RU2350745C1 - Method of operating double-head well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to development of hydrocarbon deposits with double-head horizontal wells and can be used at extraction of high viscous oil and bitumen. The method consists in exposing payout bed with a horizontal borehole and in casing the borehole with production string preliminary equipped with a filter in the interval of the exposed payout bed, then in equipping the heads, in installation of a blind packer through the first head in the interval of the payout bed of the well and in operating the well through the second head. According to the invention the blind packer is installed behind the circuit of water flooding from the side of the second head and the part of the filter apertures through which water flooding occurs is closed. The blind packer is reinstalled and additional part of apertures through which water flooding occurs is closed when the circuit of water flooding has changed in the process of operation and watering of extracted production has increased. This regulates the level of water flooding.

EFFECT: increased efficiency of method due to simplification of packer assembly in well, to possibility of packer re-assembly and due to possibility of continuous well operation through the second well.

1 dwg

Description

The invention relates to the field of development of hydrocarbon deposits by double-well horizontal wells and can be used for the extraction of high viscosity oils and bitumen.

A known method for the development of deposits of viscous oils and bitumen (RF patent for the invention No. 22600600, IPC 8 ЕВВ 43/24; published in Bull. No. 5 dated 02.10.2005), including drilling a two-well horizontal well, fixing it with a production string, dragged from one wellhead along its wellbore to another wellhead together with packers for installing the latter in the roof of a productive formation, raising and supplying oil to a flow line at one of the wellheads, and the wellhead sections of the production string are interconnected by a ground section in the form of arcs a similar pipeline with an identical inner diameter to form a closed channel, the above-ground portion of which is fixed on the support frame of the drive unit, after which an additional string is installed in the production string, which acts as a tubing in the underground part and has perforation channels for communication with the productive layer, in the cavity of the additional column at equidistant distances from each other establish a system of cylindrical elements interconnected by means of power rods with the formation of a closed traction system, while sections of the underground part of the tubing from the wellhead to the boundaries of the perforation section of the production string together with the aforementioned cylindrical elements form piston pump pairs, and during operation, the system of cylindrical elements is forcedly moved using a drive unit with continuous successive displacement of oil from the tubing by means of the piston pump pairs mentioned above.

The disadvantage of this method is the metal consumption of the structure on the surface, associated with the presence of a land section in the form of an arcuate pipeline, which is fixed on the supporting frame of the drive unit, and this leads to an increase in the cost of the structure as a whole.

The closest in technical essence and the achieved result to the proposed is a method of constructing a horizontal well (RF patent for the invention No. 2246001, IPC 8 Е21В 43/20; ЕВВ 7/04, published in Bull. No. 32 of 11/20/2000), including opening a productive formation with a horizontal wellbore and securing it with a casing production string, wellhead equipment, perforation and well development, while after installing hydrocarbon extraction equipment at the second wellhead, the well is mastered and production begins from the mouths and when the contour approaches floods to the installation site of the packer the in-pipe space of the production string in the interval of installation of the packer is blocked, for example, with a polymer swab, and the mouth located on the side opposite to the direction of movement of the waterflood is used to pump a liquid or gaseous agent to maintain reservoir pressure, and the opposite mouth for hydrocarbon production.

The disadvantages of this method are:

firstly, the complexity of installing an annular packer in the well, since it is installed as part of the production casing during the construction of a horizontal well;

secondly, the annular packer is stationary, since it is fixed in the production casing, and this does not allow it to be moved during operation, depending on the changing contour of the waterflooding of the well.

An object of the invention is to simplify the installation of the packer in the well and the ability to install the packer in the production casing with subsequent reinstallation of the packer in the opening interval in accordance with the change in the waterflood contour.

The technical problem is solved by the proposed method of operating a two-well well, including opening a reservoir with a horizontal wellbore and securing it with a casing string pre-equipped with a filter in the interval of the opened reservoir, installing wellheads and operating the well, installing a blind packer through one well in the interval of the producing well waterflood circuit, operation through a second mouth.

