Apparatus and Method for Transitioning a Tool Around the Radius of a Whipstock with Internal Guide Channel

Abstract

A method for transitioning a rigid or semi-rigid tool around a whipstock having a curved internal guide channel. The apparatus and method entail the tool meeting specific proportion criteria relative to the narrowest part of the curved guide channel through which it must pass and relative to the length and width of the tool. In lateral borehole related applications, if the wider ends portions of the tool are of approximately the same diameter of the borehole, the tool can be stabilized as it travels through the guide channels and creates and transitions a lateral borehole. The disclosure is particularly suited to tools that are rotated through the curved whipstock and in certain applications offers such tools the benefit of a reduced number of segments or links and hence reduced costs and failure points. The method described herein can be used with a variety of tool types and for a variety of purposes and may increase the applicability of tools otherwise only feasible on wellbores of a larger diameter.

What is claimed is: 
     
         1 . A method to increase the effective length of a rigid or semi-rigid tool segment that can transition around the guide channel radius of a whipstock comprising:
 providing a whipstock having an internal guide channel having an inner diameter;   providing a tool segment having an overall length, an overall width, a mid portion and end portions;   passing the tool segment through the internal guide channel of the whipstock;   wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter ranges from 0.8:1 to 0.9999:1;   wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.25 to 1;   wherein the mid portion of the tool segment has a narrower width than its end portions.   
     
     
         2 . The method of  claim 1 , wherein the tool segment has an hourglass, barbell, or dogbone profile. 
     
     
         3 . The method of  claim 1 , wherein the tool segment end portions have a radiused or chamfered profile allowing the tool segment to transition around the tightest point of the whipstock without becoming jammed. 
     
     
         4 . The method of  claim 1 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.85. 
     
     
         5 . The method of  claim 1 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.90. 
     
     
         6 . The method of  claim 1 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.95. 
     
     
         7 . The method of  claim 1 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.30 to 1. 
     
     
         8 . The method of  claim 1 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.40 to 1. 
     
     
         9 . The method of  claim 1 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.50 to 1. 
     
     
         10 . A system to increase the effective length of a rigid or semi-rigid tool segment that can transition around the guide channel radius of a whipstock without becoming jammed comprising:
 a whipstock having an internal guide channel having an inner diameter;   a tool segment having an overall length, an overall width, a mid portion and end portions capable of passing through the internal guide channel of the whipstock;   wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter ranges from 0.8:1 to 0.9999:1;   wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.25 to 1;   wherein the mid portion of the tool segment has a narrower width than its end portions.   
     
     
         11 . The system of  claim 10 , wherein the tool segment has an hourglass, barbell, or dogbone profile. 
     
     
         12 . The system of  claim 10 , wherein the tool segment end portions have a radiused or chamfered profile allowing the tool segment to transition around the tightest point of the whipstock without becoming jammed. 
     
     
         13 . The system of  claim 10 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.85. 
     
     
         14 . The system of  claim 10 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.90. 
     
     
         15 . The system of  claim 10 , wherein the ratio of the maximum width of the tool segment to the narrowest portion of the internal guide channel inner diameter is at least 0.95. 
     
     
         16 . The system of  claim 10 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.30 to 1. 
     
     
         17 . The system of  claim 10 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.40 to 1. 
     
     
         18 . The system of  claim 10 , wherein the ratio of the tool segment overall length to the tool segment overall width is greater than 1.50 to 1.