring barrel 10 which is supported in a coring position on the ocean floor by a buoyant rigging apparatus which is generally designated at 12. The rigging apparatus 12 includes a weighted bottom stand 14 and a float 16 which are interconnected by a guide wire 18. The guide wire 18 may be connected directly to the weighted stand 14 or as shown may be connected to other elements which are in turn connected to the weighted stand. Because of the action of the float 16 the guide wire 18 will assume a vertical positoin which is desirable for coring operations to be described hereinafter.

The coring barrel 10 slidably extends through the weighted stand 14 and as shown this may be accomplished by a support sleeve 20 which slidably receives the coring barrel and is connected by suitable means to the weighted stand 14. For flat bottom coring the support sleeve 20 may be rigidly connected in an upright position to the Weighted stand 14, however on an uneven bottom such an arrangement will result in a non-vertical core. To obtain vertical core samples from an uneven ocean bottom I have found it desirable to connect the support sleeve 20 to the weighted stand 14 by a gimbal arrangement 22 (see FIG. 2). The support sleeve 20 and the weighted stand 14 may form inner and outer rings respectively of the gimbals with a middle ring alternately pinned thereto at intervals. Accordingly, when the weighted stand is brought to rest on the ocean bottom the coring barrel l0 will have freedom of movement in any direction thereabove.

It is highly desirable during coring operations to obtain a vertical core sample since all coring data is documented and correlated on a vertical depth basis. The obtaining of a vertical core sample from an inclined ocean bottom is quite difiicult with conventional corers. I have enabled vertical core sampling by utilizing the vertical extension of the guide wire 18. This may be accomplished by a means which slidably interconnects the core barrel to the guide wire 18 for positioning the barrel substantially parallel to the guide wire and guiding penetration of the barrel along the vertical extension of the wire. This positioning and guidance may be simply a guide tube 24 which receives the guide wire 18 and may be rigidly connected to the side of the core barrel 10 by any suitable means such as welding.

The particular coring barrel 10 shown in FIG. 1 is powered by a vibrohammer 26 which may be rigidly connected at the top of the coring barrel 10, the coring barrel 10 having a port 28 immediately below the vibrohammer for discharging water in the coring barrel upon penetration. The vibrohammer 26 may be hydraulically operated by a pump (not shown) mounted on the weighted stand 14, or alternatively may be electrically powered by an electric cable 30 which extends from a surface ship (not shown), The electric cable 30 extends first to a ring 32 which is slidable along the guide wire 18, thence to the bottom of the float 16, and then to a spring actuated reel 34 which may be mounted at the top of the vibrohammer 26. From the reel the electric cable 30 is electrically connected to the vibrohammer and is unreeled as the coring barrel 10 penetrates the ocean bottom.

In order to facilitate penetration of the coring barrel 10 into the ocean bottom I have found it desirable to slidably mount a piston 36 within the coring barrel 10 and connect the piston to the float 16 by a wire 38 which extends longitudinally along the interior of the coring barrel 10. Accordingly, when the coring barrel is operated to penetrate the ocean bottom the piston 36 will remain stationary on the ocean bottom and provide a suction force within the coring barrel immediately above the core sample. Upon withdrawal of the coring barrel 10 from the ocean bottom there will be a tendency for the piston 36 to be drawn downwardly within the coring barrel because of suction in the coring hole immediately below the coring head of the barrel. This action would result in a loss of the core sample and is highly undesirable. Loss of the core sample may be prevented by a locking means 40 which is connected at the top of the coring barrel 10 and receives the wire 38 for locking the piston wire to prevent downward movement of the piston 36 within the coring barrel. The locking means 40 may be actuated by the vibrohammer 26 and unlocked. During raising and lowering of the rig the clamp means 40 will lock the wire 38 in place since during these periods the vibrohammer is inoperative.

