RU2163660C1 - Process of exploitation of flooded oil field and gear for its implementation - Google Patents

Abstract

FIELD: oil industry, exploitation of flooded oil fields at late stage. SUBSTANCE: in agreement with invention pool is opened by holes and pool fluid is extracted by production wells. Complex of technical equipment of vibration and seismic action having installation of waveguide device in excitation hole of existing fund or drilled specifically is assembled on section of hydrocarbon field and is matched with ground oscillation source of vibration type with controllable value of vibrations and amplitude of pushing force. Vibration and seismic action is conducted with simultaneous recording of amplitude spectrum of acoustic noise in interval of productive pool having maximum residual stock of oil. Boundaries of area of effective insonification of field are found by results of processing of amplitude spectrum of acoustic noise. Field is divided into sections of effective insonification and additional complexes of technical equipment of vibration and seismic action are mounted on them. Vibration and seismic action is conducted with simultaneous pumping of gas into intervals of pool in sections. Vibration-wave working of face zones of wells improving their filtration properties are carried out during vibration and seismic action. Repeat sessions of vibration and seismic action are conducted on sections of field. Gear for implementation of proposal includes ground oscillation source of vibration type made of power supply and control systems and vibration exciter placed into power frame aligned with reference to well-head with the aid of damping devices. Its radiating element is coupled to elastic waveguide via connected mass, waveguide is tied up by lower face mounted on radiator with matching unit. Radiator is composed of body, radiating bottom, limiting washer, implanted radiating elements and tightening elastic ring. With activation of ground oscillation source power supply and control systems control flows of fluid coming into vibration exciter which sets its radiating element in oscillatory motion and transmits vibrations to connected mass which provides for propagation of waves over waveguide, matching unit to radiator from where they are emitted into oil pool by implanted radiating elements and radiating bottom. EFFECT: increased final output of oil thanks to restoration of mobility of stuck oil, enlarged area of cover by vibration and seismic action with optimization of its boundaries. 17 cl, 9 dwg, 3 tbl

Description

 The invention relates to the oil industry, in particular to methods for the re-development of partially or completely depleted oil fields that were originally exploited under water flooding conditions by exposure to physical fields, and can be used to increase the final oil recovery.

 Known methods for developing flooded hydrocarbon deposits and devices for their implementation [1]. The method is based on synchronous vibroseismic action from a group of equidistant ground-based vibration sources located around one of the production wells that are extreme to the field contour by a linear frequency-modulated signal. After increasing the fluid inflow, the vibroseismic effect is carried out near another producing well, moving from the oil path to the center of the field.

 The main disadvantages of this method and device are the lack of choice of the effective frequency of stimulation (the exposure to a frequency-modulated signal is essentially an impact with the frequency selection performed by the control unit of the oscillation source), the absence of a time interval of exposure during operation at the excitation point, which affects the efficiency and performance.

 Closest to the proposed invention is a method of developing an irrigated oil field based on the vibroseismic effect on an irrigated area with a fixed oil phase of a ground source of oscillation installed on a well of producing wells within the area at a dominant frequency, determined based on the analysis of the amplitude spectrum of the microseismic background before and after exposure, the installation of additional sources at a distance from each other, equal to the diameter of the effective coverage area a person, and conducting vibroseismic action at a dominant frequency and a device for its implementation, a source of seismic signals containing a vehicle, a vibration agent, consisting of a loaded reactive mass and connected to the base plate through the plunger’s power frame, vibration isolation device and electro-hydraulic tracking system [2] .

 The prototype method is implemented in the following sequence of actions. At a field uncovered by producing wells, an irrigated area with a fixed oil phase is found; within the area on the well of the producing wells, a vibroseismic source is installed; a seismic receiver is placed in one of the producing wells to the depth of the reservoir and the microseismic background is measured for 2-3 days with the simultaneous determination of the percentage of oil in the borehole fluid; conduct vibroseismic exposure with frequency selection; after the termination of the vibroseismic effect, the amplitude spectrum of the microseismic background is measured, and the dominant frequency is found in the spectrum from the detected additional frequencies; produce an effect at this frequency; alternately moving the source half the wavelength until the cessation of the increase in oil content in the borehole fluid and determining the effective radius of the source; establish additional sources at a distance from each other equal to the diameter of the effective zone of action of the source; produce vibroseismic effects at the dominant frequency.

 The disadvantage of this development method is that the excess of the signal above the microseismic background does not restore oil mobility in many practical cases, which does not lead to the achievement of the goal; the determination of the effective zone of action of the source as a region of the reservoir in which the seismic signal is emitted above the background level, on the one hand, and its definition through the part of the wavelength by which the source must be moved until the increase in oil content in the well fluid ceases, on the other hand, is not this zone; a continuous vibroseismic effect is established at a dominant frequency, which leads to additional costs; the use of a ground-based vibration source in the method sharply reduces the field efficiency of the method due to the fact that most of the energy (68%) is carried away by surface waves and does not reach the oil reservoir.

 These shortcomings reduce the efficiency of restoring the mobility of trapped oil and lead to reduced productivity.

 The purpose of the invention is to increase the final oil recovery by restoring the mobility of the trapped oil and increasing the scope of the vibroseismic action while optimizing its boundaries and increasing the performance of the vibration source due to the periodicity of the vibroseismic effect.

