Downhole Tool

Abstract

A downhole tool ( 10′ ) comprises a body ( 12′ ) having a longitudinal axis and a body through-bore ( 14′ ), a slot ( 34′ ) communicating the outside of the body with the body through-bore. A sleeve actuator ( 30′ ) mandrel also has a bore and is selectively axially slidable in the body through-bore. A hollow bar ( 36′ ) is slidable with a radial component in the slot. At least two levers ( 210 ), each pivoted to the mandrel (about a first axis perpendicular the longitudinal axis) extend into the hollow bar and are pivoted thereto (about a second axis parallel the first axis). The levers lie in an actuation plane perpendicular the first and second axes and containing the slot. The levers are disposed at an inclined angle with respect to the longitudinal axis so that longitudinal motion of the mandrel translates into radial movement of the bar.

1 . A downhole tool comprising:
 a) a body having a longitudinal axis and a body through-bore, a slot communicating the outside of the body with the body through-bore;   b) a sleeve actuator mandrel having a sleeve actuator mandrel through-bore and being selectively axially slidable in the body through-bore;   c) a hollow bar slidable with a radial component in the slot; and   d) at least two levers, each pivoted to said sleeve actuator mandrel about a first axis, and each lever extending into said hollow bar and pivoted thereto about a second axis parallel said first axis, wherein an actuation plane of movement of said hollow bar on pivoting of the levers is perpendicular said first and second axes and contains said slot.   
   
   
       2 . A downhole tool as claimed in  claim 1 , in which the first and second pivot axes, at the intersection thereof with said actuation plane, define a parallelogram. 
   
   
       3 . A downhole tool as claimed in  claim 1 , in which said first and second axes are perpendicular to a line parallel to said longitudinal axis. 
   
   
       4 - 8 . (canceled) 
   
   
       9 . A downhole tool as claimed in  claim 1 , in which said sleeve actuator mandrel has a port therethrough which aligns with a jet in the body when the sleeve actuator mandrel is in its tool actuated position, whereupon the through-bore of the sleeve actuator is in fluid communication with said jet whereby drilling fluid under pressure in said mandrel through-bore is directed onto the well bore in the region of said bars. 
   
   
       10 . A downhole tool as claimed in  claim 1 , in which the axis of the slot is radial with respect to said longitudinal axis. 
   
   
       11 . A downhole tool as claimed in  claim 1 , in which seals between said sleeve actuator mandrel and body beyond both ends of said slot define, between them, and a bar seal around the bar in the slot, a chamber enclosing lubricating oil. 
   
   
       12 . A downhole tool as claimed in  claim 1 , in which the levers are captivated by pivot pins forming said first and second pivots between the levers and the sleeve actuator mandrel and the hollow bar respectively. 
   
   
       13 . A downhole tool as claimed in  claim 12 , in which said pivot pins are captured in blind bores in said hollow arms, said blind bores being formed by elements inserted in said hollow arms. 
   
   
       14 . A downhole tool as claimed in  claims 12 , in which a projection of said pivot pins in the direction of said second pivot axis intersects said bar seal. 
   
   
       15 . A downhole tool as claimed in  claim 13 , in which said elements are welded in said arms. 
   
   
       16 . A downhole tool as claimed in  claim 1 , in which the levers are pivoted to a flange connectable to the mandrel sleeve actuator. 
   
   
       17 . A downhole tool as claimed in  claim 16 , in which said flange is separate from the sleeve actuator mandrel but is locked thereon by circumferential dovetailed slots formed on a sector of the sleeve actuator mandrel adjacent an open sector thereof, and corresponding dovetails on the base of said flange engaged with said dovetailed slots of the sleeve actuator mandrel. 
   
   
       18 . A downhole tool as claimed in  claim 17 , in which the tool is assembled by inserting said flange engaged with said bar in said slot so that said dovetails bear against said open sectors of the sleeve actuator mandrel, and by rotating said mandrel so that said dovetail slots engage said dovetails, means being provided to prevent the sleeve actuator mandrel from rotating in the body during use. 
   
   
       19 . A downhole tool as claimed in  claim 18 , in which said rotation prevention means comprises a pin in the body extending into a slot in the sleeve actuator mandrel. 
   
   
       20 . A downhole tool as claimed in  1 , in which there are more than two of said levers in parallel. 
   
   
       21 - 22 . (canceled) 
   
   
       23 . A downhole tool as claimed in  claim 1 , in which there are a plurality, preferably three, of said bars and slots spaced around the longitudinal axis of the tool. 
   
