Patent Application
20060169493
The present invention relates to a remote operation wire line core sampling device equipped with a core barrel for investigating bed rocks and deposits at the sea-bottom by using a stabilized sea-bottom core drill.
In conventional sea bed sampling, there are two methods, i.e., one is a method for collecting samples on the sea-bottom surface by using a dredge that linearly collects samples from the sea-bottom surface, a grab that collects samples spread over a given width from a given place on the sea bottom surface, and the other is a method for collecting samples at a given depth from the sea bottom surface. In a method generally adopted when taking samples at a depth from the sea-bottom surface, a tool called a corer is used, and a sampling tube called a core barrel is pierced through the bottom material of the sea bed to take the samples. While the corer, which utilizes its own gravity and initial piercing velocity, can pierce the ground by ten and several meters at the maximum when the ground is soft, its capacity is substantially reduced in the case of a sand bed or a somewhat hard stratum, and sample taking is impossible when the bottom material is rock.
As compared with an ordinary corer, which pierces through the bottom material solely by virtue of gravity and piercing velocity, the stabilized sea-bottom core drill, which has a rotary device and a feeding device and which can rotatingly pierce the bottom material while performing digging through rotation of the core bit at the forward end, is capable of sample collection regardless of the hardness of the bottom material, and can exert a remarkable capacity in sea bottom sampling. On the other hand, in the stabilized sea-bottom core drill, continuous core sampling cannot be effected without letting in and out the core barrel a large number of times. Therefore, it was required to repeat retrieval and reinsertion of the core barrel and the drill rod each time. An example of retrieval is performing the next stroke, and reinsertion means performing of the reverse stroke. The deeper digging place becomes, the more frequent time of retrieval and reinsertion become in geometrical progression. Thus, due to the difficulty in operating the ship connected by a dither cable and limitations in operation time, there was a limit to the depth allowing core sampling through operation of the stabilized sea-bottom core drill. The operation procedures are in the following order: drill rod pulling out; drill rod unscrewing; chuck-opening/drill-head-raising; rod movement/accommodation through manipulator; drill head lowering; chuck closing; and return.
Further, in the conventional core sampling, each time sampling collection is effected according to an effective length of a core barrel, a core barrel and the drill rod are inserted into and pulled out of the boring hole, so the hole wall of the boring hole may collapse, making it impossible for the newly inserted core barrel to reach the hole bottom. The debris of the hole wall collapsed would flow down to the hole bottom to mix into the sample to be collected, resulting in deterioration in sample quality, which was rather difficult to cope with.
In the case of wire line core sampling performed on the ground, a core barrel outer tube with a core bit mounted to the forward end thereof and a drill rod are not retrieved but solely an inner tube assembly containing the sample is retrieved on the ground through introduction of an over-shot and operation of a wire rope, with a new inner tube assembly being dropped into the drill rod to be automatically attached to the core barrel at the forward end. If this system could be applied to a stabilized sea bottom core drill, the operation of retrieving/reinserting the drill rod would have been omitted and the above-mentioned problem of hole wall collapse must have been solved. Thus, application of this system has not realized and has been ended in a hope
However, wire line core sampling performed on the ground has needed operation to be conducted by man power, such as introduction of an inner tube assembly and separation of the over-shot and the inner tube assembly. Thus, adoption of the wire line system to a stabilized sea-bottom core drill used at the sea-bottom has not been made so far.
As another conventionally known technique, an ordinary wire line sampler recovery device is disclosed (Patent Document 1). Further, there are disclosed a sliding tube containing an expandable latch equipped with a latch spring, an engagement member (spear head) arranged at the upper end thereof, an over-shot assembly grasping this engagement member, etc. (Patent Document 2).
It is an object of the present invention to modify a conventional sea-bottom core drill as described above and an instrument for wire line core sampling conducted on the ground, and to apply the wire line system to a stabilized sea-bottom core drill for use at the sea bottom, thereby achieving an improvement in terms of operational efficiency and an improvement in core sample quality through hole wall preservation.
For remote operation of a wire line core sampling system, it is necessary to provide, in addition to the performance of a conventional stabilized sea-bottom core drill, a performance allowing the following operations, which are conducted on the ground by man power:
Further, from the viewpoint of the provision of equipment for introduction/retrieval from onboard the ship and the requisite stability with respect to external forces applied thereto at the sea bottom, the height of a stabilized sea-bottom core drill is required to as small as possible.
According to the present invention, a stabilized sea-bottom core drill is used, and an instrument for wire line core sampling conducted on the ground is modified such that the wire line system can be adopted for sea-bottom use, thereby achieving an improvement in terms of operational efficiency and hole wall preservation.
It is an object of the present invention to provide a remote operation wire line core sampling device which easily allows replacement of the core sampler under the deep sea.
It is an object of the present invention to provide a remote operation wire line core sampling device for the first time which requires no operation by man power.