This goal is achieved by the fact that in the method of developing an irrigated oil field, which includes opening a formation by wells, producing a reservoir fluid by producing wells, vibroseismic exposure at a dominant frequency to the formation from ground-based oscillation sources in areas of an irrigated hydrocarbon deposit in the zone of effective action of the sources, determining before and after the effects of the composition and amount of the produced fluid, the background values of the level of acoustic noise, on the site of the hydrocarbon deposit choose waiting for a well from an existing foundation or specially drilled and mounting elements of a waveguide device in it, pairing it with a ground source of vibrations, performing a vibroseismic action with simultaneous recording of the amplitude spectrum of acoustic noise in the interval of the reservoir having the largest residual oil reserves, according to the maximum the product of the square of the frequency and the amplitude of the displacement of the points of the medium at this frequency determine the levels equal to the acceleration of the points of the medium The productive formation, covering the exciting well in terms of plan, determines the boundaries of the area of effective sounding by a line with an acceleration of the order of magnitude, which is the larger of two values: the acceleration of gravity and the displacement pressure gradient divided by the density difference of the displacing and displaced agents in the reservoir, break the field in the field of effective sounding; mount additional vibration devices in the areas of the field within the boundaries of effective sounding matic impact on the hydrocarbon reservoir, conduct vibroseis action, T _duration of each of which is determined by the condition
(νω ^-3 ) ^0.5 / (M / ρ) ^1/3 <T _at <(νω ^-3 ) ^0.5 / d _s ,
where ν, ρ is the kinematic viscosity, m ² / s and the density of the rock in the interval of the reservoir at the boundary of the effective scoring region, kg / m ³ ; M, d ₃ - the mass of the largest, kg and the diameter of the smallest samples of the fractional composition of the rock in the interval of the reservoir at the boundary of the effective sounding region, m; ω is the dominant frequency, s ^-1 determined from the relation ω = (C / M) ^0.5 , where C is the stiffness of the rock of the oil reservoir in the areas of its weakening, N / m; at the same time as vibroseismic effects in the fields of the field within the boundaries of the areas of effective sounding, gas is pumped into oil reservoirs and vibro-wave treatments of the bottom-hole zones of the wells are performed to improve their filtration properties, and repeated sessions of vibroseismic effects in the areas of the field are carried out; moreover, the start time of a repeated session of vibroseismic exposure in each of the sections is determined at the time of the fall of the acoustic noise values in each of the sections to a level of 20-25% of the background values, repeated sessions of vibroseismic exposure are carried out until the development of this section is completely stopped, while in the exciting well they are isolated fluid flow along the borehole, the emitter of the vibroseismic device for the hydrocarbon reservoir is installed in the exciting well in the interval of the reservoir having the most lower residual reserves, so that the distance from the center of gravity of the emitter to the bottom of the formation refers to the distance from the center of gravity of the emitter to the roof of the formation, as (C ₀ C ₂ + C ₁ C ₂ -C ₀ C ₁ ) / (C ₁ C ₂ + C ₁ C ₀ -C ₀ C ₂ ), where C ₀ , C ₁ , C ₂ are the stiffness coefficients of the rocks composing the formation, covering and underlying medium, N / m; carry out the injection of free gas in portions, the total volume of which does not exceed 0.1% of the volume of the first space of the oil reservoir of a section of an irrigated hydrocarbon deposit; Vibratory treatment of bottom-hole zones of wells, improving their filtration properties, is carried out by generators that implement a frequency of impact on the bottom-hole zone of the formation equal to the frequency of vibroseismic effects on the formation; the upper end of the attached mass of the vibroseismic device is placed above the mouth of the exciting well, and its value is selected from the condition for realizing the maximum power of the ground source of vibrations when vibroseismic; registration of the level of acoustic noise is carried out in the range of 100 Hz - 20 kHz.

 In addition, this goal is achieved by the fact that in a device including a ground source of oscillations located above the well, an elastic waveguide and an emitter connected to the oscillation source located in a cased well, it is equipped with an attached mass, a matching node, a guiding element, locks, centralizers, a piston with a fishing head, an emitter, consisting of a housing, a radiating bottom, limiting washers, embedded radiating elements and a tightening elastic ring, moreover, as a ground source of oscillations, a vibration source with an adjustable value of the oscillation frequency and pushing force is used, consisting of power and control systems and a vibration exciter placed in a power frame centered relative to the wellhead by means of damping devices, the radiating element of the vibration exciter is connected through a connected mass to the waveguide from the pipe string, associated with the matching node, the lower end mounted on the emitter with the possibility of interaction with him, while at the lower end of the matching node and a guiding element is installed, centralizers and locks are installed in places of threaded connections of the elements making up the attached mass, the waveguide and matching unit, excluding the relative movements of the connected surfaces of the elements and turning them in threads under vibroseismic action, the attached mass is made in the form of a set of pipes and ingots, matching the node is made in the form of pipes and rods with an increasing cross-sectional area, the guide element is made in the form of scarves, the emitter housing is made n in the form of a pipe with windows on the side surface, the lower end of the pipe is installed on the radiating bottom with the possibility of interaction with it, inserted radiating elements are inserted into the pipe windows, a piston with a fishing head protruding above its upper end is placed in the pipe with the possibility of interacting with the introduced radiating elements , a restriction washer is installed on the upper end of the pipe, covering the piston above the location of the annular protrusion on the side surface of the piston and restricting the upward movement of the piston, which are emitted e elements are made with the possibility of interaction with the walls of the well, the radiating bottom is mounted on a cement bridge, an annular groove is made on the lateral surface of the introduced radiating elements, in which a tightening elastic ring is installed; moreover, as the causative agent of vibrations, a hydraulic actuator is used, consisting of an inertial mass and a piston placed in it, forming a cavity / cavities filled with oil with the inner walls of the inertial mass; as the causative agent of vibration, an electromechanical drive is used, consisting of rotating unbalances driven by an electric motor; an electrohydropneumatic drive is used as a vibration exciter, using compressed gas energy to excite vibrations; as a vibration exciter, a gas-dynamic source is used, using the energy of combustion / detonation of the gas mixture to excite oscillations; implantable radiating elements interact with the walls of the well through a cement spacer; the ratio of the magnitude of the attached mass to the inertial mass of the hydraulic actuator of the ground source of oscillation is selected from the range of 0.286-0.833; a ground source of oscillation is located on the vehicle.

