RU2339805C1 - Method for development of high viscous oil or bitumen deposits - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to development of hydrocarbons and can be implemented for extraction of high viscous oil and bitumen. The essence of the invention is as follows: the method includes boring of a well with two heads and securing it with a production string. At that, before securing of the well a horizontal portion of the two-head well is elongated and led to surface to form an additional bore with a head which is also secured with the production string. A middle head of the well is equipped with the pumping facility; pumping of a heat carrier and production withdrawal is carried out simultaneously. Pumping of the heat carrier is performed alternately via side heads of the well, while production withdrawal is performed through the middle head. Simultaneous pumping of the heat carrier and withdrawal of the production of the well facilitate more efficient development of a payout bed.

EFFECT: upgraded efficiency of development due to reduced labour intensiveness and costs for lowering-lifting operations.

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Description

The invention relates to the field of development of hydrocarbon deposits by double-well wells and can be used for the production of highly viscous oil or bitumen.

There is a method of developing deposits of viscous oils and bitumen (RF patent No. 2246001, IPC 7 ЕВВ 43/24, published in Bulletin No. 4 of 02/10/2005), including drilling a two-well horizontal well, fixing it with a production string dragged from one the wellhead along its trunk to another wellhead together with packers for installing the latter in the roof of the reservoir, lifting and supplying oil to the flow line at one of the wellheads, the wellhead sections of the production string being connected to each other by a land section in the form of an arcuate pipe a wire with an identical inner diameter to form a closed channel, the above-ground portion of which is fixed on the supporting frame of the drive unit, after which an additional string is placed in the production string, which acts as a tubing string in the underground part and has perforation channels for communication with productive layer, in the cavity of the additional column at equidistant distances from each other, establish a system of cylindrical elements interconnected in the middle by means of power rods with the formation of a closed traction system, while the sections of the underground part of the tubing string from the wellhead to the boundaries of the perforation section of the production string 5 together with the aforementioned cylindrical elements form piston pump pairs, and during operation, the system of cylindrical elements is forcedly moved using the drive unit with continuous successive displacement of oil from the tubing string by means of the piston pump pairs mentioned above, while the length of the power the traction between adjacent cylindrical elements is set equal to or less than the length of the tubing string section from the formation roof to the wellhead, and during the operation of the well, when the solvent and / or coolant is supplied through the mouth opposite to the flow, the direction of movement of the traction system is changed, while on the production string in at least one annular packer is installed in the zone of the reservoir, and the adjacent section of the tubing string together with the cylindrical elements forms at least , one piston pumping pair, and after the termination of operation, the underground sections of the columns are cut into two parts and removed through the wellheads, after which cement bridges are installed to prevent the technological consequences of development.

The disadvantages of this method are:

firstly, high material and financial costs for implementing the method associated with the metal consumption of the ground part of the structure (drive, oil product collection unit, solvent and coolant supply line, traction, etc.);

secondly, this method does not allow to develop a reservoir with high oil recovery due to the small flow of highly viscous reservoir fluids into the well.

The closest in technical essence is the method of developing highly viscous oil or bitumen (RF patent No. 2273729, IPC 7 ЕВВ 43/24, published in Bulletin No. 10 of 04/10/2006), including drilling a two-well well, securing it with a production string, selection of the production of the well, while the selection of production is carried out alternately with the injection of coolant, for which the coolant is pumped through the first wellhead until the coolant exits through the second wellhead, the products are taken through the first wellhead until the temperature drops to 20-40 ° C, heat is pumped the carrier through the second wellhead until the coolant exits through the first wellhead, the well products are taken through the second wellhead until the temperature drops to 20-40 ° C, the injection and selection in this mode continue until the reservoir is depleted.

The disadvantages of this method are:

- firstly, the complexity of the implementation of this method, associated with a large number of tripping operations of the tubing string, since at first through the first mouth a string of tubing (tubing) is lowered to the roof of the reservoir, then the coolant is pumped through the tubing string, then the string is pumped Tubing to the bottom of the well and products are taken using a pump along the tubing string through the first wellhead until the temperature drops to 20 ° C, after which the tubing string is lifted from the well. After that, all of the above operations are performed from the second mouth, while for each hoisting operation with the tubing string, a repair team is required, which requires additional costs for implementing this method;

- secondly, the low efficiency of the development of the reservoir by a double-wellbore, since the small length of the horizontal section of the well reduces the efficiency of the development of the reservoir. In addition, the development of a productive formation occurs alternately from one mouth, then from another, that is, not simultaneously.

