RU2311530C1 - Device with gun-powder charge for well stimulation and method therefor - Google Patents

Abstract

FIELD: oil and gas production, particularly to stimulate well zone of oil-gas reservoir for all well types, including steeply inclined and horizontal ones.

SUBSTANCE: device comprises gun-powder charge connected to logging cable and including solid-fuel members formed of non-metallized ballistite or solid rocket propellant mix and shaped as cylinders provided with central round channels, wherein channel length and diameter are related as (20...40):1. The solid-fuel members have stabilizing filler taken in amount of not more than 1.5% of charge mass. Solid-fuel members are connected to load-carrying cable extending through central channels or outside solid-fuel members. Gaps covered with combustible bushes are left between solid-fuel members. Solid-fuel members are put in protective case. Ignition unit is made as glowing filament built in one solid-fuel member or is located near solid-fuel member provided with leads along with ignition charge and is linked to current-carrying threads of logging cable. Safety shaft is arranged between logging cable and charge. Method involves applying thermal gas-chemical, pressure and vibro-wave action to productive reservoir by combusting solid-fuel charge within reservoir interval. Charge is combusted in horizontal wells with the use of above described device.

EFFECT: extended functional capabilities, possibility to reach high hydrocarbon output from well, creation of additional low-frequency vibro-wave action on productive reservoir with the use of solid-fuel charges.

2 cl, 1 dwg

Description

The invention relates to the oil and gas industry. It can be used to clean the contaminated near-wellbore zone of the oil and gas reservoir (PZNP) with solid fuel charges (TK) in order to increase the inflows of hydrocarbons.

Analogs of devices with TK and methods of thermogasochemical and pressure treatment of formations by such devices are described in patents of the Russian Federation [1 ... 6]. The devices are placed in the interval of perforation of the well near the EOR and set on fire. Processing them with rocks contributes to the appearance of cracks in them, the expansion of existing channels, etc. There are also changes in the properties of the liquid ingredients of the reservoir, stimulating an increase in oil and gas production. With a significant increase in pressure caused by the burning of TK, these processes intensify. In extreme cases, a high-temperature hydraulic fracturing occurs. New cracks and longer trunk channels appear, departing mainly from the perforation holes of the well.

Known analogues are the open-section sectional charge for gas-dynamic stimulation of the formation [1] and a method of stimulating wells with its help [2]. The charge consists of an ignition unit, channel powder sections of the charge, as well as equipment for collecting and pulling these sections close to each other.

The disadvantage of this device is the large mass and number of tooling elements. The method is not effective enough and has certain restrictions on use. In particular, the technology under consideration cannot be used for horizontal wells.

Other analogues are known - a solid fuel gas generator with an adjustable pressure pulse for stimulation of wells and a method of stimulating a formation based on its use [3,4]. The gas generator contains powder tubular armored charges, an igniter charge placed under them, and a load-bearing geophysical cable with structural attachment elements. Between igniter TK and armored charges on the outer surface there are unarmored tubular charges. The number of unarmored tubular charges relative to the armored is determined by the formulas.

When the charges included in this gas generator are burned, low-frequency (estimated up to 50 Hz) pressure pulsations can occur against the background of a general increase in pressure in the well. They arise due to changes in the area of the burning surface of TK and their number cannot be more than two or three. Nevertheless, pressure distortions from the combustion of TK lead to vibro-microwave action (BBB) on the strata. They additionally contribute to an increase in the efficiency of thermogasochemical treatment of PZNP due to the destruction of the walls of cracks and colmatants by alternating loads.

The disadvantages of analogues [3, 4] are as follows. The device is quite complicated. It is not functional in horizontal wells. Unarmored TK from friction on the bottom wall of the casing can ignite. The armor coating of other TK will collapse due to loads, as it is made of non-combustible, but easily destructible material. The ignition TK ignition system is complex and consists of several elements, including a detonating cord undesirable for use. The method of influencing the reservoir by the considered device cannot be implemented under these conditions. In addition, with the help of all the above devices and technologies, it is impossible to induce high-frequency BBB on the strata, for example, at frequencies above one kilohertz.

This type of vibration is carried out by devices and methods described in the patents of the Russian Federation [5, 6]. They further enhance the effectiveness of thermogasochemical and pressure treatment of wells. BBB in this case occurs as a result of vibrational combustion of channel TK, which occurs in its channel filled with liquid. This mode occurs when favorable resonance conditions are reached for relatively small pressure pulsations in the fuel combustion zone.

The resulting primary high-frequency pressure waves with frequencies of the order of several tens of kilohertz are generated into the surrounding wellbore. A pulsed intake of the products of charge combustion is carried out in the CAP. At sufficiently high wave intensities, hydraulic fracturing is enhanced. As a result, there are such changes in the structure of rocks and the properties of liquid ingredients filling their pores, channels and cracks, in which the outflows of these ingredients from the rocks into the well are intensified and more intensive cleaning of the EOR occurs.

Other analogs are known - the device and the corresponding method of stimulation of wells described in US patent No. 5295545 [7]. They are intended primarily for use in horizontal wells.

