RU2555686C1 - Method of well problem sections elimination - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: method includes isolation of some well sections, and monitoring of their inflow. Preliminary place of the problem section is determined, and device is run in the well, at least closing zone of the problem section inside the first completion. The device contains isolating elements located above and/or below the problem section, elements of second completion and suspension. The isolating elements and suspension contain sealing devices, isolating along the internal surface of the well string.

EFFECT: increased efficiency of elimination of the problem sections upon simultaneous decreasing of the time expenses.

13 cl, 1 dwg

Description

The invention relates to the field of hydrocarbon production and can be used in the operation of production wells.

As part of this application, the term “problem area” will be used. It means any section or object in the well that interferes with its normal operation. The problem area may be the zone of water or natural gas entry into the well, a defective pipe section in the well, etc.

Also in the framework of this application will be used the term "second completion". In the framework of this application, it means (Soloviev E.M. Well completion: A textbook for universities. - M .: Nedra, 1979. Theory and practice of well completion: 5 tons / A.I. Bulatov, P.P. Makarenko, V. . F. Budnikov et al. - M .: Nedra, 1997-1998, T. 1-5) descent of the assembly from pipes, possibly filters (liquid flows through them) or subsequent perforation, packers (insulating elements) and suspensions (fixing device (anchor) so that the whole structure is fixed in the specified place).

Known (patent RU 2382171, publ. In 2010) is a method of repairing gas and gas condensate wells with an unpressurized casing string, including killing a well, raising the surface of tubing with tubing equipment, inspection of the casing string, isolating an unpressurized casing section columns, descent into the well of tubing with downhole equipment and putting the well into operation. A packer is installed on the tubing, the tubing threaded connections during make-up when the casing is lowered into the well are treated with a hydrophobic composition above the packer installation site, and the latter, after lowering the assembly, is fixed below the identified casing leakage interval and below the closure of the casing string leakage that is used as a packer retainer during operation, and after fixing the packer, a blocking composition is pumped into the annulus and filled last for cutting space from the packer to a level above the casing leakage zone, then blocking composition is poured into the space behind the casing and into the formation by squeezing medium (liquid or gas) under a pressure exceeding the formation pressure, and then it is kept under this pressure for a period of hardening of the blocking composition .

The disadvantage of this method should be recognized the impossibility of returning this section to work in case of changing conditions in the bottomhole zone of the well.

Also known (patent RU 2446270, published in 2010) is a method of isolating formation water inflow into a well and securing a bottomhole formation zone, including injecting a silicon-containing substance into the formation, wherein a mixture of a silicon-containing substance with urea-formaldehyde concentrate or products based on it is pumped.

The disadvantage of this method should be recognized as the ability to block both aquifers and areas with good oil production. This can lead to a general decrease in oil production from the well.

Also known (patent RU 2456431, published in 2010) is a method of isolating water inflow. When implementing the known method from a solution of microdur with sulfacell and ethylene glycol with a water-cement ratio of 0.8-0.9, a process screen is installed in the terrigenous layer 5-10 m above the oil-water contact at the rate of 0.5-2.0 m ³ per 1 m effective formation thickness.

The disadvantage of this method should be recognized short-term effect, which directly depends on the accuracy of determining the position of the oil-water contact. In addition, in the case of horizontal wells, it is not possible to install a technological screen along the entire length of the barrel.

Known (patent RU 2092673, published in 1997) is a method of repairing a casing production string of pipes in a well, comprising determining the total amount of deformation of the formations uncovered by the well, creating a cavity under the lower end of the casing production string with a depth equal to the total value of the formation deformation, and application to the casing axial load casing string, moreover, the intervals of annular crossflows of formation fluids are additionally identified, the casing production casing is perforated in these intervals and produced pumping through perforations into the annular space of the plugging material with the simultaneous application of alternating axial loads to the column.

The disadvantage of this method should be recognized is the relatively high cost of repair work and the high time cost of this method with its sufficiently low efficiency. Moreover, this technique does not always work in horizontal and directional wells.

This solution was used as the closest analogue.

The technical problem solved by the developed method is to expand the range of means and methods of operating the well.

The technical result obtained by the implementation of the developed method consists in increasing the efficiency of eliminating problem areas while reducing time costs.

To achieve the specified technical result, it is proposed to use the developed method for eliminating problem areas in the well, including isolating individual sections of the well and controlling the flow from them, and first determine the location of the problem area and lower it into the well, at least partially blocking the area of the problem area, into the existing the first completion of the device, which includes insulating elements placed above and / or below the zone of the problem area, between azannymi insulating elements are elements of the second completion and suspension elements of the second set of completion, the insulating member and the suspension means comprise a seal isolating the well fluid motion (or its components) on the inner surface of the well string. Preferably, but not exclusively, the elements of the second completion may be a suspension, an insulating element (packer), a pipe, a centralizer, a well filter with a filter element, a well filter without a filter element, an inflow control device in a separate chamber with attached pipes.