The objective of the invention is to reduce the complexity of the implementation of the method by reducing the number of tripping operations of the tubing string, as well as increasing the efficiency of the development of a productive formation by a dual wellbore by increasing the length of the horizontal section of the well, as well as simultaneously pumping coolant and selecting well products.

The problem is solved by the method of developing highly viscous oil or bitumen, including drilling a two-well well, securing it with a production casing, pumping coolant through one of the wellheads one by one, the selection of the production of the well, the injection and selection in this mode are continued until the reservoir is depleted.

What is new is that prior to fixing the well, the horizontal section of the double-well well is extended and brought to the surface to obtain an additional wellbore with a wellhead, which is also fastened with a production string, equipped with pumping equipment through the middle wellhead, and the coolant is injected and the product is taken at the same time, and the coolant is injected. produce alternately through the extreme wellheads, and the selection of production wells through the middle.

The drawing shows a diagram of the implementation of the proposed method.

The proposed method is carried out in the following way.

First, a two-well well is drilled. Next, the horizontal section of the double-well well is extended (drilled) and brought to the surface to obtain an additional wellbore with wellhead 1.

Next, an additional wellbore is secured with production casing 2, and the remaining part of the well with production casing 3. Next, horizontal sections of production cores 2 and 3 are perforated in the interval of the reservoir 4.

Then, through the middle mouth 5, the well is equipped with pumping equipment. To do this, through the middle mouth 5 lower the tubing string 6, equipped with a pump 7 at the lower end. The pump 7 may be a screw or some other known design, designed for pumping highly viscous oil or bitumen.

Next, from the mouth 1 into the production string 2, the tubing string 8 with perforated holes 9 is lowered, and from the mouth 10 into the production string 3 the tubing string 11 with perforated holes 12 is lowered.

Next, the coolant is injected - water vapor with a temperature of 200 ° C, and the coolant is injected alternately through the extreme wellheads, i.e., wellheads 1 and 10.

Through the mouth 1, the coolant is fed into the tubing string 8, through which it reaches the perforated holes 9, from where, through the perforated sections of the production string 2, the coolant enters the reservoir 4, warming it.

At the same time, highly viscous oil or bitumen from the heated reservoir 4 is received by a pump 7, which pumps highly viscous oil or bitumen through a tubing string 6 through the middle mouth 5 to the surface. Next, the coolant flow through the mouth 1 to the NTK column 8 is stopped and it is fed through the mouth 10 to the tubing string 11, through which the coolant reaches the perforated holes 12, from where the coolant enters the reservoir 4 through the perforated sections of the production string 2, heating it, while the pump 7 continues to work and pump high viscosity oil or bitumen through the tubing string 6 through the middle mouth 5 to the surface.

Thus, the injection and selection in this mode continue until the development of reserves of the deposit.

According to the proposed method, the coolant is simultaneously injected and the well products are selected, which allows for more efficient development of the productive formation.

The proposed method for the development of highly viscous oil or bitumen does not require additional tripping operations during the implementation of the method, and therefore there is no need for periodic involvement of a repair team, which reduces the complexity and avoids the additional cost of implementing the method. In addition, increasing the length of the horizontal section of the well by drilling an additional wellbore with the wellhead can improve the efficiency of the development of the productive formation.

Claims (1)

A method for developing highly viscous oil or bitumen, including drilling a double-well well, securing it with a production casing, pumping coolant through one of the wellheads one by one, taking production wells, pumping and taking in this mode, continues until the reservoir develops, characterized in that it is horizontal until the well is fixed the double-well section is extended and brought to the surface to obtain an additional wellbore with a wellhead, which is also fastened with a production string through the middle well mouth fluid is equipped with pumping equipment, and the coolant is injected and the product is taken at the same time, and the coolant is pumped alternately through the extreme wellheads, and the well is sampled through the middle.