RU2260685C2 - Method for processing face-adjacent zone of well and device for realization of said method - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: in the well, pulse depression and repression effects on bed are formed in form of cycles of pulse depression-repression oscillations for swaying plugs, corking filtering channels. Pulse depression and repression effects are performed by multiple adjusted pressure pulses, which pressure appears during external thermal transformation of substances mixture, coinciding with own oscillations phase in well and in bed. Cyclically increasing amplitude is provided with providing of depression-repression oscillations pulses, equal to 15·n, where n - number of chambers, and next pressure pulse exceeds previous one, with time range τ=2πk, where k - proportionality coefficient, while number of pressure pulses is equal to chamber number. Effect on bed is performed using device, containing serially positioned implosion chambers with draining openings, geophysical head, geophysical cable. Implosion chambers are interconnected by link, isolating hollow of one chamber from another one and provided with hermetical wall. Through the latter electric conductors are let. Into each implosion chamber package with mix of substances is placed, which mix is capable of external thermal transformation, and provided with electric spiral, connected to independent ignition line.

EFFECT: higher efficiency.

2 cl, 1 dwg

Description

The invention relates to the oil industry and can be used to increase oil recovery and injectivity.

To increase the productivity of oil wells, to intensify oil inflows at oilfields, especially those at a late stage of operation, as well as containing highly recoverable, highly viscous oils, to clean the near-wellbore zone of a well (CCD) from the products of mudding, paraffin-hydrated and asphalt-tar deposits, increase permeability, injectivity and increase The rock's filtration ability uses various methods of stimulating the formation. Among the known methods include chemical, thermogasochemical, shock and other effects.

A known method of treating a productive formation in which thermochemical and pressure is applied to the formation by burning a powder charge and solid fuel material with a filler-stabilizer of combustion with a central rounded channel in the interval of the productive formation while accumulating the pressure of the powder gases in the cavity of the central charge channel with subsequent transfer of energy charge burning into the formation (RF patent No. 2103493, IPC 7 E 21 B 43/26. BI No. 3. 1998).

A known method of processing the bottom-hole zone of the formation and a device for its implementation, in which excess pressure in the well is created by exposing the formation of gaseous products of combustion of a powder charge. The overpressure in the well is created by at least two successive pressure pulses with an amplitude and duration of the first impulse sufficient to reveal natural cracks, and an amplitude and duration of the second impulse, while the second pressure impulse is created when the pressure in the well from the first impulse is 0 5 mountain pressure (RF patent No. 2106485, IPC 7 E 21 B 43/26. BI No. 7 of 03/10/1998).

The disadvantages of these methods are the use of gunpowder, which complicates the processing technology from a safety point of view, as well as the creation of a limited number of pressure pulses in the well (maximum two).

The closest in technical essence and the achieved result is a method of multi-cycle pulsed exposure to CCD, when using which the processing is carried out by alternating pulses of depression and repression. This provides up to 15-20 damped oscillations for swaying traffic jams.

The disadvantage of this method is the low efficiency due to the lack of initial pressure, as well as the lack of the ability to maintain and control the duration and amplitude of subsequent oscillations (RF patent No. 2136874. BI No. 25 of 09/10/99).

The closest in technical essence and the achieved result is a device for processing CCD oil wells, in which the processing of CCD is carried out using a device containing two implosion chambers (IR) and a perforator. The device allows thermal treatment of the CCD, implosion, then perforation followed by depressive treatment and implosion treatment again (RF patent No. 2131512. BI No. 16 of 06/10/99).

The disadvantages of this CCD processing device are the low efficiency of CCD processing as a result of using a limited number of implosion chambers and, consequently, the number of repression and depression cycles, as well as the impossibility of assembling an implosion chamber of the required sizes, the absence of a temporal pattern of the repression and depression cycle sequence, and neglect of properties downhole environment and wells.

The objective of the invention is to increase the efficiency of processing the bottom-hole zone of the well.

