RU2443854C1 - Development method of oil massive deposit and adjustable well valve - Google Patents

Abstract

FIELD: oil and gas industry. ^ SUBSTANCE: method involves investigation of the bed properties, drilling of injection wells and branched production well with horizontal sections, pumping of displacing agent to injection wells and extraction of the product through production well. At that, two horizontal sections of production well are located one above the other in the range of one productive formation. Investigations of productive capacity of each of horizontal sections are performed; after that, pressure-adjustable valve with replaceable orifice in the through channel is installed between horizontal sections. Extraction from production well is performed with one pump installed above the valve with capacity higher than that of upper horizontal section, but lower than that of two horizontal sections. Valve has the possibility of separating horizontal sections when fluid level in the well exceeds maximum allowable value, and connection in upward direction of horizontal sections when fluid level decreases below minimum allowable. Valve includes body with central and side through channels, a seat arranged in central channel below side ones, and shutoff element located above the seat with possibility of being moved upwards relative to the body. At that, central channel of the body is equipped with replaceable orifice. Body is equipped above side channels with annular constriction with upper and lower chamfers. Angle of upper chamfer to axis of body is smaller than lower one; the seat is installed in the body with possibility of tight longitudinal downward movement and pressed with a spring in upward direction, and shutoff element is equipped with a stock with a recess on the surface, into which a spring ring having the possibility of interaction with annular constriction of the body, is inserted. At that, spring stiffness, angles of chamfers and stiffness of spring ring are chosen so that when fluid level reaches maximum allowable value, under action of pressure drop, the shutoff element with stock and seat compresses the spring, and spring ring moves below annular constriction of the body when fluid level reaches minimum allowable value. ^ EFFECT: simplifying the method, increasing the monitoring efficiency of water content of the well and improving reliability of the device operation. ^ 2 cl, 3 dwg

Description

The invention relates to the oil industry and may find application in the development of oil deposits by horizontal wells.

A known method of developing deposits of a multilayer oil field (RF patent No. 2085723, IPC 8 ЕВВ 43/20, published in Bulletin No. 21 dated 07/27/1997), including drilling injection and production wells with vertical and horizontal shafts at a certain location in each productive formation, the injection of displacing fluid and production, while the horizontal wells in the reservoir are positioned so that the distance from the injection well to the horizontal well at each point is inversely proportional oil reserves in this zone and in direct proportion to the conductivity of the formations, and when developing a multilayer or large thickness of the reservoir, the horizontal wellbore is carried out in the form of several turns with the indicated pattern in each turn.

The disadvantage of this method is that in the conditions of a multi-layered oil field with water-oil zones and / or massive type, as well as at a late stage of development, premature flooding of the well’s production occurs, which leads to a reduction in the well’s working life and, consequently, to a decrease in oil withdrawal.

Also known is a method of developing deposits of a multilayer oil field with water-oil zones and / or massive type (patent RU No. 2282022, IPC 8 ЕВВ 43/30, published in bulletin No. 23 dated 08/08/2006), including measurements of oil and water production and water injection to clarify the current conditions of development and modeling of the reservoir development process, determining the minimum distance from the opened interval to the oil-water contact at which premature watering of the well’s products does not occur, branched horizontal and / or subhorizontal drilling wells, while the main horizontal and / or subhorizontal trunk is located above the oil-water contact at a minimum distance, providing an anhydrous period of operation of the wells, and horizontal and / or subhorizontal and / or vertical branches are drilled along the ascending profile with the same azimuth as at the main horizontal and / or subhorizontal trunk and / or with departure from it to the side of the roof of the reservoir or layer.

The disadvantages of this method are that its implementation requires high accuracy in measurements, i.e. determination of the minimum distance from the opened interval to the oil-water contact, drilling of branched horizontal and / or sub-horizontal wells, while the main horizontal and / or sub-horizontal well is located above the oil-water contact at a minimum distance, and an error in the calculation or during drilling can lead to flooding of the reservoir already at the initial stage of development.

