RU2081802C1 - Method of burial of industrial wastes in underground salt chamber through wells provided with pipelines - Google Patents

Abstract

FIELD: technology of burial of industrial wastes in underground salt chambers; applicable, for instance, in burial of waste of chemical production in workings formed by underground dissolving of rock salt beds. SUBSTANCE: the essence of the offered method consists in supply through pipeline to the lower part of the chamber of wastes with density exceeding the density of displaced brine by separate portions whose volume is 10-21 times as low as chamber volume free of insoluble fragments. In so doing, wastes are supplied in continuous stream at constant productivity evaluated by Richardson's criterion, whose value shall be within 0.1-1.8. Brine lifting column is installed so that distance between the bottom of brine lifting column and chamber ceiling shall not exceed 2.0 m. EFFECT: higher efficiency.

Description

 The invention relates to a technology for the disposal of industrial waste in underground chambers and can be used, for example, when disposing of chemical waste in workings formed by dissolving rock salt formations through boreholes.

Known methods for the underground dissolution of salts through boreholes with the simultaneous disposal of waste in both existing and waste chambers (US Patent N 3724898, E 21 B 43/28, 05/29/71 and A.S. N 605432, E 21 B 43 / 28, 12.0676), in which various wastes / liquid chlorine, carbon disulfide, calcium chloride, etc. / with densities exceeding the density of saturated brine are fed into the salt chamber)
The disadvantage of the method protected by patent N 3724898 is the mixing of the supplied waste with aqueous solutions of salts, as a result of which liquid chlorine and carbon disulfide, for example, when interacting with aqueous solutions forms a mixture of hydrochloric and hypochlorous acids, which leads to intense pipe corrosion in the chamber and the creation of conditions for oxidative processes. For the implementation of the method requires a complex design of the well.

 The method according to from. N 605432 can be implemented only for the conditions of two or more interacting cameras. The well-known "Method for storing liquid waste in underground chambers (prototype, German patent N 3141885, B 65 G 5/00, 10.22.81) provides for the use of a salt chamber for storing liquid waste, alkaline and acid, which are pre-neutralized on the surface. Waste may contain solids, oil products, as well as pasty and bituminous additives. During the sludge process, the lighter fraction (oil products or pure brine) is immediately forced to the surface. According to the method, liquid waste is fed to the upper part of the chamber while pumping (displacing) the appropriate amount of brine from the bottom of the chamber.

The considered method has the following disadvantages:
the supply of waste to the upper part of the chamber leads to agitation and mixing with the brine located there, which determines the need for sedimentation and separation of liquids by density;
the supplied waste products from butu enter into physico-chemical interaction with brine containing rocks:
for solid inorganic compounds sent to the chamber as waste, free deposition conditions must be ensured in the static zone of the chamber, which is not provided for by the prototype;
mixing waste with brine does not allow to completely remove the useful component from the chamber.

 The present invention is directed to solving the problem of preventing physico-chemical interaction and mixing of chemical wastes with brine and host rocks of the chamber and ensuring retrieval of the useful component contained therein.

(где V_o- объем подаваемых отходов и V_ак активный объем камеры, объем камеры без нерастворимых пород) при постоянной производительности, оцениваемой в пределах 0,1≅ Ri кр.≅ 1,8 (где R_iкр. критерий Ричардсона,

g₀ ускорение свободного падения; h расстояние от точки подачи до дна камеры или уровня нерастворимых пород в ней; V скорость истечения отходов на выходе из колонны труб; ρ_от-ρ_p плотность отходов и рассола, соответственно), а низ рассолоотводной колонны располагают не ниже 1,5 2,0 м от потолка камеры.The problem is solved as follows. Industrial waste with a density exceeding the brine density is fed in a continuous stream in portions of a volume with the ratio

(where V _o is the volume of waste supplied and V _{ak the} active volume of the chamber, the volume of the chamber without insoluble rocks) at a constant productivity estimated within 0.1≅ Ri cr. ≅ 1.8 (where R _icr. Richardson’s criterion,

g ₀ acceleration of gravity; h the distance from the feed point to the bottom of the chamber or the level of insoluble rocks in it; V the rate of outflow of waste at the exit of the pipe string; ρ _from -ρ _{p is the} density of waste and brine, respectively), and the bottom of the brine outlet column is located at least 1.5 2.0 m from the ceiling of the chamber.

