Method for performing water shutoff operations

Abstract

The invention relates to the field of constructing and using different underground structures, inter alia in the oil and gas industry, and can be used for performing water shutoff operations in production wells, injection wells, observations wells and other wells enabling the production of hydrocarbons. A method for performing water shutoff operations is based on a wave effect and is characterized in that it involves identifying, in advance of water shutoff operations, regions containing water-bearing rock where water encroachment needs to be restricted, then placing at least one wave emitter on the surface of said rock or in a well, activating the emitter, and directing waves into the water-bearing rock until an effect consisting in a reduction in the mobility of the water in the rock is achieved. The wave emitter is separated from the water-bearing rock by at least one artificial surface.

Description

[0001] Method of carrying out waterproofing works

[0002] Technical area

[0003] The claimed invention relates to the field of construction and operation of various underground structures, including the oil and gas production industry, and can be used to carry out waterproofing work on production, injection, observation and other wells that ensure the extraction of hydrocarbon raw materials.

[0004] Prior art

[0005] A method for eliminating water leaks in underground structures is known (RU 2559274, published 10.08.2015), which includes drilling boreholes and separately injecting into them through a nozzle under a pressure of 0.2-1.0 MPa strengthening waterproofing solutions of a cement-water suspension and liquid glass. As strengthening waterproofing solutions, a cement-water suspension with a W / C ratio of 1.6 - 2.5 is injected, containing 5-10% of the cement weight of amorphous silica and a 25-30% aqueous solution of liquid glass with a density of 1.15-1.2 g / cm3 at the following ratio of the said solutions, respectively, wt.%: 50-70 and 30-50.

[0006] The disadvantage of the known technical solution is the labor intensity of the process, and in the case of its application in hydrocarbon production wells, this method carries significant risks of reducing the permeability of productive formations.

[0007] A method for limiting water inflow is also known, for example, in a well (RU 2483194, published 27.05.2013), which includes pumping a solution of a water-soluble polymer and a dispersion of gel particles that swell to a limited extent in water into the formation, creating an insulating screen, wherein a mixture of polyacrylamide DR9-8177 and reagent VPRG is used as the water-soluble polymer, and a solution containing salts of polyvalent metals or mineralized Devonian formation water with a density of 1180-1200 kg / m3 is pumped in to secure the insulating screen.

[0008] The disadvantage of this technical solution is its low efficiency, due to the fact that the water-insulating capacity of the composition according to model tests does not provide precise determination of the results and is not a measure of the effectiveness of the insulation work and, as a rule, leads to contamination of the productive formation with the cement composition.

[0009] Also known is a method adopted as a prototype for processing and limiting water inflows, for example into oil wells, disclosed in patent RU 2230900 (published 20.06.2004), in which a bitumen-containing reagent is used, while the method of insulation work includes the preparation and injection into the formation of a bitumen-containing reagent or its mixture with a hydrocarbon solvent and / or mineral powder, in the form of which, in the form of a hydrocarbon solvent, still residues from the production of ethylbenzene and styrene were used - "Kore" resin, and as a mineral powder - bentonite clay.

[0010] The disadvantage of the known method of limiting the inflow of formation waters is the labor intensity of the method, associated with the complexity and duration of the preparation of the bitumen-mineral plugging composition, its multicomponent nature and the use of a hydrocarbon solvent, and, as a consequence, the high cost of implementing the technology using expensive equipment, as well as low environmental friendliness, which is a consequence of the contamination of the highly permeable, non-watered productive formation with plugging solutions.

[0011] Technical problem The technical problem of the claimed invention “Method for carrying out waterproofing works” is the high complexity and labor intensity of the process, the use of expensive equipment, and also, in relation to wells, the possible contamination of highly permeable productive formations with cement slurries.

[0012] The technical result of the claimed invention “Method for carrying out waterproofing works” is the simplification of the method, increasing its environmental friendliness, operational capabilities, reliability, efficiency and quality of waterproofing works.

[0013] Solution to the problem

[0014] The technical result achieved is that in the known method of performing water-proofing works, by means of wave action on the formation, according to the invention, before performing water-proofing works, areas with water-saturated rock are determined, where it is necessary to limit the inflow of water, then at least one wave emitter is placed on the surface of the rock or in the well, it is switched on and waves are directed into the water-saturated rock until the effect of reducing the mobility of water in the rock is obtained.

[0015] Preferably, the wave emitter is separated from the water-saturated rock by at least one artificial surface.

