The way the impact on the reservoir
(57) Abstract:The way the impact on the reservoir, including site selection, installation on a selected area of the source of elastic waves and dynamic load 100 - 500 kN, acting on the part of the surface and the exciting elastic waves. Site selection is carried out by measuring microseismic background on the study area by the geophones. As the site for the source of elastic waves choose a site with a high level of microseismic background. Maximum feel that the level of background that is different from the background level in other areas of the greatest values of the amplitude of the recorded signal corresponding to any one frequency, either - most integral in all the recorded frequency characteristic. Measurement and analysis of seismic background to carry out a trial of the impact, and/or during exposure, and/or after to determine the dominant frequencies. Under understand the dominant frequency emitted from the overall frequency spectrum maximum level detected signal. The impact on the productive layer of elastic waves is carried out on the dominant frequencies. Manufacture the slavnosti and can be used to enhance oil producing formations. The invention can also be used in the extraction of gas, gas condensate and for the intensification of the processes of degassing of coal seams.The effect of seismic waves generated in the earth's crust during earthquakes, oil production processes noted in the scientific literature since the early 20th century, but the idea of purposeful influence on the accumulation of elastic waves was first formulated in the 70-ies in [1-2]. Real impact on the accumulation of seismic waves excited by the powerful surface of vibro-exciter, was first implemented in 1986-1987 in the oil fields of the Krasnodar region and the results of this field experiment were described in . As a vibro-exciter was used electro-hydraulic seismic vibrator. During the experiment it was found that there is a single dominant frequency, the impact of which leads to the maximum response of the productive formation.Currently, there are different devices and methods wave stimulation of oil reservoirs from both the surface and using sources of elastic waves, re-entry into the wells. Closest of them to the proposed JV is ω the optimal exposure parameters. Thus, the known method  vibro impact of an oil reservoir, providing for the optimization of the process of influence by searching frequencies, determine the number and composition of the produced formation fluid before and after exposure, determined using the descent to the level of the productive formation geophone dominant frequency microseismic background layer and subsequent vibro impact of this dominant frequency.Known similar way , we adopted for the prototype, including site selection, installation on a selected area of the source of elastic waves with a dynamic load acting on the part of the surface, and exciting elastic waves, the pilot impacts on reservoir elastic waves measurement and analysis of seismic background to the trial of the impact, during and after the trial of the impact and implementation of the impact on the productive layer of elastic waves.The disadvantages of these methods is the inability to determine the optimal impact of the site on which to install the sources of fluctuations, as well as the fact that the sequential search astuto, take for optimum may be the total response to the action of the previous frequency.The problem solved by the present invention, the efficiency of oil extraction at the expense of technology optimization of the stimulation. Technological result that can be obtained by implementing the method of increasing oil recovery from water-saturated productive layers, for example, by increasing the reservoir of the filtration process.The problem is solved on the basis of the following theoretical ideas about the mechanisms of wave action on a productive stratum.In  et al. have shown that the amplitude of the elastic waves propagating in a mountain array from really used sources of elastic waves (both surface and borehole type), decreases to very small values, of the order of millionths of an atmosphere or less, when the distance from the source during the first hundreds of meters. This means that the direct impact of these waves on areas of deep-seated layers with sizes of 1-2 km may not be the cause of any significant changes in the filtration motion. It follows that the observed significant reactime geomechanical processes in the mountain, initiated or activated by wave impact and accompanied by the release of energy that is going to support these processes in large volumes of rock mass. As shown in  , such geomechanical processes can be processes unloading mountain environment from excessive stresses accumulating in her field development, accompanied by changes in reservoir pressure and the corresponding reconstruction of the stress-strain state as the reservoir and surrounding rock mass in General. While the direct cause of enhanced oil recovery water-saturated productive strata is the redistribution of stresses in the reservoir and accompanying this process, the change of direction of the local flow filtration to engage in the movement of pillars oil from inactive or stagnant areas of the reservoir. Note that the reason for the accumulation of excessive stresses in the mountain environment can also be tectonic and other processes.Based on these representations, we can conclude that when the wave impacts the processes developing in the reservoir over a large area, are secondary or derived from osnovno it is known , deformation processes in continuous media are accompanied by the generation of elastic waves, the intensity and characteristics which can be determined by spectral analysis of microseismic background. This means that the field concentration of elastic stresses in a rock mass, which according to the above views, and should be the direct object of the wave action to activate them unloading processes can be in principle detected by measuring microseismic background on the earth's surface. It can be assumed that areas with a high level of microseismic background, corresponding to areas of concentration of elastic stresses in the mountain environment with