JP2001065281A - Drilling mud treating method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve zero discharge by treating drilling mud to be reutilized as resources. SOLUTION: In this drilling mud treating device to treat drilling mud 7 to be circulated and used, muck 9a and sand 9b separated from the drilling mud 7 are cleaned by cleansing water 12. From the drilling mud 7 after the muck 9a and the sand 9b are removed, oil 25 is recovered to be burnt. The drilling mud 7 after the muck 9a and the sand 9b are removed is put into a specific gravity adjusting tank 10, where slit 9c and clay 9d are separated from waste mud 11 to provide clarified water. Thickened slurry 42 including the slit 9c and the clay 9d is dried by a hot air current.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for treating drilling mud containing earth and sand discharged from construction sites (shields and tunnels) and oil mining sites (land and sea floor). Things.

[0002]

2. Description of the Related Art For example, at an oil drilling site, a specific gravity, viscosity and chemical composition are adjusted in accordance with the geology at the site in order to prevent collapse of the drilling site and smoothly transport the swarf. Viscous mud as liquid is used during drilling. In addition, the excavated mud after excavation cannot be discharged as it is because it contains earth and sand. Therefore, the drilling mud requires some treatment.

[0003] One of the conventional methods of treating drilling mud is to use a gravity sedimentation facility, a sieve, a liquid cyclone, a coagulation sedimentation facility, a dehydrator, a sand filtration facility, etc., to transport solids in the drilling mud by truck. The wastewater is treated according to legal standards and discharged to sewers or public waters, while the solids are disposed of via landfills.

However, in the case of the above-mentioned method, since the treatment is for the purpose of landfilling solids and discharging wastewater and not for the purpose of reuse, laws and regulations are becoming stricter from the standpoint of global environmental protection. However, landfills are becoming limited, and it is expected that they will eventually reach a dead end.

[0005] As another example of a conventional drilling mud treatment method, there is a method in which an evaporative concentration method is employed in the same treatment method as described above. This means that the drilling mud after the large solids have been separated and removed is sent to an evaporative concentrator, where it is concentrated until just before it can no longer be circulated, and then sent to a continuous solidifier to be kneaded with a solidifying agent and discharged. It is like that.

However, in muddy water, bentonite or CM
It contains C (carboxymethylcellulose), various chemicals for dispersing and adding viscosity, and these components are combined with silt mixed in during excavation. It adheres and solidifies on the walls of vessels and containers and cannot be removed.

On the other hand, in recent seabed excavation, stable excavation is performed by sending muddy water into a drilling hole through a drilling device, and excavated muddy water after excavation is collected on a ship to remove sediment and then re-use. A drilling mud treatment apparatus having a mud circulation system designed to be used may be used.

FIG. 3 shows an outline of an example. First, on a ship, a muddy water 4 is formed from a chemical 2 and fresh water 3 in a muddy water adjusting tank 1 and sent to a muddy water circulation tank 5 to excavate the seabed. Then, the muddy water 4 is fed into a drilling hole through a drill pipe of a drilling device 6, and the drilled muddy water 7 containing earth and sand after being subjected to drilling.
Is collected on the ship through a riser pipe, and the shears 9a and sand 9b in the earth and sand contained in the drilling mud 7 are separated by a separator 8 composed of a vibrating sieve and a liquid cyclone, and then separated into a specific gravity adjusting tank 10 to adjust the specific gravity. It is judged whether or not the mud circulation can be used in the tank 10, and a part of the mud is returned to the mud circulation tank 5 as mud 4,
Fresh mud 4 is added for recirculation.

[0009]

However, in the case of the above-mentioned muddy water circulation system, the slip 9a and the sand 9b separated and removed from the excavated muddy water 7 by the separator 8 are not reused. The excavated muddy water 7 after separating and removing the waste 9a and the sand 9b by the separator 8 is sent to the specific gravity adjusting tank 10 for processing and reused as the muddy water 4. Even if the silt and clay remain in the excavated muddy water 7 without being separated, the specific gravity adjusting tank 1
As a result, the water is gradually accumulated in the circulation line containing 0, and as described above, although the operation of extracting a part and adding the fresh muddy water 4 is performed, it is inevitable that the water is eventually discarded.

