RU2698927C1 - Method of action on oil-saturated interval of formation in horizontal section of oil well shaft - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used to increase efficiency of impact on oil-saturated interval of formation in horizontal section of oil well shaft. Method comprises well killing with salt solution, extraction of downhole equipment, installation of production of shear-blind preventer, riser on production of X-mas equipment, blowout protection unit, sealing device, as well as an injector with a guiding arch, supply to the horizontal section of the well on the flexible tube of equipment, including a connector with a flexible pipe, set of check valves, emergency disconnector, a circulation valve and a device for plasma-pulse action, closing a calibrated metal wire of a plasma-pulse action device by an operator's command over a cable, explosion in the horizontal section of the well, lifting the downhole assembly with a device for plasma-pulse action, well development and outputting to the mode.

EFFECT: technical result consists in increasing production wells and increasing oil recovery of formations.

1 cl, 4 dwg

Description

The invention relates to the oil industry, in particular to methods of influencing the reservoir in order to increase the productivity of producing wells and increase oil recovery in general.

Today, due to the entry of most large oil fields into the late and final stages of development, as well as an increase in the share of hard-to-recover reserves, non-standard methods of increasing oil recovery, which are characterized by increased manageability, energy efficiency and environmental friendliness, are gaining more and more popularity. For hard-to-recover reserves, which are characterized by complex geological features, expressed in the heterogeneity of reservoir layers, low filtration and reservoir properties, controlled physical impact on the filtration processes will allow targeted action on areas with residual reserves. For fields with physically determined displacement difficulties caused by high oil viscosity, rheological properties, and a high proportion of microcapillaries, a direct long-term effect on fluids is required to stimulate filtration processes by reducing viscosity, shear gradient, and capillary forces.

An electromagnetic effect is an effect exerted by oscillations of waves of various ranges in order to influence an oil-containing formation and formation fluid, to change their properties, which will affect the additional extraction of oil.

The prior art methods of exposure of physical fields to the bottomhole zone of vertical wells by creating depression-repression pressure pulses [Patents RU 2276722 C1 (2006); RU 2310059 C1 (2007); RU 2373386 C1 (2009). However, these methods cannot be used in horizontal well completion due to the overall dimensions of the devices, design features and the specifics of equipment delivery to the horizontal wellbore.

There is a method of intensifying oil production and resuscitation of idle oil wells by electromagnetic resonance effects on the reservoir [Patent RU No. 2379489, IPC ЕВВ 43/16, 2008], in which using resonant wave generators located on the surface or submerged in the well, create electromagnetic directed oscillations of the same frequency in the reservoir, which are superimposed on the natural frequency of the hydrocarbon fluid, forming and controlling the resonant vibrations using hydrochloric surface equipment.

The disadvantage of this method is that its implementation requires sufficiently large resources, since when it is implemented, the wave flow from the producing well is initially set to a power significantly exceeding the power of each of the oncoming wave flows taking into account attenuation coefficients, and subsequently the power of the oscillating flow from the producing wells smoothly decrease with a simultaneous proportional smooth increase in the power of each of the oncoming oscillatory flows. Thus, the implementation of the method requires the presence of at least two adjacent wells and a high-power source of electrical energy. All this significantly increases the cost of oil production, that is, reduces the efficiency of the process as a whole.

The closest technical solution chosen for the prototype is a method and device for influencing oil-saturated formations and a bottomhole zone of a horizontal well [RF Patent No. 2600249, Published: 10/20/2016]. The method includes the delivery and placement in a horizontal wellbore of a device equipped with an electric energy storage unit, an emitter with two electrodes, which are closed by an operator’s command with a calibrated metal wire, which leads to its explosion and the formation of a directed, point high-pressure shock wave propagating radially from given points horizontal wellbore in order to increase the permeability of the bottomhole zone of the working sections of the horizontal wellbore. The technical result consists in increasing the operational efficiency of a directional well with a horizontal end.

The disadvantage of this method is its applicability in wells with a cased horizontal section (casing string diameter is 146 mm). The surface equipment scheme for working with coiled tubing is not quite clear. As a rule, a flexible coiled tubing pipe is fed into the injector circuit through a guide arch located directly above the injector, and not through a roller. Next, the flexible pipe passes through a sealing device located directly below the injector. To lower the assembly into the well, a riser should preferably be provided in the surface equipment diagram.

The challenge facing the creation of the invention is to increase the efficiency of work on the impact on the oil-saturated interval of the reservoir in a horizontal section of the trunk of an oil well.

The technical result consists in the development of an effective method of impact on the reservoir using the installation of "continuous pipe".

