RU2312981C2 - Method for reservoir penetration and treatment - Google Patents

Abstract

FIELD: oil production, particularly enhanced recovery methods for obtaining hydrocarbons.

SUBSTANCE: method involves installing hollow and gas-generation solid-fuel charge in casing pipe; initiating the charge; creating perforation channel in casing pipe and surrounding productive reservoir with the use of hollow charge; moving gas generated by solid-fuel member combustion in the channel. Reservoir penetration and treatment are accompanied by vibrowave action and hydrochloric acid treatment resulted from vibratory fuel member combustion. The hydrochloric acid is generated by reaction between hydrogen chloride and water in fuel combustion products. Method is carried out with the use of device connected to logging cable and lowered in well. Device comprises hollow-carrier jet-type gun with perforation head linked to cable head, sealed side orifices or with weakened body areas, hollow charges and head. As each hollow charge is brought into action plasma jet stream is created. The jet stream passes through side orifices or burns through weakened body areas to break its integrity. Device additionally has one or more sealed air chambers having atmospheric pressure and arranged in different perforator zones. Each chamber is provided with non-detonating highly-strong cylindrical channel solid-fuel member having channel length/diameter ratio of (6-28):1. The member is formed of heat-resistant gas-generation composition with predetermined component ratio.

EFFECT: increased well yield, productive reservoir treatment due to simplified structure and assemblage thereof, improved response and functional efficiency.

Description

The invention relates to the oil industry and is associated with methods of opening the near-wellbore zone of the formation (PZP) and additional stimulation of hydrocarbon inflows. The methods are based on the use in one device of perforators with cumulative charges (SC) of explosives that create cumulative jets, and gas generators with burning solid fuel elements (FC).

The following analogues of the method are known. The method [1] consists in installing a short hole in the casing of the borehole and at the same time a fuel cell with their subsequent initiation. The former were initiated by an electric detonator, the latter by an electric igniter and an igniter charge. First, a short circuit is triggered and perforations are made in the casing, and then TEs are ignited. During the combustion of fuel cells, gaseous products are formed that squeeze the wellbore fluid through the perforations, causing a formation of a network of cracks in the formation. As a result, there is a significant increase in the surface of the filtration of perforation channels.

The disadvantage of this method is the application of pressure through the borehole fluid, polluting the formed filtration surface and reducing its permeability compared to the initial (before processing) level. Short circuit and fuel cells are located in different places, assembly is difficult.

In the method [2] using a firing apparatus with a short circuit and alternating with them TE, lowered on a geophysical cable. Short circuit are interconnected by a detonating cord, and TE - by a quick-burning fire-conducting cord. Short circuit and fuel cells are in the borehole fluid; the apparatus has no body. Undermining of the short circuit is carried out after ignition of the fuel cell in the process of burning or after combustion. Combustion products, creating increased pressure in the well, enhance the cumulative effect and contribute to increasing the impact on the bottomhole formation zone.

The disadvantages of this method are the same as in the method [1], and also that due to the complexity of the apparatus as a whole, its use is difficult. FCs can break down and fail to operate in the well at elevated temperatures and pressures.

The method [3] is based on the use of individual blocks suspended on a cable. This complex apparatus consists of a perforator with a short circuit and a gas generator with fuel cell. The punch is placed below. The operation of the apparatus occurs with a reduced level of well fluid. Above this level, a packer can be installed. The method allows to carry out not only perforation, but also to carry out additional thermogasochemical effect on the bottomhole zone caused by the burning of fuel cells.

The disadvantage of the technology is the complexity of its practical implementation and lack of efficiency, primarily due to the separate placement of the perforator and gas generator in the absence of a common apparatus body.

The method [4] is based on well perforation and stimulation of oil and gas inflows by a device containing a cylindrical fuel cell located around the outer surface of a perforator with a short circuit. Cumulative jets from the short circuit cause ignition of the fuel cell, followed by the penetration of gases through perforations and channels in the bottomhole zone. When the gas leaves the rock, it cleans the channel, removing fragments formed during perforation.