In the embodiment shown in FIG. 1 the float 16 is utilized for the purpose of raising the coring barrel 10 to the surface of the water after a sample has been obtained. This has been accomplished by separating the guide wire 18 from the weighted stand 14 and making the float 16 sufliciently buoyant to withdraw the coring barrel 10 from the ocean bottom and lift the coring barrel, its sample, and the rigging except for the weighted stand 14 to the surface of the water. The guide wire 18 may be separated from the weighted stand 14 by an annular explosive bolt (not shown) which is disposed within the slidable ring 32. The explosive bolt will be actuated by an initiator (not shown) which is connected to and is actuated by a small electric wire (not shown) which extends along the cable 30. In order to perform the raising operation after separation of the guide wire 18, the clamp means 40 locks the piston wire 38. As a supplementary raising means, a raising head 42 may be rigidly connected at a desired location on the guide wire 18 above the sliding ring 32. This raising head 42 serves as a stop for the downward penetration of the coring barrel 10 when the head 42 comes into engagement with the bottom of the guide tube 24. When core penetration has ceased due to this stopping action, the electrical load on the vibrohammer 26 will be lessened which can be detected at the surface ship as an indication that the coring barrel has penetrated the ocean bottom to a desired depth. Upon such an indication the explosive bolt within the ring 32 can be actuated to cut the guide wire below the raising head 42. The raising head 42 may be adjustable along the guide wire 18 so as to select the desired depth of penetration of the coring barrel 10.

The float 16 may be simply a hollow spherical glass float. The weighted stand 14 may be constructed of any suitable heavy material such as concrete and should be heavy enough to provide a negative buoyancy for the entire apparatus when it is connected thereto. The weighted stand 14 preferably has a large lateral bottom area so as to ensure secure emplacement on the ocean bottom.

In the operation of the FIG. 1 embodiment the coring barrel 10 and the rigging apparatus 12 are placed in the water from a surface ship. The weighted stand 14 causes the entire assembly to descend in an upright position and come to rest on the ocean bottom. If the ocean bottom is uneven and the weighted stand 14 assumes a slanted position, as shown in FIG. 1, the float 16, by action of the guide wire 18, pivots the coring barrel 10 within the gimbals 22 to cause the coring barrel to assume an upright position. The surface ship then feeds electrical power to the vibrohammer 26 which causes the coring barrel 10 to penetrate the ocean bottom. The coring barrel 10 is guided in a downward vertical direction by action of the guide tube 24 about the guide wire 18. When the bottom of the guide wire 24 engages the top of the raising head 42 penetration ceases which will lessen the electrical load on the vibrohammer 26. When this change in electrical load is detected at the surface ship the explosive bolt charge within the sliding ring 32 is actuated to cut the guide wire 18 below the raising head 42. This then releases the float 16 and the coring barrel 10 from the weighted stand 14. The upward force of the float 16 is applied to the coring barrel through the locked clamp means 40 and/ or to the bottom of the guide tube 24 by the raising head 42 to cause Withdrawal of the coring barrel 10 from the coring hole and the support sleeve 20 and raise the entire assembly less the weighted stand to the surface of the water. The assembly will then float on the surface of the water until retrieved by the surface ship.

In FIG. 3 there is shown another embodiment of the invention which is similar to the FIG. 1 embodiment except that the FIG. 3 embodimentshows the use of a hydraulic jet type coring barrel 44 which is not gimbal mounted in a weighted stand 46. The jetting action of the coring barrel 44 is enabled by a short tube 48 which is mounted about the coring barrel just above the cutting head. The short tube 48 is sealed at its top and bottom to the coring barrel with the exception of a series of small ports 50 at its bottom end and a rigid hydraulic duct 52 which opens into the top of the tube 48 and extends longitudinally upward along the side of the coring barrel. A hydraulic pump 54 is connected to the top of the duct 52 by a hose 56 for interjecting water through the ports 50. The jetting action of the water through the ports 50 cuts the bottom sediment to allow downward penetration of the coring barrel 44. The pump 54 may be electrically powered by a cable 58 from the surface ship.

The coring barrel 44 may extend slidably through the weighted stand 46 by a support sleeve 60. The exterior of the sleeve 60 may be rigidly fixed to the weighted stand and the coring barrel 44 will be slidable therethrough. The support sleeve 60 will be provided with an annular depression (not shown) for slidably receiving the duct 52 along the side of the coring barrel.

A slip ring 62 (not containing an explosive bolt) is used for raising and lowering the whole assembly by engagement with the bottom of guide tube 24. The clamp means 40 is a one way lock of the piston wire 38 allowing the piston 36 to only slide in an up direction within the coring barrel 44. This clamp means may simply comprise a pair of eccentric clamps.