high intensity generate elastic waves are optimal for the installation of the sources that excite elastic waves. In addition, the definition of the dominant frequencies in the spectral analysis of microseisms on this site at the same time determines the frequency, the impact of which is most effective for the activation of deformation processes found in the zones of stress concentration, because it is the dominant frequencies are the characteristic or resonant processes the gene is step on one of them, then there is the problem of choosing the most effective option to be solved in practice as follows. A priori, the preferred choice will be either the frequency having the maximum amplitude characteristic as the most important of all, or select the minimum magnitude frequency, because the long-wave perturbations are propagated in an elastic medium with a lesser degree of attenuation. If technically possible simultaneous effects on multiple dominant frequencies, for example, by using multiple sources of waves, such a complex effect can greatly increase the efficiency of the processes of unloading stresses in the areas of their concentration, because in these zones will be activated resonant processes of different nature.For better analysis of the microseismic background may optionally be provided with a trial wave impact on some arbitrary frequency. Comparative analysis of microseisms before exposure, and/or during and/or after exposure will more accurately determine the optimal dominant frequency.Also note that when analyzing the frequency spectrum of the microseismic background necessary to consider the prob is imich working closely spaced engines, pumps, etc.From the above concepts, it follows that the most likely areas of concentration of elastic stresses in the mountain region are characterized by the presence of inhomogeneities of different types in the reservoir and surrounding rocks of the heterogeneity of the geological structure of the mountain environment type discharges, wykonywanie and other abrupt changes of the parameters of the productive formation - its power, physical-mechanical properties and so on, as well as the heterogeneity of technological nature, such as areas of low or high reservoir pressure. Taking into account these features on the basis of preliminary analysis of all available geological information can reduce the search to areas with elevated microseismic background in the area of deposits, as these areas should be located away from areas characterized by these inhomogeneities or any other peculiarities of the geological structure, contributing to the concentration near the elastic stress.Based on the foregoing, the inventive method can be formulated as follows.The way the impact on the reservoir, including site selection, ustanovki surface and the exciting elastic waves, the pilot impacts on reservoir elastic waves measurement and analysis of seismic background to the trial of the impact, during and after the trial of the impact and implementation of the impact on the productive layer of elastic waves using a source of elastic waves and dynamic load 100-500 kN, site selection is carried out by measuring microseismic background on the study area by the geophones and as the site for the source of elastic waves choose a site with a high level of microseismic background, while the maximum is considered a background that is different from the background in other areas of the greatest values of the amplitude of the recorded signal, corresponding to any one frequency, either - most integral in all of recorded frequencies characteristic, measurement, and analysis of seismic background to carry out a trial of the impact, and/or during exposure, and/or after to determine the dominant frequencies, which are frequency emitting from the overall frequency spectrum maximum level detected signal, and the impact on the productive layer of elastic waves carry the dominant hour is over. Seismometric measurements, for example, on a certain area of the earth surface, is limited by the number of geophones placed on this study area, and this area can be divided into a number of sections of one or the other - by the number equal to the number of geophones, and the total area is equal to the total area of the study area. Under the area with a high level of microseismic background is the part corresponding to seismogenic with the maximum level recorded them microseismic background. If necessary, allocated at this stage of the research area with further seismic studies can consistently share for more detailed microseismic analysis on a number of parcels are smaller with further seismic analysis.The concept of the maximum level of microseismic background is determined by the following options. In the first case the maximum is the background that is different from the background in other areas to the maximum value of the amplitude of the recorded signal corresponding to any one frequency. In another case, the maximum is considered to be the background with the greatest integration is astomach), that is, the frequency emitted from the overall frequency spectrum maximum (absolute or local) level detected signal. Generally, increasing the level of microseismic background corresponds to the increase of the amplitude of the recorded oscillations at all frequencies.In the case of multiple sources of elastic waves in one area they can also be customized to one particular dominant frequency.Alternatively, the method serves to produce a trial wave impact on some arbitrary frequency and selection of dominant frequencies to produce on the basis of comparative analysis of microseisms before exposure, during exposure and after him.As the experience of practical use of land-based sources of elastic waves, their capacity must be large enough to achieve a noticeable effect on the deep reservoirs. As the lower limits of the dynamic loads developed by the source of the oscillations of the surface type can be accepted value of 100 kN.The efficiency of wave action will increase if the influence of the surface will be combined with the train to be tuned to the dominant frequency. The dominant frequency for downhole sources can also be determined using borehole seismic receivers deployed in the well to the expected