Dual Tunneling and Fracturing Stimulation System

Abstract

Arrangements and methods for acid tunneling and fracturing within a wellbore. Acid is flowed into a wellbore to form a lateral tunnel which extends radially outwardly from the main wellbore. Thereafter, a fracturing bottom hole assembly is run into the lateral tunnel and isolated. Acid is then injected into the lateral tunnel to fracture portions of the formation radially surrounding the lateral tunnel.

What is claimed is: 
     
         1 . An acid tunneling and fracturing arrangement for creation of a lateral tunnel and fracturing a formation around the lateral tunnel, the arrangement comprising:
 a running string for disposing a bottom hole assembly into a wellbore;   a bottom hole assembly affixed to the running string, the bottom hole assembly having:
 an acid placement tool for transmitting acid from the running string for injection into the formation; and 
 a packer assembly to be set within the lateral tunnel to secure the acid placement tool within. 
   
     
     
         2 . The acid tunneling and fracturing arrangement of  claim 1  wherein the acid placement tool further comprises:
 a base portion; and 
 an acid injection wand which is connected to the base portion by at least one articulable joint which permits angular movement between the wand and the base portion. 
 
     
     
         3 . The acid tunneling and fracturing arrangement of  claim 1  wherein the bottom hole assembly further comprises:
 an indexing tool which permits angular rotation of portions of the bottom hole assembly with respect to the running string within the wellbore. 
 
     
     
         4 . The acid tunneling and fracturing arrangement of  claim 2  wherein the acid injection wand further comprises:
 a wand body which defines a fluid flow passage within; 
 an end nozzle disposed through the wand body to permit fluid communication from the fluid flow passage to areas external to the distal end of the wand body; 
 a lateral nozzle disposed through the wand body to permit fluid communication from the fluid flow passage to areas external to a lateral side of the wand body; and 
 a sliding sleeve member disposed within the fluid flow passage and moveable between a first position, wherein the sliding sleeve member blocks the lateral nozzle against fluid flow, and a second position, wherein the sliding sleeve member does not ii block the lateral nozzle against fluid flow therethrough. 
 
     
     
         5 . The acid tunneling and fracturing arrangement of  claim 4  wherein the sliding sleeve member is moveable by landing a ball or plug member upon a ball seat within the fluid flow passage. 
     
     
         6 . The acid tunneling and fracturing arrangement of  claim 4  wherein the sliding sleeve member is moveable by a linear actuator. 
     
     
         7 . The acid tunneling and fracturing arrangement of  claim 1  further comprising:
 at least one sensor within the bottom hole assembly to detect a downhole wellbore parameter; 
 a controller having programming for determining a location or orientation of the bottom hole assembly within the wellbore based upon the downhole parameter; and 
 a data communications conduit to transmit data representative of the downhole parameter detected by the sensor to the controller. 
 
     
     
         8 . The acid tunneling and fracturing arrangement of  claim 1  further comprising:
 a supply of acid to be flowed through the running string to the bottom hole assembly for use in tunneling or fracturing; and 
 a fluid pump to flow acid through the running string, the fluid pump being a variable speed or variable capacity pump. 
 
     
     
         9 . An acid tunneling and fracturing arrangement for creation of a lateral tunnel and fracturing a formation around the lateral tunnel, the arrangement comprising:
 a coiled tubing running string for disposing a bottom hole assembly into a wellbore;   a bottom hole assembly affixed to the running string, the bottom hole assembly having:
 an acid placement tool for transmitting acid from the running string for injection into the formation; and 
 a packer assembly to be set within the lateral tunnel to secure the acid placement tool within. 
   
     
     
         10 . The acid tunneling and fracturing arrangement of  claim 9  wherein the acid placement tool further comprises:
 a base portion; and 
 an acid injection wand which is connected to the base portion by at least one articulable joint which permits angular movement between the wand and the base portion. 
 
     
     
         11 . The acid tunneling and fracturing arrangement of  claim 9  wherein the bottom hole assembly further comprises:
 an indexing tool which permits angular rotation of portions of the bottom hole assembly with respect to the running string within the wellbore. 
 
     
     
         12 . The acid tunneling and fracturing arrangement of  claim 10  wherein the acid injection wand further comprises:
 a wand body which defines a fluid flow passage within; 
 an end nozzle disposed through the wand body to permit fluid communication from the fluid flow passage to areas external to the distal end of the wand body; 
 a lateral nozzle disposed through the wand body to permit fluid communication from the fluid flow passage to areas external to a lateral side of the wand body; and 
 a sliding sleeve member disposed within the fluid flow passage and moveable between a first position, wherein the sliding sleeve member blocks the lateral nozzle against fluid flow, and a second position, wherein the sliding sleeve member does not block the lateral nozzle against fluid flow therethrough. 
 
     
     
         13 . The acid tunneling and fracturing arrangement of  claim 9  further comprising:
 at least one sensor within the bottom hole assembly to detect a downhole wellbore parameter; 
 a controller having programming for determining a location or orientation of the bottom hole assembly within the wellbore based upon the downhole parameter; and 
 a data communications conduit to transmit data representative of the downhole parameter detected by the sensor to the controller. 
 
     
     
         14 . The acid tunneling and fracturing arrangement of  claim 9  further comprising:
 a supply of acid to be flowed through the running string to the bottom hole assembly for use in tunneling or fracturing; and 
 a fluid pump to flow acid through the running string, the fluid pump being a variable speed or variable capacity pump. 
 
     
     
         15 . The acid tunneling and fracturing arrangement of  claim 12  wherein:
 the sliding sleeve member is moveable by landing a ball or plug member upon a ball seat within the fluid flow passage or by a linear actuator. 
 
     
     
         16 . A method of acid tunneling and fracturing a wellbore, the method comprising:
 running an acid tunneling and fracturing arrangement into the wellbore until a bottom hole assembly of the arrangement is located proximate a desired location within the wellbore;   flowing acid to the bottom hole assembly to form a lateral tunnel within the wellbore;   disposing at least a portion of the bottom hole assembly within the lateral tunnel; and   flowing acid to the bottom hole assembly to fracture portions of the formation which radially surround the lateral tunnel.   
     
     
         17 . The method of  claim 16  further comprising the step of:
 isolating the portion of the bottom hole assembly within the wellbore by setting a packer within the lateral tunnel. 
 
     
     
         18 . The method of  claim 16  wherein:
 acid is flowed to the bottom hole assembly to fracture portions of formation at a greater flow rate than acid is flowed to the bottom hole assembly to form the lateral tunnel. 
 
     
     
         19 . The method of  claim 16  further comprising:
 prior to flowing acid to the bottom hole assembly to fracture portions of the formation, diverting fluid flow from end nozzles in the bottom hole assembly to lateral nozzles to allow acid fracturing through the lateral nozzles. 
 
     
     
         20 . The method of  claim 16  further comprising:
 sensing at least one downhole parameter within the wellbore with a sensor; 
 transmitting data representative of the downhole parameter detected by the sensor to a controller; 
 using the transmitted data to adjust a portion of the step to form a lateral tunnel or the step to fracture portions of the formation.