The problem is achieved in a way where pulsed depressive and repressive effects are carried out by multiple successive adjustable pressure pulses that occur during the exothermic transformation of a mixture of substances that coincide with the phase of natural vibrations in the well and in the reservoir, with a cyclically increasing amplitude with the provision of depression-repressive oscillation pulses equal to 15 · N, where n is the number of chambers and the subsequent pressure pulse exceeds the previous one with the time interval τ = 2 · π · κ, where κ = 0.5-35 is the coefficient proportionality factor, and the number of pressure pulses equal to the number of chambers.

The task is achieved by a device containing an implosion chamber with bore holes, a geophysical head and an ignition line, characterized in that the device is made up of implosion chambers in series, the implosion chambers are connected by an adapter isolating the cavity of one chamber from another, the adapter is equipped with a sealed partition through which electrical conductors are missing, and a cap with a mixture of substances capable of exothermic is placed in each implosion chamber to transformation, the cap is equipped with an electric coil connected to an independent ignition line, and the implosion chambers are opened as a result of the exothermic conversion of a mixture of substances in the chamber followed by thermochemical effects of the conversion products on the CCD, and magnesium powders are used as a mixture of substances capable of exothermic conversion or aluminum, or an alloy of aluminum with magnesium with salts of alkali or alkaline earth metals nitric acid (for example, potassium sodium nitrates i, barium, strontium), or sulfuric acid (for example, sodium, lithium, potassium, calcium, barium, strontium sulfates), or carbonic acid (for example, sodium, potassium, calcium, barium carbonates), or fluoropolymers (for example, FP- 4, FL-4N, FP-42, FP-2), or chlorine or fluorine, or fluorochlorine-containing organic compounds (for example, PVC-S, PSX-LS, SKF-26, SKF-32, FP-32L), or gunpowder, or a mixture thereof or gunpowder, or a mixture thereof.

A pressure impulse (overpressure) is created in the well as a result of opening the implosion chambers, inside which the pressure at the time of opening is larger than the hydrostatic pressure in the well. The pressure in the implosion chamber arises as a result of a chemical reaction proceeding with the release of a large amount of heat and gaseous products in a mixture of substances capable of exothermic transformation. As such a mixture, powders of magnesium, or aluminum, or an alloy of aluminum with magnesium with alkali or alkaline earth metal salts of nitric acid (e.g., sodium potassium, barium, strontium nitrates), or sulfuric acid (e.g., sodium, lithium, potassium sulfates, calcium, barium, strontium), or carbonic acid (e.g. sodium, potassium, calcium, barium carbonates), or fluoropolymers (e.g. FP-4, FP-4H, FP-42, FP-2), or chlorine or fluorine -, or fluorochlorine-containing organic compounds (for example, PVC-S, PSX-LS, SKF-26, SKF-32, FP-32L), or gunpowder, or mixtures thereof or gunpowder, or mixtures thereof. Mixtures of substances are prepared by known mixing methods.

A mixture of substances is activated (ignited) using a source of thermal energy.

A device for implementing the proposed method is presented in the drawing. The device consists of implosion chambers (1), which are interconnected via adapters (2). The entire device is attached through a geophysical head (3) to a geophysical cable (4). An implosion chamber is a thick-walled cylindrical vessel, which has several bleed holes (5) located on a cylindrical surface. During assembly, these holes are sealed. During assembly, a cap (6) with a mixture of substances capable of exothermic transformation is inserted into each chamber. The cartouche is supplied with an electric coil (7), which is connected to the ignition line (8). Each chamber is equipped with an independent ignition line, which, in turn, is connected to the electric drives of the geophysical cable through the geophysical head.

The adapter is a metal cylinder equipped with a sealed solid internal partition (9), through which electric conductors are passed for an ignition line that isolates one chamber from another.

The sequential opening of the implosion chambers according to a certain law allows increasing the efficiency of the subsequent pressure pulse as a result of using the energy of the previous pulse, that is, when using the phenomenon of mechanical resonance. The phenomenon of mechanical resonance in a well is achieved by generating forced vibrations that coincide with natural vibrations in the well and in the formation. Subsequent opening of the implosion chambers, coinciding in time with the phase of positive hydraulic shock, can significantly increase the efficiency of processing the bottom-hole zone of the well.

For CCD processing, it is necessary to open the implosion cameras of a multi-chamber device with time intervals

where κ = (0.5-35) is the coefficient of proportionality, depends on the nature of the well fluid, its hydrostatic level, the angle of inclination of the well and its condition.