The task and technical result are achieved in that the method of influencing the oil-saturated interval of the formation in the horizontal section of the oil wellbore includes killing the well with saline, extracting downhole equipment, installing shear-blank preventer, riser, blowout preventer equipment, sealing device, and also an injector with a guide arch, the supply to the horizontal section of the well on a flexible pipe of equipment including flexible spruce tree, set of non-return valves, emergency disconnector, circulation valve and plasma-pulsed device, closed circuit of a calibrated metal wire of a plasma-pulsed device on cable by an operator’s command, blasting in a horizontal section of the well, lifting the downhole assembly with the device pulse-plasma exposure, well development and output to the regime.

The method is as follows (Fig. 1-4).

An directional well (1) with a horizontal end (2) is plugged with saline (for example, 10% KCl). The composition of the saline solution and the concentration of salt (as well as its type) are selected from the well killing conditions with minimal repression on the reservoir (3). Downhole equipment (4) is removed from the well (1). After that, the well (1) is closed by the upper main valve (5) of the fountain valves (6).

Surface equipment intended for work using the “continuous pipe” installation (7), which includes (bottom-up): shear-blind preventer (8), riser (9), blowout control unit ( 10) (for example, a four-plate preventer), a sealing device (11) (for example, with a side hatch), and also an injector (12) with a guide arch for a flexible pipe (13) (Fig. 2).

Equipment (including a connector with a flexible pipe (15), a set of check valves (16), for example, is supplied to the well (1) using the “continuous pipe” installation (7) on a flexible pipe (14) with an open valve (5)) two leaf check valves with a removable sleeve), an emergency disconnector (17), a circulation valve (18) (for example, we can recommend a circulation valve protected by the RF patent for utility model No. 176624) and a plasma-pulse device (19) with a cable ( for example, a patent protected device can be recommended om RF for the invention No. 2600249) (Fig. 3).

Equipment lowered on a flexible pipe (14) using centralizers (not shown) is fed into the horizontal section (2) of the well (1) (equipped, for example, with a perforated liner with casing packers) at the required interval for processing the formation (3) (Fig. . four).

At the operator’s command, a calibrated metal wire is closed via a cable (not shown), an explosion occurs in the well, which leads to an increase in the permeability of the bottomhole formation zone and the cleaning of the pore space.

The saline solution located in the well is necessary for a multiple increase in temperature in the reservoir under the influence of the generated magnetic field, because such a solution is a good conductor of the electric field.

The enhancement of the thermal effect, especially in the approximate bottomhole formation zone, provokes a decrease in the viscosity of hydrocarbons and the removal of mechanical reservoirs.

The supply of current with high voltage (for example, 3000 V) through the cable contributes to the appearance of an electric arc, which leads to the formation of a plasma and a very rapid increase in temperature. The expansion of the plasma causes a shock wave, which propagates instantly through the saline solution located in the well.

When the plasma cools after the shock wave propagation, it causes an influx into the well due to the back pressure, due to which the well productivity increases, the pore space is cleaned, the perforation holes of the liner are cleaned, and the oil inflow increases.

After the work is completed, the downhole assembly is lifted with a plasma-pulse device (19), the well (1) is mastered (not shown) (for example, by supplying nitrogen through a newly deflated flexible pipe (14), which reduces the hydrostatic pressure on the productive layer (2)) and displayed on the mode.

EXPLANATIONS TO FIGURES

1 - Well

2 - Horizontal section of the well

3 - Productive formation

4 - Downhole equipment

5 - Upper main valve

6 - Fountain fittings

7 - Installation "continuous pipe"

8 - Shear-deaf preventer

9 - Riser

10 - Blowout control unit

11 - Sealing device

12 - Injector

13 - Guide Arch

14 - Flexible pipe

15 - Connector to a flexible pipe

16 - Check valves

17 - Emergency Disconnector

18 - circulation valve

19 - Plasma-pulse exposure device

Claims (1)

The method of influencing the oil-saturated interval of the formation in a horizontal section of the wellbore of an oil producing well, characterized in that it includes killing the well with saline, extracting downhole equipment, installing shear-blank preventer, riser, blowout preventer unit, sealing device, and an injector with a guide arch, supply to the horizontal section of the well on a flexible pipe of equipment, including a connector with a flexible pipe, a set of check valves new, emergency disconnector, circulation valve and plasma-pulse device, shorting a calibrated metal wire of a plasma-pulse device on an operator’s command by cable, blasting in a horizontal section of a well, lifting a downhole assembly with a plasma-pulse device, well development and output to mode.

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