Therefore, the present invention treats waste separated from drilling mud, sand and waste mud discharged from a specific gravity adjusting tank, and recycles as much as possible, thereby achieving zero discharge (environmental load). It is an object of the present invention to provide a drilling muddy water treatment method and apparatus capable of reducing the amount.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a drilling mud containing an earth and sand collected after the drilling rig has a component-adjusted muddy water sent to a digging point by a digging apparatus. In a method and an apparatus for excavating muddy water which are separated and removed by a separator and then guided to a specific gravity adjusting tank and circulated and used as mud, in the excavated muddy water treatment method and apparatus, And an excavating muddy water treatment method and apparatus for storing water after washing with washing water.

[0012] The washing and sand content increase the commercial value by washing, and can be used as aggregate for concrete.

[0013] Further, the muddy water whose components are adjusted is sent to the excavation point by the excavator, and the excavated muddy water containing the sediment collected after being subjected to excavation is separated and removed by a separator to remove shear and sand, and then the specific gravity adjusting tank. In the drilling mud treatment method and apparatus that is guided to and circulated and used as mud,
By recovering the oil content from the drilling mud after separation and removal of the shear and sand, the drilling mud sent to the specific gravity adjusting tank can be made free of oil.

Further, the muddy water whose components have been adjusted is sent to the excavation point of the excavator, and the excavated muddy water containing the sediment collected after being subjected to excavation is separated and removed by a separator to remove shear and sand, and then the specific gravity adjusting tank. In the method and apparatus for treating drilling mud, which is circulated and used as mud, the silt and clay components in the waste mud discarded from the specific gravity adjustment tank are roughly separated, then finely separated and clarified. By obtaining such treated water, the obtained treated water can be used as various types of working water.

Further, if the wastewater after washing the waste and sand is combined with the waste mud from the specific gravity adjusting tank to separate silt and clay, the washing wastewater can be treated as clear water. become able to.

Further, by providing a water quality inspection device for inspecting the quality of the treated water, the treated water can be used as working water or washing water, or can be discharged.

On the other hand, when the concentrated liquid containing the silt component and the clay component separated roughly and precisely from the waste mud is brought into contact with a stream of hot air to be collected and stored as a solid, the content of the silt component and the clay component is reduced. Solid matter (powder)
Can be collected as

In addition, by adding a fertilizer and a granulation aid at the time of drying the concentrate, silt can be recovered as horticultural soil.

Further, by condensing and recovering steam generated when the concentrated liquid is dried, the collected condensed water can be used as fresh water.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a drilling mud treating apparatus according to the present invention. In the drilling mud treating apparatus having a mud circulation system similar to that shown in FIG.
9a and sand (particle diameter: 0.074 to 2 mm) 9b separated from the excavated muddy water 7 by the above method can be reused and discarded from the specific gravity adjusting tank 10. The waste mud 11 is reused.

More specifically, a slip as a washing apparatus in which the washing water 12 is sprayed to each of the slip 9a and the sand 9b which are separated and taken out of the drilling mud 7 by the separator 8 to wash them. A washing wastewater storage tank 16 is provided with a washing conveyor 13 and a sand washing conveyor 14 for receiving washing wastewater 15 used by the two washing conveyors 13 and 14.
And a cleaning wastewater 15 from the cleaning wastewater storage tank 16.
And a separator 19 composed of a vibrating sieve and a liquid cyclone for separating and removing solids (mainly silt, waste) 9e in the mixed wastewater of the mixed wastewater with the working wastewater 18 from the working wastewater storage tank 17. 9 separated in the machine 19
e and the shears 9a after the cleaning with the above-mentioned shear cleaning conveyor 13
A solidification device 21 for solidifying the solidified material by adding cement 20 is provided. Further, a waste storage container 22 for storing the solidified material solidified by the solidification device 21 as a waste is prepared. To transport the waste 9a to the sand cleaning conveyor 14
Storage container 23 for storing sand 9b after washing
Is prepared and transported on land by the container transport ship 24 so that the sand 9b can be reused.

