RU2310747C1 - Method to isolate water influx in well - Google Patents

Abstract

FIELD: oil production, particularly preventing gas- or water-coning phenomena, for instance the formation of a conical column of gas or water around wells.

SUBSTANCE: method involves injecting hydrophobic composition in water influx channels; lowering and installing shutter provided with shoe at shutter end within water influx interval. The shoe may slide upwards in axial direction and is retained with shear members. The shoe has longitudinal and side communicating channels. Before hydrophobic composition injection the shutter is lowered to well bottom without supporting thereof. After that low-diameter pipe string is additionally inserted in shutter to provide airtight cooperation thereof with longitudinal channel. After hydrophobic composition injection through side channels the shutter is lowered to well bottom up to upward shoe movement with side channel closing. Low-diameter pipe string is removed from well before shutter installation.

EFFECT: improved water influx isolation.

1 dwg

Description

The invention relates to the oil industry, in particular to methods for limiting and isolating water inflows.

The known method implemented by the "Device for blocking the zone of complications in the well" (AS No. 1712581, ЕВВ 29/10, 33/13, publ. Bulletin No. 6 of 02/15/1992), including descent and installation in the interval areas of complication profile overlap.

The disadvantage of this method is the possibility of isolating water inflows of water breakthrough along the walls of the overlap, especially when drilling along the bedding of rocks.

The closest in technical essence and the achieved result is the "Method of isolating water inflows in an oil well" (patent RU No. 2114990, ЕВВ 43/32, 33/13, publ. Bulletin No. 19 dated 07/10/1998), including launching and installation in the interval of the water inflow of the shutoff, in this case, before installing the shutoff in the channels of the water inflow, a hydrophobic water-insoluble composition with a viscosity of 200-1700 mPa · s is pumped at a shear rate of 2 - 145 s ^-1 , and after injection of the composition it is kept in the water flow channels under pressure for structural hardening of the composition.

The disadvantage of this method is the large period of time between the injection of the composition into the channels of the water inflow and the installation of the shutoff in the well, spent on lowering the shutoff, which can lead to the extrusion of a significant amount of the composition back into the barrel, especially at high reservoir pressure of the water inflow.

The technical task of the invention is to improve the quality of insulation of water inflows in the well due to a significant reduction in the time between the injection of a hydrophobic composition into the water inflow channels and the installation of a shutoff.

The technical problem is solved by a method of isolating water inflows in a well, including pumping a hydrophobic composition into the channels of water inflow, launching and installing a shutoff with a shoe at the end in the interval of water inflow.

What is new is that before injecting the hydrophobic composition, the shutter is run without support on the bottom hole of the shutoff, the shoe of which is mounted with the possibility of axial upward movement, fixed by shear elements and equipped with longitudinal and lateral communicating channels, after which a pipe string is additionally lowered into the shutoff to inject the hydrophobic composition small diameter until tight interaction with the longitudinal channel, after pumping through the side channels of a hydrophobic composition, the overlap is lowered to the bottom before moving up the shoe with overlapping side channels, and before installing the shutoff, the string of pipes of small diameter is removed from the well.

The drawing shows a shutter with a column of pipes of small diameter inside.

A method of isolating water inflows in a well (not shown) is as follows.

The shutter 1 on the pipe string 2, connected through the sub 3 with the left thread 4 to the shutoff 1, which at the end is equipped with a shoe 5 with longitudinal 6 and side 7 channels, is lowered into the well without stopping at the bottom (not shown). Moreover, the shoe 5 is installed in the shutter 1 with the possibility of axial movement upwards with hermetic overlap of the side channels 7 and fixed with shear elements 8. After that, a string of pipes of small diameter 9 (for example, a string of continuous pipes) is additionally lowered into the shutter 1 until hermetic interaction with the longitudinal channel 6 A hydrophobic composition is pumped through a string of pipes of small diameter 9 through a longitudinal 6 and side 7 channels into the water inflow channels. After holding the technologically necessary time, sufficient for structural compaction, the shutter 1 is lowered to the bottom, shear elements 8 are destroyed and the shoe 5 enters the shutter 1, blocking the side channels 7. Next, the string of pipes of small diameter 9 is removed from the well, in the pipe string 2 create excess a pressure sufficient to inflate the overlap 1 to a tight interaction with the walls of the well. Then, the pipe string 2 is rotated, as a result of which the sub 3 turns away from the overlap 1 on the left-hand thread 4, after which the pipe string 2 is removed from the well. If necessary, for a better and denser pressing against the walls of the well, the overlap 1 is further expanded (for example, by a flare or mandrel). The implementation of the method is completed. If there is a need for further deepening of the well, the shoe 5 is made of easily drilled material (for example, cast iron).

The proposed method for isolating water inflows in a well allows to improve the quality of isolation of water inflows in a well by significantly reducing the time between the injection of a hydrophobic composition into the channels of water inflow and installing a shutoff.

Claims (1)

A method of isolating water inflows in a well, including injecting a hydrophobic composition into the water inflow channels, launching and installing in the water inflow interval a shutter with a shoe at the end, characterized in that before the hydrophobic composition is injected, the shutter is run without support on the bottom of the shutter, the boot of which is installed with the possibility of axial movement , fixed by shear elements and equipped with longitudinal and lateral communicating channels, after which they are additionally lowered into the shutter to pump the hydrophobic composition to a string of small diameter pipes until tight interaction with the longitudinal channel, after pumping through the side channels of a hydrophobic composition, the shutter is lowered to the bottom until the shoe moves up with the side channels overlapping, and before the shutter is installed, the string of small diameter pipes is removed from the well.