RU2718445C1 - Gravity-inertia filter for installation of electrically driven centrifugal pump - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to oil industry, namely to equipment of oil wells, and can be used in downhole equipment for filtration of well fluid from mechanical impurities to increase efficiency of oil production in complicated geological conditions and for cleaning of extracted fluid at ESP pump reception. Filter comprises filtering section. Section consists of a body and an internal pipe installed coaxially inside the body to form a cavity between the body and the pipe. Filter section comprises catch-slits. Catch-slits are installed in upper part of internal pipe, with cutouts directed counterclockwise. Filter section comprises a system of vortex blades arranged in the inner pipe. System of vortex blades is made in the form of three rows of vortex blades located in internal pipe at equidistant distances from each other. Swirler blades of each row of blade system are installed at angles to vertical axis of 10° or 20° and 30° and directed clockwise.EFFECT: higher efficiency of extracted fluid cleaning and protection of pump working elements.6 cl, 4 dwg

Description

The invention relates to the oil and gas industry and can be used to intensify the production of formation fluid and injectivity of the working agent during the second opening of wells by perforation to increase the oil recovery coefficient or gas recovery coefficient.

There is a method of intensifying fluid production from a well (patent RU No. 2224093, IPC EV 43/11, publ. 02/20/2004 Bull. No. 5), which includes the secondary opening of the well by performing perforation channels with a diameter, depth and density to provide the planned flow rate in this case, to ensure maximum flow rate of the fluid from the well, the length of the perforation channel is performed from the condition that it leaves the contaminated bottom-hole zone of the formation and the formation pressure is activated, and the diameter of the perforation channel is from the condition resistant to clogging of the work and self-cleaning of this channel under the influence of reservoir pressure, while the density of the perforation channels is taken from the condition of design equality or exceeding the total internal area of the walls and bottom of these channels formed by traditional technology with a channel diameter of 10 mm, its length from 350 mm and density of 10 channels per 1 m of column length.

The disadvantages of this method are the narrow scope due to taking into account only the total internal area of the walls and bottom of the perforation channels without taking into account the hydrodynamic resistance in the well itself, perforation is taking into account the shape and curvature of the wellbore, which significantly reduces the efficiency of the method, while the method it is intended only for producing wells with the location of the pump inlet in horizontal or deviated wells only from the mouth side.

The closest in technical essence is the method of well completion (patent RU No. 2645054, IPC ЕВВ 43/10, publ. 02/15/2018 Bull. No. 5), including a preliminary determination of the physical and rheological parameters of the fluid in reservoir conditions, taking into account its composition, placement in the borehole in the interval of the reservoir perforated liner, and the transfer of physical and rheological parameters of the fluid is carried out in the `` online '' mode, the calculation of the perforation of the liner is performed in real time according to the developed mathematical according to the program, the following conditions are met: the liner is tentatively divided into separate sections, the length of which is determined in accordance with the parameters of the formation permeability zones, the volume of oil entering the liner is the same in each section, thereby ensuring uniform distribution of oil absorption over the entire length shank, then the perforation area of each section of the shank and, accordingly, the number of through perforated holes are determined, the shank is made, consisting s of sections with varying perforation density, in which the filter elements are fixed, then the shank assembly to filter elements installed in the wellbore in the productive formation interval, taking into consideration pump inlet location in horizontal or deviated wells from the mouth only.

The disadvantages of this method are the narrow scope due to the implementation only with the help of a pre-perforated liner (liner serves to cover a certain interval in the wellbore; the upper end of the string does not reach the surface and is located inside the casing above), which excludes its cementing and reduces the borehole cross section, well construction and perforation are carried out without taking into account the shape and curvature of the wellbore, which significantly reduces the efficiency of the well ization method implementation complexity due to the selection of perforation of the shank, on the basis of the program that evaluates only the initial parameters without parameters changes during the life of the well, the method is intended only for the production wells with the input location of the pump in horizontal or deviated wells only from the mouth.

