Prevention of wireline damage at a downhole window

Abstract

A bottom hole assembly (BHA) which is transported via a wireline through downhole and lateral wellbores and thence through a wellbore window aperture, the BHA carrying with it a blocking tool which is adapted to engage the edge of a lateral wellbore window and prevent the wireline from contacting and abrading against that edge of the window, the blocking tool being detachable from the BHA which proceeds axially distally through the wellbore window while the wireline slides through the blocking tool. Upon withdrawal of the BHA the blocking tool is reattached thereto and is removed with it.

1 . A method of reducing potential damage to a wireline having a BHA coupled to its distal end when said wireline is axially extended through and past edges of a window opening that extends from the outer to the inner side of the wall of a lateral wellbore, the BHA having a proximal and distal ends, the wireline and BHA having outer diameter less than that of said window, the method comprising the steps:
 a. removably coupling a blocking tool to the proximal end of said BHA,   b. coupling said BHA to the distal end of said wireline,   c. directing said wireline and BHA to said window in said lateral wellbore,   d. directing said blocking tool to expand to a diameter greater than the diameter of said window,   e. de-coupling said blocking tool from said BHA and allowing said wireline and BHA to axially enter and traverse said window and enter said wellbore while said blocking tool prevents said wireline and BHA from contacting said edges of said window   f. subsequently withdrawing said wireline and BHA outward through said window while said blocking tool continues to prevent said wireline and BHA from contacting said edges of said window, and   g. re-coupling said BHA to the proximal end of said blocking tool as said wireline and BHA are withdrawn through said window.   
     
     
         2 . The method of  claim 2  where said blocking tool has a body part and a plurality of arms with proximal ends pivotally coupled to said body part and distal ends, the arms having a closed position and said arms being movable to an extended position where said distal ends thereof are radially outward of said body part to define a diameter of said blocking tool greater than the diameter of said window, whereby said blocking tool is barred from entering into said window. 
     
     
         3 . The method of  claim 2  where said blocking tool comprises a drive mechanism to move said arms to said extended position and to subsequently withdraw said arms to said closed position. 
     
     
         4 . The method of  claim 2  where said drive mechanism further comprises spring elements biasing said arms toward said open position thereof, and said drive mechanism restrains said arms in said retracted position until directed to allow said spring elements to drive said arms to said open position. 
     
     
         5 . The method of  claim 1  where said BHA contains wellbore logging sensors that are capable of measuring and/or monitoring properties selected from the group consisting of resistivity, conductivity, formation pressure, acoustics, radioactivity, electromagnetic and nuclear magnetic resonance of strata and their contained liquids being investigated and/or monitored. 
     
     
         6 . A method of reducing the risk of potential damage to a wireline when it is axially extended through and past edges of a window opening that extends from the outer to the inner side of the wall of a lateral wellbore, the window opening being larger than the diameter of said wireline, the method comprising the steps:
 a. providing a blocking mechanism that has width greater than the size of the window opening,   b. positioning said blocking mechanism adjacent said outer side of said lateral wellbore adjacent said window, said blocking mechanism being barred from entering and traversing said window because of its diameter being larger than said window opening, and   c. with said blocking mechanism blocking said wireline from engaging said edges of said window as said wireline is directed to enter and pass through said window, and as said wireline is subsequently withdrawn out of said window.   
     
     
         7 . A bottom hole assembly (BHA) connectable to a wireline cable, the BHA having outer diameter D1 adapted to pass through a wellbore inner pipe of predetermined inner diameter Dp, the BHA comprising:
 a. a cylindrical housing having a proximal end connectable to said wireline and a distal end, and a maximum outer diameter D1 less than Dp, and   b. a blocking tool comprising:
 i. a body part having a central axis and a distal end releasably coupled to said proximal end of said housing, 
 ii. a maximum outer diameter D2 less than Dp, 
 iii. a central bore through which said wireline cable is axially slidable, 
 iv. a blocking part carried by said body part and movable from a closed position where said blocking part extends radially outward of said central axis a distance less than Dp, and has an open position where it extends radially outward a distance greater than Dp, and 
 v. a drive mechanism adapted to move said blocking part from said closed position to said open position, and further adapted to cause separation of said blocking tool from said cylindrical body while allowing said cable to remain slidable through said blocking tool when said cylindrical housing moves axially distally away from said blocking tool. 
   
     
     
         8 . A bottom hole assembly (BHA) connectable to a wireline cable, and operable to pass through a downhole wellbore contiguous with a lateral wellbore both having diameter DP, the lateral wellbore having a lateral window aperture of maximum diameter Dw, the BHA comprising:
 a. a cylindrical housing having a proximal end connectable to a wireline and a distal end, and a maximum outer diameter D1 less than Dp, and   b. a blocking tool comprising:
 i. a body part having a central axis and a distal end releasably coupled to said proximal end of said housing, 
 ii. a maximum outer diameter D2 less than Dp, 
 iii. a central bore through which said wireline cable is axially slidable, 
 iv. a blocking part carried by said body part and movable from a closed position where said blocking part extends radially outward of said central axis a distance less than Dp, and has an open position where it extends radially outward a distance greater than Dw, and 
 v. a drive mechanism adapted to move said blocking part from said closed position to said open position, and further adapted to cause separation of said blocking tool from said cylindrical body while allowing said cable to remain slidable through said blocking tool when said cylindrical housing moves axially distally away from said blocking tool. 
   
     
     
         9 . The BHA according to  claim 8  where said blocking part comprises a pair of arms having proximal ends pivotally coupled to said body part and distal ends said arms being movable to a position where said distal ends thereof are radially outward of said body part. 
     
     
         10 . A BHA according to  claim 9  where said pair of arms are spring biased toward said open position and are restrained by said drive mechanism in said closed position until said BHA begins to enter said wellbore window. 
     
     
         11 . The BHA according to  claim 8  where said blocking part comprises a plurality of arms having proximal ends pivotally coupled to said body part and distal ends said arms being movable to a position where said distal ends thereof are radially outward of said body part. 
     
     
         12 . A BHA according to  claim 8  where said BHA contains wellbore logging sensors are capable of measuring and/or monitoring properties selected from the group consisting of resistivity, conductivity, formation pressure, acoustics, radioactivity, electromagnetic and nuclear magnetic resonance of strata and their contained liquids being investigated and/or monitored. 
     
     
         13 . A method operable with a BHA as defined in  claim 8  that is entering a lateral wellbore window, comprising the steps to prevent said wireline from engaging any edge of said lateral wellbore window:
 a. directing said drive mechanism of said blocking tool to move said blocking part to said open position to have diameter greater than Dw of said window and to engage the edge of said window and thereby block entry of said blocking tool through said window, and 
 b. separating said blocking tool from said BHA while allowing said cable to remain slidable through said blocking tool and maintaining said cable spaced from engaging said window edge, as said BHA moves axially distally away from said blocking tool.