RU2516077C1 - Method for construction and operation of vertical well for steam assisted gravity drainage of high-viscosity oil or bitumen - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes construction of a vertical well with the upper and lower intervals of communication with the formation, division of communication intervals, injection of high-temperature steam to the upper interval and extraction of the product from the lower interval of communication. According to the invention the vertical well is constructed in two stages. At the first stage the casing is cemented up to the bed roof, at the second stage a liner with a thermal compensation absorber is run in, at that it interacts hermetically with the casing and two communication intervals with the bed which are made as the respective upper and lower filters with a place for a packer between them. The upper filter is placed closer to the bed roof while the lower filter is placed closer to its bottom. Through the upper and lower filters of the liner steam is injected through the well at a temperature of about 200°C to the bed and the bed is heated around this well. After heating of the bed steam delivery is stopped and the well is shut off for thermocapillary impregnation of the bed. Steam delivery is renewed after run-out of the pipe string with the packer through the upper filter until a steam chamber is formed in the upper part of the bed. At that injection of high-temperature steam is made through tubular annulus while the product is extracted through the pipe string.

EFFECT: improving efficiency for production of high-viscous oil or bitumen from vertical wells with use of steam assisted gravity drainage.

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Description

The invention relates to the oil industry, in particular to the field of oil production by thermal methods, and can be used for the extraction of highly viscous oil or bitumen from a vertical well using the method of steam gravity drainage.

A known method of developing deposits of highly viscous oil or bitumen (RF patent No. 2274742, ЕВВ 43/24, published in Bulletin No. 11 of 04/20/2006), including the construction of a well cased with casing pipes, lowering two pipe columns into it to different depths in the interval of the reservoir with the packer, coolant injection along one pipe string and product selection along the second pipe string.

The disadvantage of this method is that for the descent of two parallel columns of tubing, it is necessary to build a large diameter well, which increases the cost of its construction. In addition, the need to use a packer and expansion joints for two pipe columns complicates the technology of their descent and increases the cost of production.

There is also known a method of producing highly viscous oil (RF patent No. 2206728, ЕВВ 43/24, publ. 06/20/2003), including the descent into the casing string of the tubing to the perforation interval, the flow of coolant along it, the rise of products along the annulus , two columns of tubing are lowered into the casing, the first before the start, and the second through the first to the end of the perforation interval and the coolant is supplied through it, and gas is supplied into the space between the casing and the first tubing string they move around the space between the tubing strings, after ensuring a given injectivity, the production is stopped, the coolant is pumped to the calculated value, while the gas supply is continued, the space between the tubing strings is filled and maintained in this state, then the well is stopped thermocapillary impregnation before the onset of an intensive decrease in fluid mobility in the near-wellbore zone, the pressure in the well is depressurized, the product entering it is taken to decrease flow rate obtained in the natural regime of the formation, the coolant injection and production selection cycle is repeated until a mobile fluid zone is created with the producing well, after which the well is transferred to the injection well, and the production is taken through the production well, production is taken out by swabbing or gas supply to the annular the space, the producing well before the creation of the zone with the moving fluid is operated in a similar way, and then transferred to the producing.

The disadvantage of this method is that the construction and operation of the well requires significant costs. In addition, this technology does not allow the use of steam gravity drainage method for the extraction of ultra-viscous oil or bitumen.

The technical task of the proposed method is to increase the efficiency of production of highly viscous oil or bitumen from vertical wells using the method of steam gravity drainage.

The stated technical problem is solved by the described method, including the construction of a vertical well with upper and lower intervals of communication with the reservoir, separation of communication intervals, injection of a high-temperature coolant into the upper interval and selection of products from the lower communication interval.