In the separator 8, the shear 9 a and the sand 9
b, the pressurized floating tank 26 for pressurizing and recovering the oil 25 from the excavated muddy water 7, an oil storage tank 27 for storing the recovered oil 25, and an appropriate storage of the stored oil 25. An incinerator 28 for incineration at the time, and an incineration ash storage container 30 for storing incineration ash 29 after incineration of the oil 25 in the incinerator 28 is prepared.
To enable transportation to land.

Further, the waste muddy water 11 discharged from the specific gravity adjusting tank 10 and the wastewater 31 of the separator 19 are treated with a processing stock solution 32.
A stock solution tank 33 adapted to be received as
3 from the undiluted solution 32 after receiving it (particle size:
0.05-0.074mm) 9c or clay (particle size: 0.0
Screw decanter 3 as a centrifugal separator for centrifuging stock solution 32 so as to roughly separate 9d.
4, a separation liquid storage tank 36 for storing a separation liquid 35 by the screw decanter 34, a membrane separation device 37 for precisely separating silt 9c and clay 9d from the separation liquid 35, and a filtrate by the membrane separation device 37. Filtrate storage tank 3 for storing 38
9 and a water quality inspection device 41 for inspecting the water quality of the filtrate 38 so that the filtrate 38 can be reused as clear treated water for the working water of the ship or the washing water 12 of the washing conveyors 13 and 14 and the like. .

On the other hand, the concentrated liquid storage tank 43 for storing the concentrated liquid 42 containing the silt component 9c and the clay component 9d separated by the screw decanter 34 and the membrane separator 37, and the concentrated liquid storage tank 43 is stored in the concentrated liquid storage tank 43. A spray drier 44 for evaporating the water content of the concentrated liquid 42 later, and a condenser 57 for condensing water vapor 40 generated when the concentrated liquid 42 is dried by the spray drier 44.
A silt storage container 45 for storing the silt component 9c and the clay component 9d which have been dried by the spray drier 44 to form a powder is prepared, and is transported on land by the container transport ship 24 to recycle the silt component 9c and the clay component 9d. Make it available.

The membrane separation device 37 has a configuration in which a filtration water tube is connected to a large number of hollow fiber membrane separation membranes, for example.

As shown in detail in FIG. 2, the spray drier 44 has a hot air supply pipe 50 near the top of a drying container 46 having a cylindrical portion 46a and a funnel portion 46b connected in the vertical direction. The air sucked through the air filter 52 by the operation of the blower 51 is heated by the hot air generator 53 into hot air, and the hot air is passed through the hot air supply pipe 50 through the hot air filter 54 to the drying container. And a liquid supply pipe 48 with a pump 47 at the center of the top of the drying vessel 46.
And the nozzle 49 connected downward is assembled downward, and the concentrated liquid storage tank 4 sucked by driving the pump 47 is attached.
The concentrated liquid 42 in 3 is sprayed in atomized form from the atomizer or the nozzle 49 through the liquid supply pipe 48 into the hot air stream so as to instantaneously evaporate the water and convert the silt component 9c into solid coarse particles. In addition, the silt 9c as solid coarse particles is collected in two stages by a cyclone 55 and a bag filter 56. Further, the steam 40 generated in the drying vessel 46 is cooled and condensed. They are reused as water. The hot-air filter 54 is not indispensable.

When drilling the seabed with the drilling rig 6, the muddy water 4 made on the ship is sent to fix the drilling hole.
The excavated mud 7 after being subjected to excavation is collected and separated from the vibrating sieve and the fluid cyclone by the separator 8 by the sediment (sludge 9a, sand 9b, silt 9c, clay 9d, etc.) contained in the excavated mud 7.
In the present invention, the following steps are performed in a state in which the shear 9a and the sand 9b therein are separated and then put into the specific gravity adjusting tank 10.

