RU2438010C1 - Procedure for development of oil deposit with low thickness - Google Patents

Abstract

FIELD: gas and oil production. ^ SUBSTANCE: procedure consists in construction of vertical producers and pressure wells, in determination of geological structure of deposit, in construction of at least one well with wave-shape section in reservoir used both for pumping working fluid and for extraction of deposit product, in development of deposit including pumping working fluid through pressure wells and withdrawal of deposit product through producers. According to the invention at determination of a geological structure there are defined zones located at external contour of oil saturation of deposit with less payable oil saturated thickness. Further, horizontal sections are led from near producers along defined oil saturated thickness and along shortest distance to external contour of the deposit without its opening. During development of the deposit the producers with horizontal sections are subjected to fast withdrawal of deposit product. When product withdrawn from these wells is watered out above an allowed level they are successively turned into pressure wells. The procedure facilitates successive extraction of oil from these zones without construction of additional wells which increases payout of development of the given deposit at 10-15 %. ^ EFFECT: raised efficiency of development of oil deposit in reservoir with low thickness due to increased coverage and inclusion of low thickness of reservoirs in zones close to periphery of external contour of oil saturation into development and due to successive withdrawal of oil from these zones without construction of additional wells. ^ 2 dwg

Description

The invention relates to the oil industry and may find application in the development of oil deposits in a heterogeneous collector of small thickness.

There is a method of developing narrow oil rims (patent RU No. 2148154, IPC 8 ЕВВ 43/20, published in Bulletin No. 36 of 04/27/2000), including the selection of oil through a system of horizontal production wells, characterized in that the horizontal production wells wells are drilled perpendicular to the contours of gas and oil and are located near the middle part of the rim, and neighboring wells are drilled into the oil rim in opposite directions, and if one of them is directed from the oil-water circuit along an ascending path to the gas-oil circuit act, then the next one is directed from the gas-oil circuit along a downward path to the oil-water contact, and the entry points of the horizontal trunk into the reservoir are located on a curve close to the sinusoid described by the general equation

Y = A × sin (x),

where A is the distance from the middle of the rim to the entry point of the horizontal well into the reservoir.

The disadvantage of this method is the high accuracy of the horizontal wellbore when entering the horizontal wellbore into the reservoir, which is very difficult to achieve, since the value A determines the degree of overlap of adjacent horizontal wellbores in terms of one another and depends on the width of the rim. The wider the rim, the smaller A can be, reducing in the limit to zero.

Also known is a method of developing a complex oil reservoir with a thin oil rim (patent RU No. 2095552, IPC 8 ЕВВ 43/20, published in Bulletin No. 31 of November 10, 1997) by pumping a displacing agent through a vertical and / or horizontal injection system wells and oil extraction through a system of producing horizontal and / or vertical wells, while the connection between the producing well and the reservoir is carried out in sections of the oil rim with a relatively high filtration resistance between the filter and the gas and oil and / or water ftyanym contacts.

The disadvantage of this method is the low efficiency of using the method, due to the small coverage of the oil reservoir with a thin oil rim, since the connection between the producing well and the reservoir is carried out in areas of the oil rim with a relatively high filtration resistance between the filter and gas-oil and / or oil-water contacts.

The closest in technical essence is the method of developing oil deposits in a heterogeneous collector of small thickness (patent RU No. 2290498, IPC 8 ЕВВ 43/16, published in bulletin No. 36 dated 12/27/2006), including wiring at least one well for a productive formation and the exit of a horizontal section to the formation, descent of the tubing string and the operation of the well as a producing or injection well, and after entering the formation, the horizontal section of the well is waved from the sole through the middle to the top of the formation and back from the roof through the middle to the bottom of the formation with the repetition of waves along the formation, the tubing string is brought into the producing formation, when operating the well as an extracting reservoir fluid, they are conducted along the entire profile of the well: from the bottom, middle and roof parts, when operating the well as an injection the working agent is conducted along the entire profile of the well: in the plantar, middle and roofing parts of the reservoir.

The disadvantage of this method is the small coverage of the oil reservoir containing formations with small thicknesses in areas close to the periphery of the outer contour of the oil saturation, i.e. oil pillars located inside the developed network of wells in formations with small thicknesses near the external oil saturation loop remain not involved in the development, i.e. undeveloped, and drilling additional wells on the periphery of the external oil contour is fraught with additional costs for the construction of these wells, as well as the fact that it is practically hard to get (open) small thicknesses in the reservoir.

The objective of the invention is to increase the efficiency of the development of oil deposits in the formation with small thicknesses by increasing the coverage and involvement in the development of small thicknesses of the layers in areas close to the periphery of the external oil saturation circuit, and the consistent production of oil from these areas without the construction of additional wells.