As insulating elements can be used, in particular, various kinds of packers (swellable, hydraulic, hydromechanical, etc.) or bridge plugs. Packers, in some embodiments, are rubber products that, with certain triggering methods, are able to increase in transverse dimensions and thus overlap existing gaps between surfaces (casing and inner pipe, open barrel and drain pipe, etc.). Swellable packers, for example, can expand when interacting with oil or water, the work of hydromechanical packers is based on extruding the rubber part under the action of moving parts when a certain pressure is exceeded inside the descent assembly, etc.

As a means of sealing, the same packers can be used, part of which are rubber elements, which, by increasing the transverse dimensions, can serve as a seal, thus isolating individual sections.

The suspension is also provided with an insulating element (suspension packer) to isolate the interval after the suspension. This is to ensure that all liquid and gas can only flow through equipment installed below the suspension.

The descent completion equipment consists of serially connected (screwed) suspension elements, insulating elements (packers) and parts intended for collecting the produced fluid (perforated filter tubes, etc.). These elements can be arranged in different sequences. The number of elements depends on the length of the open hole, as well as the properties of the formation.

The figure shows the type of device that can be used in the implementation of the method, with the following notation: suspension 1 with an insulating element (suspension packer), an insulating element (packer) 2, parts intended for collecting the produced fluid 3.

The problem area may be a water breakthrough zone, a natural gas breakthrough zone, or a well repair zone.

In the process of eliminating the problem area, it is possible to isolate one or several sections of the production well.

Moreover, if there are several problem areas in one well at the same time as water and / or natural gas inflows, it is preferable to control the inflow from each isolated zone (problem area) independently of other problem areas.

In a preferred embodiment, it is desirable to install the second completion of a smaller diameter with the possibility of further extraction. Moreover, after extracting the second completion, it is possible, if necessary, to change its characteristics. In this embodiment, a second completion with changed characteristics may be lowered into the well to eliminate the next problem area.

It is also possible to fill the annulus between the pipes of the first and second finishes with granules, including proppants, of a predetermined size to prevent sand and other mechanical impurities from being transported into the production pipe.

The advantage of the proposed method is to recognize the ability to change the settings of the completion equipment based on the current production parameters with high efficiency measures to bring wells to acceptable working conditions. The most important problem for oil producing wells is the breakthrough of gas and water into the well. This leads to a halt in production and incomplete production of oil reserves. Using the proposed method allows not only to postpone the moment of the breakthrough, but also to continue to operate the wells after the breakthrough has occurred.

With regard to eliminating the breakthrough of natural gas into a working well, the developed method is implemented as follows: lowering the second completion consisting of a suspension, filters with inflow control devices or inflow control devices with pipes and insulating elements (packers). The insulating elements are installed above and / or below the interval from which the gas flows. Inflow control devices are configured in such a way that they limit the flow of gas from the problem interval. In this case, it is undesirable to completely block the problem areas from which gas is supplied, since gas can go to other production intervals and displace oil.

In relation to eliminating a water breakthrough into a working well, the developed method is implemented as follows: lowering the second completion consisting of suspension 1, filters with inflow control devices or inflow control devices with pipes and insulating elements (packers) 2. The insulating elements are installed higher and / or lower interval from which water comes. Inflow control devices are configured in such a way that they limit the flow of water from the problem interval. In this case, it is undesirable to completely block the problem areas from which water comes, since oil also comes from these areas.

In the case of well repair, the developed method is implemented as follows: in case of damage to the non-producing interval of the well, the second completion is lowered, consisting of suspension 1, pipes and insulating elements (packers) 2. Insulating elements are installed above and / or below the damaged interval of the casing string. In this case, the damaged area is isolated. It is also possible to install flow control devices along the remaining length of the production intervals of the well to optimize production.

Claims (13)

1. A way to eliminate problem areas in the well, including isolating individual sections of the well and controlling the flow of them, characterized in that the location of the problem area is determined and lowered into the well, at least blocking the area of the problem area, into the existing first completion of the device, in the composition of which includes insulating elements placed above and / or below the zone of the problem area, elements of the second completion and suspension, and the insulating elements and suspension contain means of sealing Niya, insulating the inner surface of the well string. 2. The method according to claim 1, characterized in that the second completion elements are an insulating element, a pipe, a centralizer, a well filter with a filter element, a well filter without a filter element, an inflow control device in a separate chamber with attached pipes. 3. The method according to claim 2, characterized in that the suspension is used as an insulating element. 4. The method according to claim 2, characterized in that the packer is used as an insulating element. 5. The method according to claim 1, characterized in that the problem area is a zone of water breakthrough. 6. The method according to claim 1, characterized in that the problem area is a natural gas breakthrough zone. 7. The method according to claim 1, characterized in that the problem area is a well repair zone. 8. The method according to claim 1, characterized in that they block at least one problematic section of the well. 9. The method according to claim 1, characterized in that the inflow from each isolated zone is controlled independently of the remaining zones. 10. The method according to claim 1, characterized in that the second completion of a smaller diameter is set with the possibility of further extraction. 11. The method according to claim 10, characterized in that after the second completion is extracted, its characteristics are changed and the second completion with changed characteristics is lowered into the well to eliminate the problem area. 12. The method according to claim 1, characterized in that they additionally fill the annular space between the pipes of the first and second completion with granules of a given size to prevent sand and other mechanical impurities from being transported into the production pipe from the formation. 13. The method according to p. 12, characterized in that the proppants are used as granules.