Due to the danger of the destruction of the fuel cell from cumulative jets and restrictions on the use of the device at high temperatures or small pipe sizes, caused, for example, by the insufficient thickness of the fuel vault and the complexity of the design, the method is dangerous, it is not used and effective in all cases.

The method [5] includes placing a casing cumulative perforator (CCP) opposite the reservoir, containing a short circuit and an adjacent gas-generating channel fuel cell, performing a perforation channel in the casing and surrounding rocks with the penetration of gases from the short circuit and fuel cells into them. A feature of the method is the initiation of TE from the channel by cumulative jets from the short circuit. Together with the gases formed, a chemical reagent and proppants can additionally move into the perforation channel. The method does not say anything about how this movement will occur. The method is complicated primarily due to limitations in the size of short-circuit and fuel cells, as well as because of the difficulty in selecting fuel, the development of technology for the manufacture of fuel cells and the design of TK, working in the CCP together in the design mode, as well as the difficulty of assembly and its practical implementation.

The closest analogue of the present invention is a method of well completion using KKP with KZ and TE [6]. According to this method, the impact on the PPP is carried out by a short circuit, TE and a chemical reagent in a glass capsule. TE and capsule have a central channel through which cumulative jets from the short circuit pass. They ignite the fuel and destroy the capsule. Hydrochloric acid can be used as a chemical reagent, which penetrates into the bottomhole zone at elevated temperatures and pressures after cumulative jets from short-circuit and gases from fuel cells. It enhances the efficiency of processing the reservoir in comparison with other methods-analogues, but without acid.

However, the method is not effective enough. The location of the short circuit, TE and capsules on the same axis limits its use. It cannot be used in small diameter wells; it is difficult to practically implement. Ignition of fuel cells from faults is undesirable, since fuel cells can be destroyed by the effects of a cumulative jet at high temperatures, leading to an unbalanced mode of operation of the heat pump. In addition, with such a design of the checkpoint, a vibro-microwave effect (BBB) on the PPP cannot be carried out.

BBB is a consequence of the occurrence of a vibrational combustion regime due to the presence of acoustic high-frequency pressure waves in the cavity of a cylindrical channel of a fuel cell. When BBB is carried out, the pulsed combustion products of the fuel cell are pulsed into the PZP. It leads to the formation of additional microcracks and channels in the rocks, a decrease in the degree of PZP heterogeneity, a decrease in the viscosity of the liquid filling the voids in the rocks, and other favorable processes for increasing inflows.

BBB ultimately reduces the maximum pressure at which a "hot" hydraulic fracturing occurs, complementing the thermogasochemical effect, and generally enhances the efficiency of well treatment.

If the source of the appearance and movement of the chemical reagent into the perforation channel is the fuel itself and its products of combustion, then there will be no need to place the capsule with this reagent in the casing. The method will be simplified.

The purpose of the invention is to increase the efficiency of complex processing of a productive formation (perforation and additional stimulation) with an apparatus including a cumulative case-shaped perforator and gas generator, by simplifying its design and assembly, improving operation and functioning, as well as using a specific form and composition for a gas generator burning in vibration mode and emitting hydrochloric acid, including at high pressures and temperatures.

The goal is achieved by the fact that in the known method of well completion, which includes installing a gas generating charge from a solid fuel in a casing from an explosive, followed by the initiation of a cumulative and gas generating charge, performing a perforation channel in the casing and the surrounding reservoir with a cumulative charge and moving to the perforation the channel of the gas generated during the combustion of fuel cells is new, that the opening and treatment of the formation is supplemented by vibrating microwave exposure with hydrochloric acid and processing is performed using lowered on logging cable device including PAC, a perforation head is connected to the cable head, with sealed side holes or refined places in the housing, and the tip of RS. When each of the cumulative charges is triggered, the plasma cumulative jet passes through the side openings or burns out delicate places in the housing and violates its sealing. The device additionally provides one or more sealed air chambers with atmospheric pressure located in different places of the perforator, for example, at the lower end or at the ends of the perforator, with a non-detonating high-strength cylindrical channel TE located in each chamber. The ratio of the length of the TE channel to its diameter is (6 ... 28): 1. It is made of a heat-resistant gas-generating composition with the following ratio of components, wt.%: Polydivinyl isoprene rubber with epoxy end groups - 7 ... 9, transformer oil - 5.60 ... 6.50, titanium disilicide - 0.60 ... 1.50, strontium carbonate - 0.10 ... 0.50, combustion modifier - 0.20 ... 0.30, aromatic amino acid - 0.03 ... 0.11, aromatic amine - 0.01. ..0.06, curing catalyst - 0.01 ... 0.1, ammonium chloride - the rest.