New is that the well is operated continuously through the second wellhead, and the deaf packer is installed with the possibility of removal and reinstallation in the interval of opening the reservoir in accordance with the change in the waterflood contour.

The proposed method is as follows.

First, the productive formation 1 is opened by a horizontal wellbore 2, which is then fixed by the casing production string 3. Then, the mouths 4 and 5, respectively, of the double-well well are equipped. In addition, before the descent of the production casing 3 into the horizontal barrel 2, it is equipped with a filter 6 in the interval of the opened reservoir 1.

Next, through the second mouth 5, the tubing string 7 is lowered with the pump 8 at the end. The pump 8 may be of any known design, for example, electric centrifugal (ESP), designed for pumping highly viscous oil or bitumen.

Next, at the second wellhead 5 of the double-well well, the tubing string 7 is sealed with wellhead fittings 9 and the double-well well begins to operate. In the process of operating a two-well well, the opened producing formation 1 begins to be watered, as evidenced by an increase in the water content of the products produced from the well (high viscosity oil or bitumen).

In order to reduce the water cut of the produced products into the double-well well from the first wellhead 4 on the tubing string or flexible pipe (not shown in the drawing), the deaf packer 10 (inflatable) is lowered with the possibility of subsequent reinstallation in production casing 3.

The deaf packer 10 is installed in the production casing 3 behind the waterflooding circuit (not shown), from the side of the pump 8, after which the deaf packer 10 is planted in the production casing 3, and the tubing string or flexible pipe is removed to the surface. As a result, the deaf packer 10 cuts off part of the production casing 3 from the side of the first wellhead 4, disconnecting part of the openings of the filter 6 of the production casing 3, through which the produced products are flooded from the double-well.

During the further operation of the double-well well, due to the operation of the pump 8, the waterflood circuit is pulled towards the pump 8, and water through the openings of the filter 6 of the production casing 3 before the deaf packer 10 begins to flow into the production casing 3. As a result, the water content of the products produced from the well increases again.

In order to reduce the water cut of the produced products into the two-well well from the first wellhead, that is, from the wellhead 4, the tubing string or flexible pipe (not shown) is again lowered.

After that, the deaf packer 10 is grabbed by the fishing head 11 (conventionally shown) and the deaf packer 10 is broken. Next, the tubing string or flexible pipe is pulled into the double-well well, i.e., the deaf packer 10 is reinstalled so that the deaf packer 10 is located beyond the waterflooding circuit. Next, the deaf packer 10 is re-planted in the production casing 3, while the deaf packer 10 further disconnects part of the openings of the filter 6 of the production casing 3, through which the produced products were flooded from the two-well borehole.

Thus, the operation of the well (production of highly viscous oil or bitumen to the surface) is carried out continuously through the second wellhead 5 of the two-wellhead, and the deaf packer is lowered through the first wellhead 4 and installed with the possibility of removal and reinstallation in the interval of the productive formation 1 in accordance with the change in the waterflood contour.

The proposed method simplifies the installation of the packer in the well, since the packer is installed directly in the production string, and the possibility of subsequent reinstallation of the packer in the production string in the interval of the reservoir in accordance with a change in the waterflood circuit allows you to adjust the water cut of the produced products, which makes the operation of a double-well well more efficient.

Claims (1)

A method of operating a two-well borehole, including opening a reservoir with a horizontal wellbore and securing it with a casing production string, previously equipped with a filter in the interval of the borehole, opening the wellhead, installing a blind packer through the first wellhead in the interval of the producing wellbore, and operating the well through a second wellhead that a blank packer is installed behind the waterflood circuit from the side of the second mouth with the part of the filter openings disconnected through the cat In the event of flooding of the produced product, and when the waterflood contour changes during the operation of the well with an increase in the water content of the produced product, the deaf packer is reinstalled and some of the filter openings through which the flooding occurs are switched off, thereby regulating the value of this flooding, while the wells are continuously operated through the second wellhead .