[0016] Positive effects of the invention

[0017] There is the following cause-and-effect relationship between the distinctive features and the achieved technical result. For carrying out waterproofing works it is proposed to use the impact on water-saturated rock by waves of various types of disturbance (mechanical, electromagnetic, gravitational), both separately and in various combinations. Using the impact of waves of various types of disturbance on water-saturated rocks allows achieving a multiple reduction in the mobility of water in the pores of the rock and, as a result, to obtain a waterproofing effect. Placing a wave emitter in a well or on the surface of the rock, if necessary separated from the water-saturated rock by artificial surfaces, and turning it on causes a wave disturbance with the transmission of the wave to water-saturated rocks, which leads to an increase in the density of the rock to those values ​​at which the water located between the particles of the rock becomes a binding substance, i.e.the rock and the water contained in it pass into a bound state. Such wave action on water-saturated rocks was carried out by lowering into a well or placing on the rock surface a wave emitter capable of generating waves of mechanical, gravitational and electromagnetic types of disturbance both separately and in any combination thereof. When wave action on water-saturated rock occurs, the effect of redistribution (re-arrangement) of both fairly large rock particles with a diameter of up to several millimeters and pelitic and iron-containing particles occurs into a denser structure, which leads to very weak mobility of water in the rock. In this case, the water contained in the rock becomes, as it were, an "adhesive" substance.This effect of water "gluing" rock particles together is due to the fact that water on the surface of any solid substance creates a structure of pseudocrystals on its surface consisting of water molecules and minerals dissolved in it, which try to repeat the crystal lattice of the rock, and the effect of the formation of pseudocrystals by water is observed only at a small distance from the surface of the solid substance and disappears nonlinearly as it moves away from the surface of the solid substance. The effect of the formation of pseudocrystals of water on the surface of solids is well known in physics and is studied by one of the fundamental sections of the mechanics of liquid and gas motion - "boundary layer theory". In a number of rare cases, if additional waterproofing is required, classical methods of waterproofing work can be used on hydrocarbon wells, i.e.use cement slurries, install packers, cement bridges, and perform additional cementation of the artificial face.

[0018] As a result of the applicant's analysis of the state of the art, including a search of patent and scientific and technical sources of information containing information on analogues of the claimed method of carrying out waterproofing work, limiting, for example, the inflow of formation water to construction sites in flooded areas or to production wells, no analogue was found that is characterized by features identical to all the features of the claimed method of carrying out waterproofing work.

[0019] Consequently, the claimed method for carrying out waterproofing works meets the patentability requirement of “novelty”.

[0020] According to the applicant, the essence of the claimed invention “Method for carrying out waterproofing work” does not follow clearly from the known level of technology, since it does not reveal a set of distinctive features with the above-mentioned influence on the claimed technical result.

[0021] This allows us to conclude that the claimed method for carrying out waterproofing works meets the patentability criterion - inventive level.

[0022] The set of essential features characterizing the essence of the claimed invention in flooded zones, in comparison with the use of known similar methods of limiting the inflow of formation waters, in particular the prototype, allows to obtain a technical result consisting in simplifying the method, increasing the environmental friendliness, operational capabilities, reliability, efficiency and quality of water-proofing works, including ensuring the possibility of removing the blockage of productive formations by water, which allows to draw a conclusion about the compliance of the claimed method of carrying out water-proofing works with the criterion of "industrial applicability".

[0023] Description of embodiments

[0024] The essence of the claimed invention “Method for carrying out waterproofing works” is explained by the description.

[0025] The method for carrying out waterproofing works is carried out as follows.

[0026] For waterproofing works, mechanical, gravitational and electromagnetic waves of disturbance types are used, and the waves can be used both in any combination and separately. Before waterproofing works, zones, sections with waterlogged rock, intervals of water inflows that are subject to waterproofing are determined. Then, at least one emitter is placed on the rock surface or in the well, which is separated from the waterlogged rock by at least one artificial surface, and it is put into operation. The emitter causes wave disturbance directed at water-saturated rocks. The impact on the water-saturated rock by a combination of waves is carried out until the effect of reducing the mobility of water in the waterlogged rock is obtained due to the redistribution (re-arrangement) of large, pelitic and iron-containing particles into a denser structure.

[0027] Industrial applicability

[0028] The claimed invention “Method for Carrying Out Waterproofing Work” assumes its use primarily in carrying out waterproofing work during the construction and operation of production, injection, observation and other wells that ensure the extraction of hydrocarbon raw materials, but can also be used in general civil and special construction, as well as in the operation of underground structures.

[0029] The use of the claimed method of waterproofing operations allows to significantly reduce the high complexity and labor intensity of the process of waterproofing operations in water-saturated rocks, eliminate the use of expensive equipment, as well as the possibility of reducing the reservoir properties of productive formations due to their contamination with cement slurries. In addition, the claimed method of waterproofing operations increases the environmental friendliness of waterproofing operations. This method can be widely used for waterproofing operations during the construction and repair of wells involved in the extraction of hydrocarbon raw materials, in general civil and special construction and in the operation of underground structures.

Claims

Invention formula 1. A method for carrying out waterproofing work by means of wave action, characterized in that before carrying out waterproofing work, areas with waterlogged rock are determined where the water inflow needs to be limited, then at least one wave emitter is placed on the surface of the rock or in a well, it is turned on and waves are directed into the waterlogged rock until the effect of reducing the mobility of water in the rock is achieved.

2. A method for carrying out waterproofing work according to paragraph 1, characterized in that the wave emitter is separated from the waterlogged rock by at least one artificial surface.