The technical alleged invention is the expansion of functionality through the implementation in injection wells, which are built in the form of ascending or descending ends of the shafts located in the reservoir, eliminating simultaneous descending or ascending local sections, respectively, and casing the production casing along the entire length without reducing the cross section wells, and the secondary opening is carried out after casing the production string along the entire length of the ascending or walking barrel with different densities, wherein the perforation is carried out with the sampling interval location capability or injection anywhere upstream or downstream of the wellbore.

The technical problem is solved by the method of constructing a well, including drilling a well in a productive formation along an ascending or descending path of the wellbore, lowering and cementing the production string, preliminary determination of the physical and rheological parameters of the fluid in the reservoir, taking into account its composition, re-opening the formation with different perforation densities, providing uniform distribution of pressure drop along the entire length of the ascending or descending section of the well between the reservoir and downhole th space.

What is new is that the ascending or descending ends of the bores in the reservoir are drilled at an angle that excludes local descending or ascending sections for the corresponding ends of the bores, while the production casing is installed over the entire length of the well, followed by casing, and the well is used as an injection, with perforation carried out after casing of the well using perforators or punch-free method, taking into account the selected interval of suction or injection in the ascending or descending eat the wellbore.

New is also the fact that a hammerless opening of the ascending or descending end of the wellbore is carried out using whipped hollow plugs or bushings with acid-soluble plugs.

What is new is that the suction or injection interval in the ascending or descending end of the wellbore is located in the formation zone with the lowest permeability.

The method is implemented in the following sequence.

It is known that during the construction of wells, its trunk is only conventionally considered straightforward (vertical, horizontal, relatively vertical, etc.), in fact, the well with a redistributed pitch (for deposits in the Republic of Tatarstan, the pitch is 50-80 m) deviates from the given direction in that or the other side (for deposits in the Republic of Tatarstan, the deviation is up to 5 m). Taking into account the use of small diameter wells (for production casing with a diameter of not more than 114 mm). To ensure the guaranteed absence of natural gas hydraulic seals (since the fluid in the well most often contains several phases) in the fields of the Republic of Tatarstan, to exclude:

the descending sections for the ascending wellbore, the zenith angle must be at least 95 °;

ascending sections for the descending wellbore zenith angle should be no more than 85 °.

Taking into account wells with production cores with a diameter of at least 146 mm in the fields of the Republic of Tatarstan, to exclude:

the descending sections for the ascending wellbore, the zenith angle must be at least 93 °;

ascending sections for the descending wellbore zenith angle should be no more than 87 °.

In this case, the second restriction on the inclination of the wellbore is also taken from the consideration of obtaining the maximum possible coverage by the impact from the well on the productive formation opened by this wellbore.

For other fields and other well parameters, this value of the zenith angle for the wellbore may vary.

Based on the data obtained, a well is drilled with ascending or descending ends of the bores at a selected zenith angle in the reservoir with determination of the physical and rheological parameters of the fluid in the reservoir, taking into account its composition. Preliminarily determine the interval for the selection of production of the formation or injection of the working displacing agent, on the basis of this, the necessary density of the secondary opening is determined taking into account permeability along the length of the inclined end of the barrel and hydrodynamic losses along its length (see Features of the nature of the flow of fluids in horizontal wells according to depth studies: abstract Thesis ... Candidate of Technical Sciences: 25.00.17 / Nazimov Nafis Anasovich; [Place of protection: Tatar scientific and research and design institute of oil]. - Bugulma, 2007. - 26 p.). It is recommended to choose the interval for product suction or working agent injection, the formation zone with the lowest permeability (if any) to ensure maximum pressure difference between the formation and the downhole space in it to provide more effective coverage of the formation. After drilling, the casing production string of pipes is lowered into the well to the bottom, followed by casing (cementing) and technological exposure. This ensures the same inner diameter without narrowing and eliminates annular fluid flows, which significantly worsen the distribution of pressure along the length of the inclined end of the wellbore.