The closest in technical essence is the method of developing an oil field by horizontal wells (patent RU No. 2274738, IPC 8 ЕВВ 43/30, published in Bulletin No. 12 of 04/20/2006), including wiring in the well of the main horizontal transport well, drilling from the main transport horizontal well of additional branched shafts to the working sections of the formation and the inclusion of the well in the oil production operation, characterized in that the main horizontal transport well is drilled obliquely through the thickness of the formation in the direction of water water contact, additional branched trunks are drilled ascending, bottom marks of additional ascending branched trunks are drilled with lowering marks of their bottoms towards the end of the main horizontal transport trunk, the bottom mark of the last additional branched ascending trunk is assigned based on the ratio of the vertical distance from the lower point of the main horizontal transport trunk , which is simultaneously a mark of the mouth of the last additional branching ascending trunk, up to water clear contact to the distance from the bottom of the last additional branch ascending trunk to the oil-water contact, equal to 0.3-0.5, the bottom mark of the first additional branch ascending trunk is assigned based on the ratio of the vertical distance from the mouth of the first additional branch ascending trunk to the oil-water contact to the distance from the bottom of the first additional branch ascending trunk to the oil-water contact equal to 0.6-0.8, the bottom mark of the additional branch ascending the trunk in the interval between the first and last additional branched ascending trunks is appointed based on the ratio of the vertical distance from the mouth of the corresponding additional branched ascending trunk to the oil-water contact to the distance from the bottom of the same additional branched ascending trunk to the oil-water contact of 0.3-0, 8, the main horizontal transport trunk is provided with a tubing string with placement of the bottom of the tubing string at the bottom of the base -traveled horizontal shaft, and produce oil via the selection of supplementary uplink branched trunks.

The disadvantages of this method are:

- firstly, oil recovery remains low due to the premature raising of bottom water cones in the main horizontal transport trunk and to the bottom faces of additional ascending shafts, since it is not possible to reduce the water cut of produced products during field development, which is carried out by regulating the volumes of withdrawal from the shafts;

- secondly, the complexity of the implementation of the method, since the drilling of the ascending additional trunks is carried out according to marks, which can lead to erroneous calculations.

The closest device for implementing the method is a casing valve (patent RU No. 2298640, IPC 8 ЕВВ 34/10, published in Bulletin No. 13 of 05/10/2007), including a stop with a seat and with axial and side channels, a hollow a sleeve installed in the axial channel of the limiter on the shear elements above the side channels with the possibility of their tight shutoff, a spring-loaded poppet check valve made with the possibility of tight interaction with the seat, characterized in that the limiter is provided with through channels, located between the axial channel and the seat, and its axial channel is equipped with a plug from below, and the poppet valve is made with the possibility of axial movement without blocking the side channels of the limiter, relative to which it is spring-loaded upwards.

The disadvantage of this valve is that the valve is not regulated by pressure, that is, it does not work (opens or closes) in a certain range of hydraulic pressures, but opens only when there is pressure on the valve, compressing the spring, and closes due to the return force of the spring in the absence of pressure on him.

The objective of the invention is to simplify the implementation of the method of developing a massive oil reservoir with the possibility of a gradual and uniform oil production from the reservoir with a control of the water cut of the branched trunks (sections) of the producing well and a decrease in the water content of the produced products during the development, as well as expanding the functionality of the valve intended for implementing this method due to its operation (opening or closing) in certain intervals of hydraulic pressures in the well.

The problem is solved by the method of developing a massive oil reservoir, including the study of the properties of the reservoir, drilling injection wells and a branched production well with horizontal sections, pumping the displacing agent into the injection wells and selecting products through the producing well.

What is new is that two horizontal sections of the production well are located one above the other within the same reservoir, studies of the horizontal sections on the productivity of each are carried out, after which a pressure-controlled valve with a replaceable nozzle in the passage channel is installed between the horizontal sections, and selection from the production well is carried out one pump installed above the valve, with a productivity greater than the productivity of the upper horizontal section, but less than the productivity of two ASTK, wherein the valve is configured to uncoupling of the horizontal portions in excess of the liquid level in the well above the maximum allowable value, messages from bottom to top horizontal portions at lower liquid level below the minimum.

