RU2377398C1 - Method of hydrocarbone field development - Google Patents

Abstract

FIELD: oil-and-gas production.

SUBSTANCE: invention related to oil-and-gas production, can be used for oil and gas fields development. Essence of invention: during hydrocarbons reservoir production execute vibroseismic treatment, oil withdrawal though production wells and pumping in of working agent through injection wells. Separate crack areas with sub vertical cracks, which forms crystal foundation hydrodynamic connections to production stratum reservoir. Choose stimulation wells with similar values of bottomhole depth it this area. If necessary align bottonhole depth with boring or cementing. Determine general for all of the holes resonant dominant action frequency and form intense wave field towards sub vertical feeding canals to bottom zones of hydrocarbons generation. Form intense field in active zones with developed cracks with simulating wells of dilatation - wave action or other well low frequency vibration sources, operating at one dominant frequency. Set up according primary phase shifts between vibration sources fluctuation for creating fields maximums in chosen active bottom areas. From time to time not less than once in a half a year simultaneously change primary phases of all vibration sources on 180°, additionally to seted up earlier once, scan field along whole active generation and feeding area, initiating hydrocarbon fluids filtration from bottom zones to the field.

EFFECT: intensity increase in reservoir wave treatment and multiple enhancement of reservoir feeding with bottom hydrocarbons.

1 ex, 1 dwg

Description

The invention relates to the oil and gas industry and can be used in the development of oil and gas fields.

There is a method of developing an oil field by flooding productive formations or injecting other displacing agents into the formations in order to maintain reservoir pressure (RPM) and increase the hydrocarbon recovery ratio (KIU) (Yu.P. Zheltov et al. Development of oil fields. M .: Nedra, 1986, p. 95).

The disadvantages of this method are the low efficiency of the RPM system, the rapid depletion of recoverable reserves, the deterioration of the properties of oils and reservoirs, the flooding and failure of wells at low KIU.

There is a method of developing an oil and gas field using seismoacoustic effects on reservoirs in order to improve the mobility of residual oil and increase KIU (RF patent No. 2213855, published. 2003.10.10.).

The known method improves oil recovery, but does not reduce the rate of depletion of deposits and does not affect the reserves of hydrocarbons (HC) in traps.

Closest to the proposed method according to the technical essence is a method of developing a waterlogged oil field, which consists in the following. Open the reservoir with wells. Produce formation fluid through a cluster of producing wells. Perform vibroseismic effects on the reservoir from ground-based sources of vibration and control the average flow rate of the influx of reservoir fluid. After its reduction, the vibration sources are moved radially from the producing well by half the wavelength. Vibroseismic effect is carried out until the cessation of the increase in fluid flow. Set the grid spacing of production wells equal to half the depth of the formation. Simultaneously with oil production from the latter, sequential injection of a displacing agent, thickener and water into the formation through injection wells is carried out to maintain reservoir pressure and synchronous vibroseismic action from a group of N ground-based HB vibration sources located around one of the production wells extreme to the contour of the field on a circle of radius R _{K the} linear frequency-modulated (LFM) signal given in the description text. After increasing the flow of fluid, the vibroseismic effect of the LFM signal is produced near another producing well, moving from the oil content circuit to the center of the field (RF patent No. 2057906, published. 1996.04.10 - prototype).

The specified method has the following disadvantages.

1. Low coverage of productive volumes of deposits by simultaneous wave action and low intensity of the wave field in the reservoir, due to the fact that when using a ground vibration source, the vast majority (more than 90%) of energy is carried away by surface and transverse waves that do not reach the oil reservoir. The rest of the energy of the longitudinal waves experiences a large geometric attenuation and scattering on the layered heterogeneity, as a result of which the level of seismic energy reaching the reservoir is extremely small and the impact efficiency is low.

2. The absence of a dilatation field, localizing wave processes in the interval of the reservoir and stimulating the flow of oil to the wells.

3. The inaccessibility of the deep zones of hydrocarbon generation and subvertical channels connecting these zones to the field for wave action, as a result of which the intensity of hydrocarbon generation and field feeding by them is low, does not provide effective replenishment of reserves and reservoir pressure.