The above objects of the present invention can be achieved by the following composition.
That is, the present invention provides a composition of the remote operation wire line core sampling device including: a water swivel assembly; a drill rod coaxially connected to the water swivel assembly; a wire line core barrel coaxially connected to a lower end of the drill rod and having at a forward end a bit for annularly digging the ground; an inner tube assembly detachably set in the wire line core barrel; and an over-shot assembly endowed with a function of grasping an upper end portion of the inner tube assembly, characterized in that the water swivel assembly has water supply ports at an upper position and a lower position thereof, and accommodates the over-shot assembly at an intermediate position, and a pressurized fluid is supplied from the upper water supply port to make it possible to lower the over-shot assembly to the inner tube through the drill rod.
Further, the above objects can be achieved by the following composition. That is, the present invention provides the remote operation wire line core sampling device: water supply ports are provided in upper and lower parts, and a water swivel with an over-shot with a piston residing therein is arranged therebetween. Drilling heat generated through rotational digging by a core bit arranged at a forward end is removed by inflow of a fluid from the lower water supply port. At the same time, digging mud (slime) is washed away from the hole bottom. Upon completion of one sampling, an over-shot assembly is lowered to a spear head portion at the upper end of an inner tube assembly at the hole bottom through inflow of a fluid from the upper water supply port, and is engaged with the spear head in the upper portion of the inner tube assembly by a lifting dog. Solely the inner tube assembly is raised for replacement to allow an unused inner tube assembly to descend again.
Further, the above objects can be achieved by the following composition. That is, the present invention provides a remote operation wire line core sampling device including: a drill head portion of a sea-bottom core drill; a chuck rotatably mounted to the drill head portion; a drill rod grasped by the chuck; the wire line core barrel connected to the drill rod and having at a forward end the bit for annularly digging the ground; the inner tube assembly detachably provided inside the wire line core barrel; and the over-shot assembly endowed with a function of grasping an upper end portion of the inner tube assembly and raising the inner tube assembly through the drill rod, characterized in that the remote operation wire line core sampling device has a mechanism by means of which, with the drill rod being retained in a hole, the drill head is lifted upwards to extract the inner tube assembly out of the drill rod.
With the above construction, the remote operation wire line core sampling device of the present invention can attain the following effects.
There has been devised a novel water swivel in which two water supply ports are provided. From the lower water supply port, there is supplied boring water to be used for bit cooling and removal of slime from the hole bottom in boring. A novel over-shot assembly with a piston resides in the water swivel. When pressure water of a boring pump is supplied from the upper water supply port, it descends within the drill rod to reach the core barrel upper portion at the hole bottom, and the spear head at the upper end of the inner tube assembly is grasped by the lifting dog.
When a drill rod of the same effective length as the core sample collection length of the core barrel is used, and a core barrel and an inner tube assembly that are longer than the drill rod are inserted or retrieved, it is necessary to temporarily increase the retrieval stroke thereof, so there is provided a lift mechanism by means of which the drill head of the sea-bottom core drill is raised.
At the time of digging with the drill rod, a rotational torque reaction force is exerted, so the machine height is adjusted such that the core bit at the forward end of the initial core barrel comes into contact with the sea bottom surface after the lift of the drill head has been restored.
In performing core sampling with the stabilized sea-bottom core drill, the bottom material is cut annularly by rotating and feeding the bit at the forward end, accommodating the core sample remaining within in the core barrel. In the process, to cool the core bit constituting the cutter heated by drilling and to wash away the slime (drilling mud) resulting from the drilling, boring water is supplied to the hole bottom from a digging pump provided in the stabilized sea bottom core drill main body through the water swivel connected to a delivery hose, utilizing the interior of the drill rod, which is a hollow tube. The water swivel is a rotatable instrument provided with a packing and a rotary bearing to supply water from the hose to the interior of the rotating drill rod.
When digging has been performed by the sampling length of the core barrel, the core barrel is replaced. In conventional boring, the drill rod is all retrieved each time the core barrel is to be replaced, replacing the core barrel at the forward end. In the novel core sampling, a wire line core barrel is used. Solely the inner tube assembly containing the core sample is extracted by a wire rope without retrieving the core barrel outer tube with the bit attached thereto and the drill rod, and is replaced with an unused inner tube assembly.
In the remote operation wire line core sampling device of the present invention, when the inner tube 22 of the inner tube assembly is filled with the sample, the overshot is lowered by water pressure while keeping the core barrel outer tube and the drill rod as they are, and solely the inner tube assembly containing the core sample is extracted and retrieved, dropping a novel unused inner tube assembly to the hole bottom and connecting a novel drill rod to resume core sampling. Thus, it is possible to omit the operations of retrieving and reconnecting the drill rod.
In the following, an embodiment of the present invention will be described with reference to the drawings.