An adjustable downhole valve for implementing the method comprises a housing with a central and lateral passage channels, a seat located in the central channel below the side channels, and a locking element located above the seat with the possibility of moving upward relative to the housing.

What is new is that the central channel of the casing is equipped with a replaceable nozzle, the casing above the side channels is provided with an annular narrowing with upper and lower chamfers, the angle of the upper chamfer to the axis of the casing being less than the lower, the seat is inserted into the casing with the possibility of hermetic longitudinal movement down and spring-loaded upward, and the locking element is equipped with a rod with a sample on the surface into which a spring ring is inserted, made with the possibility of interaction with the annular narrowing of the housing, while the spring stiffness, bevel angles and stiffness the spring ring is selected so that when the fluid level reaches the maximum permissible value, under the influence of pressure differences, the locking element with the rod and the saddle compress the spring, and the spring ring moves below the annular narrowing of the housing, when the liquid level reaches the minimum acceptable value, the saddle and the locking element with the rod under the action of the spring moves up, and the spring ring - above the annular narrowing of the housing to its original position.

In figures 1 and 2 depicts the implementation of the proposed method for developing a massive oil reservoir in the process of flooding the lower horizontal section of the producing well.

The figure 3 shows an adjustable downhole valve with a packer.

The essence of the proposed method is as follows.

Drill the formation 1 by injection wells (not shown in FIGS. 1, 2, 3) and a branched production well 2 with horizontal sections 2 ′; 2 ″ ....... 2 ⁿ . For example, we consider as an option the horizontal production well 2 (see Fig. 1) with two horizontal sections 2 ′ and 2 ″, while the horizontal sections 2 ′ and 2 ″ of the production well 2 are located one above the other within the same reservoir 1.

A study of the properties of the reservoir is carried out, after which the development of a massive oil reservoir begins, while the injection wells are injected with a displacing agent (for example, wastewater), and pumping equipment (for example, a tubing string) is lowered into production well 2 (s) pump 4, for example, an electric centrifugal pump (ESP) and packer 5 and start it up.

As the development of a massive oil reservoir, production well 2 begins to be watered. Therefore, the production well 2 is stopped, the tubing string 3 is removed from it with an ESP pump 4 and packer 5, and its horizontal sections 2 ′ and 2 ″ are studied for water cut in each.

According to the research results, it turns out, for example, that the water cut of the horizontal section 2 ″ in the percentage ratio is 40%, and the water cut of the horizontal section 2 ′ of the producing well 2 is 5%.

Then, between the horizontal sections 2 ′ and 2 ″, a pressure-controlled valve 6 is installed, configured to disconnect and communicate the horizontal sections 2 ′ and 2 ″ by installing it above the packer 5 (see Figs. 1, 2, 3).

The pressure-controlled valve 6 (see FIGS. 1, 2, 3) is equipped with a replaceable nozzle 7 with a passage diameter d (for example, 25 mm) installed in the central channel 8 of the valve 6.

The selection of products from production well 2 is carried out by one ESP pump 4 installed above valve 6 (see Figs. 1 and 2) with a productivity higher than the productivity of the upper horizontal section, but lower than the productivity of two horizontal sections 2 ′ and 2 ″ of production well 2, i.e. :

where Q _n - pump capacity, m ³ / day;

Q _{2 ′} - productivity of the upper horizontal section of the producing well 2, m ³ / day;

Q _{2 ″} - productivity of the lower horizontal section of the producing well 2, m ³ / day.

The valve 6 is installed above the packer 5 and has the ability to disconnect the horizontal sections 2 ′ and 2 ″ when the liquid level H ₁ exceeds the valve 6 in the production well 2 of the maximum allowable value - N _max (see figure 1).

The valve 6 has the ability to communicate from the bottom up of the horizontal sections 2 ′ and 2 ″ with a decrease in the liquid level - H ₂ below the minimum allowable - N _min (see figure 2).

So, for example, if H _max = 700 meters (see figure 1), and the liquid level - H ₁ above valve 6 is 800 m, then valve 6 closes, cutting off the horizontal section 2 ″, and further selection of production from production well 2 lead only from its horizontal section 2 ′.

