EA002074B1 - Acoustic method (arwl) for applying an action on a well and on the layer of a field of mineral resources - Google Patents

Abstract

1. An acoustic method (ARWL) for applying an action on a well an on a layer of a field of mineral resources comprising steps of acoustic application of an action on perforated zones of the well with sequentially treatment and combining pressure and time of application, characterized in that involves applying a complex acoustic action and carrying out a selective treatment of the perforation interval and of the producing strata of the layer using a directed acoustic field in order to combine the pressure, the duration and the range of the action, using sound and ultrasonic signals with directivity characteristics from 10 to 180 degree , acoustic pressure values from 10 to 70 kPa during time equal to the effective period of application, with the range of action equal to the initial effective range of action from 0,05 to 10 m. 2. The method of claim 1, characterized in that the treatment is carried out according to a basic mode that involves sequentially treating the well perforation interval and the producing strata of the layer using three acoustic signals, having the following features: the directivity characteristics 45 degree , the acoustic pressure 10 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 0,05 m; the directivity characteristics 15 degree , the acoustic pressure 45 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 3 m; the directivity characteristics 10 degree , the acoustic pressure 70 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 10 m. 3. The method of claim 1, characterized in that separate stretches of the perforated zone are treated by a combination of the basic mode signals: mudded zones of the perforated intervals of injection and production wells are treated in the basic mode that involves sequentially treating the well perforation interval and the producing strata of the layer using three acoustic signals, having the following features: the directivity characteristics 45 degree , the acoustic pressure 10 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 0,05 m; the directivity characteristics 15 degree , the acoustic pressure 45 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 3 m; the directivity characteristics 10 degree , the acoustic pressure 70 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 10 m; working zones of the perforation interval of injection wells with a low injectivity or production low-watered wells are treated by a combination of second or third signals of the basic mode, having the following features: the directivity characteristics 15 degree , the acoustic pressure 45 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 3 m; the directivity characteristics 10 degree , the acoustic pressure 70 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 10 m, working zones of the perforation interval of injection wells with a high injectivity or production highly-watered wells are treated by a combination of third signals of the basic mode, having the following features: the directivity characteristics 10 degree , the acoustic pressure 70 kPa during 2 hours per meter of perforation, with the range of action equal to the initial effective range of action 10 m.

Description

The invention relates to the field of mining, developed by the well method and can be used in the oil, gas, mining, exploration industry, and most widely in the technology of oil and gas, especially during rehabilitation works on wells and formations (acoustic rehabilitation of wells and ARSiP) for enhanced oil recovery and enhanced oil recovery.

The level of technology

There are known devices for vibro-wave and, in particular, acoustic impact on wells and productive formation (RF patent No. 2063508, class E 21 B 43/20, 07.07.96, Bull. No. 19), which provide an acoustic signal for affecting a well and reservoir in a wide range of signal characteristics and providing a direct acoustic effect on the well and reservoir.

The known devices do not provide the selectivity and directionality of the acoustic impact on the well and the reservoir in a wide range of signal characteristics.

Known methods of impact on the well to enhance oil recovery by complex sequential impact on the well and the reservoir (RF patent No. 2068083, class E 21 B 43/22, 18.02.91).

The disadvantage of such methods is the lack of unification of the impact, the impossibility of directional, controlled and selective effects on the well bottom zone and formation, the use of chemical reagents.

Also known, adopted by the applicant for the prototype, the method of acoustic effects on the well and the reservoir of mineral deposits, including the operation of acoustic effects on the perforated zones of the well with sequential processing and a combination of pressure and exposure time (RF Patent No. 2026969, class E 21 V 43/25 01/20/95).

The disadvantages of this method

1. The inability to impact on remote parts of the reservoir.

2. The complexity of performing operations on non-fountain wells.

Summary of Invention

Technical task

The technical challenge is to eliminate these drawbacks and create a method to enhance oil recovery and intensify oil production, allowing for a unified integrated effect on all types of wells with different types of operation, both in working condition (with subsequent start-up) and in non-working state ;

to carry out direct and selective acoustic effects on the perforation zone of the well and productive formation in a wide range of acoustic signals at the fields with various types and indicators of development.

