RU2184220C2 - Thermal gas producer to treat face zone of productive pool of oil wells and process of its manufacture - Google Patents

Abstract

FIELD: oil and gas production. SUBSTANCE: thermal gas producer is furnished with thermally stable solid-fuel pots which enable gas producer to be used to treat wells with temperature up to 220 C across face. Solid-fuel pots are protected against exposure to well fluid by protective jacket into which fuel mass is put in process of pot manufacture. Pots are installed vertically one on another by face surfaces with the aid of assembling facility. Protective jackets are produced from combustible rubberized cloth, type 500E. Combustible elements of solid-fuel pots include oxidizer, fuel and technological additives. Pot is fitted with igniter with heating element and attachment unit. 12-27 mas.% of ethylenepropylene combustible binder, 70-80 mas. % of perchlorate oxidizer and 1-12 mas.% of functional additives are mixed at 30-50 C in the course of 1-1.5 h. Produced mass is vacuumed for 0.5-1.0 h, and is formed and subjected to gradual polymerization. EFFECT: development of effective multipurpose thermal gas producer. 2 cl, 2 dwg, 1 tbl

Description

 The invention relates to the oil industry and is intended to increase oil recovery of low-rate oil wells by thermogasochemical effects on the reservoir structure with gases generated by a special device - a thermogas generator.

 Known thermogas generators (patent 2124630 from 13.02.97, patent 2123591 from 06/18/96., Patent 2124121 from 10.22.96, application 97118505/03 from 10.27.97, "Handbook of perforating and explosive equipment" edited by L. Ya. Fridlyander, M .: Nedra, 1983), used for this purpose.

 However, they are either not efficient enough, or structurally complex and, accordingly, expensive, or can be operated within strictly limited temperature-time limits, that is, their operating range is limited by the depth and geothermal conditions of the wells.

Thermogas generators similar in chemical nature to the proposed material, for example, powder pressure generators (type PGD) and pressure accumulators for wells (type ADS), have insufficient heat resistance (100-150 ^o C).

 The closest in design and technical nature to the claimed object is a thermogas generator (patent 2124630 from 02.13.97) for treating the bottom-hole zone of oil wells, containing a block of combustible elements in a combustible or fireproof housing, an igniter, a heating element and an attachment unit, and a block of combustible elements from a material containing 50-75 wt. % of fuel, which is used as a powder of magnesium, or aluminum, or their alloy, and 19-40 wt.% oxidizing agent (nitrates of alkali or alkaline earth metals) and 5-6 wt.% technological additives (resins or their solutions in industrial oils) .

 However, this prototype has a number of significant disadvantages. The use of a large amount (up to 75%) of powdered hydroreacting metals (aluminum, magnesium and their alloy) in the composition of combustion elements significantly increases the risk of manufacturing, storage and operation of products and leads to a significant increase in their cost. In addition, the efficiency of a thermogas generator equipped with such a composition is significantly reduced due to solid slag formed during the oxidation of metals - metal oxides and their salts, clogging the well and lowering the reservoir characteristics of the formation. So, for example, during the oxidation of 1 kg of aluminum (or magnesium), about 2 kg of oxides are formed. In addition, the composition shown in the formula of the prototype is clearly not balanced by the content of the oxidizing agent (up to 40 wt.%), Which will lead to non-optimal yield of oxidation products - working gases. In balanced energy-intensive materials (gunpowders, fuels), the oxidizer content ranges from 65-85 wt.%.

An object of the present invention is to increase the efficiency of a gas and gas generator, expand the temperature and time range of its operation, ensure simplicity of design and technology of its manufacture, increase the safety of manufacturing and operation, reduce cost, that is, create an effective universal gas and gas generator for use in wells of various depths with different geothermal conditions (up to 220 ^o C) and the method of its manufacture.

