JPS59189982A - Removal of crude oil sludge of rock underground oil storage facility - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for removing crude oil sludge from a rock underground oil storage facility.

BACKGROUND ART A bedrock underground oil storage facility using underground rock has been proposed as a facility for storing crude oil on a large scale.

For example, when building a crude oil storage base of 150,000 kiloliters, this would be 20 m high x 15 m wide x 600 m long.
The idea is to create large cavities such as these in underground rock, and store crude oil in these cavities while keeping them isolated from the atmosphere. In this case, it is expected that about 2% of the oil storage amount, or about 3000 kiloliters if the oil storage amount is 150,000 kiloliters, will be deposited. Normally, this sludge has a specific gravity higher than crude oil and lower than water, so it is deposited at the interface between the aqueous phase and the oil storage in the shoe. This sludge cannot be transported to the ground using a pump (submerged pump) unless some fluidization method is used.

The present invention was made for the purpose of transporting the sludge deposited at the bottom of this oil storage layer, and a protection pipe is inserted from the working chamber to the crude oil sludge layer formed at the bottom of the oil storage tank in a bedrock underground oil storage facility. The present invention proposes a method in which the inside of the protective tube and the working chamber are replaced with an inert gas, and then the sludge is mechanically transported to the working chamber through the protective tube.

The content of the present invention will be specifically explained below based on the drawings.

・Figure 1 schematically shows the layout of equipment for carrying out the present invention, and the main components of this equipment are an airtight work room 2 built above the rock oil storage tank 1, and an airtight work room 2 built above the rock oil storage tank 1. A protection pipe 4 communicating between the chamber 2 and the sludge reservoir 3 at the bottom of the rock storage tank, and a sealing valve 5 attached to the upper part of the protection pipe 4.

A sludge tank 6 provided in the work chamber 2, a sludge transport device 8 that allows the bucket 7 to move between the sludge reservoir 3 and the sludge tank 6 through the inside of the protection pipe 4, and the protection pipe 4.
The operation of the sealing valve 5, sludge transport device 8, gas replacement device, etc. is controlled remotely from outside the work chamber. It is supposed to be done.

As mentioned earlier, the bedrock oil storage tank 1 is a cavity in which crude oil 9 is stored in the underground bedrock, and the bottom 1 of this bedrock oil storage tank 1
A is a substantially flat surface, and a sludge reservoir 3 (pit) is provided in a part of the surface. A weir 10 is provided around this sludge reservoir 3. This weir 10 serves to prevent the lower water phase 11 from flowing into the sludge tank 3 when the sludge in the sludge tank 3 is carried out by the operation described later, and also serves to prevent the water phase 11 and the sludge floating above it from flowing into the sludge tank 3. Provides the effect of separating the A vertical shaft 1b is dug in the upper bedrock corresponding to this sludge reservoir 3.

This shaft 1b is also connected to a working chamber 2 formed in the bedrock. A blocking board 12 is provided at a suitable location in the shaft 1b, and the atmospheric passage leading to the rock oil storage tank 1 is blocked by the blocking board 12.

The work chamber 2 is surrounded by an explosion-proof wall 2a, and is configured as an airtight chamber that substantially prevents leakage of internal gas even if the indoor pressure becomes considerably high.

A protection pipe 4 is installed extending from the working chamber 2 through the vertical shaft 1b below to the sludge sump 3 of the rock oil storage tank 1. The lower end of the protection pipe 4 opens into the sludge sump 3, and the upper end A sealing valve 5 is attached. The protection pipe 4 penetrates the closure panel 12 of the shaft 1b, but a sealing process is performed so that no gap is created between the through hole and the outer periphery of the protection pipe.

The inner diameter of the protection tube 4 is large enough to allow a bucket 7, which will be described later, to move freely.

The sealing valve 5 has a shutter or a lid attached to the upper end of the protection tube 4 that opens and closes using high-pressure gas (for example, high-pressure nitrogen gas), and when this is closed, the inside of the protection tube 4 and the inside of the work chamber 2 are closed. When the gas flow is cut off and the opening is opened, an opening is formed through which the bucket 7 can freely enter and exit. The opening/closing operation of the sealing valve 5 using high-pressure gas is performed by remote control from outside the work chamber 2.

A sludge tank 6 and a sludge transport device 8 are installed inside the work chamber 2. Hot water 14 is supplied to the sludge tank 6 from outside through a hot water pipe 13 to heat and fluidize the sludge in the tank. The heated and fluidized sludge 7 is carried out of the system by the pump 15. The sludge conveyance device 8 is a device that conveys sludge from the sludge reservoir 3 to the sludge tank 6 using a bucket 7, and includes a rail 16, a drive device 17 that runs on this rail 16, and a bucket 7 connected to this drive device 17. , consists of. The drive device 17 is driven by high pressure gas (high pressure nitrogen gas), and its operation is performed remotely from outside. This remote control is installed at an appropriate location in the room-6. . 11
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Gas replacement equipment is installed to replace the gas with a gas such as nitrogen gas. In FIG. 1, 19 indicates a nitrogen gas outlet into the working chamber 2, and 20 indicates a nitrogen gas outlet into the protective tube 2. It leads to the source. Moreover, 23 is an indoor gas suction port, which communicates with the exhaust air ta24 via a control valve also placed outdoors. The exhaust fan 24 and the control valve are driven and controlled by a differential pressure detector 25 installed indoors.
and the instruction signal from the gas concentration meter 26 is received by the control panel 27,
This is done based on this signal. The control panel 27 also controls high pressure gas for operating the sludge discharge device 8 and the sealing valve 5 described above.