For wire line core sampling conducted on the ground, there are produced instruments for vertical boring and instruments for horizontal boring, of which the latter are generally referred to as underground instruments. In an underground instrument, dropping to the hole bottom by gravity cannot be expected, so an inner tube assembly with a piston and an over-shot are sent to the hole bottom by utilizing the pressure and amount of water discharged from a boring pump.
In vertical wire line core sampling conducted on the ground, a wire line core barrel as shown in
In underground wire line sampling, the inner tube assembly itself is equipped with a piston, and is pushed down to the hole bottom by water pressure.
In the inner tube assembly shown in
In the present invention, the core barrel assembly as shown in
A spindle 1 is mounted to the rotary spindle of a drill head 28 in a watertight fashion by a screw or the like. A housing 11 has in its lower part a digging water supply port 3 and in its upper part an over-shot water supply port 4, with the built-in type over-shot assembly 5 being accommodated in an intermediate hollow part therebetween. At the time of digging, boring water is supplied through the digging water supply port 3. When, after the completion of digging, the inner tube assembly is to be extracted, water is supplied through the over-shot water supply port 4 to lower a piston 6 of the built-in type over-shot assembly 5, sending the over-shot assembly down to the hole bottom. On the digging water supply side, there is provided a check valve (not shown), forming a structure not allowing over-shot supply water to flow out to the digging water supply side. The wire rope 8 is connected to the top portion of the built-in type over-shot assembly 5, and is connected to a winch (not shown) by way of the sheave 7.
The drill head 28 is composed of a frame 15, a lift cylinder 16, a guide 17, an oil motor 19 for rotation, a gear case 20, and a hydraulic chuck 21, and a water swivel 18 with a built-in over-shot is mounted thereto.
Wire line core sampling by using the stabilized sea-bottom core drill for use in the present invention is conducted in the following order.
The manipulator 29 extracts the wire line core barrel from the pipe rack 30, and moves it to the digging core. In this process, the drill head 28 is moved to the uppermost position of the drill mast 27 by the feeding device (not shown), and is further lifted by the drill head lift device to secure the insertion space.
The drill head 28 is lowered to the core barrel chuck position by the lift, the chuck is closed, and the manipulator retracts. Then, the lift descends, and the core barrel forward end reaches the sea bottom surface. Thereafter, supply of boring water and rotation are started to perform digging with the core barrel by an effective length.
Water supply through the over-shot water supply port 4 is started, and the built-in type over-shot assembly 5 is sent down to the hole bottom. Its arrival at the hole bottom is detected from a reduction in the water supply pressure. At this time, the drill rod is retained in the hole.
Next, with the drill rod position remaining the same, as shown in
The manipulator 29 extracts a new drill rod from the pipe rack 30, and moves it to the digging core, retracting after the lowering of the drill head and the closing of the chuck.
After the drill rod is connected to the core barrel upper portion by a screw, the drill head starts boring water supply and rotation to perform digging.
After the completion of the digging, the procedure returns to the step of retrieving the inner tube assembly by the built-in type over-shot assembly, and digging is repeatedly performed.
When digging has been effected to a predetermined depth, the screw of the drill rod used for digging is successively unfastened while retaining the drill rod in the boring hole by the drill head 28 and a holder (not shown) so as to prevent it from falling to the hole bottom, and is accommodated in the pipe rack 30 by the manipulator 29.
The invention of the remote operation wire line core sampling device has made it possible to perform wire line core sampling in an environment where the operation by man power has been impossible, such as under water. This helps to omit the retrieval and reinsertion time for the drill rod regardless of the digging depth. Further, after the recovery of the core sample, it has become possible to quickly and easily perform the next digging operation successively from that digging depth. Further, since the core sample can be easily recovered, it is possible to determine the length of the core barrel and the drill rod without taking into consideration the requisite time and effort for their retrieval and re-insertion. Their length can be minimized to thereby achieve a reduction in the size of the core sampling device as a whole.
Further, it is possible to prevent the hole wall from collapsing due to retrieval and reinsertion each time digging is performed by the core barrel effective length, thus realizing a safe boring operation.
Due to the above effects, the efficiency in the boring operation is enhanced, and there is to be expected a contribution to an improvement in the quality of a stabilized sea-bottom core drill, in which limitations in terms of time are to be taken into consideration.
The present invention paves the way to remote operation and operational automation of wire line core sampling, and contributes to labor saving and automation in general geological survey.
The remote operation wire line core sampling device of the present invention is applicable to a core sampling device operated automatically or semiautomatically when performing core sampling, etc. in resources surveys and scientific research under the deep sea, and allows replacement of an inner tube assembly connected to a stabilized sea-bottom core drill to accommodate a core sample efficiently and in a short time.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2003-313972 | Sep 2003 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP04/13001 | 9/1/2004 | WO | 3/20/2006 |