level installation of these sources.In addition to the wave impact on the Deposit may be impacts on the reservoir using physico-chemical methods, that is injected into the producing formation of chemically active substances. This increases the efficiency of interaction of chemically active reagents with the breed due to their better mixing in the pore space, i.e. increases the efficiency of the technology physico-chemical stimulation. However, increases the efficiency of wave stimulation due to the additional impact on the filtration characteristics of the reservoir. Injection of chemicals into the formation may be preceded by wave impact or be performed simultaneously with him.Concentrations of elastic stresses in a rock mass can be formed additionally by using technological methods, for example by increasing the volume of water injection into the reservoir or increase sampling of reservoir fluids from producing wells.Lifespan the oil (or extracted hydrocarbon) in the impact zone. The practice of using various means and methods of shock-wave effects in order to achieve areal effects shows that rational the exposure time is in the range from several weeks to several months.An example of using the proposed method.Using seismic equipment on the ground surface above the water-saturated reservoir determine the area with the highest level of microseismic background. The most likely location of this area are the area characterized by the presence of geological discontinuities of various types - discharges, wykonywanie etc. Methods of spectral analysis to determine the dominant frequency microseismic background, set the source of elastic waves of any type in this area and produce a wave effect on the dominant frequency. As the wave source can be used serial seismic vibrators or specially designed for long-term exposure to the device surface or downhole type that will significantly reduce the cost of technology.Wave action can be repeated after determining nishna implemented technologies of wave action on the water-saturated layer will decrease the water content of products produced on site with an approximate diameter sizes 1-2 km or more in a few months after exposure.To enhance the effect of exposure on the site may have multiple sources of elastic waves that are configured on a single dominant frequency.For a more qualitative analysis of microseisms is a trial effect on some arbitrary frequency, and performed a comparative analysis of microseisms with regard to this impact.When using sources of elastic waves surface type should meet the following requirement, namely that the dynamic load on the breed, develop every source, would be not less than 100 kN (10 tons).An example of using this method in combination with other technological methods of stimulation.In addition to the actions required to implement the proposed method described above, prior to or simultaneously with the wave effect processing bottom-hole zones of wells chemically active reagents.To strengthen the effect in the reservoir are pre-created zones of stress concentration by increasing the volume of injection fluid into the injection well and/or increased fluid extraction from wells.Naibolee hydrocarbon recovery from reservoirs, and the method can be applied to the degassing of coal seams to enhance processes of degassing.LITERATURE
1. Surguchev M. L., Kuznetsov, O. L., Simkin, E. M. Hydrodynamic, acoustic and thermal cyclic effects of oil reservoirs. - M.: Nedra, 1975, 320 S.2. Gadiev C. M. the Use of vibrations in oil. - M.: Nedra, 1977, 180 S.3. Seismic vibrohvostami an oil reservoir/ Sat.article ed Sadowski, M. A. and A. Nikolaev Century Inst. of physics of the Earth Russian Academy of Sciences. - M., 1993, 240 S.4. Copyright St-in the USSR 1596081, CL E 21 In 43/00, 1990.5. RF patent 2070285, CL E 21, 1996.6. Swallow A. M. On the mechanism of wave action on a productive stratum//Oil industry, 1996, 7, S. 26-27. 1. The way the impact on the reservoir, including site selection, installation on a selected area of the source of elastic waves with a dynamic load acting on the part of the surface and the exciting elastic waves, the pilot impacts on reservoir elastic waves measurement and analysis of seismic background to the trial of the impact, during and after the test exposure and the subsequent effects on the productive layer of prohibi plot carried out by measuring microseismic background on the study area by the geophones and as the site for the source of elastic waves choose a site with a high level of microseismic background when this maximum is considered a background level that is different from the background level in other areas of the greatest values of the amplitude of the recorded signal corresponding to any one frequency, either - most integral in all of recorded frequencies characteristic, measurement and analysis of microseismic background to carry out a trial of the impact, and/or during exposure, and/or after to determine the dominant frequencies, which are frequencies allocated from the shared frequency spectrum, the maximum level detected signal, and the impact on the productive layer of elastic waves is carried out on the dominant frequencies.2. The method according to p. 1, characterized in that select one or more areas to use one or more sources of elastic waves, in the case of selecting multiple areas sources of elastic waves set in these areas and set up a dominant frequency of these sites, and if you choose one site and use multiple sources of elastic waves, the last tune on one dominant frequency of this section.3. The method according to p. 1 or 2, characterized in that it further assests the
FIELD: oil extractive industry.
SUBSTANCE: method includes electro-hydraulic treatment of bed at resonance frequency and extraction of oil from bed. According to invention bed is excited by resilient pulses at broad frequency range from 0 to 10 kHz. Frequencies are set, at which bed is treated. Resonance frequency is kept by singular, periodical, radially focused electro-hydraulic pulses with generation frequency, divisible by bed resonance frequency. Concurrently in adjacent well bed excitation frequency is controlled by resilient pulses and corrected according to measurements results.
EFFECT: higher efficiency.