The set of essential features

In contrast to the known method, which includes acoustic impact operations on perforated zones of a well with sequential processing and a combination of pressure and exposure time, in the proposed method, a complex acoustic impact is performed with sequential selective processing of the perforation interval and the productive stratum with a directional acoustic field to enable any types of wells with different types of operation, with the possibility of combining pressure, time neither impact range, to ensure effective impact on fields with different types and indicators of development, carried out by sound signals and signals of ultrasonic ranges with directional characteristics up to 180 °, indicators of acoustic pressure from the minimum values necessary for making changes in the current well operation, to the maximum values limited by the elastic limits of the rock, for a time equal to the effective exposure time, with an impact range equal to initial effective range of exposure from 0.05 to 10 m.

The limiting minimum values of acoustic pressure are determined by the presence of an aftereffect and are minimally necessary to make changes in the current well operation. The upper level of acoustic pressure is determined by the limits of the strength characteristics of the collectors. The optimal averaged value is determined based on the values of the required initial effective impact range. In this case, the impact is carried out during the effective exposure time, for example, within two hours per meter of perforation, with an initial impact range of 0.05 to 10 m, in particular, 3 m as the most appropriate initial effective impact range for various types of formations. The limiting minimum value of the initial effective range is determined by the distance from the acoustic emitter to the walls of the casing, the size of the zone of greatest clogging of the bottom-hole zone of drilling mud, fur. impurities of well-killing liquids, highly viscous deposits of formation fluids and acoustic, geological and physical characteristics of the rocks composing the reservoir.

To ensure the aftereffect sufficient (i.e., there is no need to calculate additional radiation modes) there may be a basic mode — sequential processing of the perforation interval of the well and the productive stratum with three acoustic signals with characteristics:

- the first signal is the acoustic pressure of 10 kPa, the initial effective impact range of 0.05 m, the directivity characteristic 45 ° for 2 hours per meter of perforation;

- the second signal - acoustic pressure of 45 kPa, the initial effective impact range of 3 m, the directivity characteristic of 15 ° for 2 hours per meter of perforation;

- the third signal is the acoustic pressure of 70 kPa, the initial effective impact range of 10 m, the directivity characteristic of 10 ° for 2 hours per meter of perforation.

Or, individual sections of the perforated zone of the well are processed by a combination of signals of the base mode, taking into account the data of the current well performance and the state of the field development.

The percolation zones of the perforation interval of injection and production wells are processed in the basic mode;

the working zones of the perforation interval of injection wells with low pickup or producing low-watered wells are processed by a combination of the second and third signals of the basic mode:

acoustic pressure 45 kPa, initial effective exposure range of 3 m, directivity characteristic 15 ° for 2 hours per meter of perforation (signal 2), acoustic pressure 70 kPa, initial effective exposure distance of 1 0 meters, directivity characteristic 10 ° for 2 hours perforation meter (signal 3).

The working zones of the perforation interval of injection wells with high pickup or production of highly watered wells are processed by the third signal of the basic mode:

acoustic pressure is 70 kPa, the initial effective impact range is 1 0 m, the directivity characteristic is 10 ° for 2 hours per meter of perforation.

List of figures

FIG. 1 shows the zone of influence of various signals; FIG. 2 is a graph of the effective exposure time; FIG. 3 shows the data of geophysical studies at the well of FPD No. A in Western Siberia before conducting ARS and P and after conducting ARSiP; FIG. 4 is a graph of the average daily oil production of the area of wells that make up the environment of well No. A, in FIG. 5 shows the data of geophysical surveys at the IND No. B well of Western Siberia prior to ARSiP and after ARSiP; FIG. 6 is a graph of average daily oil production in the area of wells making up the environment of well Sh1D No. B, in FIG. 7 data of geophysical studies at production well No. In Western Siberia before ARSiP and after ARSiP, in FIG. 8. - graph of the average daily water production of well № B before and after ARSiP, FIG. 9 is a graph of average daily oil production of well No. B before and after ARSiP; FIG. 10 - data of geophysical studies at the production well No. G of Western Siberia before ARSiP and after ARSiP; in FIG. 11 is a graph of daily average fluid production of well # D; FIG. 12 shows a well model, FIG. 13 shows the grid model - well layout.

Description of the method

The drawings show 1 - acoustic emitter, 2 - well, 3 - productive formation; 4, 5, 6 — acoustic signals, 7 — well perforation zone, 8 — aps curve, 9 — perforation zones receiving injected water, 10 — well inflow profile, 11 emitter, 12 — well casing, P1, P2 — values indicators of current efficiency, Ζ is the longitudinal axis of the well, B is the axis perpendicular to the longitudinal axis of the well, N1, N2 are arbitrary points located along the axis of the well Ζ, b3 is the distance between points N1 and N2, b is the distance from the radiator to point N1, 2H, 2B - linear dimensions of the radiator, and - the inner radius of the casing of the well , Bc is the outer radius of the casing of the well, 01 is the area characterizing the well fluid, 02 is the area characterizing the well casing, 03 is the area characterizing the near-wellbore environment, p. | 1 - wellbore - casing well The boundary corresponding to the contact casing is near-wellbore, b is the surface simulating a borehole radiator, b1 is the distance to the first arbitrary point of the borehole space.

