Indexing tool for coiled tubing

Abstract

An indexing tool for use with flexible coiled tubing in downhole applications to clear obstructions is provided. The indexing tool includes a housing having a central longitudinal bore. A plunger having a longitudinal axis and biased by a spring is received and movable longitudinally within the bore between retracted and extended positions. A channel formed on the plunger receives channel followers in the form of guide pins to cause the plunger to rotate about its longitudinal axis as the plunger is moved between the retracted and extended position. A limiting member of the plunger engages stop members to limit the movement of the plunger beyond the retracted and extended position, so the guide pins do not bear the longitudinal forces exerted on plunger. The guide pins are also provided with a head having a seating surface to facilitate tightening of the guide pins and to prevent further insertion of the guide pins.

I claim:  
     
         1 . An indexing device for use with coiled tubing in downhole applications for directing the tubing around downhole obstructions, the device comprising: 
 a housing adapted for securing to a length of coiled tubing, the housing having a longitudinal cylindrical internal bore;    a plunger having a longitudinal axis that is received within the internal bore and is moveable longitudinally within the internal bore between a retracted and extended position, the plunger having a channel that extends around at least a portion of the circumference of the plunger, the channel having opposite extents which are longitudinally spaced apart from each other;    a biasing member disposed within the housing for biasing the plunger toward one of the retracted and extended positions;    a channel follower that engages the channel as the plunger is moved between the retracted and extended positions, the channel follower causing the plunger to be rotated about the longitudinal axis as the plunger is moved between the retracted and extended positions;    a limiting member joined to the plunger; and    first and second stop members that each engage the limiting member when the plunger is moved between the extended and retracted positions, respectively, so that movement of the plunger beyond the extended and retracted positions is prevented, and wherein the channel follower is prevented from fully contacting the extents of the channel when the plunger is moved to the extended and retracted positions.    
     
     
         2 . The device of  claim 1 , wherein: 
 a fluid passage is formed through the housing and plunger to allow the passage of fluid through the indexing device.    
     
     
         3 . The device of  claim 1 , further comprising: 
 a tool connector that is coupled to the plunger for coupling a desired tool to the indexing device.    
     
     
         4 . The device of  claim 1 , wherein: 
 the housing has width of from 1 to 1.5 inches.    
     
     
         5 . The device of  claim 1 , wherein: 
 cycling of the plunger from a first extended or retracted position to a second extended or retracted position, respectively, causes the plunger to rotate about the longitudinal axis within a range of from 30 degrees to 120 degrees.    
     
     
         6 . The device of  claim 5 , wherein: 
 the range is from 72 degrees to 120 degrees.    
     
     
         7 . The device of  claim 1 , wherein: 
 the tool connector has a longitudinal axis that is at an angle of greater than zero degrees relative to the longitudinal axis of the plunger.    
     
     
         8 . The device of  claim 1 , wherein: 
 the channel follower includes a guide pin having a head and a shank extending from the head, the shank having a threaded portion, which is received within and engages an aperture formed in a wall of the housing, and a non-threaded channel engagement portion, the head of the guide pin having a stop flange that abuts against an exterior surface of the housing wall to limit insertion of the guide pin through the aperture and to facilitate securing of the guide pin within the aperture, the channel engagement portion projecting from an interior surface of the housing into the internal bore.    
     
     
         9 . The device of  claim 8 , wherein: 
 the exterior surface of the housing wall has a recessed portion in communication with the aperture, the head of the guide pin being received within the recessed portion.    
     
     
         10 . The device of  claim 1 , wherein: 
 the biasing member is a coiled spring.    
     
     
         11 . The device of  claim 1 , wherein: 
 the biasing member exerts a biasing force on the plunger of from 30 lbs to 100 lbs.    
     
     
         12 . The device of  claim 1 , wherein: 
 there are two channel followers.    
     
     
         13 . A method for directing coiled tubing around a downhole obstruction, the method comprising: 
 securing an indexing device to a length of the coiled tubing, wherein the indexing device includes: 
 (a) a housing with a longitudinal cylindrical internal bore;  
 (b) a plunger having a longitudinal axis that is received within the internal bore and is moveable longitudinally within the internal bore between a retracted and extended position, the plunger having a channel that extends around at least a portion of the circumference of the plunger, the channel having opposite extents which are longitudinally spaced apart from each other;  
 (c) a biasing member disposed within the housing for biasing the plunger toward one of the retracted and extended positions;  
 (d) a channel follower that engages the channel as the plunger is moved between the retracted and extended positions, the channel follower causing the plunger to be rotated about the longitudinal axis as the plunger is moved between the retracted and extended positions;  
 (e) a limiting member joined to the plunger; and  
 (f) first and second stop members that each engage the limiting member when the plunger is moved between the extended and retracted positions, respectively, so that movement of the plunger beyond the extended and retracted positions is prevented, and wherein the channel follower is prevented from fully contacting the extents of the channel when the plunger is moved to the extended and retracted positions;  
   securing a well tool to the plunger of the indexing device;    directing the coiled tubing assembly formed from the length of coiled tubing with the indexing device and well tool secured thereto downhole within a wellbore until an obstruction is encountered; and    alternately forcing the coiled tubing assembly against the obstruction and retracting the coiled tubing assembly from the obstruction so that the plunger is cycled from a first extended or retracted position to a second extended or retracted position, respectively, and wherein the plunger is rotated about the longitudinal axis to reorient the well tool secured thereto to bypass the obstruction.