SU1253895A1 - Method of monitoring the level of dissolving-inhibiting agent in underground dissolving of salts - Google Patents

Description

2.CnocoS by rt. 1, that is, that each hermetic test container, after its installation, is raised with inert compressible medium at a pressure not exceeding the fluid pressure at the wellhead, after connecting the tank with a corresponding The process column controls the pressure drop in the tank between the liquid and the compressible medium and, when the pressure drop changes, restores it by connecting the tank to an external source with increased pressure.

3. Method according to paragraphs. and 2j is that by measuring the pressure drop between the control tank and the additional damping tank, which is set

The invention relates to the field of mining and can be used in the extraction of salts by the method of underground dissolution through wells with the use of liquid non-solvents to control the formation of underground chambers.

Known methods for controlling the level of nonsolvent in the well, including switching the control tubes or sensors into the annulus of the well to the boundaries of the water and nonsolvent l.

The main disadvantages of the known methods are the complexity of the descent of the lifting operations due to the large depth of the wells, frequent damage to the control tubes or cables.

The closest to the present invention is the control of the level of nonsolvent in a well during underground salt dissolution, including the creation in a control pressurized tank of pressure equal to the pressure of a non-solvent at the wellhead, maintaining the specified pressure for the time between measurements and measuring the pressure drop between the solvent and test hermetic capacitance . At the same time

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between the column and the control tank,

A. The method according to claim 2, characterized in that gas is used as compressible medium in hermetic containers. , 5. The method according to paragraphs. 1-4, which is based on the fact that measurements are made during the period when the water supply to the well is interrupted.

6. The method according to paragraphs. 1-5, which means that with a decrease in the pressure drop at the mouth of the water column, the water supply to the well is reduced, and with a decrease in the difference between the pressure drops in the water column and the non-solvent column, the non-solvent is pumped.

in the wellbore part above the solution chamber, the wellbore section is changed at fixed intervals and forcefully change the position of the interface between the media, entering it into the area of the changed diameter of the wells, registering the moments of change in pressure drop 2j.

The disadvantages of this method are the laboriousness of the operation to expand the cross-section of the well bottom zone, as well as the large error in determining the level of nonsolvent outside the reference cut-off due to

disregarding possible changes in brine density.

The purpose of the invention is to improve the control accuracy by eliminating the effect of variable brine density.

The delivered goal is achieved by the fact that according to the method of controlling the level of nonsolvent in the well during the underground dissolution of salts, including the creation in the control

sealed pressure tank equal to the pressure of the non-solvent at the wellhead, keeping the specified pressure constant at the time between measurements and measuring the pressure drop between the non-solvent and hermetic test tank, additionally establish a second test sealed tank and create a pressure equal to the pressure of the water on the wellhead wells, keep this pressure constant for the time between measurements, while simultaneously measuring the pressure differential between the first control tank and the non-solvent the wellhead measures the pressure drop between the additional control tank and the water at the wellhead, and determines the difference between the measured pressure drops.

After its installation, each pressurized test container is filled with an inert compressible medium at a pressure not exceeding the fluid pressure at the wellhead. After connecting to the corresponding process column, the pressure drop in the reservoir between the fluid and the compressible medium is controlled and, if the pressure differential changes. tanks to an external source with high blood pressure.

The pressure drop between the control tank and the additional damping tank, which is established between the column and the control tank, is measured.

Gas is used as a compressible medium in hermetic containers.

Measurements are made during the period when the water supply to the well stops.

When pressure drops at the mouth of the water column are reduced, the flow of WATER into the well is reduced, and when the difference between the pressure drops in the water column and the non-solvent column decreases, the solvent is pumped.

SUMMARY OF THE INVENTION The essence of the invention is that at the equilibrium of pillars of liquids (brine, water and insoluble matter) in process columns, the pressure at the wellhead in the water column and the nonsolvent column are determined by the height of the columns of these liquids and the difference in their density. brine affects water and nonsolvent in the same way. In practice, the pressure differential between the water column and the non-solvent column reaches 15-20 atm, and the change in this difference due to the movement of the non-solvent level is hundredths of the atmosphere, therefore direct measurement of the pressure difference between the columns does not provide the required accuracy for determining the non-solvent level. The use of control hermetic containers allows a significant increase in accuracy due to the fact that only the measured

pressure in the columns for a certain period of time, compare them with each other and determine the change in the level of nonsolvent and change in the density of the brine, using the relations: аРв-аР