If, for example, N _min = 300 meters (see figure 2), and the liquid level N ₂ above valve 6 is 200 m, then valve 6 is opened and products from the horizontal section 2 ″ of the production well 2 are received by pump 4 and further the selection of products from the producing well 2 is conducted from both horizontal sections 2 ′ and 2 ″.

In the range of the liquid level from 300 to 700 m (see FIGS. 1 and 2), the valve is closed when the level decreases, or open when the liquid level in the well rises, since the selection of products from production well 2 is carried out by one ESP pump 4 installed above valve 6, with a productivity higher than the productivity of the upper horizontal section, but less than the productivity of two horizontal sections 2 ′ and 2 ″ of the production well 2, that is:

where Q _n - pump capacity, m ³ / day;

Q _{2 ′} - productivity of the upper horizontal section of the producing well 2, m ³ / day;

Q _{2 ″} - productivity of the lower horizontal section of the producing well 2, m ³ / day.

During the operation of production well 2, if it becomes necessary to separate the horizontal sections 2 ′ and 2 ″, the valve can be closed by pumping fluid into the annulus through the annular valve, while the liquid level rises and valve 6 divides the horizontal sections 2 ′ and 2 ″. The selection of products from the production well 2 is continued from one upper horizontal section 2 ′.

The valve 6 (see figure 3) adjustable borehole for the implementation of the method described above comprises a housing 9 with a central 8 and side 10 passage channels, a seat 11 located in the Central channel 9 below the side 10, and a locking element 12 located above the seat 11 with the ability to move upward relative to the housing 9.

The central channel 8 of the housing 9 is equipped with a replaceable nozzle 7.

The housing 9 above the side channels 10 is equipped with an annular narrowing 13 with the upper 14 and lower 15 chamfers.

The angle of the upper chamfer 14 to the axis of the housing 9 is less than the angle of the lower chamfer 15.

The saddle 11 is inserted into the housing 9 with the possibility of hermetic longitudinal movement down and pressed by the spring 16 up.

The locking element 12 is equipped with a rod 17 with a sample 18 on the surface into which a spring ring 19 is inserted, made with the possibility of interaction with the annular 13 narrowing of the housing 9.

The stiffness of the spring 16, the angles of the upper 14 and lower 15 chamfers and the stiffness of the spring ring 19 are selected so that when the liquid level reaches the maximum permissible value of N _max under the action of a differential pressure, the locking element 12 with the rod 17 and the seat 11 compress the spring 16, while the spring ring 19 has the ability to move below the annular narrowing 13 of the housing 9.

Then, when the liquid level reaches the minimum permissible value of N _{min, the} seat 11 and the locking element 12 with the rod 17 under the action of the spring 16 are able to move up, and the spring ring 19 - move above the annular narrowing 13 of the housing 9 to its original position.

The adjustable downhole valve operates as follows.

An adjustable downhole valve 6 is installed in the well together with the packer 5 (see FIGS. 1, 2, 3) after conducting geophysical studies, the results of which show that the water cut in the lower horizontal section 2 ″ exceeds the economically viable amount of production from production well 2.

Install the adjustable borehole valve in the production well 2 as shown in Fig.3.

Valve 6 (see figure 3) is installed above the packer 5, while the shut-off element 12 is located on the seat 11. Select products from both horizontal sections 2 ′ and 2 ″ of the production well 2, because:

where Q _n - pump capacity, m ³ / day;

Q _{2 ′} - productivity of the upper horizontal section 2 ′ of the producing well 2, m ³ / day;

Q _{2 ″} - productivity of the lower horizontal section 2 ″ production wells 2, m ³ / day.

