RU2427708C1 - Procedure for development of oil massive pool - Google Patents

Abstract

FIELD: oil and gas production. ^ SUBSTANCE: procedure consists in analysis of reservoir properties, in drilling pressure wells and branched producer with horizontal sections, in pumping replacing agent into pressure wells and in withdrawal of production through producer. According to the invention the horizontal sections of the producer are arranged one over another within the boundaries of one pay. The horizontal sections are analysed for product water-cut in each of them. At proportional decrease of oil withdrawal on the basis of oil water- cut in horizontal sections oil is withdrawn from the producer with one pump by means of replaceable nozzles in structure of a removable packer installed at input to a corresponding horizontal section of the producer. When summary water-cut of production from the producer exceeds that of allowable, water shut-off operations are performed in horizontal sections with water-cut production. Horizontal sections, where water invasion after water shut-off operations exceeds 95 %, are isolated with backfilling compositions, for example, with cement grout. Further, oil is extracted from the producer with one pump with consideration of water-cut of production in horizontal sections used for extraction. ^ EFFECT: simplified procedure, gradual and uniform extraction of oil from reservoir with control over water-cut in all branched boreholes -sections of producer; reduced water-cut of extracted production up to complete water isolation of one or several branched sections of producer. ^ 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-layer 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 life, and therefore to a decrease in oil withdrawal.

Also known is a method of developing a multi-layer oil field with water-oil zones and / or massive type (patent RU No. 2282022, IPC 8 ЕВВ 43/30 publ. In Bulletin No. 23 dated 08/08/2006), including measurements of oil, water 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, ensuring 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 the main horizontal and / or subhorizontal trunk and / or with the departure from it towards the roof of the reservoir or layer.

The disadvantages of this method is 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 transport horizontal well, drilling from the main horizontal transport trunk of additional branched shafts into the working sections of the formation and the inclusion of the well in the oil production operation, characterized in that the main horizontal transport trunk is drilled obliquely through the thickness of the formation in the direction of the 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 branched ascending trunk, to water-oil 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 with the trunk in the interval between the first and last additional branched ascending trunk 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, equal to 0.3-0, 8, the main transport horizontal barrel is provided with a tubing string with placement of the bottom of the tubing string at the lower point of the main horizontal transport trunk, and the selection of oil is carried out through additional branched ascending trunks.

The disadvantages of this method are:

- firstly, oil recovery remains low due to the premature rise of bottom water cones in the main horizontal transport trunk and to the bottom faces of additional ascending trunks, since it is not possible to reduce the water cut of produced products during field development, as well as waterproofing the watered trunk or several trunks;

- 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 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 control of the water cut of all branched trunks (sections) of the producing well and the reduction of water cut of the produced products as necessary up to the complete waterproofing of one or more branched sections of the producing 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 the horizontal sections of the producing well are located one above the other within the same reservoir, the horizontal sections are examined for water cut in each, oil is taken from the producing well with one pump with a proportional decrease in oil selection, based on the water content of horizontal sections, interchangeable jets, as part of a removable feed-through packer, which is installed at the entrance to the corresponding horizontal section of the producing well, upon reaching the total water cut of products from a production well is higher than permissible in horizontal sections with waterlogged products, water insulation works are carried out, and horizontal sections in which water cut after water insulation works remained above 95% are isolated with plugging compounds, for example cement mortar, after which production from a production well is carried out with one pump taking into account the watering of products in the horizontal sections used for mining.

Figure 1 shows a diagram of a production well at the initial stage with two horizontal sections.

Figure 2 shows a diagram of the proposed method for developing a massive oil reservoir in the process of flooding a horizontal section of a producing well.

Figure 3 shows a replaceable nozzle as part of a removable feed-through packer.

The essence of the proposed method is as follows.

Drill the formation 1 with injection wells (not shown in FIGS. 1, 2, 3) and branched production well 2 with horizontal sections 2 '; 2 "... 2 ⁿ . For example, 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 positioned one above the other within one 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) electric centrifugal pump (ESP) 4 and packer 5 (see figure 1) and run it into operation.

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 electric centrifugal pump (ESP) 4 and packer 5 (see Fig. 1), and its horizontal sections 2 'and 2 "are examined for water cut in everyone.

According to the results of studies, it turns out that, for example, the water cut of the horizontal section 2 "as a percentage is 40% of the water cut, and the water cut of the horizontal section 2" of the producing well 2 is 5%.