SW JH .. - aPB P ia

(I)

(2)

where 4 is the measurement of the level of a non-solvent; iPg, DRc - change in water pressure and

non-solvent;

HC And the proportion of water and nonsolvent; Lou - specific weight change

brine;

g is the length of the water column. The subtraction of the values of the pressure drop of water and the non-solvent is performed using known hydraulic or electrical devices, and known pressure gauges, such as differential pressure gauges, are used as pressure differential sensors. Monitoring of the pressure retention in the control hermetic tanks is made according to the level of separation of the media in these measurement tanks, for example, the pressure difference between the liquid and the compressible medium. The change in pressure in the DR column is proportional to the change in the level of separation of media uh in the control tank

uh

P, S v,

(3)

where J is the specific gravity of the fluid; R | , V, - pressure and volume of compressible medium;

S is the cross section of the control capacitance in-situ of the displacement of the interface.

For damping possible hydraulic shocks between the control vessels and the columns, additional tanks are installed and the pressure differential between them is measured.

J 253895

To eliminate the influence of changes in the ambient temperature, the control tanks are thermostated. Measurements are made during a period of short breaks in the water year, not affecting the process.

The invention is the basis for automating the dissolution of salt fields by using signals proportional to changes in brine density and non-solvent levels, dp controlling pumps and spikes in the water and non-solvent lines,

The pre-steam method can be used to control the level of petroleum in underground tanks.

FIG. 1 shows a system with two con- trols for capacitances; in fig., 2 system with two control

Q - pump performance,

.

After that, start the water supply to the well,

5 When developing brine from the pillar of the lifting column 3 according to manometers: it is established that the pressure at the mouth of the water column is J5 bari, and the pressure at the head of the column is non-solvent 10 bodies is 30 bargains.

Via a reducer and valve B5, each control tank K and K is successively connected to a cylinder with compressed air B and B at 160 air 15 and brought with pressure from valve B1-B4, B1-B4 to closed to 15 and 7.5 ati respectively. After that, stopping the supply of water and non-solvent, open the ventil- and two additional damping 20 tils B1, B2, Bl and B2 and fill

capacitance

Figs, t and 2 K and k are control vessels of the I lines of the non-solvent and water; P and g are additional (working) containers; D and D - devices for pressure measurements or pressure drops; C-registered handheld device; B1-B6, B1 - valves; Bv - cpe; w sources with poesh (pressure.

containers about half of their volume of oil and water from process columns. Then the valves B1, B2, B1 and B2 close and open the valves VZ, B4, VZ and B4. Turning on differential pressure gauges and. the recorder sets zero values on their scales.

After closing the valves B1, B2,

The method is carried out by follow-up ob-30 and B2 continue to supply water at once to the well. At the same time periodically, once

P RIM ER (FIG.) To change-over the change in the number of underground wells of differential pressure gauges and dissolution with a depth of 1000 m when they deviate from the installed ones, two hermetic capacitive zero values are applied. These KIs and a volume of 20 liters, designed for pressure up to 100 MPa, establish two differential gauges D and D of a class of 0.13% with a measuring range

10 m of water, st, and electric convert the water supply to the well and open sig1 (ala, and recorder C of the type of valves B and Bl, pressure in KSP-4,

In the space between the obs, tsn 1 and the water 2 columns of the well with the help in the tank until the initial readings of the differential pressure gauges are restored,

After two days, the temporarily precrivodic column increased by Wm of water, and in the column of non-solvent — by 9.95 m of water, art. On the self-recording of the pump I51 of the tank with oil products-45 D, the difference between

a volume with a specific weight of 0.85 g / cm is pumped into an energy source up to a given depth f,

Closing time is determined by the ratio

t. J- ° ° - °) ..

where D is the internal diameter of the casing bore, m;

these indications are 0.05 m water.

It follows from formulas (1) and (2) that the level of nonsolvent increased by 50–33 cm, and the brine density increased by 0.01 g / cm. By means of short-term pumping of nonsolvent and other measurements, the differential pressure difference between the water co. The effective diameter of the water tank is 55 and the column is non-solvent to

 In If, lotgl, m ;.

 mark of the roof of the chamber, m;

original value

Example 2 (FIG. 2), Measuring then the system of Example 1 is complemented

Q - pump performance,

.