Its initiation with subsequent combustion, including vibrational, and the appearance of hydrochloric acid in the fuel combustion products occurs from the initiator connected by an electric wire to the cable head, for example, from an explosive cartridge located in the fuel cell channel or at its end, and connected to the detonating cord, and / or from detonation products when the detonating cord connected to the short circuit is triggered, and from the short circuit itself.

The method is implemented using the CCP, for example, type PK-105E, to which a sealed air chamber with fuel cells can be connected from below. The tip from the PK-105E can also be used by connecting it to the camera with the FC from below. Between cameras with a short circuit and a fuel cell, disks are installed with holes for delivering an initiator, for example, an explosive cartridge of the PG-170 type, to a fuel cell, holding the fuel cell in the chamber and partially protecting it from detonation products from the CCC. Gaskets between chambers provide sealing of the device. The fuel cell has a special burning coating that protects it from moisture and mechanical stress. Between the FC and the metal parts of the chamber with which it is in contact, there are gaskets, for example polyurethane rings in the annular gap between the FC and the camera. With several fuel cells in the same chamber there are bushings between them. In the lower part of the device there is a crash device for measuring the maximum pressure created by its operation.

Vibrational combustion mode, leading to explosive attack on the formation in the form of elastic pressure waves, occurs in the cavity of the FC channel after its initiation and the beginning of combustion. It exists for several fractions of a second TE in the form of high-frequency acoustic pressure waves with frequencies of the order of several kilohertz and amplitudes reaching 10 MPa. Vibration mode is provided only with the above ratio of the length of the channel of the element to its diameter in the case of using FC from the composition of TG-1 [7]. In this case, vibrational combustion without destroying the fuel cell due to excess pressure in the channel over the pressure outside the element will occur at temperatures up to + 150 ° C and pressures up to 80 MPa. In the products of fuel combustion of TG-1 during the interaction of hydrogen chloride with water, an acid reagent is formed in the form of hydrochloric acid in a vapor state, its mass is at least 20% by weight of the fuel.

An example of a specific method. The assembled device, which includes the CCP and a sealed air chamber with a fuel cell connected to it from below, with a fuel cell having a channel length to its diameter of 24: 1 and made of TG-1 fuel, is lowered into the well to a depth of five kilometers at a temperature of + 150 ° C. At the same time, short circuit and fuel cells do not come into contact with the environment located outside the CCU. Gradually, with increasing depth, the temperature inside the device rises to the outside.

After the device is lowered, a current is supplied to it via a geophysical cable. It works. Upon short-circuit detonation, plasma cumulative jets are formed, tearing off the plugs from the perforator body and closing the side openings. In parallel with this, TE is initiated and subsequently burns, which goes into vibration mode. Due to the difference in the response times of the short circuit and the fuel cell, the combustion of the latter occurs after the plugs are broken, accompanied by short-term non-stationary changes in pressure and temperature inside the device, as well as the movement of liquid and gaseous products. Cumulative jets, bypassing the medium inside the casing, pierce it and create channels in the rocks. Combustion products of fuel cells containing hydrochloric acid from the chamber in which it was located, through the internal cavity of the device and the holes in the perforator body and the casing, enter the perforation channels through the perforation channels. During vibrational combustion of fuel cells, this intake occurs in a high-frequency pulse mode.