That is, the waste 9a and the sand 9b taken out by the separator 8 are sent to the shear cleaning conveyor 13 and the sand cleaning conveyor 14 for cleaning, where the cleaning water 12 is sprayed under pressure to separate the adhering muddy water. After the removal, they are stored in the shear storage container 22 and the sand storage container 23. At this time, the washing wastewater 15 that has been subjected to washing is once stored in a washing wastewater storage tank 16, and then stored in a working wastewater storage tank 17.
It is sent to a separator 19 comprising a vibrating sieve and a fluid cyclone together with the working wastewater (used in the shipboard work) 18 stored therein, so as to take out a solid content 9e. The removed solids 9 d are put into a solidifying device 21, mixed with the waste 9 a to be stored in the above-mentioned waste storage container 22, and solidified by the addition of the cement 20.
Note that the solidifying step of the solid content 9d is not indispensable, and therefore, the solidifying device 21 may not be necessary.

On the other hand, the separator 9 and the sand 9
In the case where the drilling muddy water 7 after removing b contains oil 25, the oil 25 is collected in the pressurized floating tank 26 and temporarily stored in the oil storage tank 27. The oil 25 is incinerated in the incinerator 28, and the incinerated ash 29 is stored in the incinerated ash storage container 30.

Further, in the specific gravity adjusting tank 10, after the shear 9 a and the sand 9 b in the mud are separated and removed by the separator 8, the excavated mud 7
And the muddy water 4 is sent to the muddy water circulation tank 5. However, since the silt 9c and the clay are not separated and accumulate in the muddy water, those that are not used for circulation are discarded muddy water (including excess muddy water). ) 11, and wastewater 15, 18 in separator 19
And the wastewater 31 from which the solids 9e have been removed from the mixed water.
Next, the undiluted solution 32 is roughly separated from the silt component 9c and the clay component 9d by the screw decanter 34, and the separated solution 3
5 is temporarily stored in a separation liquid storage tank 36, and the separation liquid 35 is subjected to precision separation of a silt component 9c and a clay component 9d by a membrane separation device 37, and the filtrate 38 is stored in the filtrate storage tank 3
9 to be stored as clear treated water. When the obtained filtrate 38 is discharged, it is discharged after being inspected by a water quality inspection device 41. When the filtrate 38 is used as the cleaning water 12 of the cleaning conveyors 13 and 14 without being discharged, the water quality inspection is not performed, and the water quality is not inspected. To be used as working water for When the water is discharged, the water is treated by a predetermined method until the water quality satisfies the reference value.

Further, the silt component 9c and the clay component 9d roughly separated by the screw decanter 34 and precisely separated by the membrane separator 37 are temporarily stored as a concentrate 42 in a concentrate storage tank 43, and thereafter, The concentrated liquid 42 is sent to a spray dryer 44 to recover the silt 9c and the clay 9d as solids, and store the solids in a silt storage container 45. In this case, concentrate 4
2 is dried by an ordinary evaporative concentrator, particles adhere to the wall of the heat exchanger and the container and solidify, and cannot be finally removed. However, in the present invention, as shown in FIG. The concentrated liquid 4 is introduced into the hot air stream fed into the container 46.
2 is sprayed in the form of a mist to instantaneously evaporate the water, so that most of the solid coarse particles are carried on the air stream without being attached to the container wall and collected by the cyclone 55 and the bag filter 56. Is done.

In the above, the waste 9 a stored in the waste storage container 22, the sand 9 b stored in the sand storage container 23, the silt 9 c stored in the silt storage container 45, and stored in the incineration ash storage container 30 Incineration ash 29
Is transported to land by the container transport ship 24,
Reused or disposed of.

The above-mentioned waste 9a and sand 9b can be reused as concrete aggregate, roadbed improving material and the like. In addition, 9 for silt
c is granulated by adding a fertilizing component (N or P) and a granulation aid at the time of drying with a spray drier 44 (1 to 2).
mmφ), and can be discharged and reused as horticultural soil, and can also be used as a raw material for clay or ceramic style during the production of cement.

On the other hand, the filtrate 38 obtained by the membrane separation device 37
Since is a clear treated water containing no solid matter, it can be reused as water for working on a ship or the like, shearing water, or washing water for sand. At this time, the filtrate 38 contains a soluble component (dye, chloride ion, or the like), but it is possible to add a necessary advanced treatment in accordance with the reuse application. Further, the steam 40 generated by the spray dryer 44 is condensed by the condenser 57 and collected as fresh water, which can be used as drinking water or can be reused for replenishing the working water and the washing water.