The essential features of the method:
1. opening the formation with wells;
2. formation fluid production wells;
3. vibroseismic impact on the dominant frequency on the reservoir from ground-based sources of vibration in areas of flooded hydrocarbon deposits in the zone of effective action of the sources;
4. determination before and after exposure to the composition and amount of produced fluid and background values of the level of acoustic noise of the rock;
5. the choice on the site of the hydrocarbon deposits of the exciting wells from the existing fund or specially drilled;
6. installation in the exciting well of the elements of the device vibroseismic effects on hydrocarbon deposits;
7. pairing the waveguide device with a ground source of oscillations;
8. the implementation of vibroseismic effects with simultaneous registration in the vicinity of the exciting well in the interval of reservoirs changes in time the level of acoustic noise;
9. determination of the maximum product of the square of the frequency and the amplitude of the displacement of the medium points at this frequency of the levels of equal accelerations of the medium points of the reservoir, which cover the exciting well in plan;
10. determination of the boundary of the region of effective scoring by a line with acceleration of the order of magnitude, which is the greater of two values: the acceleration of gravity and the displacement pressure gradient divided by the density difference between the displacing and displaced agents in reservoir conditions;
11. dividing the field into areas of effective scoring;
12. installation on the site of the field within the boundaries of the areas of effective sounding of additional devices for vibroseismic impact on the hydrocarbon deposit;
13. conducting vibroseismic effects, the duration of each of which is determined from the conditions:
(νω ^-3 ) ^0.5 / (M / ρ) ^1/3 <T _at <(νω ^-3 ) ^0.5 / d _s ,
where where ν, ρ is the kinematic viscosity, m ² / s and rock density in the interval of the reservoir at the boundary of the effective sounding region, kg / m ³ ; M, d ₃ - the mass of the largest, kg and the diameter of the smallest samples of the fractional composition of the rock in the interval of the reservoir at the boundary of the effective sounding region, m; ω is the dominant frequency, s ^-1 determined from the relation ω = (C / M) ^0.5 , where C is the stiffness of the rock of the oil reservoir in the areas of its weakening, N / m;
14. the simultaneous implementation of vibroseismic exposure to areas of the flooded oil reservoir gas injection into oil reservoirs;
15. conducting microwave treatments of the bottom-hole zones of wells that improve their filtration properties;
16. conducting repeated sessions of vibroseismic impact on the site of the field;
17. determination of the start time of a repeated session of vibroseismic exposure in each of the sections at the time of falling acoustic noise values in each of the sections to a level of 20-25% of the background values;
18. conducting repeated sessions of vibroseismic exposure until the cessation of development of this site;
19. isolation in the exciting well of fluid flow along the wellbore;
20. installation of the emitter of the vibroseismic device on the hydrocarbon reservoir in the exciting well in the interval of the reservoir having the largest residual reserves, so that the distance from the center of gravity of the emitter to the bottom of the reservoir refers to the distance from the center of gravity of the emitter to the roof of the reservoir, as (C ₀ C ₂ + C ₁ C ₂ -C ₀ C ₁ ) / (C ₁ C ₂ + C ₁ C ₀ -C ₀ C ₂ ),
where C ₀ , C ₁ , C ₂ are the stiffness coefficients of the rocks composing the formation, covering and underlying medium, N / m;
21. registration of the level of acoustic noise in the range of 100 Hz - 20 kHz.

22. the implementation of the injection of free gas in portions, the total volume of which does not exceed 0.1% of the pore space of the oil reservoir of a section of an irrigated hydrocarbon deposit;
23. the implementation of the microwave wave treatments of the bottom-hole zones of the wells, improving their filtration properties, by generators that realize the frequency of impact on the bottom-hole zone of the formation, equal to the frequency of vibroseismic effects on the formation;
24. placement of the upper end of the attached mass of the vibroseismic device above the mouth of the exciting well;
25. the choice of the magnitude of the attached mass from the conditions for the realization of the maximum power of the ground source of oscillations during vibroseismic exposure;
Signs 1-4 are common with the prototype;
5-16 - the essential features of the proposed method;
17-25 - private signs of the proposed method.

Salient features of the device:
1. ground source of oscillation;
2. a waveguide from a pipe string;
3. attached mass;
4. matching node;
5. guide element;
6. locks;
7. centralizers;
8. a piston with a fishing head;
9. a radiator, consisting of a housing, radiating bottoms, limiting washers, embedded in the walls of the casing, radiated elements, tightening rings;
10. the matching node with the bottom end is mounted on the emitter with the possibility of interaction with it, and the top is connected through the waveguide from the pipe string with an attached mass connected to the oscillation source;
11. The guide element is mounted on the lower end of the matching unit;
12. centralizers and locks are installed in the places of the threaded connections of the elements making up the connected mass, the waveguide and the matching unit and excluding the relative movements of the elements and their rotation in the threads under vibroseismic action;
13. The attached mass is made in the form of a set of pipes and rods;
14. matching unit is made in the form of pipes and rods;
15. The guide element is made in the form of scarves;
16. the case of the emitter is made in the form of a pipe with holes on the side surface;
17. The bottom end of the pipe of the emitter body is mounted on the radiating bottom with the possibility of interaction with it;
18. implantable emitted elements are inserted into holes on the side surface of the pipe of the emitter body;
19. a piston with a fishing head protruding above its upper end is placed in the tube of the emitter housing with the possibility of interaction with implantable radiating elements;
20. at the upper end of the pipe of the emitter housing, a washer restricting the piston stroke upward is installed, covering the piston above the location of the annular protrusion on the side surface of the piston;
21. implantable radiated elements configured to interact with the walls of the well;
22. a radiating bottom mounted on a cement bridge;
23. An annular groove is made on the lateral surface of the introduced elements, in which a tightening elastic ring is installed;
24. As the actuator, a hydraulic actuator is used, consisting of a hydraulic cylinder, which is an inertial mass, and a piston placed inside it, forming a cavity / cavities filled with oil with the inner walls of the hydraulic cylinder;
25. An electromechanical drive is used as an actuator, consisting of rotating unbalances driven by an electric motor;
26. An electrohydropneumatic drive is used as a vibration exciter, using compressed gas energy to excite vibrations;
27. a gas-dynamic source is used as the causative agent of vibrations, using the energy of combustion / detonation of the gas mixture to excite vibrations;
28. the introduced radiating elements interact with the walls of the well through a cement spacer;
29. the ratio of the magnitude of the attached mass to the reactive mass of the hydraulic actuator of the ground source of vibration is selected from the range of 0.286-0.833;
30. a ground source of oscillation is located on the vehicle.

Signs 1-2 - common with the prototype;
3-23 - the essential features of the claimed device;
24-30 - private signs of the claimed device.

 The invention is illustrated by drawings, where in FIG. 1-2 shows a device for implementing the method; FIG. 3 is a model of a porous medium mounted on a vibrating stand; FIG. 4 - dependence of the critical length of the rear sight on the oscillation frequency; FIG. 5 - distribution of residual oil in a porous medium model before and after vibration exposure; FIG. 6 - amplitude of oscillations of the zero level block; FIG. 7 - the amplitude of the oscillations of the blocks from zero to eighth level inclusive; FIG. 8 - levels of acoustic noise of the rock before and after vibroseismic exposure; FIG. 9 - technological indicators of the development of the experimental plot as a result of vibroseismic exposure.

