Extended Reach Methods for Multistage Fracturing Systems

Abstract

A method and system of treating a horizontal wellbore having multiple production zones. A bottom hole assembly connected to coiled tubing is positioned within the horizontal wellbore. The friction between the casing of the horizontal wellbore and bottom hole assembly and coiled tubing may prevent the bottom hole assembly from traversing the entire length of the horizontal wellbore. After treating a zone within the wellbore, a flush fluid with a lubricant may be pumped down the annulus between the coiled tubing and the casing. The lubricant may reduce the coefficient of friction between the casing and the coiled tubing permitting the bottom hole assembly to travel farther into the horizontal wellbore. The bottom hole assembly may include a vibratory device that may be actuated to reduce the coefficient of friction between the casing and the coiled tubing permitting the bottom hole assembly to travel farther into the horizontal wellbore.

1 . A method of treating a horizontal wellbore comprising:
 positioning a bottom hole assembly within a horizontal wellbore adjacent a first production zone of the horizontal wellbore, the bottom hole assembly being connected to a coiled tubing string;   creating a flow path between the first production zone and an annulus between the coiled tubing string and a casing string of the horizontal wellbore;   pumping a first pad fluid down the annulus to the first production zone;   pumping a first treatment fluid down the annulus to the first production zone;   pumping a first flushing fluid down the annulus beyond the first production zone; and   reducing a coefficient of friction between the casing string and the coiled tubing string by pumping lubricant within the first flushing fluid.   
     
     
         2 . The method of  claim 1 , wherein reducing the coefficient of friction further comprise pumping fluid down an interior of the coiled tubing string to actuate a vibratory device connected to the coiled tubing string. 
     
     
         3 . The method of  claim 1 , wherein the first treatment fluid further comprises sand or proppant. 
     
     
         4 . The method of  claim 3 , wherein the pumping the first treatment fluid fractures the first production zone. 
     
     
         5 . The method of  claim 4 , wherein pumping the first flushing fluid moves proppant or sand into the fractures of the first production zone and substantially removes the proppant or sand from the horizontal wellbore adjacent the first production zone. 
     
     
         6 . The method of  claim 1 , further comprising modeling the reduction of the coefficient of friction between the casing string and the coiled tubing string between the first production zone and a second production zone. 
     
     
         7 . The method of  claim 6 , wherein the amount of lubricant pumped within the first flushing fluid is based on the modeling. 
     
     
         8 . The method of  claim 7 , wherein the amount of lubricant pumped within the first flushing fluid is a predicted amount to cover the casing between the first production and the second production zone. 
     
     
         9 . The method of  claim 7 , further comprising pumping fluid down the coiled tubing string to actuate a vibratory device connected to the coiled tubing string, wherein the actuation of the vibratory device is based on the modeling. 
     
     
         10 . The method of  claim 6 , further comprising positioning the bottom hole assembly adjacent the second production zone of the horizontal wellbore. 
     
     
         11 . The method of  claim 10 , wherein creating the flow path between the first production zone and the annulus further comprises moving a first sleeve to open a first port in the casing string. 
     
     
         12 . The method of  claim 11 , further comprising creating a flow path between the second production zone and the annulus. 
     
     
         13 . The method of  claim 12 , further comprising:
 pumping a second pad fluid down the annulus to the second production zone,   pumping a second treatment fluid down the annulus to the second production zone;   pumping a second flushing fluid down the annulus beyond the second production zone; and   reducing the coefficient of friction between the casing string and the coiled tubing string by pumping lubricant within the second flushing fluid.   
     
     
         14 . The method of  claim 13 , wherein the second pad fluid is substantially comprised of the first flushing fluid. 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . A method of treating a horizontal wellbore comprising:
 positioning a bottom hole assembly within a casing string of a horizontal wellbore adjacent a first production zone of the horizontal wellbore, the bottom hole assembly being connected to a coiled tubing string;   treating the first production zone;   reducing a coefficient of friction between the casing string and the coiled tubing string; and   moving the bottom hole assembly adjacent a second production zone of the horizontal wellbore.   
     
     
         20 . The method of  claim 19 , wherein treating the first production zone comprises pumping fluid down an annulus between the coiled tubing string and the casing string to fracture the first production zone. 
     
     
         21 . The method of  claim 20 , wherein reducing the coefficient of friction comprises actuating a vibratory tool. 
     
     
         22 . The method of  claim 21 , wherein the vibratory tool is a fluid hammer tool. 
     
     
         23 . The method of  claim 19 , wherein reducing the coefficient of friction comprises pumping flushing fluid down the annulus between the coiled tubing string and the casing string, the flushing fluid including a lubricant. 
     
     
         24 . The method of  claim 19 , further comprising treating the second production zone and reducing the coefficient of friction between the casing string and the coiled tubing string after treating the second production zone.