RU2593283C1 - Method of extracting packer from well - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention can be used when extracting a packer from a well. When extracting a packer from a well, casing valve is opened, tool is tensioned and liquid is pumped under packer, liquid under packer is pumped under pressure of saturation of bore-hole zone, after saturation of borehole pressure is increased to pressure of not more than permissible for production string. Liquid used is liquid with density 1.04-1.27 g/cm³ or formation water of said deposit. Liquid can also be a surfactant solution in formation water of said deposit or surfactant solution in water with density 1.04-1.1 g/cm³.

EFFECT: higher efficiency of extracting wedged packer from well.

3 cl

Description

The invention relates to the oil industry and may find application in removing the packer from the well.

A known method of extracting the packer from the well, according to which the lower and upper centralizers, a sliding milling cutter with cutters and a bayonet lock for connecting to the packer are included in the arrangement. The assembly is carried out, its descent into the well on the pipe string to the calculated depth. The crackers of the packer fixing mechanism are freed from the compressive load on the production string by pulling the pipe string and removing the packer from the well. Clarify the place of cutting the sleeve of the locking mechanism of the packer and carry out its cutting 1-2 cm below the crackers of the locking mechanism of the packer. Unload the pipe string and connect the bayonet lock to the packer. Removing the packer from the well begins with the extraction of its upper part, including crackers and a sealing element. After that, the lower part is removed using a tube (RF patent No. 2182643, class ЕВВ 31/00, Е21В 33/12, publ. May 20, 2002).

The method is complex and difficult to perform, requires the use of additional tools, often not providing the necessary accuracy of the joining of elements.

Closest to the proposed invention in technical essence is a method of overhaul of wells, associated with the capture and extraction from the wells of devices with a central channel, for example packers, according to which, simultaneously with the creation of a tool tension, a thickened viscous fluid is pumped into the well (RF patent No. 2108444, CL E21B 31/00, publ. 10.04.1998 - prototype).

The method is simple, it does not require the use of additional tools, however, the method of extracting the packer cannot create the necessary force for a long-running and jammed packer even when a viscous fluid is pumped through it.

The proposed invention solves the problem of increasing the efficiency of extracting jammed packer from the well.

The problem is solved in that in the method of extracting the packer from the well, including tensioning the tool and injecting the fluid under the packer, according to the invention, the annular valve is preliminarily opened, the fluid under the packer is pumped under saturation pressure of the near-wellbore zone, after saturation of the near-wellbore zone, the pressure is increased to a pressure not more than acceptable to the production casing.

The liquid used is produced water of a given field, water with a density of 1.04-1.27 g / cm ³ , a solution of a surfactant in produced water of a given field, or a solution of a surfactant in water with a density of 1.04-1, 10 g / cm ³ .

SUMMARY OF THE INVENTION

When removing the stuck packer, which has served the well for more than one year, it is not possible to break the packer due to the inability to create the necessary force on the packer even when a viscous fluid is pumped through it. Viscous fluid is inevitably filtered into the near-wellbore zone, thereby reducing the pressure under the packer. In addition, the viscous liquid itself has a low density, which does not contribute to increasing the pressure under the packer and stalling the packer. The proposed invention solves the problem of increasing the efficiency of extracting jammed packer from the well. The problem is solved as follows.

When removing the packer from the well, the annular valve is opened and the pressure is released from the annulus. The tension of the tool is carried out - pipe columns and injection under the packer along the liquid pipe string. The fluid under the packer is pumped under the saturation pressure of the near-wellbore zone, and after saturation of the near-wellbore zone, the pressure is increased to a pressure not exceeding the allowable for the production casing. The liquid used is produced water of a given field, water with a density of 1.04-1.27 g / cm ³ , a solution of a surfactant in produced water of a given field, or a solution of a surfactant in water with a density of 1.04-1, 10 g / cm ³ .

A liquid with a higher density creates more pressure on the packer from below, contributing to its breakdown. The surfactant in the liquid wets the surface of the tearing packer and the walls of the well, causing a proppant that promotes the delamination of the packer elements from the well. The use of formation water of the field, which is opened by a well with a packer, allows to avoid the negative impact of water on the near-wellbore zone, to preserve the productivity of the well.

As a result, it is possible to disrupt the packer and remove it from the well.

Case Studies

Example 1. Produce stall and extract from the well packer. The packer is located at a depth of 1850 m in a production casing with a diameter of 168 mm. The packer is connected to the wellhead with a tubing string of 89 mm diameter. The packer was installed in the well for the hydraulic fracturing process. Before the breakdown, the packer was in the well for 2 days. It is not possible to break the packer by lifting the tubing string.

Open the annular valve. Simultaneously with the tension at the wellhead of the tubing string with a force of 24 tons, the produced water of this field is pumped under the packer into the tubing string. The density of produced water is 1.18 g / cm ³ . First, the produced water is pumped under the pressure of saturation of the near-wellbore zone in the range of 3-4 MPa at the wellhead, and after saturation and cessation of the injectivity of the well, the injection pressure is increased to a maximum of 7 MPa for the production casing. The packer is torn off and lifted from the well along with the tubing string.

Example 2. Perform as example 1. As a liquid, water with a density of 1.04 g / cm ^{3 is used} .

Example 3. Perform as example 1. As a liquid, water with a density of 1.27 g / cm ^{3 is used} .

Example 4. Perform as example 1. As a liquid, water with a density of 1.09 g / cm ^{3 is used} .

Example 5. Perform as example 1. As a liquid, a 0.1% solution of the surfactant ML-81B in produced water of a given field is used.

Example 6. Perform as example 1. As a liquid, use a 3% solution of the surfactant ML-80 in the formation water of this field.

Example 7. Perform as example 1. As a liquid, use a 2% solution of the surfactant ML-72 in produced water of this field.

Example 8. Perform as example 1. As a liquid, use a 3% solution of the surfactant ML-81B in water with a density of 1.04 g / cm ³ .

Example 9. Perform as example 1. As a liquid using a 0.1% solution of the surfactant ML-80 in water with a density of 1.10 g / cm ³ .

As a result, according to examples 1-9, it is possible to disrupt the packer and remove it from the well.

The application of the proposed method will improve the extraction efficiency of the jammed packer from the well.

Claims (3)

1. A method of extracting the packer from the well, including tensioning the tool and injecting a fluid packer, characterized in that the annular valve is pre-opened, the fluid is pumped under saturation pressure of the near-wellbore zone, after saturation of the near-wellbore zone, the pressure is increased to a pressure not exceeding the allowable for the production casing, in this case, a liquid with a density of 1.04-1.27 g / cm ³ or produced water of a given field is used as a liquid. 2. The method according to p. 1, characterized in that the liquid used is a solution of a surfactant in the formation water of a given field. 3. The method according to p. 1, characterized in that the liquid used is a solution of a surfactant in water with a density of 1.04-1.10 g / cm ³ .