Drill string components resistant to jamming

Abstract

Aspects of the present invention include drill string components having a thread extending around a body. The leading end of the thread can have a configuration that resists jamming and cross-threading. In particular, the leading end of the thread can include a planar surface normal to the body. The leading end of the thread can provide an abrupt transition to full thread depth that helps reduce or eliminate cross-threading. The leading end of the thread can be oriented at an angle relative to the axis of the drill string component. When mating male and female threads are similarly structured, the mating threads slide together along an interface at the thread start face and are drawn into a fully thread-coupled condition. The thread starts may have full circumference mating with no jamming positions.

What is claimed is: 
     
         1 . A threaded drill string component that resists jamming and cross threading, comprising:
 a hollow body having a first end, an opposing second end, and a central axis extending through the hollow body; and   a thread positioned on the first end of the hollow body;   wherein:
 the thread comprises a plurality of helical turns extending along the first end of the hollow body, 
 the thread has a thread depth and a thread width, 
 the thread comprises a leading end proximate the first end of the hollow body, 
 the leading end of the thread is orientated at an acute angle relative to the central axis of the hollow body, and 
 the leading end of the thread faces toward the first end of the hollow body. 
   
     
     
         2 . The drill string component as recited in  claim 1 , wherein the leading end of the thread comprises a planar surface extending normal to the hollow body. 
     
     
         3 . The drill string component as recited in  claim 2 , wherein the planar surface of the leading end of the thread extends the full thread width. 
     
     
         4 . The drill string component as recited in  claim 1 , wherein the leading end of the thread has a height equal to the thread depth. 
     
     
         5 . The drill string component as recited in  claim 4 , wherein the thread width is greater than the thread depth. 
     
     
         6 . The drill string component as recited in  claim 5 , wherein thread width is at least two times the thread depth. 
     
     
         7 . The drill string component as recited in  claim 1 , wherein the acute angle is between approximately 15 degrees and approximately 75 degrees. 
     
     
         8 . The drill string component as recited in  claim 7 , wherein the acute angle is between approximately 30 degrees and approximately 60 degrees. 
     
     
         9 . The drill string component as recited in  claim 8 , wherein the acute angle is between approximately 40 degrees and approximately 50 degrees. 
     
     
         10 . The drill string component as recited in  claim 1 , wherein the hollow body is a thin-walled body having a wall thickness between approximately 5 percent and 15 percent of an outer diameter of the hollow body. 
     
     
         11 . The drill string component as recited in  claim 1 , wherein the first end comprises a box end and the thread comprises a female thread. 
     
     
         12 . The drill string component as recited in  claim 11 , further comprising
 a second thread positioned on the second end of the hollow body;   wherein:
 the second thread comprises a plurality of helical turns extending along the second end of the hollow body, 
 the second thread comprises a leading end proximate the second end of the hollow body, 
 the leading end of the second thread is orientated at an acute angle relative to the central axis of the hollow body, and 
 the leading end of the second thread faces toward the leading end of the hollow body. 
   
     
     
         13 . The drill string component as recited in  claim 12 , wherein the second end comprises a pin end and the second thread comprises a male thread. 
     
     
         14 . The drill string component as recited in  claim 1 , wherein the drill string component comprises one of a drill rod, a casing, an adaptor coupling, a reamer, a drill bit, a core lifter, a locking coupling, a landing ring, or a stabilizer. 
     
     
         15 . The drill string component as recited in  claim 1 , wherein the leading end of the thread is offset from the first end of the hollow body by a distance equal to or less than about the thread width. 
     
     
         16 . A threaded drill string component that resists jamming and cross threading, comprising:
 a body, a box end, an opposing pin end, and a central axis extending through the body;   a female thread positioned on the box end of the body, the female thread having a depth and a width;   a male thread positioned on the pin end of the body, the male thread having a depth and a width;   wherein:
 each of the female thread and the male thread comprises a leading end, 
 the leading end of each of the female thread and the male thread comprises a planar surface extending normal to the body, 
 the planar surface of the leading end of the female thread extends along the entire width and the entire depth of the female thread, and 
 the planar surface of the leading end of the male thread extends along the entire width and the entire depth of the male thread. 
   
     
     
         17 . The drill string component as recited in  claim 16 , wherein:
 each of the female thread and the male thread comprises a plurality of helical turns;   the leading end of the female thread faces toward the box end of the body; and   the leading end of the male thread faces toward the pin end of the body.   
     
     
         18 . The drill string component as recited in  claim 17 , wherein the planar surfaces of the female thread and the male thread each extend at an acute angle relative to the central axis of the body. 
     
     
         19 . The drill string component as recited in  claim 18 , wherein the acute angle is between approximately 15 degrees and approximately 75 degrees. 
     
     
         20 . The drill string component as recited in  claim 19 , wherein the drill string component comprises a drill rod. 
     
     
         21 . The drill string component as recited in  claim 20 , wherein the drill rod is hollow and thin-walled. 
     
     
         22 . A method of making a joint in a drill string without jamming or cross threading, comprising:
 inserting a pin end of a first drill string component into a box end of a second drill string component;   rotating the first drill sting component relative to the second drill string component and thereby abutting a planar leading end of a male thread on the pin end of the first drill string component against a planar leading end of a female thread on the box end of the second drill string component;   wherein the planar leading end of the male thread is oriented at an acute angle relative to a central axis of the first drill string component;   wherein the planar leading end of the female thread is oriented at an acute angle relative to a central axis of the second drill string component; and   sliding the planar leading end of the male thread against and along the planar leading end of the female thread guides the male thread into a gap between turns of the female thread.   
     
     
         23 . The method of making a joint in a drill string as recited in  claim 22 , wherein sliding the planar leading end of the male thread against and along the planar leading end of the female thread causes the first drill string component to rotate relative to the second drill string component due to the acute angle of the planar leading ends of the male and female threads. 
     
     
         24 . The method of making a joint in a drill string as recited in  claim 22 , further comprising automatically rotating and advancing the first drill sting component relative to the second drill string component. 
     
     
         25 . The method of making a joint in a drill string as recited in  claim 22 , wherein:
 the planar leading end of the female thread extends along an entire depth of the female thread;   the planar leading end of the male thread extends along an entire depth of the male thread;   when rotating the first drill sting component relative to the second drill string component the depths of the planar leading ends of the female thread and the male thread prevent jamming or wedging of the male and female threads.