SU140369A1 - Method of constructing underground tanks for petroleum, petroleum products and liquefied gases in rock salt formations - Google Patents

Description

There is a known method for constructing underground tanks for oil, oil products and liquefied gases in high-power rock salt deposits by scouring salt along the vertical axis of the well. The brine is removed through the boreholes, and the prepared container is in the shape of an elongated ellipsoid.

The disadvantage of this method is that it can be used only in salt formations of high power.

The present invention allows the construction of underground reservoirs in salt formations of low power. This is achieved by making the container in the form of a horizontal gallery. For this, the well is drilled obliquely with access to the horizontal in the lower part of the rock salt formation. Then, the production pipelines, which are used to wash the tank with water, are lowered into the well. Water is fed through the end of the pipeline with a gradual shortening of the pipeline from the bottom to the wellhead or through the side openings of the pipe.

In the second embodiment, the holes in the pipe are located in a section equal to the length of the container.

On the territory of the Soviet Union there are numerous deposits of rock salt that occupy a large area, but the salt layers in them lie at a considerable depth and have a small thickness. Often these fields coincide with areas where there is a great need for the construction of large-scale underground farms for the storage of oil, petroleum products, liquid and compressed gases. An example of such a deposit is the huge deposits of rock salt in the central part of the European part of the Soviet Union.

The proposed method makes it possible to practically use all the deposits of rock salt with a reservoir thickness of 10, "and higher for the construction of tanks in them.

No. 140369- 2 Construction of tanks for the proposed method is as follows;

1. Burits oblique well with access to the horizontal, if possible in the lower part of the reservoir. Horizontal wellbore is made in large containers as large as possible.

2. The well is lined with pipes. Casing pipes, depending on the rocks forming the ceiling, are lowered to the beginning of the salt-bearing formation or when low-reliable rocks are lowered into the salt. The casing is carefully tamponized to form a lock at the beginning of the casing.

3. A production string of pipes of smaller diameter is run down the well to the bottom of the well.

During the washout period, water is supplied to the well in this column, and brine is collected through the annulus. During the period of operation, the brine is taken out through the inner tube when the product is pumped into the tank, and the brine is fed when the product is taken out. The product flow and its selection are carried out in the annular space of the casing - the production pipe.

4. The washing-out of the gallery capacity can be carried out according to two developed schemes.

FIG. 1 shows a diagram of the washing-out of the vessel by the grippers through the pipe end; in fig. 2 - part of the tank washed at the beginning of erosion by the grippers; in fig. 3 is a section along A-A in FIG. one; in fig. 4-circuit erosion immediately to the entire length of the tank using perforated pipes.

Stone salt /, in which capacity 2 is eroded, lies between the suprasalt 3 and subsalt 4 rocks and the alternate erosion of the grippers 5, 6, 7, 8, 9, 10, 11 and 12 begins.

The fundamentally new, nowhere unknown, method of scouring, which was named according to the first scheme by the "grips," water J3 at the initial stage is supplied to the face and the form shown in FIG. 2. By virtue of the difference in the specific gravities of water 13 and brine 14, after the water is saturated with salt, the brine drops down, and new portions of fresh water rise up. The residence time of the water in the bottom is insufficient for complete saturation and therefore a weak brine is formed there, which is saturated with salt movement along the well.

Initially, the salt around pipe 15 is uniformly eroded in all directions, then the camera’s upward trend gradually increases, but the continuous mixing of water and brine, the activity of salt dissolving with weak brine, gathering at the bottom, results in the absence of a clearly defined ceiling.

After the first "grab" is eroded, the production pipe is pulled in (rises from the well to the measured length) - and it starts | Washed out the next “seizure.

Scouring should be done so that the ceiling galleries had a rise to the casing. This will ensure complete screening of the scour product during operation.

According to the second scheme, erosion is performed immediately over the entire length of the gallery capacity. The horizontal part of the production pipe 15 has, at certain intervals, openings 16 for the passage of water and a well. The size of the holes. Adjusts the volume and pressure of the water supplied to the erosion.

If it is necessary to build very large reservoirs in the layers, several horizontal wells pass from one inclined shaft, and a gallery type reservoir is eroded around each of them.

Subject invention

The method of constructing underground tanks for oil, petroleum products and liquefied gases in rock salt formations by scouring it with removal of brine through boreholes, characterized in that, in order to maximize the capacity of reservoirs in low-thickness formations by making the capacity of a horizontal gallery, a well is drilled sloping with access to the horizontal in the lower part of the bed of rock salt, the production pipelines are lowered into the well and are used to wash the tank by supplying water or through the end of the pipeline with gradual by shortening the latter from the well to the wellhead or through the holes located on the side surface of the pipeline along the entire length of the tank.

No. 140369

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