Still another embodiment of the present invention is shown in FIG. 4. The FIG. 4 embodiment differs from the previously described embodiments in that two guide wires 18 are used for interconnecting the float 16 to the weighted stand 14. A coring barrel 64 is slidably mounted through the weighted stand 14 by the support sleeve 20 and gimbal means 22. The coring barrel 64 is disposed between the guide wires 18 and at its top it is provided with a rotary head 66 for rotatably driving the coring barrel 64 into the ocean bottom. Upon such driving action ports 68 within the top of the coring barrel 64 discharge water trapped therein.

A pair of guide tubes 24, each receiving a respective guide wire 18, are mounted at opposite sides to the rotary head 66. The rotary head 66 may be operated hydraulically by a pump 54 which is connected to the head by a hose 56. If expendable, the pump 54 may be mounted on the stand 14 and if not it may be mounted on top of the rotary head 66. The hose 56 is provided with a quick pull disconnect 70 and may be fed into the top of the head by a pulley 72 mounted at the bottom of the float 16.

Since operation of the rotary head 66 will tend to apply a twisting action to the guide wires 18, oppositely directed ports 74 may be provided within the head for providing a jetting action to counteract the torque of the rotary head.

In a manner similar to the FIG. 1 embodiment, each of the guide wires 18 of the FIG. 4 embodiment is provided with a respective lifting head 42 and an explosive bolt ring 32 for cutting the guide wire 18 therebelow.

The operation of the FIG. 4 embodiment is similar to the FIG. 1 embodiment. When the bottom of the guide tubes 24 come to rest on the lifting heads 42 the load on the rotary head 66 is lessened and this indication tells surface personnel to actuate the explosive rings 32. The explosive rings 32 cut the guide wires 18 and the float 16 lifts the whole assembly with the exception of the weighted stand 14 and the pump 54 to the water surface. The hose 56 will be disconnected by the quick disconnect 70.

It is now readily apparent that the present invention provides a deep sea coring apparatus which is considerably more efficient to handle than conventional corers.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

I claim:

1. In combination with an underwater powered core barrel, a buoyant rig comprising:

a weighted bottom stand adapted to rest on the ocean bottom, said core barrel extending slidably therethrough;

at least one guide wire connecting the float to the stand so that the float will extend the wire substantially vertically upright from the stand; and

means slidably interconnecting the core barrel to the guide wire for positioning the barrel substantially parallel to the guide wire and guiding penetration of the barrel along the vertical extension of the wire.

2. The combination as claimed in claim 1 including:

means for separating the guide wire from said stand.

3. The combination as claimed in claim 2 wherein:

said float is sufliciently buoyant to lift the rig and barrel with a sample after separation of the guide.

wire.

4. The combination as claimed in claim 1 wherein:

gimbal means slidably interconnects the core barrel to said stand.

5. A combination as claimed in claim 1 including:

a second guide wire connecting the float to the stand so that the float will extend the second wire substantially vertically upright from the stand;

a second means slidably interconnecting the core barrel to the second guide wire and cooperating with the first mentioned positioning means for positioning the barrel substantially parallel to the guide wires and guiding penetration of the barrel along the vertical extension of the wires.

6. A combination as claimed in claim 1 including:

a piston slidably mounted within the core barrel and adapted to remain stationary on the ocean bottom and provide a suction within said barrel as the barrel penetrates the ocean bottom;

a second wire, the second wire extending along the interior of the barrel and interconnecting the float and said piston; and

one way locking means connected to the core barrel for locking the piston wire to prevent downward movement of the piston within the core barrel.

7. A combination as claimed in claim 6 wherein:

gimbal means slidably interconnects the core barrel to said stand.

8. A combination as claimed in claim 7 including:

means for separating the guide wire from said stand.

9. A combination as claimed in claim 8 wherein:

said float is sufliciently buoyant to lift the rig and barrel with a sample after separation of the guide wire.

10. A combination as claimed in claim 9 including:

a lowering cable; and

means slidably connecting the lowering cable to the guide wire.

References Cited UNITED STATES PATENTS 3,279,547 10/1966 Berne et a1. 1756 3,372,760 3/ 1968 Raymond et al. 175-5 3,373,827 3/ 1968 Biron et al. 175-6 ERNEST R. PURSER, Primary Examiner.

U.S. Cl. X.R. 245, 248

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