The processing method of the CCD is as follows. At the bottom of the well, implosion chambers are assembled. A cap with a mixture of substances is placed in each chamber, the ignition line conductors are connected, and the chambers are hermetically sealed with self-sealing gaskets that isolate the chamber cavity from the external environment. Then deliver the assembled device to the CCD on a geophysical cable. The mixture of substances is ignited by an electric pulse. The interval between the moments of ignition of mixtures in the chambers is estimated by the formula (1) based on data on hydrostatic pressure in the well (hydrostatic level of the fluid), density of the borehole medium, hydraulic and local resistance coefficients. Highly heated interaction products located in the chamber after increasing the pressure above the hydrostatic pressure, open the gaskets and rush into the well, producing thermochemical and pulsed processing of the CCD. The well fluid rushes into the freed chamber, producing a water hammer, as a result of which an increased pressure impulse is created in the CCD region. The high-pressure pulse generates in the well its own damped oscillations of the borehole medium, transmitting the positive and negative phases of pressure change. The opening of the next chamber is performed after a time multiple of the calculated one and corresponding to the phase of the positive increase in pressure, which will allow superimposing subsequent oscillations on the previous ones. As a result of this, the pressure impulse from opening the next implosion chamber will significantly exceed the previous impulse. When the subsequent chamber is opened, the pressure pulse exceeds the reservoir pressure. As a result of the cyclic operation of the device, chemically active products of thermal transformation are injected into the formation, which increases the processing efficiency. After processing, the device is removed from the well, disassembled and cleaned.

The advantages of this method and device are integrated well treatment by creating controlled oscillations of a large-amplitude well column in combination with thermochemical processing, the use of standard equipment, compact implosion devices, and the absence of the need for complex injection equipment.

As a result of the implementation of the proposed method and device, a highly effective complex CCD processing is provided: thermochemical, allowing to clean the perforation holes from asphaltenes and paraffins, heating of the CCD, cyclic implosion treatment and long cyclic mechanical treatment of the well and CCD by increasing the pressure in the well, allowing both CCD and to carry out hydraulic fracturing, and therefore, increase its porosity and permeability. The simultaneous action of all these factors can improve the efficiency of both producing and injection wells.

Claims (3)

1. The method of processing the bottom-hole zone of the well, including the descent into the well on the cable chamber with atmospheric pressure and the creation of pulsed depressive and repressive effects on the reservoir in the form of cycles of pulsed depressive-repressive vibrations for swaying plugs, clogging the filter channels, characterized in that the pulsed depression and repressive effects are carried out by multiple successive controlled impulses of pressure arising from the exothermic transformation of a mixture of substances coinciding transmitting with the phase of natural oscillations in the well and in the formation, with a cyclically increasing amplitude with the provision of depression-repression oscillation pulses equal to 15 n, where n is the number of chambers, and the subsequent pressure pulse exceeds the previous one, with a time interval τ = 2 π k, where K is the coefficient of proportionality, moreover, the number of pressure pulses is equal to the number of chambers. 2. A device for treating a bottomhole zone of a well, comprising an implosion chamber with bore holes, a geophysical head and an ignition line, characterized in that the device is made with successively located implosion chambers, the implosion chambers are interconnected by an adapter isolating the cavity of one chamber from another, the adapter is equipped with a sealed partition through which electric conductors are passed, and in each implosion chamber a cap is placed with a mixture of substances capable of otermicheskomu conversion, provided elektrospiralyu cap attached to the independent ignition line, the implosion cameras have the option of opening due to the exothermic conversion of a mixture of substances present in the chamber, followed by exposure to the thermochemical conversion of the bottomhole formation zone products. 3. The device according to claim 2, characterized in that as a mixture of substances capable of exothermic conversion, powders of magnesium, or aluminum, or an alloy of aluminum with magnesium, with alkali or alkaline earth metal salts of nitric acid, or sulfuric acid, or carbonic acid, or fluoropolymers, or chlorine or fluorine, or fluorochlorine-containing organic compounds, or gunpowder, or a mixture thereof.