The technical result is achieved as follows:
- the expansion of the temperature-time range of operation of the device is achieved by the fact that the solid fuel checkers from which the thermogas generator is assembled are prepared from heat-resistant powder containing 12-27 wt.% ethylene-propylene combustible binder material, 70-87 wt.% perchlorate oxidizer and 1-12 wt. .% functional additives;
- high efficiency is ensured by the low content, up to the complete absence, of a solid condensed phase (slag) in the combustion products due to the insignificant metal content in the fuel composition (0-10 wt.%);
In addition, the presence of hydrochloric acid (HCl) in the fuel combustion products provides additional chemical activity of the gases formed as agents for chemical cleaning of the oil reservoir structure;
- improving the safety of the manufacture, storage and operation of the thermogas generator is ensured by the hydrophobicity of the fuel blocks, which reliably protects against uncontrolled exothermic interaction of metals with water, which leads to spontaneous ignition of the composition during its manufacture and unauthorized operation of the thermogas generator during its storage;
- the low cost of the gas generator is ensured by the simplicity of its constructive solution, method of manufacture and operation;
- a method of manufacturing a thermogas generator allows you to get a simple and effective completely combustible design of a thermogas generator, and its technical and economic efficiency is ensured by molding powder bombs directly into soft forming shells without the use of intermediate equipment, which makes it possible to shorten the technological cycle by eliminating the phases of manufacturing and preparation of forming equipment, pressing products and applying a protective coating on them. In addition, the mold-forming shell used as technological equipment serves in the future (during storage and operation of the thermogas generator) as a protective coating against aggressive media, including well fluid.

 The device is as follows.

 The thermogas generator consists of a series of powder bombs (pos. 11) consecutively assembled on a geophysical cable (pos. 11) with a diameter of 70-100 mm, a length of 1000 mm and a central channel with a diameter of 14-17 mm from a tube (pos. 10) made of aluminum alloy and firmly bonded with a powder composition enclosed in a soft combustible shell made of waterproofing rubberized fabric, which is a two-layer diagonally duplicated fabric, with an aluminized coating on the front side (500I fabric), and an assembly device (items 5-9, 11, 12). One of the powder checkers is an igniter (item 1). The igniter is installed at the bottom of the assembly. The maximum number of powder checkers in a thermogas generator is 12 pcs. The actuation (ignition) of the powder charge of the thermogas generator occurs from the electric current supplied to the heating element (pos. 4) from the remote control at the wellhead through the geophysical cable (pos. 11) from the coil installed in the igniter or to the EV-PT electric igniter (pos. 3 ) installed in a special hole in the ignition element. The delivery of the thermogas generator to the processing zone is carried out on a geophysical cable. The design of the gas generator is schematically shown in the drawing.

 The assembly device, consisting of a suspension 5, a sleeve 6, a screw 7, a cover 8, a pallet 9, a geophysical cable 11, a wire 12, is intended for assembling a battery and connecting it to a wireline cable.

 After the initiation of ignition, sequential combustion of solid fuel blocks occurs, as a result of which the thermogaschemical effect on the productive formation of the bottomhole zone is carried out.

A method of manufacturing a device (thermogas generator) consists of 2 main technological processes:
1. The manufacture of heat-resistant powder checkers.

 2. Assembling a thermogas generator.

The manufacture of heat-resistant powder blocks, including a flammable element, is carried out by sequentially mixing 12-27 wt.% Ethylene-propylene combustible binder, 70-87 wt.% Perchlorate oxidizing agent and 1-12 wt.% Functional additives (combustion stabilizer - aluminum; processing aids and others) at 30-50 ^o C for 1-1.5 hours, followed by evacuation of the resulting mass for 0.5-1.0 hours; molding the mass into a soft combustible shell of rubberized balloon fabric (fabric 500I) and stepwise curing according to the following modes: 50-60 ^o C - 1 day; 60-70 ^o C - 1 day; 70-80 ^o C - 1 day; 80 ± 5 ^o C - 5 days.

The temperature range for mixing the composition (30-50 ^o C) is limited by the temperature-time resource for maintaining the mass of a viscous-fluid state, which ensures defect-free filling of checkers of a given shape.

 The time range for mixing the composition (1-1.5 hours) was established experimentally and provides the required degree of averaging of the components of the composition.

 Evacuation for 0.5-1.0 hours is necessary and sufficient for the manufacture of monolithic blocks without air inclusions.

 Step curing under the above conditions ensures the preservation of the forming shells by ensuring the minimum additive (volume expansion) of the checker during thermostating process.

 At the end of the powder checker of the igniter, a socket is formed for installing an electric igniter.

 The gas and gas generator is assembled immediately before its operation at the wellhead at a special site. Powder blocks using an assembly device, starting with a flammable element, are strung on a cable cable passed through the central channel of the powder blocks.

 An example of the method of manufacturing a thermogas generator type ADS-200U in pilot industrial conditions.

Were made 2 versions of the ADS-200U using heat-resistant gunpowder of different formulation:
I - on gunpowder ТН-15/5, containing 70 wt.% Ammonium perchlorate as an oxidizing agent; 15 wt. % combustible binder - ethylene propylene rubber brand SKEPT-40, plasticized with oil VNIINP-1 in a ratio of 70/30; 5 wt.% Aluminum powder AC D-1 and 2.5 wt.% Technological additives.