 A method for developing an irrigated hydrocarbon reservoir is as follows.

In the area of the flooded hydrocarbon deposit, an exciting well 29 is selected in which fluid flow through the bore 13 is limited. The emitter 21 of the vibroseismic device is installed in the exciting well 29 in the interval of the reservoir 30 having the largest residual oil reserves. If the underlying and covering media have different stiffnesses, the emitter 21 is placed in the formation near the boundary of a softer medium, so that the distance from the center of gravity of the emitter to the bottom of the formation refers to the distance from the center of gravity of the emitter to the roof of the formation, as (C ₀ C ₂ + C ₁ C ₂ -C ₀ C ₁ ) / (C ₁ C ₂ + C ₁ C ₀ -C ₀ C ₂ ), where C ₀ , C ₁ , C ₂ are the stiffness coefficients of the rocks composing the formation, covering and underlying environments, H / m

 After the emitter 21 is installed in the well 29, the remaining elements of the vibroseis device are successively mounted: a matching unit 16 with a guiding element 17, a waveguide of pipes and rods 10, 11, an attached mass 8 using centralizers and locks 9, 12, 15, centering the layout in the column 13 and excluding the rotation of its elements in threaded connections. At the mouth, a connection is made with a ground source of oscillations, consisting of a vibration exciter (hydraulic actuator) 1 as part of an inertial mass 4, a piston 3, which form cavities for liquid 2 coming from the power supply and control system 5.

 Simultaneously with the installation of the device for vibration in neighboring wells in the interval of productive formations, the background level of acoustic noise is determined, i.e., the total amplitude of the oscillation points of the geophysical medium in the frequency range 100 - 20,000 Hz.

A vibroseismic exposure session is performed with simultaneous recording of the amplitude spectrum of acoustic noise in the interval of the formation having the largest residual oil reserves in wells in which the background values of acoustic noise were recorded at the same pickets. Using the maximum product of the square of the frequency and amplitude revealed in the spectrum at this frequency, lines of equal accelerations of the points of the medium of the oil reservoir are constructed, covering the excitation well in plan, having a greater value from the acceleration of gravity or the pressure gradient in this section divided by the density difference between the displacing and displaced phases . The area of the inner region and the radius of the region of effective scoring are determined. The area of the flooded hydrocarbon reservoir is divided into sections of effective scoring. Install additional sources on the plots. A vibroseismic effect is carried out, the duration of which in each of the sections is chosen from the condition
(νω ^-3 ) ^0.5 / (M / ρ) ^1/3 <T _at <(νω ^-3 ) ^0.5 / d _s ,
where where ν, ρ is the kinematic viscosity, m ² / s and rock density in the interval of the reservoir at the boundary of the effective sounding region, kg / m ³ ; M, d ₃ - the mass of the largest, kg and the diameter of the smallest samples of the fractional composition of the rock in the interval of the reservoir at the boundary of the effective sounding region, m; ω is the dominant frequency, c ^-1 , determined from the relation ω = (C / M) ^0.5 , where C is the stiffness of the rock of the oil reservoir in the areas of its weakening, H / m

 Simultaneously with vibration exposure in the areas, free gas is injected within up to 0.01% of the volume of the first space of the oil reservoir in the area.

 Vibro-wave treatments of bottom-hole zones of the formation are carried out, improving their filtration characteristics.

 Re-vibration in each of the sections is carried out when the level of acoustic noise decreases and amounts to 20-25% of the background in each of the sections. Vibration in the sections is stopped when the development of these sections is completely stopped.

 We present the results of laboratory and field studies confirming the possibility of implementing the method.

где σ - коэффициент межфазного натяжения, H/м;
θ краевой угол смачивания, град;
Δρ - разность плотностей фаз, кг/м³;
g - ускорение свободного падения, м/с²;
r - радиус каналов пористой среды, м;
α - угол наклона фрагмента нефти к горизонту, град;
A, ω - амплитуда, м и частота колебаний, с^-1 в окрестности фрагмента нефти;
dP/dx - градиент давления вытеснения, H/м³;
l - длина фрагмента нефти, м.To determine the boundaries of the areas of effective vibration exposure, a series of experiments were carried out to determine the conditions under which pillars of various liquids in a porous medium acquire mobility and influence on the vibration impact mobility. Mobility of pillars was noted visually. The experiments confirmed the existence of the mobility criterion [4], which has the form

where σ is the interfacial tension coefficient, H / m;
θ wetting angle, deg;
Δρ is the difference in phase densities, kg / m ³ ;
g is the acceleration of gravity, m / s ² ;
r is the radius of the channels of the porous medium, m;
α is the angle of inclination of the oil fragment to the horizon, deg;
A, ω — amplitude, m and frequency of oscillations, s ^-1 in the vicinity of the oil fragment;
dP / dx — displacement pressure gradient, N / m ³ ;
l is the length of the oil fragment, m

For the case when there is no pressure filtration (dP / dx = 0), the test was carried out on a two-dimensional flat model, which was installed vertically using the fixing plates on the ST-80 stand (Fig. 3). Thus, the total acceleration vector was equal to the sum of the constant gravitational acceleration and vibration acceleration reported to the model during operation of the stand. The frequency range of the vibrating stand was chosen so as to ensure, on the one hand, stable operation of the stand, depending on its design features, determined by the stability of the frequency of the vibrations at a constant amplitude, and, on the other hand, to exclude mutual movement of the balls during model vibration. It was experimentally noted that, starting from a frequency of 40 Hz, high-frequency oscillations of the balls relative to the location are observed, and then, with increasing frequency, the mutual movement of the balls between the plates is observed. This is due to the fact that the force acting on the glass ball as a result of vibration
_Vibrate F = mω ² A,
where m is the mass of the ball, kg;
ω is the oscillation frequency, s ^-1 ;
A is the oscillation amplitude, m;
becomes greater the rest friction force arising from the clamping of plexiglass plates pulled together by two fixing iron strips. Note that the amplitude of the movement of the vibrating table in the range of 15-40 Hz is constant and equal to 0.45 · 10 ^-3 m

A certain amount of liquid was injected into the model using a syringe through the inlet fitting, which formed the whole. In this way, water pillars with a width of (4-5) · 10 ^-3 and a length of up to 33 · 10 ^-3 m, which were at rest, were obtained in a porous medium filled with air.