At the same time, the liquid level in the production well 2 (see FIGS. 1, 2, 3) rises, while pressure is exerted on top of the rod 17 of the locking element 12, which moves down along with the seat 11 on which the locking element 12 sits, relative to the remaining stationary body 9 of the valve 6, compressing the spring 16. The movement of parts 11, 12, 16, 17, 19 continues until the spring ring 19, located in the sample 18, bypassing the chamfer 14 of the annular narrowing 13, is not under the chamfer 15. In as a result, the valve 6 closes, cutting off the horizontal section 2 ″ mining wells, while the liquid level in the producing well exceeds the maximum allowable value - N _max, equal, as noted above, N _max = 700 m and is H ₁ = 800 m

The selection of products from production well 2 is continued from one horizontal section 2 ′, and since:

where Q _n - pump capacity, m ³ / day;

Q _{2 ′} - productivity of the upper horizontal section 2 ′ of the producing well 2, m ³ / day;

The liquid level in the production well 2 decreases and, accordingly, the pressure exerted on top of the rod 17 of the shut-off element 12 decreases, and when the liquid level in the production well 2 reaches the value of N _min = 300 meters and due to the return force of the spring 16, the spring ring 19 located in the sample 18, it goes up from under the chamfer 15 of the annular narrowing 13 and the parts 11, 12, 16, 17, 19 begin to move upward relative to the body 9 of the valve 6 remaining stationary, while the spring 16 is straightened. The movement of the parts 11, 12, 16, 17, 19 continues until the spring ring 19, located in the sample 18, is above the chamfer 14 of the annular narrowing 13. As a result, the valve 6 opens and the horizontal section 2 ″ of the production well communicates with the sub-pump the space of the producing well 2, while the liquid level in the producing well decreases below the minimum allowable value - N _min , equal, as noted above, N _min = 300 m and is N ₂ = 200 m

The selection of products from production well 2 continues from both horizontal sections 2 ′ and 2 ″, and since

,

,

where Q _n - pump capacity, m ³ / day;

Q _{2 ′} - productivity of the upper one, m ³ / day;

Q _{2 ″} - productivity of the lower horizontal section 2 ″ production wells 2, m ³ / day.

The fluid level in production well 2 begins to rise. Subsequently, the valve operation cycle is repeated as described above.

The proposed method for developing a massive oil reservoir is simple to implement and allows for the gradual and uniform production of oil from the reservoir with control of the water cut of all branched horizontal sections of the production well and a decrease in the water content of the produced products from the lower horizontal section of the production well through the use of a pressure-controlled well valve which is triggered (opens or closes) at certain intervals of hydraulic pressure in important, that is, the valve closes when the pressure created by the liquid level H ₁ in the producing well is exceeded above the maximum allowable pressure created by the level N _max , and opens from bottom to top when the pressure created by the liquid level H ₂ decreases below the pressure created by the minimum allowable level N _min .

Claims (2)

1. A method of developing a massive oil reservoir, including the study of reservoir properties, drilling injection wells and a branched production well with horizontal sections, pumping the displacing agent into the injection wells and selecting products through the production well, characterized in that the two horizontal sections of the producing well are stacked on top of each other within the same reservoir, conduct research of horizontal sections on the productivity of each, after which between horizontal sections a pressure-controlled valve with a replaceable nozzle in the passage channel is removed, the selection from the production well is carried out by one pump installed above the valve with a productivity higher than the productivity of the upper horizontal section, but less than the productivity of two sections, while the valve is capable of uncoupling horizontal sections when the liquid level is exceeded in the well above the maximum allowable value, messages from bottom to top of horizontal sections when the liquid level drops below the minimum permissible. 2. An adjustable downhole valve for implementing the method, comprising a housing with a central and lateral feedthrough channels, a seat located in the central channel below the side channels, and a locking element located above the seat with the ability to move upward relative to the housing, characterized in that the central channel of the housing is equipped with a replaceable with a nozzle, the casing above the side channels is equipped with an annular narrowing with the upper and lower chamfers, the angle of the upper chamfer to the axis of the casing being less than the lower, the seat is inserted into the casing with the possibility of hermetic of longitudinal movement down and preloaded by the spring up, and the locking element is equipped with a rod with a sample on the surface into which a spring ring is inserted, made to interact with the annular narrowing of the housing, while the spring stiffness, bevel angles and spring ring stiffness are selected so that when the fluid level reaches the maximum permissible value, under the action of a differential pressure, the locking element with the rod and the saddle compress the spring, and the spring ring moves below the annular narrowing of the housing, when as the liquid level reaches the minimum permissible value, the saddle and the locking element with the rod move upward under the action of the spring, and the spring ring - above the annular narrowing of the housing to its original position.

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