Device and method of productive formation selective processing

Abstract

There are proposed a method for selective processing of a productive formation and a device for implementation thereof coupled with a tubing. The device is lowered to the formation’s lowest interval and fixed therein. Working fluid is supplied into the device’s hydraulic fracturing port, the interval is isolated with sealing elements, and hydraulic fracturing is executed. An annular gap is flushed with flush fluid, the lower packer is activated and debris is washed out of the gap through a hydraulic fracturing port. The device is turned to the transport position. The tubing is moved shifting the device’s hollow rod and flushing holes are opened. Flush fluid is then fed into the tubing, the sealing elements are activated and debris is washed out of the gap’s lower area pushing the mixture along the device’s inner cavity into the well. Then the device is moved to the next interval for further processing.

1 . A device for selective processing of a productive formation essentially coupled with a tubing insertable into a well casing associated with the productive formation; said well casing defines an inner sidewall surface thereof and has a diameter; said tubing defines an outer surface thereof; said device defines an outer surface thereof; wherein an annulus space is defined to include:
 a space between the outer surface of said device and the inner surface of said well casing, and   a space between the outer surface of said tubing and the inner surface of said well casing; 
 wherein said device comprises sequentially mounted on the tubing from bottom to top:
 a mechanical anchor; 
 a collar locator; 
 a lower feedthrough packer equipped with a number of cup seals; said lower feedthrough packer defines a lower packer inner cavity provided therein; said lower feedthrough packer has a hollow rod capable of axial movement at least within the inner cavity of said lower feedthrough packer; said hollow rod is partially passed through the collar locator, and partially passed through and rigidly connected to the mechanical anchor; 
 a hydraulic fracturing port divided by a partition into an upper part including an upper cavity provided with windows and a lower part provided with a recess and flushing holes communicated with the recess; said number of cup seals of the lower feedthrough packer are directed towards the hydraulic fracturing port; 
 an upper feedthrough packer equipped with a number of cup seals directed towards the hydraulic fracturing port; and 
 a centralizer; 
 
 wherein: an inter-packer annular gap is defined as a portion of the annulus space located between the outer surface of said device and the inner sidewall surface of said well casing, vertically limited by positions of the upper feedthrough packer and the lower feedthrough packer; said flushing holes provide for hydraulic connection of the inter-packer annular gap with said recess in the partition lower part; and 
 wherein: a distance between the lower feedthrough packer and the flushing holes does not exceed said diameter of the well casing multiplied by two. 
   
     
     
         2 . The device according to  claim 1  wherein seals placed above and below the flushing holes. 
     
     
         3 . The device according to  claim 1 , wherein said hollow rod defines a rod inner cavity within thereof; said collar locator defines a collar inner cavity within thereof, and wherein the rod inner cavity, the lower packer inner cavity and the collar inner cavity form a single flushing channel. 
     
     
         4 .  A method for selective processing of the productive formation using the device according to  claim 1 ; wherein the productive formation includes a number of intervals; said method comprising the steps of:
 lowering the tubing with the device to a lowest interval chosen from said number of intervals;   setting up the lowest interval within the inter-packer annular gap;   fixing the device to the well casing by the mechanical anchor;   supplying working fluid under pressure into the tubing and into the hydraulic fracturing port;   isolating the lowest interval by said number of cup seals of the lower feedthrough packer and said number of cup seals of the upper feedthrough packer;   providing hydraulic fracturing of the lowest interval by the working fluid;   feeding the flush fluid into the inter-packer annular gap;   activating the lower feedthrough packer and washing debris out of an upper portion of the inter-packer annular gap through said windows of the hydraulic fracturing port and up the tubing;   turning the device into a transport position;   axially moving up the tubing thereby shifting the hollow rod and opening the flushing holes;   feeding the flush fluid under pressure into the tubing;   activating said number of cup seals of the lower feedthrough packer and said number of cup seals of the upper feedthrough packer and washing debris out of a lower portion of the inter-packer annular gap and pushing a mixture of the flush fluid and the debris mixture along said inner cavity of the device into the well casing;   moving up the device to a next interval chosen from said number of intervals, and repeating the steps above.   
     
     
         5 . The method according to  claim 4  wherein said well casing defines a top entrance thereof and a ground surface surrounding the top entrance, and wherein the flush fluid is supplied by a pumping unit positioned on the ground surface. 
     
     
         6 . The method according to  claim 4  wherein the step of turning the device into the transport position is provided by deactivation of the mechanical anchor. 
     
     
         7 . The method according to  claim 4  wherein said well casing defines a top entrance thereof and a ground surface surrounding the top entrance; and wherein the debris froman upper portionof the inter-packer annular gap is pushed up along the tubing and being disposed of on the ground surface. 
     
     
         8 - 9 . (canceled)