As a result of all types of impacts on the casing string and PZP caused by cumulative jets and combustion products of fuel cells, not only perforation channels arise, but also new channels, cracks and other structural changes of rocks are created. During vibrational combustion of fuel cells, leading to explosives on the reservoir, additional shaking of the rocks occurs, as well as their dissolution, favorable in terms of increasing inflows from the bottomhole formation zone. Corresponding changes in the properties of the medium in the voids of the rocks, caused by the action of hydrochloric acid, also occur. After the penetration of products into the reservoir, as pressure decreases, their reverse movement into the device through holes in the housing occurs. Solid ingredients in the form of KZ fragments, cement stone residues, rock particles, etc. enter the chamber in which the fuel cell was located before the device was triggered. An additional effect is created that cleans the PZP.

The technical result of the proposed method is its relative simplicity and speed, the combination of several types of effects on the casing and PZP, the ability to use under extreme conditions at high pressures and temperatures, high efficiency, which can significantly increase inflows from the reservoir. The method is relatively cheap, suitable for various geological conditions. It can be used in the development of new wells, as well as for wells that have been operating for a long time, including for reanimation of old ones.

Information sources

1. Bondarenko V.N. and others. Geophysical and perforating blasting in wells. M .: Nedra, 1976, p. 231-233.

2. US patent No. 5355802 from 10/18/94, IPC 42B 3/300. Method and device for perforating wells and creating fractures in the reservoir.

3. US patent No. 5551344 from 09/03/96, IPC 42B 3/300. Method and device for perforating wells and creating fractures in the reservoir.

4. Feldman I.I. Stim-Gun assembly and Owen Oil Tools Stim-Tube. Scientific and Technical Bulletin "Logger", No. 67, ed. AIS, Tver, 2000

5. RF patent No. 2119045 from 09.20.1998, IPC 6 ЕВВ 43/117. Well completion method.

6. RF patent №2138623 from 29.03. 1999 IPC 6 ЕВВ 43/11. The completion method is a prototype.

7. RF patent No. 2233975 of 4.11.2002, IPC 7 ЕВВ 43/248. Heat-resistant gas-generating composition for high-strength well elements.

Claims (1)

A method of opening and treating a formation, including installing a cumulative charge from an explosive in a casing string, a gas generating charge from solid fuel, followed by initiating a cumulative and gas generating charges, performing a perforation channel in the casing and the surrounding formation by a cumulative charge, and transferring gas generated into the perforation channel during the combustion of a solid fuel element, characterized in that the opening and processing of the formation is supplemented by a vibrating microwave action with lanocarbon treatment and is carried out using a device lowered on a geophysical cable, including a case-shaped cumulative perforator with a perforator head connected to the cable head, with sealed side holes or thinned places in the case, cumulative charges and a tip, while the cumulative plasma jet when each of them is triggered charges passes through the side openings or burns out delicate places in the case and violates its sealing, and in the device One or more sealed air chambers with atmospheric pressure located at different places of the perforator, for example, at the lower end or at the ends of the perforator, with a non-detonating high-strength cylindrical channel solid fuel element located in each chamber, which has a ratio of the channel length to its diameter (6, are specifically provided). ..28): 1 and is made of a heat-resistant gas-generating composition in the following ratio of components, wt.%: Polydivinyl isoprene rubber with terminal epoxy groups - 7 ... 9, trans transformer oil - 5.60 ... 6.50, titanium disilicide - 0.60 ... 1.50, strontium carbonate - 0.10 ... 0.50, combustion modifier - 0.20 ... 0, 30, aromatic amino acid - 0.03 ... 0.11, aromatic amine - 0.01 ... 0.06, curing catalyst - 0.01 ... 0.1, ammonium chloride - the rest, and its initiation with subsequent combustion, including vibrational, and the appearance of hydrochloric acid in the fuel combustion products comes from an initiator connected by an electric wire to a cable head, for example, from an explosive cartridge located in the channel of a solid fuel element and whether at its end face and connected to the detonating cord, and / or from detonation products when the detonating cord connected to the cumulative charges and cumulative charges are triggered.