The problem is solved by the method of developing oil deposits with small thicknesses, including the construction of vertical production and injection wells, determining the geological structure of the reservoir and the construction of at least one well with a undulating section in the reservoir, used both for injecting a working agent and for producing products deposits, and the operation of the deposits, including the injection of the working agent through injection wells and the selection of production of deposits through production.

What is new is that when determining the geological structure, zones located at the outer contour of the oil saturation of the deposit are determined with an oil-saturated thickness less profitable, after which horizontal sections are drawn from nearby producing wells for a certain oil-saturated thickness at the shortest distance to the outer contour of the deposit without opening it, in reservoir operation time production wells with horizontal sections are transferred under forced selection of reservoir products, and after sequential watering If the products produced from these wells are higher than the permissible value, they are subsequently converted into injection ones.

Figure 1 shows schematically a section of an oil reservoir with small thicknesses.

Figure 2 shows a diagram of oil deposits with small thicknesses.

The proposed method is as follows.

Deposit 1 (see FIGS. 1 and 2) of oil, represented by an inhomogeneous reservoir, is drilled with a rare grid of wells, i.e. on oil reservoir 1 with a thickness of formation 2, the construction of vertical producing 3; 3 'and injection 4 wells and carry out their arrangement. The geological structure of reservoir 1 is determined and additional construction of at least one well 5 with a undulating section 6 in the oil reservoir 1 is carried out.

A horizontal well 5 in formation 2 is drilled as described in patent No. 2290498, IPC 8 EV 43/16, publ. in bull. No 36 of December 27, 2006

Initially, well 5 with a wave-like section 6 was launched to take products (oil) from reservoir 1. It should be noted that the filtration surface of well 5 in reservoir 2 increases by several times, making it possible to introduce non-drained reserves into development, increase the coverage factor for their production and increase oil recovery. In the case of watering the well 5 below a cost-effective value, it is transferred under injection.

A displacing agent, for example, waste water, is injected into injection wells 4 and formation fluid (oil) is produced through production wells 3; 3 '.

During operation, oil, water, injection and reservoir pressure are measured. Using the information obtained on newly drilled wells or on a drilled fund for production facilities, the geological structure of the reservoir, the distribution of the reservoir over the area and section of reservoir 1, and the change in its filtration-capacitive properties are clarified. Maps of effective oil-saturated thicknesses are built, oil and water-oil zones are separated, when determining the geological structure, zones 7 are located located at the outer contour 8 of oil saturation of reservoir 1, with oil-saturated unprofitable formation thickness 2 '; 2 '' (see figure 2); 2 '' '... 2' '(not shown in FIGS. 1 and 2), along the perimeter of formation 2, the thickness of which is up to 1.5 meters. The thickness is 2; 2 '; 2 ''; 2 '' '... 2' 'formation 2 is recognized as unprofitable individually for each oil reservoir 1, in this example, this thickness is 1.5 meters.

Having determined zones 7 located at the outer contour 8 of oil saturation of reservoir 1, for example, formation 2 with a thickness of 2 'and 2' 'along the perimeter equal to or less than 1.5 meters, from nearby production wells, for example, from production wells 3', drill) horizontal sections 9 'over a certain oil-saturated thickness over the shortest distance to the outer contour 8 of reservoir 1 without opening it.

Producing injection of a working agent, for example, waste water through injection wells 4, and the selection of products of reservoir 1 is carried out through production wells 3; 3 ', while producing wells 3' with the corresponding horizontal sections 9 'are transferred under forced selection of products of reservoir 1, exceeding the volumes of selection from other producing wells 3 by 10-15%. After sequential watering of products (determined by analysis of samples taken at the mouths of these wells), extracted from these production wells 3 ', above the permissible level, they are successively transferred to injection wells.

The proposed method for developing oil deposits with small thicknesses allows to increase the efficiency of developing oil deposits with small thicknesses by increasing the coverage and involvement of small thicknesses in reservoirs in areas close to the periphery of the external oil saturation contour by drilling horizontal sections along the shortest path from existing production wells, which allows for the consistent production of oil from these zones without the construction of additional wells, which undoubtedly increases the profitability of development and this oil deposit by 10-15%.

Claims (1)

A method of developing an oil reservoir with small thicknesses, including the construction of vertical production and injection wells, determining the geological structure of the reservoir and the construction of at least one well with a undulating section in the reservoir, used both for pumping the working agent and for producing the reservoir products, and exploitation of a deposit, including injection of a working agent through injection wells and selection of production of a deposit through production wells, characterized in that when determining the geological structure, there are zones located near the outer contour of the oil saturation of the deposit with an oil-saturated thickness less profitable, after which horizontal sections of a certain oil-saturated thickness are drawn from nearby production wells along the shortest distance to the outer contour of the reservoir without opening, during operation of the reservoir, production wells with horizontal sections are transferred for forced selection of the product of the deposit, and after sequential watering of the products extracted from these wells, above their permissible tion translate into injection.

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