The invention solves the problem of increasing the intensity of the wave action on the reservoirs and repeatedly enhancing the recharge of deposits with deep hydrocarbons.

The problem is achieved in that in the method of developing a hydrocarbon deposit, including vibroseismic exposure, oil selection through production wells, injection of a working agent through injection wells, according to the invention, fracture zones with subvertical fracturing are identified, which form hydrodynamic bonds of the crystalline basement with the reservoir of the reservoir, are selected in in these zones exciting wells with a similar bottom depth, if necessary, level the depth of the bottom By cementing or cementing, the resonant dominant frequency of the action, common to all exciting wells, is determined and an intense wave field is formed in the direction of the subvertical feed channels to the deep zones of hydrocarbon generation, an intense field is formed in active zones with developed fracturing by exciting wells of dilatation-wave action or other low-vibration borehole sources frequency and high power, working at the same dominant frequency, set the corresponding initial phase shifts between vibrations of vibration for field maxima to selected areas of the underlying active.

Periodically, at least once every six months, the initial phases of all vibration sources are simultaneously changed by an additional 180 ° in addition to the previously established ones and the field is scanned throughout the entire active generation and recharge area, initiating the filtration of hydrocarbon fluids from deep zones to the field.

The features of the invention are:

1) vibroseismic effect;

2) oil extraction through production wells;

3) injection of a working agent through injection wells;

4) the allocation of fault zones with subvertical fracturing, forming hydrodynamic bonds of the crystalline basement with the reservoir of the reservoir;

5) the choice in these zones of exciting wells with a similar bottom depth;

6) if necessary, leveling the depth of the faces by drilling or cementing;

7) determination of the total resonant dominant frequency of the impact, common to all exciting wells, and the formation of an intense wave field in the direction of the subvertical feed channels to the deep zones of hydrocarbon generation;

8) the formation of an intense field in active zones with developed fracturing by exciting wells of dilatation-wave action or other borehole vibration sources of low frequency and high power, operating at the same dominant frequency;

9) setting the corresponding initial phase shifts between vibrations of vibration sources to obtain field maxima in the selected active deep regions;

10) periodically, at least once every six months, for all vibration sources, at the same time, the initial phases change by another 180 ° in addition to those previously established and the field is scanned across the entire active generation and recharge area, initiating the filtration of hydrocarbon fluids from deep zones to the field.

Signs 1-3 are common with the prototype, signs 4-9 are the salient features of the invention, sign 10 is a particular feature of the invention.

SUMMARY OF THE INVENTION

Oil and gas fields are formed as a result of the accumulation of hydrocarbons in traps during their migration to the earth’s surface from the deep generating layers of the earth’s crust. The entry of hydrocarbons into the trap ceases when certain (reservoir) pressures are reached in it, the value of which is set by the mountain mass of overlying layers of the earth's crust.

During the operation of the field as a result of the selection of hydrocarbons from it, the reservoir pressure drops and the supply of hydrocarbons to traps (drains) from the generation zones (sources) resumes, providing some replenishment of reserves (recharge). In normal operation, the rate of fluid selection from the reservoir is many times higher than the rate of their natural recharge and the field is rapidly depleted. The applied method of maintaining reservoir pressure (RPM) by injecting water or aqueous solutions through injection wells into the reservoir does not always give the desired result, but always leads to severe negative consequences that limit the oil recovery factor (ORF). In addition, such an RPM system reduces the pressure drop (depression) between the drain and the source and weakens the make-up.

The present invention allows to repeatedly enhance the natural processes of replenishment of hydrocarbon deposits entering traps from the deep layers of the lithosphere, maintain reservoir pressure without using water flooding or with very significant water flooding restrictions and at the same time force production, up to the establishment of balanced modes of selection and recharge.

A positive effect is achieved by the action of a high-intensity elastic wave field on deep lithosphere-generating hydrocarbon layers and on zones of subvertical fracturing, which form the hydrodynamic bonds of the crystalline basement with the reservoir of the oil and gas reservoir.

