Perforation tool having dissolvable plugs and methods of using same

Abstract

Described herein is a perforation tool having dissolvable plugs and methods of using same. The tool may have a tubular housing having holes where each hole extends through the wall, and dissolvable plugs placed in the holes. The dissolvable plugs may be made of dissolvable material that extends from an interior face of the tool to an exterior face of the tool. The tool may be placed in a well proximal to the formation, the dissolvable plugs may be dissolved, and fluid may be provided to the formation. More than one tool may be used to sequence fracturing of respective formations. After a first formation is fractured a diverter may be used to divert fluid away from holes communicating to the fractured formation so that fracturing of the second formation may be selectively performed.

1 . A perforation tool for use in a production well, the perforation tool comprising:
 a tubular housing having a wall defining a channel, the housing comprising one or more holes, each hole extending through the wall; and   one or more dissolvable plugs, each dissolvable plug connected to the housing in order to seal the respective hole, wherein each dissolvable plug comprises dissolvable material that extends from an interior face of the housing to an exterior face of the housing such that when the dissolvable material is dissolved, fluid communication through the wall is enabled via the holes.   
     
     
         2 . The perforation tool according to  claim 1 , wherein each dissolvable plug and respective hole are connected by complementary screw threads. 
     
     
         3 . The perforation tool according to  claim 1 , wherein the dissolvable material comprises magnesium. 
     
     
         4 . The perforation tool according to  claim 1 , wherein the housing comprises between about 5 and about 50 holes. 
     
     
         5 . The perforation tool according to  claim 1 , wherein each hole has a cross section at the interior face of the housing of between about % and about % inch. 
     
     
         6 . The perforation tool according to  claim 1 , wherein the holes are arranged in a longitudinal spiral about the housing, each hole being radially disposed between 30° and 90° from a neighboring hole in the longitudinal spiral. 
     
     
         7 . The perforation tool according to  claim 1 , wherein the housing further comprises:
 a first section with a box thread to connect the housing to a first section of production casing; and   a second section with a pin thread to connect the housing to a second section of production casing.   
     
     
         8 . A method for fracturing a production zone, the method comprising the steps of:
 providing a perforation tool according to  claim 1  in a well proximal to the production zone;   dissolving one or more of the one or more dissolvable plugs; and   providing fluid to the production zone through holes with a dissolved plug to fracture the production zone.   
     
     
         9 . The method according to  claim 8 , wherein the dissolving step is performed at between about 2,000 and about 10,000 psi. 
     
     
         10 . The method according to  claim 8 , wherein the dissolving step is substantially completed within about 3-7 days. 
     
     
         11 . The method according to  claim 8 , wherein the tubular housing forms part of the production casing. 
     
     
         12 . The method according to  claim 8 , wherein the dissolving step is performed at between about 10 wt % and about 25 wt % chlorides. 
     
     
         13 . The method according to  claim 8 , wherein the dissolving step is performed at between about 0 wt % and about 10 wt % chlorides. 
     
     
         14 . The method according to  claim 8 , wherein the dissolving step comprises providing an acid to the dissolvable plugs. 
     
     
         15 . The method according to  claim 8 , further comprising the steps of:
 providing a second perforation tool according to  claim 1  in the well proximal to a second production zone;   dissolving one or more of the one or more dissolvable plugs of the second perforation tool; and   providing fluid to the second production zone through holes of the second perforation tool with a dissolved plug to fracture the second production zone.   
     
     
         16 . The method according to  claim 15 , further comprising the step of providing a diverter to the first perforation tool to prevent fluid flow to the first production zone. 
     
     
         17 . The method according to  claim 16 , wherein the providing the diverter step is performed simultaneously with the providing fluid to the first production zone. 
     
     
         18 . The method according to any  claim 15 , wherein the dissolvable plugs of the second perforation tool dissolve at a slower rate than the dissolvable plugs of the first perforation tool. 
     
     
         19 . The method according to  claim 15 , wherein the first production zone and the second production zone belong to a same formation. 
     
     
         20 . The method according to  claim 15 , wherein the step of dissolving one or more of the plurality of dissolvable plugs of the first perforation tool comprises providing a first dissolving fluid to the first perforation tool, and the step of dissolving one or more of the plurality of dissolvable plugs of the second perforation tool comprises providing a second dissolving fluid to the second perforation tool.