The device is a set of cylindrical TK with a channel made of mixed non-detonating solid fuel based on ammonium perchlorate and an organic binder, hermetically sealed in flexible pipes. With their help, the device is delivered to the PPZN interval.

Ignition of TK comes from a hydrodetonator located in the fuse of the first charge, installed at the beginning of the horizontal section of the well and triggered by the pressure of the fluid pumped from the surface of the pump. Subsequent transfer of combustion to other TK occurs through a fire-conducting element.

The device has the following disadvantages. Ignition is not reliable enough, there is a danger of non-ignition of TK from the liquid supplied from the surface. The flame-retardant element can be destroyed under sharp pressure gradients caused by the combustion of TK. Sealing charges, especially at high temperatures and pressures, is difficult to implement. Ignition of individual TK after some time cannot create the necessary pressure levels for hydraulic fracturing, as a result of which this method is not effective enough. In addition, the effectiveness of thermogasochemical and baric effects on ECD can be increased with the help of additional explosives due to the combustion of TK.

The closest analogues of the invention are a device for perforating wells and fracturing in the formation according to US Pat. RF №2170339 [8] and the method described on its basis.

The device contains various variants of a cumulative perforator with explosive charges and a powder pressure generator with solid fuel elements connected to a cable cable for lowering into the well. TK are made of nonmetallized ballistic or mixed solid rocket fuel in the form of cylinders with a central round channel, in which the length and diameter of the central channel are related by the ratio (20 ... 40): 1, and the content of the filler-stabilizer of combustion to the mass of TK is not more than 1 ,5%.

The method of stimulation of the well, which implements the considered device, allows you to create additional BBB on the reservoir. However, the proposed technology is not suitable for horizontal wells. The use of a cumulative punch in this case complicates it. For the considered wells, in the design of the device with TK, it is necessary to provide a sufficiently flexible and durable load-bearing cable and other equipment elements.

The objective of the invention is to expand the capabilities of the method of stimulation of wells, achieving a high increase in the production rate of hydrocarbon feed from FZNP in horizontal wells and creating for them a reliable device based on TK without cumulative charges from explosives to the reservoir.

The solution to the problem is achieved in that in the known device with a powder charge for stimulating wells, containing a powder charge connected to a geophysical cable, consisting of solid fuel elements made of nonmetallized ballistic or mixed solid rocket fuel in the form of cylinders with a central circular channel in which the length and the diameter of the central channel is related by the ratio (20 ... 40): 1, and the content of the filler-stabilizer of combustion to the mass of the charge is not more than 1.5%, new is that the hardness charge fuel elements are mounted on a load-carrying cable passing through the central channels or outside the solid fuel elements, there are gaps between the solid fuel elements closed by combustible bushings, in addition, the solid fuel elements are enclosed in a protective casing, and the ignition unit is made in the form of an incandescent coil mounted in one of solid fuel elements or is located with an ignition cartridge near a fuel cell with lead wires, connected to current-carrying conductors of a geophysical cable, When in use, between the logging cable and the charge has a safety bar. The role of the protective casing can be performed by a segment of the tubing or the combustible bushings themselves between charges.

An incandescent spiral is installed in an annular gap on the outer surface of the technical specifications, closed with insulating tape and filled with heat-resistant sealant to prevent the spiral from contacting the well fluid. Outgoing from the spiral electric wires are isolated from the liquid. The ends of the wires are connected to the veins of the geophysical cable and the joints are isolated during assembly of the device before being lowered into the well.

Moreover, in the method of stimulating wells, including thermogasochemical, baric and vibro-microwave effects on the reservoir by burning a solid fuel charge in the reservoir interval, it is new that the charge is burned in horizontal wells using the device under consideration.

The device, docked with the cable at the wellhead, is lowered into the well and installed opposite the PPD in its horizontal section. It is shown in the drawing. It contains a set of charges 1, an ignition unit 2 and a snap. The latter includes a load-bearing cable 3, a tip 4, rigidly fastened with a geophysical cable 5 (according to the patent of the Russian Federation No. 2105326), a rod 6, an adapter 7, a protective casing (pipe) 8 with connecting sleeves 9 and a fairing 10 with a crash device 11 for measuring maximum pressure . At the top, the cable is connected to the rod 12, at the bottom - to the grill 13. The spring 14 in the upper part of the charge gives rigidity to the assembled garland TK. The wires from the ignition unit are connected to live conductors of the cable.

A device with a conventional geophysical cable is only applicable to vertical wells. Using a device with a geophysical cable repeating the direction of the well, according to RF patent No. 2105326 [9], unlike conventional cables, it is possible to achieve high tensile strength (120 ... 230 kN) and a sufficiently high rigidity for pulling TK with rigging in horizontal sections of wells after passing vertical sections of wells. This cable consists of three or more insulated current-carrying veins, covered with two or three pairs of armor layers with oppositely directed coils of wires in each pair, the second and third pairs of armor layers made of wire, the diameter of which is 1.3 ... 2.5 times the diameter of the wires of the first pair of layers of the armor, while on top of each pair is pressurized a coating of plastic adhesive material filling the gaps between the wires of the armor, and the outer diameter of the cable is calibrated over the entire length and range of 15 ... 32 mm.