The wave field dramatically enhances the processes of generation of hydrocarbons, many times accelerates the filtration migration and diffusion processes. In the wave field, the degassing of rocks is sharply enhanced with the release of hydrocarbon gases. When exposed to hydrocarbon deposits from the surface of the earth by a low-frequency wave field (fractions are the first units of hertz), as a result of a sharp increase in diffusion, the content of hydrocarbon gases over the field increases hundreds of times, the speed of flotation and gravity segregation of dispersed oil increases. These effects were used in the invention to intensify the recharge of deposits with deep hydrocarbons.

To implement the method at the development site, oil is sampled through production wells and the working agent is injected through injection wells. According to seismic data, fracture zones with subvertical fracture are identified, which form hydrodynamic bonds of the crystalline basement with the reservoir of the reservoir, exciting wells with a similar bottom depth are selected in these zones. Excitation wells in the interval below the pump suspension should be relatively vertical with deviations of the barrel of not more than 20 °, should be equipped with sucker rod pumps and should not have disturbances in the production string. If necessary, align the depths of the faces of exciting wells by drilling or cementing. According to the existing DVV well design methodology (RD-153-39.0-263-02), the resonant dominant frequency of the action, common for all exciting wells, is determined and an intense wave field is formed in the direction of the subvertical feed channels to the deep zones of hydrocarbon generation by the simultaneous operation of all exciting wells. An intense field is formed in active zones with developed fracturing by exciting wells of dilatation-wave action or other borehole vibration sources of low frequency and high power, operating at the same dominant frequency. To obtain field maxima in the selected active deep regions, initial phase shifts between vibrations of vibration sources corresponding to differences of distances from vibration sources (bottom holes) to the center of the impact zone are set.

Periodically, at least once every six months, the initial phases of all vibration sources are simultaneously changed by an additional 180 ° in addition to the previously established ones and the field is scanned throughout the entire active generation and recharge area, initiating the filtration of hydrocarbon fluids from deep zones to the field.

The use of exciting wells of equal depth in the fault zone allows them to be excited at the same dominant (resonant) frequency. The operation of wells at one frequency allows you to get a synergetic effect (antinodes of the field) as a result of the addition of waves in zones of coincidence of the phases of vibration of vibration sources. During the in-phase operation of vibration sources, such zones are separated from the radiation centers — the bottoms of exciting wells — by an integer number of wavelengths.

Setting the corresponding phase shifts between the oscillations of the exciting wells allows you to create field antinodes in any predetermined volume of rocks of the fault zone, and changing phase shifts allows you to scan the field antinodes and cover the entire filtering and hydrocarbon generation zone with them.

In aggregate, these features provide an intense wave field in the entire field of hydrocarbon filtration and generation, including remote deep zones, and, as a result, multiple enhancement of field recharge.

Multiple recharge enhancement at a balanced rate of selection allows you to maintain reservoir pressure without flooding.

An example of the method

The drawing shows the principle of formation of field antinodes in the deep zones 1 ′, 2 ′, 3 ′ by exciting wells 1802; 1592; 1598 with faces at points 1, 2, 3. In the drawing

- крупные межблоковые разрывные нарушения;

- large interblock discontinuous violations;

- мелкие внутриблоковые нарушения.

- minor intra-block violations.

On the development map, a fault zone is identified (see drawing), containing a large interblock violation, spread from a depth of h = 15 km A'-B 'to the reservoir of the A-B oil and gas reservoir. Choose 3 sites: 1; 2; 3 with exciting wells, respectively: No. 1802 - depth of artificial bottom hole Bottom ₁ = 1452 m, dynamic level Nd ₁ = 864 m, No. 1592 - Bottom ₂ = 1455 m, Nd ₂ = 680 m, No. 1598 - Bottom ₄ = 1457 m, Nd ₄ = 804 m. Determine the total averaged bottom depth for all wells as

Максимальное отклонение глубины забоя от средней величины наблюдается у скважины №1598 и составляет 1453-1447=6 м или 6/1447=0,4%. Для низкодобротных колебательных линий, каковыми являются скважины, допустимый разброс длин волн можно принять равным 2%, поэтому полученные в нашем случае отклонения ничтожны и ими можно пренебречь. Необходимыми условиями резонанса колебаний в скважине с защемленной с двух сторон НКТ являются равенства

и

где n и m- целые числа; λо - резонансная длина волны; Lx - длина хвостовика. Поскольку насос должен находиться под динамическим уровнем, необходимо третье условие

.