In the above-described embodiment, the treatment of the drilling mud generated by the sea bottom excavation has been described. However, the processing of the drilling mud generated by other drilling work can be similarly applied, and the gist of the present invention. Of course, various changes can be made without departing from the scope.

[0036]

As described above, according to the drilling muddy water treatment method and apparatus of the present invention, the following excellent effects are exhibited. (1) The muddy water whose component is adjusted is sent to the excavation point by the excavator, and the excavated muddy water containing sediment collected after being subjected to excavation is led to the specific gravity adjustment tank after separating and removing shear and sand by a separator. In the method and apparatus for treating drilling mud, a part of which is circulated as mud, the shears and sand separated from the drilling mud are washed with washing water and stored. Therefore, the commercial value of the waste and the sand can be increased by washing, and the stored waste and the sand can be reused as a concrete aggregate, a roadbed improvement material, and the like. (2) The mud whose component has been adjusted is sent to the excavation point by the excavator, and the excavated mud containing soil and sand collected after being subjected to excavation is led to the specific gravity adjustment tank after separating and removing shear and sand by a separator. In a drilling mud treatment method and apparatus in which a part is circulated as mud, oil is recovered from drilling mud after separating and removing shear and sand, and incinerated. Therefore, the drilling mud containing no oil can be sent to the specific gravity adjusting tank. (3) The mud whose composition has been adjusted is sent to the excavation site by the excavator, and the excavated mud containing soil and sand collected after being subjected to excavation is led to the specific gravity adjustment tank after separating and removing shear and sand by a separator. In the method and apparatus for treating drilling mud which is configured to partially circulate as mud, the silt component and the clay component in the waste mud discarded from the specific gravity adjustment tank are roughly separated, and then finely separated. Since clear treated water is obtained, the obtained treated water can be reused as various working waters. (4) To efficiently clarify a large amount of wastewater by combining the wastewater after washing the waste and sand with the waste mud from the specific gravity adjustment tank to separate silt and clay. Can be. (5) By providing a water quality inspection device for inspecting the quality of the treated water, the treated water can be used as working water or cleaning water, or discharged, and can be arbitrarily treated. (6) by contacting the concentrated liquid containing the silt component and the clay component, which have been roughly and precisely separated from the waste mud, with a hot air stream to collect and store it as a solid,
The silt component and the clay component can be collected as a solid by putting them in an air stream, and the collected silt component and the clay component can be used as a raw material at the time of cement production or a ceramic-style raw material. (7) By adding a fertilizer component and a granulation aid at the time of drying the concentrate, the recovered silt can be reused as horticultural soil. (8) By condensing and recovering steam generated when the concentrated liquid is dried, the collected condensed water can be used as fresh water. (9) According to the above items, zero discharge can be achieved.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of a drilling muddy water treatment apparatus according to the present invention.

FIG. 2 is a detailed view of a spray dryer used in the drilling mud water treatment device of the present invention.

FIG. 3 is a schematic diagram illustrating an example of a drilling muddy water treatment device having a muddy water circulation system.

[Explanation of symbols]

 Reference Signs List 4 muddy water 6 drilling equipment 7 drilling muddy water 8 separator 9a shear 9b sand 9c silt 9d clay 10 specific gravity adjusting tank 11 waste muddy water 12 cleaning water 13 shear cleaning conveyor (cleaning device) 14 sand cleaning conveyor (cleaning device) 22 shear Storage container 23 Sand storage container 25 Oil 26 Pressurized flotation tank 28 Incinerator 29 Incinerated ash 32 Stock solution 33 Stock solution tank 34 Screw decanter (centrifuge) 35 Separate solution 37 Membrane separator 38 Filtrate 40 Steam 41 Water quality inspection device 42 Concentrate 44 Spray dryer 45 Silt storage container 57 Condenser

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Ryuta Ono 2-1-1 Otemachi, Chiyoda-ku, Tokyo Ishikawashima-Harima Heavy Industries, Ltd. (72) Tetsuya Yoshida 3-2-2 Toyosu, Koto-ku, Tokyo No. 16 Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center

Claims (15)