Acoustic emitter 1, located in borehole 2, opposite reservoir 3 is processed sequentially and selectively near-wellbore space and reservoir by acoustic signals 4, 5, 6 with different impact characteristics during the effective exposure time (Fig. 2), determined by the condition: K = Κί > Ό, with a range of exposure equal to the initial effective range of exposure from 0.05 to 10 m, where K is the coefficient of effective exposure time, Κί = [(P2 -P1) / P1] 100%, P1, P2 values of the indicators of the current effect NOSTA, Ό - parameter characterizing the level measuring technique - the measurement error,%.

Individual sections of the perforated zone of the well are processed, taking into account the data of the current well performance and the state of the field development by radiation modes calculated on the basis of specific geological and physical characteristics of the layers.

The effectiveness of the acoustic impact on the reservoir is due to the occurrence of mass transfer processes in the reservoir. Experimental evidence of the movement of particles in a saturating medium relative to the pore channels is the occurrence of a potential difference between different points of the medium, which is observed during the propagation of acoustic waves (seismoelectric effect E). The mass transfer in the field of acoustic waves is due to the appearance at each point of the pore space of the medium of high alternating (tensile and compressive) pressure gradients, which are variable in time.

The effect of the acoustic field on the filtration of a homogeneous fluid is to increase the filtration rate due to the destruction of the rheological structure of the fluid, including within the surface layers adjacent to the walls of the pore channels.

The appearance of elastic oscillations with amplitudes of pressures exceeding shear stresses (~ 10 Pa) leads to the destruction of the structure of the surface layer and its transformation into a Newtonian fluid with a viscosity equal to the viscosity in the volume. In this case, the nature of fluid flow in the pore channels becomes close to Poiseuille while simultaneously increasing the effective cross section.

This makes it possible to perform the tasks of intensifying oil production (in low-watered reservoirs), accelerating the processes of gravitational separation of oil and water (in highly watered reservoirs at the late stage of oil field development in the waterflood mode), and also involve additional volumes of oil in the filtration process. , fixed with traditional mining methods.

In addition, the so-called gravitational effects arise in the high-intensity acoustic field, which lead to the cleaning of the bottom-hole zone from mechanical impurities, dirt, paraffin wax, and salts.

Also in the high-intensity acoustic field, permeability is restored due to the destruction of water films, which have increased shear strength compared to oil. The mechanism of such destruction is as follows. Intense acoustic fields cause solid currents on sections of solid-fluid phases. In rocks, this effect is realized in the form of interstitial water turbulence. During vibration of the walls of capillaries (rock grains) and turbulent movement of water (fluid), as a result of the interaction of the flow current and the magnetic fields caused by it, transverse magneto-hydrodynamic pressure (MHD) is generated. At speeds of 1 cm / s in a capillary with a radius of 10 microns, the magnitude of the MHD can reach 10 ^-3 -10 ^-5 Pa. This means that water films with an average shear strength of about 10 ^-3 Pa will partially or completely collapse in the acoustic field, and the rock permeability will increase.

This allows the processing of bottom-hole zones of specific wells using the ARSiP technology to perform the tasks of increasing the injectivity and leveling the injectivity profiles (absorption) of injection wells, intensifying the inflow of production wells with the inclusion of low-permeability and kolmatny interlayers.

Acoustic impact parameters are selected based on the design features of the well, geological and physical characteristics of the bottomhole (near-wellbore) zone and formation, as well as the required depth of wave penetration into the formation. In this case, the well is adopted as a piecewise homogeneous medium with cylindrical interfaces and axial symmetry of properties. FIG. 12 shows a well model, the wave movements in which are described by a vector equation:

(λι + X ₂ ) dgas! άϊν and + λ ₂ ν ² and = p ^ and / ^ ² , (1) where λ-ι, λ ₂ are Lame constants; and is the displacement vector.