The maximum deviation of the bottom depth from the average value is observed at well No. 1598 and is 1453-1447 = 6 m or 6/1447 = 0.4%. For low-Q oscillatory lines, such as wells, the permissible wavelength spread can be taken equal to 2%, therefore, the deviations obtained in our case are negligible and can be neglected. The necessary conditions for resonance of oscillations in a well with a tubing pinched on both sides are equalities

and

where n and m are integers; λо - resonant wavelength; Lx is the length of the shank. Since the pump must be under a dynamic level, a third condition is necessary

.

The maximum dynamic level Nd _poppy = 864 m has well No. 1802. To ensure that the pump is submerged under a dynamic level, the same level is conventionally assumed for all other wells. Then

Обращаясь к условию (2), при m=1 получим Lx=(2m-1)λo/4=2906/4=726,5 м, что не удовлетворяет условию (3), требующему неравенства Lx<589. При m=2 получают еще более длинный хвостовик Lx=3λo/4=3×2906/4=2179,5 и резко усугубляют нарушение условия (3), поэтому используют более короткую резонансную волну, приняв в условии (1) n=2. Тогда

Из условия (2) при m=1 находят Lx=λo/4=1453/4=363,25, что удовлетворяет условию (3) и другим условиям резонанса.When probing large depths, longer waves are preferable, then in condition (1) they take n = 1 and get

Turning to condition (2), for m = 1 we obtain Lx = (2m-1) λo / 4 = 2906/4 = 726.5 m, which does not satisfy condition (3), which requires the inequality Lx <589. For m = 2, an even longer shank Lx = 3λo / 4 = 3 × 2906/4 = 2179.5 is obtained and the violation of condition (3) is sharply aggravated, therefore, a shorter resonance wave is used, assuming in condition (1) n = 2. Then

From condition (2) with m = 1, Lx = λo / 4 = 1453/4 = 363.25 is found, which satisfies condition (3) and other resonance conditions.

For the calculated resonant wavelength λo = 1453 m at an elastic wave velocity in steel tubing tubing V≈5000 m / s, the resonance frequency is found from the relation λo = V / Fo as Fo = V / λo = 5000 / 1453≈3.44 Hz.

According to the results of the calculations, all exciting wells are equipped according to RD-153-39.0-263-02 with sucker rod pumps and shanks 363.25 m long, made up of two or three stages, or other borehole high-power vibration sources with a frequency of 3-4 Hz.

The depth of intense sounding at frequencies of units of hertz can reach hundreds of kilometers or more. The field densities arise during the interference of waves coming from various sources, where the phases of the waves coincide. When the sources work in phase, antinodes are formed in areas remote from the sources by an integer number of wavelengths. To form the field antinode in a given place, for example, in the regions 1 ', 2', or 3 ', see the drawing, where the phase sources do not coincide during the in-phase operation, the initial phase shifts of the sources are set so as to equalize in the given regions of the phase. Taking, for example, the depth h = S _{11 ′} = S _{22 ′} = S _{33 ′} = 15 km, the distances between the bottom faces of the wells S ₁₂ = 5 km, S ₂₃ = 8 km, calculate the distances S _{21 ′} ,