 The hanging pillar was kept at rest in order to stabilize its boundary, which could change its shape due to effects such as capillary impregnation and thermal expansion (narrowing) of the pillar due to the temperature difference between the model and the liquid.

After turning on the vibration stand, the model was subjected to vibration, starting from the minimum frequency, then slowly increasing it. The moment of the beginning of the movement of the border of the pillar was noted and the readings were taken at the amplitude of movement of the vibrating table X ₀ = 0.45 · 10 ^-3 m of the vibration frequency. The data are given in table. 1.

Тогда зависимость критической длины целика от частоты колебаний имеет вид

Зависимость (3) приведена на фиг. 4.For comparison, in FIG. Figure 4 shows the dependence of the critical length of a pillar of water in air on the frequency of longitudinal vibrations applied to the model. The curve was constructed as follows. From an experiment to determine the criterion of mobility with pillars of water in a porous medium filled with air, it is known that in the model the minimum length of the pillar at which they begin to move is 33 · 10 ^-3 m. Then, due to the universality of the criterion of mobility, ceteris paribus (equality of other parameters included in the criterion), the relation
l _cr g _in = const (2)
where g _in - the sum of gravitational and vibrational accelerations, m / s ² . The value of const is known:

Then the dependence of the critical length of the rear sight on the oscillation frequency has the form

Dependence (3) is shown in FIG. 4.

The expression for determining vibrational acceleration includes two independent quantities: the frequency and amplitude of the oscillations. Consider whether these values in the complex or each individually affect. To do this, conducted the following experiment. Using the adjusting screw, the vibration amplitude of the vibrating table was changed in the operating frequency range and made it equal to 3 × 10 ^-4 m. The model formed a pillar with a length of 17 × 10 ^-3 m. Then, if (3) is true, then for pillars of the same of length ω ² · A = const.
From previous experiments it is known that the frequency at which a pillar of this length begins to move is 22 Hz (with an oscillation amplitude of the vibrating table of 0.45 · 10 ^-3 m). If the beginning of the movement is affected by the frequency, then its value should not change. The measured frequency, at which the beginning of the movement of the pillar in this experiment was observed at X ₀ = 0.3 · 10 ^-3 m, turned out to be equal to 27 Hz, which is in complete agreement with the idea that the mobility criterion depends on vibration acceleration (calculated value of the frequency equal in this case to 26.94 Hz).

Близкие значения частоты, полученные в экспериментах как с целиками воды в воздухе, так и с целиками керосина в воде, свидетельствуют о том, что вибрация влияет только через создание дополнительного виброускорения, а с ним и силы, действующей на целик определенной массы.To check the effect of vibration on the mobility of the pillars of kerosene in water, a pillar was created in the model, which, after standing alone in a vertical position on the stand, had a length of 27 · 10 ^-3 m. When vertical vibrations were applied to the model, the movement of the lower boundary was noted at a frequency of 19 Hz, the vibration amplitude of the vibrating table was 4.5 · 10 ^-4 m. It is not difficult to estimate the calculated frequency at which the rear of the kerosene should start moving:

Close values of the frequency obtained in experiments with both pillars of water in air and with pillars of kerosene in water indicate that vibration affects only through the creation of additional vibration acceleration, and with it the force acting on the rear of a certain mass.

 For the case when pressure displacement is realized, the mobility limit is determined by the level of vibration accelerations comparable with the pressure gradient divided by the density difference between the displacing and displaced phases.

т. е. для того, чтобы был отмечен эффект от вибровоздействия, величина создаваемого виброскорения должна иметь порядок
a ~ Δρ^-1dP/dx (5)
Проверка проводилась на экспериментальной установке, предназначенной для визуального изучения микрокинетики процессов фильтрации в пористых средах. Перед проведением эксперимента по вибровоздействию отвакуумированная модель насыщалась водой и закреплялась в термостате. После присоединения к модели подводящих линий в модели создавалась остаточная нефтенасыщенность путем насыщения ее нефтью и последующей прокачки через нее с расходом 0,1·10^-6 м³/час воды. При прокачке ≈6 поровых объемов выноса нефти в мерную емкость не наблюдалось.The mobility criterion in this case has the form

i.e., in order for the effect of vibration exposure to be noted, the magnitude of the created vibration acceleration must be of the order
a ~ Δρ ^-1 dP / dx (5)
The test was carried out on an experimental setup designed for the visual study of the microkinetics of filtration processes in porous media. Before conducting the vibration experiment, the evacuated model was saturated with water and fixed in a thermostat. After connecting the supply lines to the model, the residual oil saturation was created in the model by saturating it with oil and then pumping through it with a flow rate of 0.1 · 10 ^-6 m ³ / hour of water. When pumping ≈6 pore volumes of oil transfer to the measured tank was not observed.

Next, we studied the effect of elastic vibrations on the mobility of fragments of residual oil by fixing the distribution pattern on the film and visually. The generator operating mode (frequency) was set in such a way that the amplitude of vibration acceleration monotonically increased. At each fixed frequency, a picture was taken of the distribution of the residual oil on the film. With increasing frequency from 1 to 8.5 kHz, the picture of the saturation change did not change and is shown in figa. At a frequency of 8.6 kHz, fragments of residual oil were strained and the saturation pattern changed (see Fig. 5b). The value of vibration acceleration at the time of stragging was 144 m / s ² .

 Let us estimate the magnitude of vibration acceleration a under assumption (5).

The hydrodynamic pressure gradient at a flow rate of 0.1 · 10 ^-6 m ³ / h through a model with residual oil was
ΔP / L = 2.78 · 10 ⁴ N / m ³
(The experiments used a model length of 0.09 m). Then the value of vibration acceleration (when the difference between the densities of water and oil Δρ is 200 kg / m ³ ) will be 139 m / s ² , which is in full agreement with the value obtained in the experiment.

 Therefore, the mobility of residual oil during pressure filtration also depends on the magnitude of vibration acceleration.

 An important conclusion that follows from experimental and theoretical studies of the mobility of pillars in the field of elastic vibrations is that for a significant change in the mobility criterion (within tens of percent), vibration acceleration in the vicinity of the pillar should have the order of acceleration of gravity or the external pressure gradient divided by the density difference of the displacing and displaced phases.