Then, a replaceable nozzle 6 (see FIGS. 1 and 3) with a through diameter - d (for example, 20 mm) is lowered into the production well 2 as part of a removable through packer 7 of any known design, which is installed at the entrance to the horizontal section 2 ’(see Fig. 1) of a production well 2. Then, pumping equipment (for example, a tubing string 3 with an electric centrifugal pump (ESP) 4 and a packer 5 (see Fig. 1) is lowered again into a production well 2) and start her to work.

As a result of installing a replaceable nozzle 6, the flow of products from the horizontal section 2 "to the intake of the pump 4, which pumps the products to the surface through the pipe string 3, is limited, therefore, the total water cut of the products from the horizontal sections of the producing well 2 is reduced.

With the operation of the producing well 2, the water cut of the produced products from its horizontal sections 2 'and / or 2 "again increases.

Therefore, the production well 2 is again stopped, the tubing string 3 is removed from it with an electric centrifugal pump (ESP) 4 and a packer 5 (see Fig. 1), and its horizontal sections 2 'and 2 "are examined for water cut in each. According to the results of studies, it turns out that, for example, the water cut of the horizontal section 2 "of the producing well 2 has increased and as a percentage is 60% of the water cut, and the water cut of the horizontal section 2" of the producing well 2 is 10%.

Then, a replaceable nozzle 6 '(see FIG. 3) is lowered into the production well with a through diameter of d less than the initial (e.g. 15 mm) as part of the removable through packer 7 of any known design, which is installed at the entrance to the horizontal section 2 "( see figure 1) production wells 2.

Then again pumping equipment (for example, tubing string 3) with an electric centrifugal pump (ESP) 4 and packer 5 (see FIG. 1) is lowered into the production well 2 and put into operation.

Thus, the selection of oil from the producing well 2 is carried out by one pump 4 with a proportional decrease in the selection, for example, interchangeable nozzles 6, 6 ", 6 '" ... 6 ⁿ (see figure 3), which are installed in a horizontal section 2' (see Fig. 1) and / or horizontal section 2 "based on the water content of the horizontal sections 2 'and 2" of the producing well 2.

When the total water cut of production from production well 2 is higher than the permissible value, which is determined based on the profitability of each deposit separately, for example, when 90% is reached, then waterproofing works are carried out in horizontal sections 2 'and / or 2 "of production well 2 with waterlogged products.

To do this, stop the production well 2, remove the pumping equipment from it and make waterproofing, for example, a horizontal section 2 "of the production well 2.

As a water-insulating composition, for example, an aqueous suspension of polyacrylamide, which does not lead to a change in the permeability of the rock by hydrocarbons, is pumped into the horizontal section 2 "of the production well 2, for example, through a pipe string (Figs. 1, 2). is not a physical block and delays or blocks only the flow of water in the matrix of the formation 1, without interfering with the flow of oil into the horizontal section 2 "of the producing well 2.

Then again pumping equipment is lowered into the production well 2 and put into operation.

The horizontal sections 2 ′ and / or 2 ″ of the production well 2, in which the water cut after the waterproofing works remained above 95%, are isolated by plugging compositions, for example cement mortar, the water cut after the waterproofing works in the horizontal section 2 ”of the production well 2 remains above 95%, and it is isolated with cement mortar 8 (see figure 3).

Additionally, you can completely disable the horizontal section 2 "of the production well 2 from the development of the reservoir 1 by installing at the entrance to the horizontal section 2" (see Fig. 1) the production well 2 of a deaf packer of any known design.

Next, production from production well 2 is carried out by pump 4, taking into account the watering of products in the remaining horizontal sections 2 '; ... 2 ⁿ used for production, in this embodiment, one horizontal section 2' of production well 2.

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 producing well and the reduction of water cut of the produced products, as necessary, up to the complete waterproofing of one or several branched sections of the producing well.

Claims (1)

A method of developing a massive oil reservoir, including researching the properties of a formation, drilling injection wells and a branched production well with horizontal sections, pumping a displacing agent into the injection wells and selecting products through the production well, characterized in that the horizontal sections of the producing well are stacked on top of each other within the same reservoir, conduct research of horizontal sections for water cut in each, the selection of oil from the producing well is carried out they are driven by one pump with a proportional decrease in oil withdrawal, based on the water content of horizontal sections, by interchangeable jets as part of a removable feedthrough packer, which is installed at the entrance to the corresponding horizontal section of the production well, when the total water cut of production from the production well is higher than permissible in horizontal sections with watered production carry out waterproofing works, and horizontal sections in which flooding after waterproofing works remained above 95%, from iruyut plugging compositions, for example cement mortar, whereupon the extraction of the production well produce one pump with the watering products used for the extraction of the horizontal sections.

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