Method and apparatus for hydraulic treatment of a wellbore

Abstract

A method and apparatus for applying hydraulic treatment and diversion treatment to a wellbore are described. The method involves isolating a wellbore segment using hydraulic seals; applying fluid treatment and perforation diverters within the isolated segment; and scraping a portion of the wellbore after termination of treatment to remove any lodged perforation diverters from the wellbore. A collection chamber may also be provided for collecting used diverters for return to surface following treatment. In one embodiment, diverters used and collected within a first segment may be reused during treatment of a successive wellbore segment.

1 . A method for applying hydraulic treatment to a wellbore comprising the steps of:
 reversibly setting hydraulic seals against a wellbore above and below a first wellbore segment of interest to isolate said first wellbore segment;   delivering hydraulic treatment to the isolated wellbore segment;   delivering perforation diverters to the isolated wellbore segment;   terminating the delivery of hydraulic treatment to the isolated segment;   unsetting the hydraulic seals from the wellbore; and   scraping the wellbore segment to dislodge perforation diverters therefrom.   
   
   
       2 . The method as in  claim 1  further comprising the step of collecting deployed perforation diverters from the wellbore. 
   
   
       3 . The method as in  claim 1  wherein the hydraulic seals are packer assemblies. 
   
   
       4 . The method as in  claim 1  wherein the hydraulic seals are pressure actuated sealing members. 
   
   
       5 . The method as in  claim 1  wherein the wellbore segment of interest bears two or more perforations. 
   
   
       6 . The method as in  claim 1  wherein the hydraulic treatment is fracturing fluid, acidizing or energizing treatment, proppants, or cleaning fluid. 
   
   
       7 . The apparatus as in  claim 6  wherein the hydraulic treatment is in liquid state, gaseous state, or a combination of liquid and gaseous state. 
   
   
       8 . The method as in  claim 7  wherein the hydraulic treatment further includes solids, waxes, biodegradables, or other particles suspended therewithin. 
   
   
       9 . The method as in  claim 1  wherein the perforation diverters are delivered to the isolated wellbore segment during delivery of the hydraulic treatment fluid. 
   
   
       10 . The method as in  claim 1  wherein the perforation diverters are ball sealers. 
   
   
       11 . The method as in  claim 10  wherein the ball sealers are formed from polymeric or elastomeric materials, biodegradable material, ceramics, composites, or wax. 
   
   
       12 . The method as in  claim 1  wherein the number of perforation diverters deployed within the segment is less than or equal to the number of perforations within the segment. 
   
   
       13 . The method as in  claim 1  wherein the number of perforation diverters deployed within the segment is greater than the number of perforations within the segment. 
   
   
       14 . The method as in  claim 1  wherein scraping is performed by abrading the wellbore with a scraper. 
   
   
       15 . The method as in  claim 14  wherein the perforation diverter is a ball diverter and wherein the scraper is a rigid cup-shaped scraper for dislodging ball diverters from the wellbore. 
   
   
       16 . The method as in  claim 14  wherein the perforation diverter is gel or foam and wherein the scraper is a wire brush for scrubbing the gel or foam from the wellbore. 
   
   
       17 . The method as in  claim 14  wherein a diverter collection chamber is operatively attached to the scraper for collecting used perforation diverters from the wellbore segment. 
   
   
       18 . The method as in  claim 1  further comprising the steps of:
 reversibly setting the hydraulic seals against the wellbore above and below a second wellbore segment of interest to isolate said second wellbore segment;   applying hydraulic treatment to the isolated second segment;   deploying perforation diverters within the isolated second segment;   terminating the application of treatment fluid to the isolated segment;   unsetting the hydraulic seals from the wellbore; and   scraping the second wellbore segment to dislodge perforation diverters therefrom.   
   
   
       19 . The method as in  claim 18  wherein one or more of the perforation diverters deployed within the first isolated segment is collected and then redeployed within the second isolated segment. 
   
   
       20 . The method as in  claim 18  wherein the first and second segments are within the same wellbore. 
   
   
       21 . The method as in  claim 18  wherein the first and second segments are within independent wellbores. 
   
   
       22 . An apparatus for use in hydraulic treatment of a wellbore, the apparatus comprising:
 upper and lower sealing assemblies for reversibly setting at least two hydraulic seals within a wellbore to isolate a portion of the wellbore between the seals;   a hydraulic treatment assembly for applying a hydraulic treatment within the isolated portion of the wellbore;   a diversion assembly operatively attached to the hydraulic treatment assembly for delivering perforation diverters to the isolated portion of the wellbore during hydraulic treatment; and   a scraper assembly for scraping lodged perforation diverters from the wellbore segment.   
   
   
       23 . The apparatus as in  claim 22  wherein the upper and lower sealing assemblies comprise pressure-activated sealing members for sealing against the wellbore. 
   
   
       24 . The apparatus as in  claim 22  wherein the scraper assembly includes at least one scraper extending outwardly towards the wellbore to a radial distance less than or equal to the wellbore drift diameter. 
   
   
       25 . The apparatus as in  claim 22  wherein the scraper is helically disposed about the longitudinal axis of the apparatus. 
   
   
       26 . The apparatus as in  claim 22  wherein two or more scrapers are arranged radially about the apparatus. 
   
   
       27 . The apparatus as in  claim 22 , further comprising a collection assembly associated with the scraper assembly for collecting deployed perforation diverters within the wellbore. 
   
   
       28 . The apparatus as in  claim 27  wherein the collection assembly includes a collection chamber having a collection port adjacent the scraper assembly such that scraping action directs used perforation diverters into the collection chamber through the collection port. 
   
   
       29 . The apparatus as in  claim 28  wherein the hydraulic treatment assembly is continuous with the collection chamber such that when hydraulic treatment fluid is applied to the isolated wellbore segment, at least a portion of the treatment fluid passes through the collection chamber to cause perforation diverters within the collection chamber to be expelled therefrom and delivered to the isolated wellbore segment through the collection port. 
   
   
       30 . A diverter scraping and collection assembly for use in removing lodged perforation diverters from a wellbore, the assembly comprising:
 a tubular body for suspension within a wellbore;   a scraping member extending radially from the tubular body for scraping a wellbore surface to remove lodged diverters therefrom;   a collection chamber operatively attached to the tubular housing for collecting perforation diverters from the wellbore; and   a diverter collection port adjacent the scraper and continuous with the collection chamber for directing dislodged perforation diverters to the collection chamber.