 Thus, the mobility of the pillars of oil is determined by the level of vibration acceleration at a given point in the oil reservoir.

 Choosing the magnitude of vibration acceleration, the larger of the two quantities, we satisfy the condition for the realization of mobility in both gravitational and pressure conditions.

 The duration of vibration exposure is determined by the ability of the rock to energy saturation. Based on the ideas about the rock as a block-hierarchical structure [3], the mathematical model can be represented by a system of blocks nested into each other (three blocks of the next level represent one block of the previous one). Such a partition approximately corresponds to the experimentally determined [4] polymodal partition of inhomogeneities in the oil reservoir. Blocks of the same level are absolutely rigid, and viscous friction and elastic bonds on variable contact surfaces prevent their displacement.

 Schematically, this situation can be represented as follows. Each block of an i-ro level consists of three blocks of (i + 1) -ro level. An external force acting on the blocks simulates a seismic wave traveling through a rock from a vibration source.

 We write the equations, excluding the geometric dimensions of the contact areas of the blocks. To do this, consider a block of level 0 with mass M.

где ρ - плотность материала породы блока, к/м³; M - масса элемента, кг; μ - эффективная вязкость на поверхности контакта, Па·с; C - эффективная упругая жесткость, H/м³; f - смещение, вызываемое источником внешнего воздействия, м.

where ρ is the density of the material of the rock of the block, k / m ³ ; M is the mass of the element, kg; μ is the effective viscosity on the contact surface, Pa · s; C is the effective elastic stiffness, N / m ³ ; f is the displacement caused by the source of external influence, m

= 6000 кг/м³ и μ = 10⁴Па·с.For the amplitude of external influence A = 10 ^-6 m and the mass of the zero-level block 3 kg, Fig. 6,7 shows the results of calculating the amplitude of oscillations of the zero-level block and subsequent (up to the 8th) for values of C = 10 ⁹ N / m,

= 6000 kg / m ³ and μ = 10 ⁴ Pa · s.

From the analysis of the graphs it can be seen that in this case, the zero-level block also performs high-frequency oscillations with a decreasing amplitude around a position defined by an external driving force, which varies with a low frequency according to a harmonic law. With constant external exposure, the energy of the vibrations is redistributed from zero to subsequent levels of the system. The characteristic time of involvement of higher-level blocks in the oscillatory motion is
T _in = (νω ^-3 ) ^0.5 / (M / ρ) ^1/3
and all variables are defined above.

 Therefore, the vibration exposure session takes a time interval from involvement in the oscillatory movement of the zero-level block until the moment when the minimum-sized block comes into motion.

The duration T _in vibration exposure is determined from the condition
(νω ^-3 ) ^0.5 / (M / ρ) ^1/3 <T _at <(νω ^-3 ) ^0.5 / d _s ,
where ν, ρ is the kinematic viscosity, m ² / s and rock density in the interval of the reservoir at the boundary of the effective sounding region, kg / m ³ ; m, d ₃ - the mass of the largest, kg and the diameter of the smallest samples of the fractional composition of the rock in the interval of the reservoir at the boundary of the effective sounding region, m; ω is the dominant frequency, s ^-1 .

 The start time of repeated vibration exposure is determined by the reaction of the rock. Calculations show that when the level of acoustic noise drops to 20-25% of the background energy costs, its increase sharply increases.

 Special experiments determined that the injection of free gas in volumes up to 15% does not affect the development as a displacing agent, while at the same time in the oscillation field increases the relative phase permeability for oil and reduces it for water. When gas was injected up to 0.1%, its breakthroughs were not observed during vibrations.

 The microwave treatment of the bottom-hole zone of the formation, which improves its filtration properties, at a frequency equal to the frequency of the area vibroseismic effect, increases the efficiency of the method, improving the filtration of residual oil to the bottom of production wells.

The solution of the problem of choosing the location of the emitter in the interval of the oil reservoir in a strict formulation is reduced to solving the boundary value problem of the dynamic theory of elasticity. It is known that the power radiated into the medium is N = F · v, where F is the force acting on the medium, H; v is the speed of their movement, m / s. If the medium is absolutely rigid, then the velocity of the points of the medium will tend to zero, and, consequently, the power leaving the medium from the emitter will tend to zero. Let us estimate what the distance from the boundary of a more rigid medium should be so that the radiated power is maximum. Let this distance be x ₀₁ . We denote by C ₁ , C ₂ and C _{0 the} rigidity of the covering, underlying media and oil reservoir, N / m. In this case, the point x _{1 the} layer is divided into interlayers with stiffnesses C ₀₁ and C ₀₂ . In order for the radiation to be optimal, it is necessary that the total stiffnesses of the media above and below the border passing through x ₀₁ be equal. From this condition we obtain a system of two equations for determining the optimal location of the center of gravity of the emitter. In its final form, C ₀₁ = 2C ₁ C ₂ C ₀ / (C ₁ C ₂ -C ₀ C ₂ + C ₀ C ₁ ), and C ₀₂ = 2C ₁ C ₂ C ₀ / (C ₁ C ₂ + C ₀ C ₂ -C ₀ C ₁ ). Since x ₀₁ ≈1 / C ₀₁ , the distance from the center of gravity of the emitter to the bottom of the formation refers to the distance from the center of gravity of the emitter to the roof of the formation as (C ₀ C ₂ + C ₁ C ₂ -C ₀ C ₁ ) / (C ₁ C ₂ + C ₁ C ₀ -C ₀ C ₂ ), where C ₀ , C ₁ , C ₂ are the stiffness coefficients of the rocks composing the formation, covering and underlying media, N / m.

Calculations show that filling a well with water leads to a sharp drop in the efficiency of the waveguide device. In the table. 2 shows data on the relative change in the amplitude of the oscillations propagating along the waveguide, if it is filled with water (U ₀ is the amplitude of the oscillations in a dry well)
From the analysis of the above data, it follows that the dispersion of the energy of vibrations propagating through a waveguide device 2 km long in a well filled with water is more than 71%, which leads to the need for preliminary (before the descent of the waveguide) insulation work.