The operating procedure of the crude oil sludge removal apparatus for a bedrock underground oil storage facility having the above configuration will be explained in detail below based on FIG. 2. FIG. 2 schematically shows the operating procedure of the method of the present invention in the order of steps A to F, and the control operation of the equipment in each step is performed by remote control using a monitoring television as described above. The numbered elements in Figure 2 are the first
It is the same as explained in the figure.

Step A is the crude oil storage state before the sludge is carried out. In this state, the space of the oil storage tank 1 (the space above the liquid level of crude oil) is filled with nitrogen gas. The pressure of this sealed nitrogen gas is, for example, 0.5 kg/aA.

Nitrogen gas at the same pressure is also sealed in the protection tube 4. Therefore, the liquid level in the protection tube 4 is substantially equal to the liquid level in the oil storage tank. At this stage, the sealing valve 5 is in a closed state.

Step B is a stage in which nitrogen gas is pressurized into the protective tube 4 through the blow-off port 20 (FIG. 1) with the sealing valve 5 closed. This sealing pressure is 1, for example 2.5 to 3.0 k
g/ca. As a result, the crude oil in the protection tube 4 is pushed out into the oil storage tank, and the inside of the protection tube 4 is replaced with nitrogen gas.

Next, in step C, the exhaust fan 24 (FIG. 1) is driven to exhaust the air in the work chamber 2, and nitrogen gas is introduced into the work chamber 2 from the blower outlet 19 (FIG. 1). This gas replacement operation is performed until the gas concentration measured by the gas concentration meter 26 becomes below the lower explosive limit, and the sealing pressure is 2.5 to 3.0 kg/cl, which is the same as that of the protective tube 4 in step B. do. Then, the sealing valve 5 is opened. In this state, the inside of the work chamber 2 and the protection tube 4 will be replaced with nitrogen gas at a rate of 2.5 to 3.0 kg/c, but while confirming with the gas concentration meter 26 that it is below the lower explosive limit, Start preparing to drive the sludge transport device.

The process includes the step of lowering the bucket 7 into the sludge reservoir 3 through the protection tube 4 under this gas exchange and grabbing the sludge therein, and the bucket 7 passes through the sealing valve 5 and enters the work chamber. 2, close the sealing valve 5. Step E is entered with the sealing valve 5 closed, and in this step E, the bucket 7 travels by rail to the sludge tank 6, and the sludge taken at t19 =Zi is charged into the sludge tank 6.

In step E, hot water 14 is introduced into the sludge tank 6, and the pump 15 is driven to pump the sludge fluidized by the hot water to the outside of the system. During this time, the nitrogen gas pressure in the second working chamber 2 is automatically controlled to a predetermined set pressure based on the detection signal of the differential pressure gauge 25. After step E, the sealing valve 5 is opened and the process is repeated again as many times as necessary.

After repeating the steps E-D a necessary number of times, once the sludge in the sludge tank 6 has been removed, all of the operating equipment 2 is stopped, and the nitrogen gas pressure in the work chamber 2 is lowered to atmospheric pressure. The nitrogen gas pressure in the protection tube 4 is also approximately 0, which is the same as the pressure in the oil storage tank.
．． Return to 5kg/cn+.

This is step F, and the sludge removal work is completed.

As described above, according to the present invention, accumulated sludge in a rock underground oil storage facility can be removed reliably and safely without the risk of explosion.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing the equipment arrangement of equipment for implementing the method of the present invention, and FIG. 2 is an illustrated process diagram schematically showing the procedure for implementing the method of the present invention. 1. Rock oil storage tank, 2. Working room, 3. Sludge reservoir, 4. Protection pipe, 5. Seal valve, 6. Sludge tank, 7. Bucket,
8. Sludge transport device, 10. Weir. 11... Water phase, 14... Hot water, 15... Sludge discharge pump, 16... Rail, 27... Control panel. Inside Kajima Construction Co., Ltd., Motoakasaka-chome 2-7, Minato-ku, Tokyo.

Claims (1)

[Claims] (i+ A protective tube is inserted from the working chamber to the crude oil sludge layer formed at the bottom of the oil storage tank in the rock underground oil storage facility. After replacing the inside of this protective tube and the working chamber with inert gas, A method for removing crude oil sludge from a bedrock underground oil storage facility, which comprises mechanically transporting the sludge to a work chamber through this protection pipe. (2) An airtight work chamber 2 built above the bedrock oil storage tank 1, A protection pipe 4 that communicates between the work chamber 2 and the sludge layer 3 at the bottom of the rock storage tank, a sealing valve 5 attached to the upper part of the protection pipe 4, and a sludge tank 6 provided in the work chamber 2. and a sludge transport device 8 that allows the bucket 7 to move between the sludge layer 3 and the sludge Sakai 6 through the inside of the protection tube 4, and the gas inside the protection tube 4 and the work chamber 2 is replaced with an inert gas. Crude oil sludge removal equipment for underground rock storage facilities, consisting of gas replacement equipment and oil storage facilities.