After that, start the water supply to the well,

When brine is developed from the pillar of the lifting column 3 according to manometers: it is established that the pressure at the mouth of the water column is J5 bari, and the pressure at the head of the column of non-solvent is 30 bargains.

Through a reducer and valve B5, each control vessel K and K is alternately connected to a cylinder with compressed air B and B at 160 atm, and adjusted with valves B1-B4, B1-B4 closed in valves K and K to 15 and 7 , 5 ati respectively. After that, stopping the flow of the shift, they monitor the change in the readings of the differential pressure gauges and, if they deviate from the set zero values, pump up

liquids in the tank until the initial readings of the differential pressure gauges are restored,

After two days, the water supply to the well is temporarily stopped and valves B and Bl are opened. Pressure in

the water column increased by Wm Vod.st ,, and in the column nonsolvent - by 9.95 m of water, Art. On self-indications, it is equal to 0.05 m of water.

It follows from formulas (1) and (2) that the level of nonsolvent increased by 33 cm, and the brine density increased by 0.01 g / cm. By a short pumping of the nonsolvent and repeated measurements, the differential pressure difference between the water source value

Example 2 (FIG. 2), Measuring then the system of Example 1 is complemented

two capacitances P and P, an; 1 log. capacitance m K and K. Using a gas cylinder B, pressure in the tank P is set to 15 MPa, and in the tank P - 7.5 MPa and, opening valves B1 and 81, these tanks are connected to process columns and 2,

The scale of the differential manometer D is graduated in accordance with formula (2) in mules of G / CM, and the scale of the recorder C is in centimeters in accordance with formula (1).

In the process of dissolving, the containers K and K are insulated from process columns with the help of valves B2 and B2, and the pressure in these tanks is controlled with differential pressure gauges with open valves VZ, B4.83, B4 and closed valves Vb, Vb.

After 5 days, the supply of BREAKS was briefly stopped for a short time, the VZ and VZ valves were closed and valves 86 and Wb were opened. The brine density decreased by 0.02 g / cm, and the level of non-solvent decreased by 50 cm. Without shutting down the systems, pumping non-solvent before the level is restored, and after shutting down the system, the water supply is resumed with a reduced flow rate.

The proposed method (in comparison with the known ones) significantly increases the accuracy of control of the non-solvent level and thereby improves the quality of constructed underground tanks, eliminates the waste of non-solvent, improves the stability of the brine composition, and automates production.

. - ..---- L

B2 B

BT

 I

-ix} l-ChhI

V1 vg

FIG. 2

Compiled by N. Rudenko Editor A. Revin Tehred M.Hodanich Proofreader E. Sirohman

Order 4678/23 Circulation 833 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Design, 4.

Claims (6)

1. METHOD FOR CONTROL OF NON-DISSOLUTION IN A WELL WHILE UNDERGROUND SALT SOLUTIONS, including creating a pressure in the test tight tank equal to the pressure of the non-solvent at the wellhead, keeping the specified pressure constant / for the time between measurements and measuring the pressure drop between the non-solvent and the tight control the fact that, in order to improve the accuracy of control by eliminating the influence of variable density of the brine, additionally establish a second control tight container spine and create therein a pressure equal to the water pressure at the well head, the pressure is maintained constant at a time between the measurements, together with measurements of differential pressure between the first control container and a nonsolvent for the _mouth; q wells measure the pressure drop between the additional control tank and water at the wellhead and determine the difference between the measured pressure drops. 1 253895 2. The method according to claim 1, it is distinguished that each hermetic control tank after its installation is filled with an inert compressible medium at a pressure not exceeding the liquid pressure at the wellhead, after connecting the tank to the corresponding process column, the pressure drop in the tank is controlled between the liquid and the compressible medium and when the pressure drop changes, restore it by connecting the tank to an external source with high pressure. 3. The method according to PP. 1 and 2, characterized in that they measure the pressure drop between the control tank and the additional damping tank, which is installed between the column and the control tank, 4. The method of pop. 2, characterized in that gas is used as a compressible medium in sealed containers. about 5. The method of popp, 1-4, about t l and the fact that the measurements are made during the period of the cessation of water supply to the well. 6. The method according to PP. 1-5, which consists in the fact that with a decrease in the pressure drop at the mouth of the water column, the water supply to the well is reduced, and with a decrease in the difference between the pressure drops in the water column and the non-solvent column, the non-solvent is pumped. I