What is new is that a vertical well is built in two stages, on the first of which the casing is cemented to the top of the formation, and on the second, the liner is lowered with a thermal expansion joint, hermetically interacting with the casing, and two communication intervals with the formation, made in the form the corresponding upper and lower filters with a place for the packer located between them, the upper filter being placed closer to the roof of the formation, and the lower filter closer to its sole, through the upper and lower filters of the bottom of the hearth t through the well steam with a temperature of about 200 ° C into the formation and warm it around this well, after heating the formation, the steam supply is stopped and the well is stopped for thermocapillary impregnation of the formation, steam supply is resumed after the pipe string with the packer is lowered through the upper filter until it forms at the top formation of the steam chamber, while high-temperature steam is injected into the upper interval along the annular space of the well, and the selection of products is carried out along the pipe string.

The drawing shows a diagram of the proposed method for the construction and operation of a vertical well for steam gravity drainage of high viscosity oil or bitumen.

The method is carried out in the following sequence. A well 1 is constructed at the field and cased to the roof of the formation 2 by casing pipes 3. Then a liner 4 is lowered into it to a depth below the bottom of the formation 2. The liner 4 with casing 3 forms a pair 5, where the expansion joint 6 is installed, which is a sealant 7 The shank 4 is equipped with an upper 8 and lower 9 filters and a seat seat 10 between them for the packer 11 of the pipe string 12. The upper filter 8 is placed closer to the roof of the formation 2, and the lower filter 9 is closer to its sole. The wellhead 1 is sealed by known methods, and its annular space 13 is in communication with a ground steam line 14, and the pipe string 12 with a flow line 15.

Before the pipe string 12 is lowered into the well 1, a coolant (steam) with a temperature of about 200 ° C is supplied to the well annulus 13 through the ground pipe 14 to the well annulus 13. In this case, the liner 4, moving in conjunction 5 together with the seal 7, compensates for its thermal expansion. The materials of all structural elements of the well 1 must be workable in these conditions. Through the upper 8 and lower 9 filters of the liner 4, steam penetrates the formation 2 and warms up highly viscous oil or bitumen around the well 1. After heating the formation, the steam supply to the well 1 is stopped and it is stopped for thermocapillary impregnation of the formation 2. Then, the pipe string 12 is lowered into the well 1 with the packer 11 before it is planted in the seat saddle 10 of the shank 4. The packer 11 hermetically separates the upper filter 8 from the lower filter 9 of the shank 4. It is possible to use both metallic and non-metallic packer. Steam supply resumes. Through the annulus 13 of well 1 and the upper filter 8 of the liner 4, steam penetrates into the formation 2 and warms up its upper part, forming a vapor chamber 16. Under the action of steam and gravitational forces, high-viscosity oil or bitumen in the formation 2 drains into the zone of the lower filter 9, penetrates into the cavity 17 of the shank 4, and along the pipe string 12 it is raised to the surface by a pump (not shown) or in another cost-effective way.

The proposed technical solution allows you to build inexpensive wells of small diameter using mobile compact drilling rigs and increases the efficiency of production of high viscosity oil or bitumen from vertical wells using the method of steam gravity drainage.

Claims (1)

 A method of constructing and operating a vertical well for steam gravity drainage of highly viscous oil or bitumen, comprising constructing a vertical well with upper and lower communication intervals with the formation, separating communication intervals, injecting high-temperature steam into the upper interval and selecting products from the lower communication interval, characterized in that the vertical the well is built in two stages, on the first of which the casing is cemented to the top of the formation, and on the second, the liner with compensator t thermal expansion, tightly interacting with the casing, and two communication intervals with the formation, made in the form of the corresponding upper and lower filters with a place for the packer located between them, the upper filter being placed closer to the roof of the formation, and the lower filter closer to its bottom, through the upper and lower liner filters steam is supplied through the well with a temperature of about 200 ° C into the formation and it is heated around this well, after heating of the formation, the steam supply is stopped and the well is stopped for thermocapilla impregnation of the formation, steam supply is resumed after the pipe string with the packer is lowered through the upper filter until a steam chamber is formed in the upper part of the formation, while high-temperature steam is injected into the upper interval along the annulus of the well, and production is selected along the pipe string.

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