 A device for implementing the method, i.e. The vibroseismic action device consists of a ground source of oscillation, which contains a vibration exciter (hydraulic actuator) 1, consisting of a piston 3 and an inertial mass 4, forming cavity 2 for the fluid coming from the power supply and control system 5. Vibration exciter 1 is placed in the power frame 7, centered by means of damping devices 6 relative to the wellhead 29. The piston 3 of the vibration exciter 1 is connected to the attached mass 8, connected via a lock 9 to the upper end of the waves yes 10, the elements 11 of which in the threaded connections 12 are connected by locks 9 and centered relative to the walls of the exciting well 13 by centralizers 14. The lower end of the waveguide 10 is connected by a lock 15 to the upper end of the matching node 16. A guide element 17 is installed on the lower end of the matching node 16. the end part of the matching node 16 is made a recess 18 under the fishing head 19 of the piston 20, located in the emitter 21, consisting of a housing in the form of a cylinder with windows 22, into which the inserted radiating elements 23 are inserted, limiting th washer 24 and the radiating bottom 25. An annular protrusion 26 is made on the lateral surface of the piston 20, an annular groove 27 is made on the lateral surface of the introduced radiating elements 23, in which a tightening ring 28 is mounted.

 Device vibroseismic exposure works as follows. In a selected area, tubing is removed from the well and preparatory operations are carried out to lower the emitter 21, the emitting bottom 25 of which is mounted on the cement bridge so that the center of gravity of the emitter 21 is closer to the medium with less rigidity. In this position, the annular protrusion 26 of the piston 20 touches the limiting washer 24. Then the matching assembly 16, the waveguide 10, the attached mass 8 are lowered and mounted on the emitter 21, which are assembled on the mouth, providing locks 9, 15 and centralizers 14 at the joints. under the influence of the weight of the arrangement, the piston 20 pushes the introduced radiating elements 23, which interact with the walls of the borehole 13, and abuts against the radiating bottom 25. In this case, the end surface of the transition device 16 interacts with the limiting washer 24. Pos e mounted above the well of the ground vibration source emitting element (the plunger 3) is connected with the associated weighing 8 waveguide device. After carrying out the described installation works, an oscillation source is included, the power and control system 5 of which controls the fluid flows entering the cavities 2 of the vibration exciter 1. The vibration exciter 1 generates oscillations of a given amplitude and frequency of the piston 3, which are transmitted to the connected mass 8 and propagate further along the waveguide 10 matching node 16, reaching emitter 21, where the introduced radiating elements 23 are converted into shear waves (transverse waves), and by the radiating bottom 25 into longitudinal compression waves stringing.

 The rigid connection of the emitter with the rock provides excitation in the medium of vibrations that propagate along the rock skeleton with low attenuation at low frequencies.

 In the device vibroseismic impact attached mass 8 is a load for the oscillation source. The power developed by the source depends on its value, and, consequently, the radius of the effective sounding region. Studies of the influence of the magnitude of the attached mass on the amplitude of the force action show that the limits of its change relative to the magnitude of the reactive mass are in the range of 0.28-0.83. The data of mathematical modeling are given in table. 3.

 Compared with the prototype, the proposed method and device for its implementation have high efficiency and productivity.

 An example of a specific implementation. The method for developing an irrigated hydrocarbon deposit described in the application was tested in one of the Volga fields. Within the field, an irrigated pilot plot located in its northern part was selected, where 2 formations are being developed at depths of 992-1022 m, 1045-1084 m. The water cut of production wells in the area was 72.4%. At this site, an exciting well was chosen, in which the installation of the waveguide device was carried out. Before installing the emitter in the interval 993-1001 m, cement was injected into the reservoir in order to limit water inflow. In the neighboring well, which is 1 km away from the exciting one, we recorded the level of acoustic noise in the interval of oil reservoirs using an acoustic sound level meter. Changes in the level of acoustic noise are shown in Fig. 8. Data analysis showed that the radius of the effective sounding area is 890 m. Therefore, the second exciting well was chosen so that its distance from the first was no more than 1.5-1.7 km (890 + 890 = 1780). The calculations showed that for the given geological and physical conditions of bedding, the exposure duration is 12 days, and the interval between impacts is 5 months.

At the same time that vibroseismic treatment was conducted into the well in 1 section separated from the stimulation well at a distance of 300 m, air was injected with an SD 9/101 compressor in a volume of 90,000 m ³ , which amounted to 0.01% of the free volume of the formation in the area. Technological development indicators are shown in FIG. 9 and confirmed by Test Acts.

 In the method for developing an irrigated hydrocarbon reservoir, a device for implementing the method was performed as follows. As an oscillation source, an electro-mechanical type source was used.

 The waveguide device consisted of an attached mass made of UBT 4 '', actually a waveguide of BAM 3 '', a transition device of pipes with a diameter of 108 mm and 133 mm and pigs with a diameter of 140 mm. The waveguide, the attached mass and the adapter were isolated from the casing by centralizers in the form of bushings made of shockproof oil-resistant rubber. The bushings were placed at the junction of the elements and were fixed with locks in the form of welded plates.

 On average, an increase in oil production by 32% occurred as a result of vibroseismic exposure. Additional production amounted to 5961 tons for the first month of work, 5450 tons for the second, for the third 6340 tons, for the fourth - 7160 tons, for the fifth - 6100 tons.

Literature
1. A method of developing a waterlogged oil field. Pat. 2057906 (Russia), class E 21 B 43/00, bull. 10, 1996.

 2. A method of developing a waterlogged oil field. A.S. 1596081 (USSR), class E 21 B 43/00, bull. 36, 1990 (prototype).

 3. Sadovsky M. A. A new model of the geophysical environment // BAN, N2, Sofia, 1986.

 4. Lopukhov G.P. Vibroseismic stimulation for rehabilitation of highly watered reservoirs // Proceedings the 9th European IOR Symposium, Hague, Holland, October, 20-22, 1997, # 053.