FIG. Figure 13 shows a grid model of a well markup. The boundary ς ₁ corresponds to the interface of the well fluid (region ^ ₁ ) - near-wellbore (casing string) - region ^ ₂ . The boundary ς ₂ corresponds to the contact casing - near-wellbore environment. In the case of an open well, the boundary ς ₂ is removed to the edge of the grid (the 0 ₃ region is absent). Surface b simulates a downhole radiator. Rewriting equation (1) in the components of the displacement and, resulting in a dimensionless form for the region Ob, we obtain:

and ² / dv = qdbi ^ dg ² + bi / gEg - and / g ² + ^ em / agbg), w ² / bR = Κ-ι (5τσ ² / δζ ² + + di / gdg). (2)

For the region ₂ and 0 ² / <R ² = aX / Sr + ² SU / gag - and / r ² + Κ23υι ² / 3ζ ² + K3 d ^ / DGDG. (3) where K! = C ² p1 / C ² p2; K2 = C ² 52 / C ² p ₂ ; K3 = 1 - K ₂ ; And _Mr. - and; υ _ζ —— ω.

Cp is the propagation velocity of longitudinal • waves in 1 medium;

С ₈ f is the speed of propagation of transverse th waves in a medium;

ω is the vector of the radiation function.

Solving equations (2) and (3) using the method of finite-difference approximation, we obtain the parameters of acoustic effects at various points in the near-wellbore space.

FIG. 3 shows the data of geophysical studies at the well of the FPD № A of Western Siberia before the ARSiP and after the ARSiP. The well has two perforation sections 7, which, prior to ARSiP, did not accept the injected water, the pickup rate of 0 m3 / day. at 95 atm., the reservoir characteristic is determined by the APS 8 curve. After processing the ARSiP well in the basic mode: sequential processing of the perforation interval of the well and the reservoir with three acoustic signals with characteristics: acoustic pressure 10 kPa, initial effective impact range 0.05 m , directivity 45 ° for 2 h per meter of perforation (first signal), acoustic pressure 45 kPa, initial effective range of 3 m, directivity characteristic 15 ° for 2 hours per meter of perforation (second signal), acoustic pressure 70 kPa, initial effective impact range of 10 m, directivity characteristic 10 ° for 2 hours per meter of perforation (third signal), perforation areas that receive injected water completely cover the perforation zones wells 7, the injectivity was 104 cubic meters / day.

From the graph data of FIG. 4 shows that the treatment of well No. A and the surrounding area of the reservoir using the ARS & P method allowed to radically change the dynamics of oil production in this area, i.e. ARSiP allowed not only to stop the fall, but also to create an increase in oil production at the site.

FIG. Figure 5 shows the data of geophysical studies at the IND No. B well in Western Siberia before ARSiP and after ARSiP. The reservoir characteristic is determined by the APS 8 curve. The perforation zone of the well 7 and the near-wellbore space are 60% kolmatically, as a result of which the injected water enters only a limited area of the perforation zone and the formation, and almost half of the injected water received only 1 m of perforation and, as a result, the well has insufficient pickup 470 m cubic / day. at 120 atm. This leads to the fact that most of the oil-bearing capacity of this area of the reservoir remains uncovered by water flooding and oil production from surrounding wells decreases. Processing the perforation zone of the well and the reservoir using the ARSiP method was carried out selectively using both the basic mode and separately only the third signal of the basic mode (combination), i.e. the upper and middle part of the perforation zone was processed in the basic mode, and the lower one only with the third signal of the basic mode , which made it possible to put into operation the parts of the perforation zone that had not previously taken the injected fluid and to increase the injectivity in those parts of the perforation zone where it was insufficient. As a result, the perforation areas 9, which receive the injected water, almost completely cover the perforation zone of the well 7, and the injectivity is 650 cubic meters / day. at 120 atm. The processing results are presented in FIG. 6

FIG. 6 shows a graph of the average daily oil production of the well site that surrounds the 1P1D well B.

FIG. 7 presents the data of geophysical studies at production well No. In Western Siberia before ARSiP and after ARSiP. Before ARSiP, the inflow came from almost the entire perforation zone of well 14, except for the lower part, but the well worked (periodically started) with 100% water cut. The reservoir properties of the reservoir are represented by the APS 13 curve. The graph of the average daily water production of the well № B is shown in FIG. 8. Processing of the perforation zone of the well and the reservoir using the ARSiP method was carried out selectively with a combination of the base mode and the third base mode signal, i.e. that part of the perforated formation from which the fluid flow was only processed with the third base mode signal, i.e. The aim of the work was to influence the reservoir, and the inoperative part of the perforation zone and the corresponding part of the reservoir were processed in the base mode. As a result of selective and complex effects on the perforation zone and the formation, the inflow of oil from the bottom 15, the previously not working part of the perforation zone, which has worse reservoir properties, was obtained. This made it possible to solve the problem posed before the treatment, i.e. it was possible to reduce the water content of the product (FIG. 8) from 100% to 70% (on average) and to obtain the flow of oil. The daily average oil production schedule for well # B is shown in FIG. 9.

