Stress-buffer release lever and downhole plugging apparatus

Abstract

The present invention discloses a stress-buffer release lever, which comprises an outer lever and an inner lever; the outer lever consists of a front end and a back end, wherein external threads are provided on both ends of the outer lever; a weakened section is set between the front end and the back end of outer lever; a co-axial through-hole is provided inside the outer lever, and internal threads are set on an inner surface of the through-hole; the inner lever's outer surface is provided with an external thread, the inner lever is set within the through-hole of the outer lever and is connected to the outer lever by the threads; the tensile strength of the inner lever is lower than that of the outer lever. The current invention also discloses a downhole plugging apparatus.

What is claimed is: 
     
         1 . A stress-buffer release lever, comprising:
 an outer lever  9  and an inner lever  10 , wherein the outer lever  9  consists of a front end  91  and a back end  92 , external threads are threaded on both the front end  91  and the back end  92 ;   a weakened section  93  is provided between the front end  91  and the back end  92 ;   a coaxial through-hole  94  is provided inside the outer lever  9 , wherein an interior surface of the through-hole is internally threaded;   an external thread is threaded on an outer surface of the inner lever  10 , wherein the inner lever  10  is arranged in the through-hole  94  of the outer lever  9  and is connected to the outer lever  9  by threading; and,   a tensile strength of inner lever  10  is lower than that of the outer lever  9 .   
     
     
         2 . According to  claim 1 , the stress-buffer release lever further comprising: the weakened section  93  is an annular groove on the outer lever  9 . 
     
     
         3 . According to  claim 2 , the stress-buffer release lever further comprising:
 a cross-section of the annular groove is semicircle-shaped.   
     
     
         4 . According to  claim 2 , the stress-buffer release lever further comprising:
 The cross section of the annular groove is U-shaped.   
     
     
         5 . According to  claim 1 , the stress-buffer release lever further comprising: the outer lever  9  is made of hard alloy steel, the inner lever  10  is made of copper. 
     
     
         6 . According to  claim 2 , the stress-buffer release lever further comprising: the outer lever  9  is made of hard alloy steel, the inner lever  10  is made of copper. 
     
     
         7 . According to  claim 3 , the stress-buffer release lever further comprising: the outer lever  9  is made of hard alloy steel, the inner lever  10  is made of copper. 
     
     
         8 . According to  claim 4 , the stress-buffer release lever further comprising: the outer lever  9  is made of hard alloy steel, the inner lever  10  is made of copper. 
     
     
         9 . A downhole plugging apparatus, comprising:
 (a) a mandrel  1 ;   (b) a seal assembly set on the mandrel  1 ;   (c) an upper anchor assembly and (d) a lower anchor assembly, both of which are connected to the upper and the lower end of the mandrel  1 , respectively;   (e) a stress-buffer release lever that is connected to the top of mandrel  1  by threading;   the stress-buffer release lever includes an outer lever  9  and an inner lever  10 ,   Wherein the outer lever consists of a front end  91  and a back end  92 , external threads are threaded on both ends, and the back end  92  is connected to a upper end of the mandrel  1  by threading, and, a weakened section  93  is set between the front end  91  and the back end  92  of outer lever  9 ;   a coaxial through-hole  94  inside the outer lever  9 , and internal thread was provided on an inner surface of the coaxial through-hole  94 , wherein an external thread is threaded on an outer surface of the inner lever  10 , and the inner lever  10  is arranged within the through-hole  94  of the outer lever  9  and is connected to the outer lever  9  by threading; and,   a tensile strength of inner lever  10  is lower than that of the outer lever  9 .   
     
     
         10 . According to  claim 9 , the downhole plugging apparatus further comprises: the weakened section  93  is an annular groove on the outer lever  9 . 
     
     
         11 . According to  claim 10 , the downhole plugging apparatus further comprises: a cross-section of the annular groove is semicircle-shaped or U-shaped. 
     
     
         12 . According to  claim 9 , the downhole plugging apparatus further comprises: the outer lever  9  is made of hard alloy steel; the said inner lever  10  is made of copper. 
     
     
         13 . According to  claim 10 , the downhole plugging apparatus further comprises: the outer lever  9  is made of hard alloy steel; the said inner lever  10  is made of copper. 
     
     
         14 . According to  claim 11 , the downhole plugging apparatus further comprises: the outer lever  9  is made of hard alloy steel; the said inner lever  10  is made of copper. 
     
     
         15 . According to  claim 9 , the downhole plugging apparatus further comprises:
 the upper anchor assembly comprises (a) a upper lock nut  2  which is connected to threads  101  at an upper end of the mandrel  1 , (b) a stripper ring  3  that contacts the upper lock nut  2 , (c) a plurality of slips  4  that contact the stripper ring  3  and (d) a conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly;   the said lower anchor assembly comprises (a) a lower lock nut  8  which is connected to the threads  101  at a lower end of the mandrel  1 , (b) the plurality of the slips that contact the lower lock nut  8 , (c) the conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly.   
     
     
         16 . According to  claim 10 , the downhole plugging apparatus further comprises:
 the upper anchor assembly comprises (a) a upper lock nut  2  which is connected to threads  101  at an upper end of the mandrel  1 , (b) a stripper ring  3  that contacts the upper lock nut  2 , (c) a plurality of slips  4  that contact the stripper ring  3  and (d) a conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly;   the said lower anchor assembly comprises (a) a lower lock nut  8  which is connected to the threads  101  at a lower end of the mandrel  1 , (b) the plurality of the slips that contact the lower lock nut  8 , (c) the conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly.   
     
     
         17 . According to  claim 11 , the downhole plugging apparatus further comprises:
 the upper anchor assembly comprises (a) a upper lock nut  2  which is connected to threads  101  at an upper end of the mandrel  1 , (b) a stripper ring  3  that contacts the upper lock nut  2 , (c) a plurality of slips  4  that contact the stripper ring  3  and (d) a conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly;   the said lower anchor assembly comprises (a) a lower lock nut  8  which is connected to the threads  101  at a lower end of the mandrel  1 , (b) the plurality of the slips that contact the lower lock nut  8 , (c) the conical slip holder  5  that contact the slips  4 , and the conical slip holder  5  also contacts the seal assembly.