For opening with a perforator (cumulative or hydromechanical), it is lowered into the well with reference to the opening interval in the inclined wellbore and a sequential opening is performed with the previously selected density. For types of cumulative perforators (see RU patents for PM No. 70929, IZ No. 2656262, etc.) and hydromechanical perforators (see RU patents for PM No. 142126, 178557, etc.), the author does not claim.

For non-perforated secondary opening, the casing before the descent can be equipped with whipped hollow plugs or bushings with acid-soluble plugs with a previously selected density. After technological exposure, the reservoir is opened mechanically (by knocking the inside of the hollow plugs) or chemically (by dissolving the plugs with acid in the bushings). On the form and methods of opening hollow plugs (see patents RU No. 2137911, 2182650, 2200230, 2439309, etc.) and bushings with acid-soluble plugs (RU patents for PM No. 174918, for IZ No. 2109128, 2375555, etc. .) the author does not claim.

To produce products, pumping equipment is lowered into the well with an inlet selected in the suction interval and put into operation to select formation products. Due to the selected opening density, taking into account the placement of the inlet of the pumping equipment in the suction interval and hydrodynamic losses along the length of the inclined wellbore, the maximum possible flat front of the depression on the formation along the entire length is provided, which increases the coverage of the formation and the efficiency of product selection. As tests have shown, the oil recovery coefficient (CIN) increased by 3-7% at no additional cost compared to the closest analogue.

To inject the working agent into the reservoir, the production string is lowered to the end in a predetermined interval of the barrel in the reservoir. Due to the selected opening density, taking into account the placement of the output of the process string in the injection interval and hydrodynamic losses along the length of the inclined wellbore, the maximum possible smooth compression front from the well to the formation along the entire length is provided without additional costs, which increases the coverage of the formation by displacement. The savings amounted to 20% compared with similar injection wells in the same field.

The proposed method of well construction allows you to expand the functionality through the implementation in injection wells, which are built in the form of ascending or descending shafts, excluding descending or ascending sections, respectively, and cased with a production string along the entire length without reducing the borehole cross section, to provide secondary opening after casing production casing along the entire length of the ascending or descending trunk with different densities, taking into account the possibility of location sampling interval or injection at any desired location upstream or downstream of the wellbore.

Claims (14)

1. The gravitational inertial filter containing

at least one filtering section, consisting of a housing and an inner pipe mounted coaxially inside the housing, with the formation of a cavity between the housing and the pipe;

slit traps made in the upper part of the inner pipe, with petals directed counterclockwise;

swirl blade system located in the inner tube,

the system of swirl blades is made in the form of three rows of swirl blades located in the inner pipe at a distance equally spaced from each other,

moreover, the swirl blades of all rows of the system of blades are installed at an angle to the vertical axis of 10 ° or 20 ° or 30 ° and are directed clockwise.

2. The filter according to claim 1, characterized in that the gravitational inertial filter is made in the form of three filter sections, while in one section only one angle of the swirl blades is installed, located in the following order:

the lower section is equipped with swirls with blades mounted at an angle to the vertical axis of 10 °;

the middle section is equipped with swirls with blades mounted at an angle to the vertical axis of 20 °;

the upper section is equipped with swirls with blades mounted at an angle to the vertical axis of 30 °.

3. The filter according to claim 1, characterized in that the housing is made in the form of a pipe.

4. The filter according to claim 1, characterized in that the cavity between the housing and the inner pipe is a storage container for the accumulation of mechanical impurities separated from the flow of formation fluid.

5. The filter according to claim 1, characterized in that the system of swirl blades and slit traps are made of high strength steel.

6. The filter according to claim 1, characterized in that a cuff assembly is installed on top of the filter, configured to exclude liquid from entering the pump bypassing the filter.

Images