FIG. 10 presents the data of geophysical studies at the production well No. G of Western Siberia before ARSiP and after ARSiP. The well has three perforation sections 16. The reservoir properties of the reservoir are represented by the curve Aps 17. Immediately prior to the work on the ARSiP, the well was transferred to the upstream horizon. According to well logging data, after the transfer to the above-lying horizon, fluid inflow into the well from the lower perforation section was obtained. As a result of selective and complex processing of this well and the surrounding part of the reservoir using the ARSiP method, i.e., the upper and middle perforations were processed in the base mode, and the lower one was obtained by the third signal of the base mode, the inflow from the upper and middle perforations 18. The daily average The production of the well fluid No. G is shown in FIG. eleven.

The implementation of the method and industrial applicability

The method can be implemented on known devices and devices of general industrial use, in particular, on known devices that provide reception of acoustic impact signals on a well and a producing formation in a wide range of signal characteristics and providing a direct acoustic impact on a well and producing formation.

A set of equipment for implementing the method should include an emitter placed directly in the working area of the well, a ground source and a connecting cable line. Electro-acoustic source of the development of the VNII can be used as a radiator (Justification of application criteria and evaluation of the effectiveness of wave impact on the formation by methods of IMASH of the Academy of Sciences of the USSR. Research Report of the VNII, pp. 12-13, M .: 1990, State reg. No. 01.8.90.056124) . As a ground-based power source, common industrial generators of the PGU-08-36, PPCh1.5-30 type can be used (Shapiro SV, Kazantsev VG, Kartashev VV, Kiyamov RN Thyristor generators of ultrasonic frequency M., Energoatomizdat, 1986), which are connected to the radiator with a standard geophysical cable.

Such a set of equipment provides receiving acoustic impact signals on the well and reservoir in a wide range of signal characteristics corresponding to the parameters and parameters of the method.

Claims (3)

1. The acoustic method of influencing the well and the formation of mineral deposits, including the acoustic operation of the perforated zones of the well with sequential processing and combining the pressure and time of exposure, characterized in that they carry out complex acoustic treatment with sequential selective processing of the perforation interval and the productive formation thickness directed acoustic field with a combination of pressure, time and range of exposure to signals sound and signals of ultrasonic ranges with directivity characteristics from 10 to 180 °, acoustic pressure indices from 10 to 70 kPa, for a time equal to the effective exposure time, with the exposure range equal to the initial effective exposure range from 0.05 to 10 m. 2. The method according to claim 1, characterized in that the processing is carried out in the basic mode, sequential processing of the interval of perforation of the well and the reservoir stratum with three acoustic signals with the following characteristics: directivity 45 °, acoustic pressure 10 kPa, for 2 hours per meter of perforation, with a range equal to the initial effective range of 0.05 m; directivity characteristic 15 °, acoustic pressure 45 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of 3 m; directivity characteristic 10 °, acoustic pressure 70 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of 10 0 m. 3. The method according to claim 1, characterized in that the individual sections of the perforated zone of the well are processed by a combination of signals of the basic mode: the zoned zones of the perforation interval of the injection and production wells are processed in the basic mode - sequential processing of the interval of the perforation of the well and the reservoir thickness by three acoustic signals with characteristics : directional characteristic 45 °, acoustic pressure 10 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of exposure of 0.05 m; directivity characteristic 15 °, acoustic pressure 45 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of 3 m; directivity characteristic 10 °, acoustic pressure 70 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of 10 m; the working zones of the perforation interval of injection wells with low injectivity or producing low-flooded wells are treated with a combination of the second and third signals of the basic mode - directional characteristic 15 °, acoustic pressure 45 kPa, for 2 hours per meter of perforation, with an exposure range equal to the initial effective exposure range 3 m, directional characteristic 10 °, acoustic pressure 70 kPa, for 2 hours per meter of perforation, with a range of exposure equal to the initial effective range of impact 1 0 m, the working zones of the perforation interval of injection wells with high injectivity or producing highly water-borne wells are treated with a third basic mode signal, directional characteristic 10 °, acoustic pressure 70 kPa, for 2 hours per meter of perforation, with an exposure range equal to the initial effective exposure range 10 m