[Claims] 1. A drilling machine, comprising: feeding a mud whose component is adjusted to an excavation point of an excavator, and excavating the mud including sediment collected after being subjected to excavation; In the excavating mud treatment method, wherein the cuttings and sand separated from the excavating mud are washed with washing water and stored. Drilling mud treatment method. 2. A specific gravity adjusting tank which sends mud whose composition has been adjusted to an excavating point by an excavator and separates and removes excavated mud containing soil and sediment by a separator. In a drilling mud treatment method wherein the oil is recovered from the drilling mud after separation and removal of shear and sand, and is incinerated. Drilling mud treatment method. 3. A specific gravity adjusting tank which sends mud whose component has been adjusted to an excavation point by an excavator and separates and removes excavated mud containing soil and sediment by a separator. In the excavation mud treatment method, which is used to circulate and use as mud, the silt and clay components in the waste mud discarded from the specific gravity adjustment tank are roughly separated, and then finely separated for clear treatment. A drilling muddy water treatment method characterized by obtaining water. 4. The excavated mud treatment method according to claim 3, wherein the waste water after washing the shear and sand is combined with the waste mud from the specific gravity adjusting tank to separate silt and clay. 5. The drilling mud treatment method according to claim 3, wherein the clarified treated water is used as working water or washing water, or is discharged. 6. The method according to claim 3, wherein the concentrated liquid containing the silt component and the clay component separated roughly and precisely from the waste mud is brought into contact with a stream of hot air to be collected as a solid and stored. Drilling mud treatment method. 7. The method for treating drilling mud according to claim 6, wherein a fertilizer component and a granulation aid are added during drying of the concentrated liquid. 8. The excavation mud treatment method according to claim 6, wherein steam generated when drying the concentrated liquid is condensed and recovered. 9. A specific gravity adjusting tank which sends mud whose component is adjusted to an excavation point by an excavator and separates and removes excavated mud containing soil and sediment by using a separator after excavation is performed after excavation. In the excavating muddy water treatment apparatus, which is guided to be circulated and used as muddy water, a washing apparatus configured to wash the sludge and the sand separated by the separator with the washing water, and a shear after the washing. And an excavating muddy water treatment apparatus characterized in that the excavating muddy water treatment apparatus has a configuration in which sand is stored in a storage container and a sand storage container. 10. A specific gravity adjusting tank which sends muddy water whose composition has been adjusted to an excavating point by an excavating apparatus, and separates and removes excavated muddy water containing sediment and sand collected after being subjected to excavation by a separator. In the excavating muddy water treatment system, which is used to circulate and use as muddy water, the oil contained in the muddy water after separation and removal of shear and sand by the separator is pressurized and floated to recover. An excavation mud water treatment device having a configuration including a pressure flotation tank, an incinerator for incinerating collected oil, and an incineration ash storage container for storing incineration ash. 11. A specific gravity adjusting tank which sends muddy water whose composition has been adjusted to an excavating point by an excavator and separates and removes excavated muddy water containing sediment and sand collected after being subjected to excavation by a separator. In the drilling mud treatment apparatus that is used to circulate and use as mud, a centrifugal separator for roughly separating silt and clay in waste mud discarded from the specific gravity adjustment tank, and a centrifugal separator after centrifugation A drilling mud water treatment device, comprising: a membrane separation device for precisely separating silt and clay components from a separated liquid. 12. A stock solution tank for combining waste water from a washing device for shear and sand with waste mud from a specific gravity adjusting tank, and sending the stock solution in the stock solution tank to a centrifuge. Item 13. A drilling mud water treatment apparatus according to Item 11. 13. The drilling mud water treatment device according to claim 11, further comprising a water quality inspection device for inspecting the water quality of the filtrate after the silt component and the clay component are precisely separated by the membrane separation device. 14. A spray dryer for drying a concentrated liquid containing silt and clay separated by a centrifugal separator and a membrane separator with hot air and recovering it as a solid, and a silt and clay recovered as a solid. The excavated muddy water treatment apparatus according to claim 11 or 12, further comprising: a silt storage container for storing the wastewater. 15. The drilling mud water treatment apparatus according to claim 14, further comprising a condenser for condensing steam generated when the concentrated liquid is dried.