 II - on gunpowder ТН-18 / 5К, containing 67 wt.% Potassium perchlorate as an oxidizing agent; 18 wt. % combustible binder - ethylene propylene rubber grade SKEPT-40, plasticized with MS-20 oil in a ratio of 75/25; 5 wt. % aluminum powder AC D-1 and 8 wt.% technological additives.

The manufacturing technology of the ADS-200U was the same in both cases. A powder mass was prepared on a continuous mixer by sequential mixing of the components (SKEPT-40 plasticized rubber; oxidizing agent; technological additives and ASD-1 aluminum powder) at 30-50 ^° C for 1.5 hours without vacuum and 0.5 hours with vacuum and molded powder bombs into a mold-forming shell made of rubberized balloon fabric number 500I TU 38.1051901-89. Checkers were formed using a special technological device for the manufacture of powder elements.

 Using a clamp, nozzles are connected to the mixer adapter so that its center line is parallel to the plane of the tray on which the gutter is mounted.

 Assembling technological equipment for forming combustible elements is carried out in the following order. The fabric cover is turned inside out, the core tube is inserted into it. The end of the cover is evenly collected on the outer surface of the tube and knotted manually with twine of the ШЛ-2,5 (0.4) HI GOST 17308-88 mark or carded twisted technical thread TU 17 RSFSR 46-4023-95. The cover is turned on the front side. An extension cord is put on the screed and a rubber ring is installed, after which it is inserted into the core tube from the side opposite to the attached end of the cover until it stops. On the screed, sequentially put on the plate, insert and tighten it with a nut.

 The assembly of technological equipment for the formation of igniter elements is carried out in the following order. An GOST 1621486 PVC insulating tape is applied to a section from one of the ends of the core tube, after which a heating element (spiral) is installed on the insulated section of the tube, and it is fixed with a PVC insulating tape. The core tube is inserted into the cover, the cover is evenly assembled into the corrugation around the tube and manually tied with twine ШЛ-2,5 (0.4) HI GOST 17308-88 or with a carded technical thread TU 17 RSFSR 46-4023-95. An extension cord is put on the screed and a rubber ring is installed, after which it is inserted from the side of the loose cover into the core tube until it stops and tightened with a nut.

 Before filling the igniter and burning elements with the powder mass, the core tube is inserted into the central needle nozzle all the way, the cover is put on the nozzles, passing it under the rubber ring, and collected on the nozzle in the corrugation.

 When filling under pressure the powder mass into the case, the latter is gradually filled, comes off the nozzle and moves along the gutter.

 The end of the filling of the powder element is determined both visually on television by leaving the nozzle of the black strip, previously applied on the cover, and by the actuation of the limit switch, disconnecting the screw when filling the element with a length of 1000 mm.

 Of the cured powder checkers, 2 batches of ADS-200U products (thermogas generators) were completed. Of these, 12 sets of ADS-200U were tested on-site in deep wells in Ukraine.

 In the process of testing the ADS-200U, 7 treatments of exploratory wells were carried out. The test results are shown in the table.

 According to the results of production tests, the ADS-200U is recommended for industrial production and use in oil wells.

Claims (2)

 1. Thermogas generator for processing the bottom-hole zone of a productive formation of oil wells, containing an igniter with a heating element, an attachment unit, a block of combustion elements from a composition including an oxidizing agent, fuel, processing aids, characterized in that the combustion elements are heat-resistant solid fuel blocks mounted vertically to each other on each other on end surfaces using an assembly device, protected from the effects of well fluid by individual protective combustible casings chkami of rubberized fabric 500 a balloon type. 2. A method of manufacturing a thermogas generator, including the manufacture of combustible elements, an igniter element and the assembly of a thermogas generator, characterized in that the combustible and igniter elements are made of heat-resistant fuel by mixing at 30-50 ^o C for 1-1.5 hours 12-27 wt. % ethylene propylene combustible binder, 70-87 wt. % perchlorate oxidizer and 1-12 wt. % functional additives, subsequent evacuation for 0.5-1.0 hours, filling the resulting mass of the forming soft shell and step polymerization at 50-60 ^o C for 1 day, at 60-70 ^o C - 1 day, at 70- 80 ^o С - 1 day, at (80 ± 5) ^o С - 5 days.

Images