Claims (17)

1. A method of developing a flooded oil field, including opening a reservoir with wells, producing reservoir fluid by producing wells, vibroseismic exposure at a dominant frequency to the reservoir from ground-based oscillation sources in areas of a flooded hydrocarbon deposit in the effective zone of sources, determining before and after the composition and amount of produced fluid and background values of the level of acoustic noise of the rock, characterized in that on the site of the hydrocarbon deposits choose waiting for a well from an existing foundation or specially drilled and mounting elements of a waveguide device in it, pairing it with a ground source of vibrations, performing a vibroseismic action with simultaneous recording of the amplitude spectrum of acoustic noise in the interval of the reservoir having the largest residual oil reserves, according to the maximum the product of the square of the frequency and the amplitude of the displacement of the medium points at this frequency determines the levels of equal accelerations of the medium points The productive formation, covering the exciting well in terms of plan, determines the boundaries of the area of effective sounding by a line with an acceleration of the order of magnitude, which is the larger of two values: the acceleration of gravity and the pressure gradient of the displacement divided by the density difference of the displacing and displaced agents in the reservoir, break the field in the field of effective scoring, mount additional vibroseis devices in the areas of the field within the boundaries of effective scoring areas the effect on the hydrocarbon reservoir, a vibroseismic effect is carried out, the duration T _in each of which is determined from the condition (νω ^-3 ) ^0.5 / (M / ρ) ^1/3 <T _at <(νω ^-3 ) ^0.5 / d ₃ , where ν, ρ is the kinematic viscosity, m ² / s and rock density in the interval of the reservoir at the boundary of the effective sounding region, kg / m ³ ; m, d ₃ — mass of the largest, kg and diameter of the smallest fractional rock composition in the interval of the reservoir at the boundary of the effective sounding region, m; ω is the dominant frequency, s ^-1 , determined from the relation ω = (C / M) ^0.5 , where C is the stiffness of the rock of the oil reservoir in the areas of its weakening, n / m; at the same time as vibroseismic exposure in the areas of the field within the boundaries of the areas of effective sounding, gas is pumped into oil reservoirs, during the course of vibroseismic treatment, they carry out vibration microwave treatments of the bottom-hole zones of the wells, improving their filtration properties, and conduct repeated sessions of vibroseismic exposure in the areas of the field.  2. The method according to claim 1, characterized in that the start time of the second session of vibroseismic exposure in each of the sections is determined at the time the acoustic noise in each section falls to a level of 20 - 25% of the background values.  3. The method according to claim 1, characterized in that repeated sessions of vibroseismic exposure are carried out until the cessation of development of this site.  4. The method according to claim 1, characterized in that in the exciting well isolate the flow of fluid along the barrel. 5. The method according to claim 1, characterized in that the emitter of the device for vibro-seismic impact on the hydrocarbon reservoir is installed in the exciting well in the interval of the formation having the largest residual reserves, so that the distance from the center of gravity of the emitter to the bottom of the formation refers to the distance from the center of gravity of the emitter to formation roofs, as (CoC ₂ + C ₁ C ₂ - C ₀ C ₁ ) / (C ₁ C ₂ + C ₁ C ₀ - C ₀ C ₂ ), where C ₀ , C ₁ , C ₂ - rock hardness factors, composing the layer, covering and underlying medium, N / m  6. The method according to claim 1, characterized in that the registration of the level of acoustic noise is carried out in the range of 100 Hz - 20 kHz.  7. The method according to claim 1, characterized in that the free gas is injected in portions, the total volume of which does not exceed 0.1% of the pore space of the oil reservoir of a section of an irrigated hydrocarbon deposit.  8. The method according to claim 1, characterized in that the microwave processing of the bottom-hole zones of the wells is carried out by generators that implement the frequency of impact on the bottom-hole zone of the formation equal to the frequency of the vibroseismic effect on the formation.  9. The method according to p. 1, characterized in that the upper end of the attached mass of the vibroseismic device is placed above the mouth of the exciting well, and its value is selected from the condition for realizing the maximum power of the ground source of vibrations during vibroseismic exposure.  10. The device vibroseismic effects on the hydrocarbon reservoir, including a ground source of vibration located above the well, associated with the source of vibration of the elastic waveguide and emitter located in the cased hole, characterized in that it is equipped with an attached mass, matching node, guide element, locks, centralizers , a piston with a fishing head, an emitter, consisting of a housing, radiating bottoms, limiting washers, embedded radiating elements and a tightening elastic ring, and as a ground source of oscillations, a vibration source with an adjustable value of the oscillation frequency and pushing force is used, consisting of power and control systems and a vibration exciter placed in a power frame centered relative to the wellhead by means of damping devices, the radiating element of the vibration exciter is connected through an attached mass to the waveguide from pipe columns connected to the matching node by the lower end mounted on the emitter with the possibility of interaction with him, while a guiding element is installed on the lower end of the matching unit, centralizers and locks are installed in the places of the threaded connections of the elements making up the attached mass, a waveguide and matching unit, excluding the relative movements of the connected surfaces of the elements and turning them in threads under vibroseismic action, the attached mass is made in the form of a set of pipes and discs, the matching unit is made in the form of pipes and rods with an increasing cross-sectional area, the guide element is made in the form of son, the case of the emitter is made in the form of a pipe with windows on the side surface, the bottom end of the pipe is mounted on the radiating bottom with the possibility of interaction with it, embedded radiating elements are inserted into the windows of the pipe, a piston with a catching head protruding above its upper end is placed in the pipe with implantable radiating elements, a restriction washer is installed on the upper end of the pipe, covering the piston above the location of the annular protrusion on the side surface of the piston and restricting the stroke rshnya up implemented by the radiating elements adapted to cooperate with the walls of the well, bottom emitting installed on a cement bridge, implemented on the side surface of the radiating elements is formed an annular groove in which the resilient ring is set astringent.  11. The device according to claim 10, characterized in that a hydraulic actuator is used as a vibration exciter, consisting of an inertial mass and a piston placed in it, forming a cavity / cavities filled with oil with the inner walls of the inertial mass.  12. The device according to claim 10, characterized in that the electromechanical drive is used as the vibration exciter, consisting of rotating unbalances driven by an electric motor.  13. The device according to claim 10, characterized in that the electrohydropneumatic drive using the energy of compressed gas to excite the vibrations is used as the vibration exciter.  14. The device according to claim 10, characterized in that a gas-dynamic source using the energy of combustion / detonation of the gas mixture to excite vibrations is used as a vibration exciter.  15. The device according to p. 10, characterized in that the introduced radiating elements interact with the walls of the well through a cement gasket.  16. The device according to claim 10, characterized in that the ratio of the magnitude of the attached mass to the inertial mass of the hydraulic actuator of the ground-based oscillation source is selected from the range 0.286 - 0.833.  17. The device according to claim 10, characterized in that the ground source of oscillation is located on the vehicle.

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