 A similar method of chemical waste disposal in underground salt dissolution chambers can be used when using waste products that must be fed into the chamber while maintaining the phase boundary and stable stratification of liquids along the height of the chamber.

According to this method, a complex of laboratory and pilot works with organochlorine wastes / VC wastes / Sayanskkhimprom JSC was carried out. Waste is a heavy mobile oily liquid ρ ²⁰ from 1,320 kg / m ³ to 1,365 kg / m ^{3 of the} second hazard class, sparingly soluble in water.

Laboratory studies on the interaction with brine and carbonate rocks present in the chamber showed the following:
Separate brine and BX wastes are inert with respect to rock salt and dolomite;
upon contact of VC waste with brine, the latter acquires acidic properties and becomes active in relation to carbonate rocks;
organochlorine components during hydrolysis accumulate to a depth of 40 cm from the phase boundary;
acid evolution as a result of contact of VC waste with brine leads to the formation of CO ₂ , which at a pressure of 20.0 MPa at a temperature of 20 ^o C in the underground chamber will be in a liquid state of aggregation, however, with a decrease in pressure, CO ₂ can be released into the gas phase:
for the case of the outflow of a flooded stream from an infinitely thin tube (an analogue of the ratio of the productive pipe string to the chamber size), the compactness and stability of the waste stream is ensured by the conditions of the Richardson criterion in the range 0.1 to 1.8.

 Pilot operations were carried out at well No. 1 of the Sayanskkhimprom AS brine field.

Well chamber N 1 was created in the depth interval 1709 1756 m, in the salt layer USh-1. According to location surveys, the lower part of the chamber is littered with collapsed rocks to the level of 1724 m. The average diameter of the chamber is 65 m. The calculated active volume of the chamber is 35 thousand m ³ .

The design of well N 1 is as follows:
⌀ 820 mm direction set to a depth of 28 m;
jig o 530 mm installed at a depth of 423 m and cemented;
the main casing string o 324 mm is installed at a depth of 1278 m and cemented;
intermediate column o 219 mm lowered to a depth of 1630 m;
working column o 146 mm lowered to a depth of 1710.5 m;
working column o 73 mm lowered to a depth of 1722m.

 Thus, the brine-lifting pipe string o 146 mm is installed so that its end is 1.5 m below the ceiling of the chamber, the pipe string o 73 mm for feeding waste 2 m above the level of insoluble rocks.

Waste was delivered to the well with a constant productivity of 10 11 m ³ / h in portions of 1.5-2.5 thousand m ³ / h, which, in combination with other factors, ensured the compactness of the jet and the maintenance of a stable phase boundary (R _i.cr = 1 , 61). The work was carried out during the period 23.04.93-12.10.93. During this time, about 15.3 thousand m ^{3 of} waste was fed into the chamber. The brine was displaced through the annular space between the pipe columns with a diameter of 146 and 73 mm.

The NaCl content in the brine remained at the same level, the values of the concentration of Ca and Mg in it slightly decreased to 2.7 kg / m ³ and 0.35 kg / m ^3, respectively. According to chemical analysis, during the entire injection period, organochlorine components were absent in the displaced brine.

Claims (1)

 A method of disposing of industrial waste in underground salt chambers through wells equipped with pipelines, comprising supplying waste in the form of liquids with a density higher than the density of the displaced brine through pipelines to the lower part of the spent chamber and removing brine through pipelines from the chamber, characterized in that the waste is fed into the chamber in separate batches, the volume of which is 10 21 times less than the chamber volume free from insoluble debris, while the waste is fed in a continuous stream at a constant production ti, estimated criterion Richardson whose values must be in the range 0.1 to 1.8, and the column rassolopodemnuyu set so that the distance between the chamber ceiling and the bottom rassolopodemnoy column should not exceed 2.0 m.