и

, откуда S_21′≈15,8 км, S_31′=19,85 км. Выделяют из расстояний S_11′=15000 м, S_21′=15800 м и S_31′=19850 м целое число длин волн 15000/1453=10+0,323, 15800/1453=10+0,874, 19850/1453=13+0,66 или 15000=10λ₀+0,323λ₀; 15800=10λ₀+0,874λ₀, 19850=13λ₀+0,66λ₀ и получают остатки пути в долях длины волны 0,323λ₀, 0,874λ₀ и 0,66λ₀, которые подлежат компенсации заданием начальных фаз.S ₃₁ like

and

, whence S _{21 ′} ≈15.8 km, S _{31 ′} = 19.85 km. From the distances S _{11 ′} = 15000 m, S _{21 ′} = 15800 m and S _{31 ′} = 19850 m, an integer number of wavelengths 15000/1453 = 10 + 0.323, 15800/1453 = 10 + 0.874, 19850/1453 = 13 + 0 , 66 or 15000 = 10λ ₀ + 0.323λ ₀ ; 15800 = 10λ ₀ + 0.874λ ₀ , 19850 = 13λ ₀ + 0.66λ ₀ and get the rest of the path in fractions of the wavelength of 0.323λ ₀ , 0.874λ ₀ and 0.66λ ₀ , which are compensated by setting the initial phases.

The wavelength is formed during the full period of oscillations λ ₀ = VxT ₀ , and the phase angle φ ₀ = ωT ₀ = 2πF ₀ T ₀ = 2πF ₀ / F ₀ = 2π = 360 ° corresponds to it, from this we find the initial compensating phase angles of the vibration sources :

for well No. 1802 S _{11 ′} = 0.323 × 360 ° = 116.3 °; for well No. 1592 S _{21 ′} = 0.874 × 360 ° = 314.64 ° (or -45.36 °), for well No. 1598 S _{31 ′} = 0.66 × 360 ° = 237.6 ° (or -122, 4 °). In the case of the use of wave-dilatation installations, before starting the pumping units, the balancers are set to the positions corresponding to the initial phase shifts and the wells are launched simultaneously. In this case, the ratios of the working resonant frequency and the plunger stroke frequency are taken into account. If in our case the operating frequency is F ₀ = 3.44 Hz, and the number of plunger strokes per minute is N = 6 (frequency Fx = 0.1 Hz), then the shear angles will be proportionally changed and will be 0.1 × 116 for well No. 1802, 3 ° / 3.44 = 3.4 °, for well No. 1592 0.1 × 314.64 ° / 3.44 = 9.14 °, for well No. 1598 0.1 × 237.6 ° / 3.44 = 6.9 °. Periodically, at least once every six months, the initial phases are additionally changed by an additional 180 ° for all vibration sources at the same time and are affected by the field antinodes on rock areas that were previously in the shade. Similar calculations and actions are performed when creating field antinodes in other areas (2 ', 3') of the fault zone.

As a result, the recharge of productive formations of this field with hydrocarbons increased 100 times and amounted to 10% of the annually extracted reserves.

The application of the proposed method greatly increases the intensity of the recharge of hydrocarbon deposits and ensures the replenishment of their reserves.

Claims (2)

1. A method of developing a hydrocarbon reservoir, including vibroseismic exposure, oil extraction through production wells and pumping a working agent through injection wells, characterized in that fracture zones with subvertical fracturing are identified, which form hydrodynamic bonds of the crystalline basement with the reservoir of the reservoir, and exciting zones are selected in these zones wells with a close bottom depth, if necessary, level the depth of the bottom by drilling or cementing, determine for all exciting wells, the resonant dominant frequency of the impact and they form an intense wave field in the direction of the subvertical feed channels to the deep zones of hydrocarbon generation, an intense field is formed in active zones with developed fracturing by exciting wells of dilatation wave action or other borehole vibration sources of low frequency and high power, operating at the same dominant frequency, set the corresponding initial phase shifts between vibrations of the vibration source maximums for field to selected areas of the underlying active. 2. The method according to claim 1, characterized in that periodically, at least once every six months, the initial phases of all vibration sources are simultaneously changed by an additional 180 ° in addition to those previously set and the field is scanned across the entire active generation and recharge area, initiating hydrocarbon filtration fluids from deep zones to the field.

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