The implementation of the method using the proposed device is as follows. After applying electric current through the geophysical cable, the igniter assembly is triggered. Ignition and subsequent combustion of all TK occurs, which goes into vibrational mode. High-frequency waves with frequencies of the order of several kilohertz - tens of kilohertz pressure are generated in the cavity of the channels of each of the charges.

Combustion of TK is accompanied by complex thermogasochemical, baric and explosive explosives on the reservoir. As a result, such changes occur in the reservoir, at which stimulation of the inflows occurs.

After combustion of the TK, a cable that withstands due to the safety rod located between it and the charge, is exposed to high temperatures, pressures and vibrations, with the rest of the equipment raised to the surface.

Using the claimed method and device, it is possible to process oil and gas wells with horizontal sections up to 500 m long at depths of up to 4 km and temperatures up to + 120 ° C.

Information sources

1. RF patent No. 2183740. IPC E21B 43/263. Sectional uncharged charge for gas-dynamic impact on the formation. Paderin M.G., Gazizov F.M., Efanov N.M., Rudakov V.V., Paderina N.G. Claim 08/22/2001. Publ. 06/20/2002. BIPM No. 17.

2. RF patent No. 2183741. IPC E21B 43/263. The method of gas-hydraulic stimulation. Paderin M.G., Efanov N.M., Paderina N.G. Claim 08/31/2001. Publ. 06/20/2002. BIPM No. 17.

3. RF patent No. 2175059. IPC E21B 43/263. Solid fuel gas generator with adjustable pressure pulse for stimulation of wells. Kroshchenko V.D., Gribanov N.I., Gaivoronsky I.N., Pavlov V.I., Sanasaryan N.S., Zalogin V.P., Zharkov A.S., Maryash V.I., Maksimovich Yu. .I., Kodolov V.V. Claim 10/06/1999. Publ. 10/20/2001.

4. Application for the invention of the Russian Federation No. 97100628. IPC 6 Е21В 43/25, 43/263. The method of stimulating the formation with pulsating pressure of powder gases. Kroshchenko V.D., Sanasaryan N.S., Pavlov V.I., Mikhailov A.A., Derzhavets A.A., Zalogin V.P., Stefankevich Z.B., Shkitkin B.V. Claim 03/27/1999.

5. RF patent №2151282. IPC 7 Е21В 43/45. Device for thermogasochemical treatment of the reservoir. Pivkin N.M., Pelykh N.M., Kuznetsova L.N., Karpov A.A., Alikin V.N., Soloviev N.M. Claim 02/08/1999. Publ. 06/20/2000. Bull. Number 17.

6. RF patent No. 2176728. IPC 7 Е21В43 / 25, 43/27. The method of processing the reservoir and charge. Baldin A.V., Novoselov N.I., Pelykh N.M. Pivkin N.M., Kuznetsova L.N., Yuzhaninov P.M. Claim 12/27/2000. Publ. 12/10/2001. Bull. Number 34.

7. US Patent No. 5295545. IPC E21B 43/263, 1994. The method of fracturing using solid fuel.

8. RF patent No. 2170339. IPC 7 Е21В 43/117. A device for perforating wells and fracturing in a formation. Kuzmitsky G.E., Alikin V.N., Ilyasov S.E., Yuzhaninov P.M., Pivkin N.M., Pelykh N.M., Duvanov A.M., Vorobev L.S. Claim 07/27/99. Publ. 07/10/2001. Bull. No. 19 is a prototype.

9. RF patent No. 2105326. MKI 6 G01V 1/40, 3/18. Geophysical cable for the study of deviated and horizontal wells and a method for the study of these wells. Korzhenevsky A.G., Korzhenevsky A.A., Aleinikov V.N. Claim 01/20/97. Publ. 02/20/98. Bull. No. 5.

Claims (2)

1. A device with a powder charge for stimulation of wells, containing a powder charge connected to a geophysical cable, consisting of solid fuel elements made of nonmetallized ballistic or mixed solid rocket fuel in the form of cylinders with a central circular channel, in which the length and diameter of the central channel are related by the ratio ( 20 ... 40): 1, and the content of the filler-stabilizer of combustion to the mass of the charge is not more than 1.5%, characterized in that the solid fuel charge elements are mounted on a load There are gaps between the solid fuel elements between the solid fuel elements, closed by combustible sleeves, the solid fuel elements are enclosed in a protective casing, and the ignition unit is made in the form of an incandescent coil mounted in one of the solid fuel elements or located with an ignition cartridge near a fuel cell with lead wires connected to current-carrying conductors of a geophysical cable, and between the geophysical cable and its charge etsya safety bar. 2. A method of stimulating wells, including thermogasochemical, baric, and microwave effects on the reservoir by burning a solid fuel charge in the reservoir interval, characterized in that the charge is burned in horizontal wells using the device according to claim 1.