   
       24 . A downhole tool as claimed in  claim 23 , in which said tool is an under-reamer and said bars are provided with cutting elements to effect under-reaming when the tool is actuated in a well bore having a pilot hole receiving the tool. 
   
   
       25 . A downhole tool as claimed in  claim 24 , in which said body is thickened in the region of said slots and bars to support said bars. 
   
   
       26 . A downhole tool as claimed in  claim 24 , in which said body has fins ahead of said slots having dimensions to match said pilot hole and bear against its surface and stabilise the tool, in use, said fins being provided with a hardened wear surface to minimise wear. 
   
   
       27 . A downhole tool as claimed in  claim 23 , in which the tool is an adjustable stabiliser, said bars being provided with hardened wear surfaces to minimise wear of the bars, in use. 
   
   
       28 . A downhole tool as claimed in  claim 1 , in which the tool is an azimuth controller, wherein one or more bars in one or more slots are arranged asymmetrically around the longitudinal axis of the tool. 
   
   
       29 . A downhole tool as claimed in  claim 28 , further comprising one or more static blades. 
   
   
       30 . A downhole tool comprising:
 a) a body having a longitudinal axis and a body through-bore, a slot communicating the outside of the body with the body through-bore;   b) a hollow bar slidable with a radial component in the slot;   c) a sleeve actuator having an actuator through-bore and being axially slidable in the body through-bore between a tool actuated position and a tool deactuated position;   d) a mandrel having a mandrel through-bore and being selectively axially slidable in the body through-bore between a tool actuated position, an interlock position and a sleeve-lock position; and wherein:   e) an extension of the mandrel is a close sliding fit inside a first end of the sleeve actuator;   f) said first end captivates a lock element;   g) said body has an internal groove positioned so that, when said sleeve actuator is in said tool deactuated position, said lock element is aligned with said groove and held in engagement therein by said extension while the mandrel is between its interlock and sleeve-lock positions;   h) said mandrel has an external recess positioned so that, when said mandrel is in said interlock position, said lock element is aligned with said recess, whereupon movement of the mandrel towards said tool actuated position releases said lock element from said groove permitting said sleeve actuator to be moved by the mandrel to said tool actuated position, said mandrel and sleeve actuator being locked together by the body holding said lock element in said recess between said interlock and tool actuated positions of the mandrel; and   i) at least two levers, each pivoted to said sleeve actuator mandrel about a first axis, and each lever extending into said hollow bar and pivoted thereto about a second axis parallel said first axis, wherein an actuation plane of movement of said hollow bar on pivoting of the levers is perpendicular said first and second axes and contains said slot.   
   
   
       31 . A downhole tool as claimed in any of  claims 30 , in which said lock element is a ball. 
   
   
       32 . A downhole tool as claimed in  claim 30 , in which seals between said sleeve actuator and body beyond both ends of said slot define, between them, and a bar seal around the bar in the slot, a chamber enclosing lubricating oil. 
   
   
       33 . A downhole tool as claimed in  claim 30 , in which the levers are captivated by pivot pins forming said first and second pivots between the levers and the sleeve actuator and the hollow bar respectively. 
   
   
       34 . A downhole tool as claimed in  claim 33 , in which said pivot pins are captured in blind bores in said hollow arms, said blind bores being formed by elements inserted in said hollow arms. 
   
   
       35 . A downhole tool as claimed in  claim 30 , in which the levers are pivoted to a flange connectable to the mandrel sleeve actuator. 
   
   
       36 . A downhole tool as claimed in  claim 30 , in which there are more than two of said levers in parallel. 
   
   
       37 . A downhole tool as claimed in  claim 30 , in which there are a plurality, preferably three, of said bars and slots spaced around the longitudinal axis of the tool. 
   
   
       38 . A downhole tool as claimed in  claim 37 , in which said tool is an under-reamer and said bars are provided with cutting elements to effect under-reaming when the tool is actuated in a well bore having a pilot hole receiving the tool. 
   
   
       39 . A downhole tool as claimed in  claim 38 , in which said body is thickened in the region of said slots and bars to support said bars. 
   
   
       40 . A downhole tool as claimed in  claim 38 , in which said body has fins ahead of said slots having dimensions to match said pilot hole and bear against its surface and stabilise the tool, in use, said fins being provided with a hardened wear surface to minimise wear. 
   
   
       41 . A downhole tool as claimed in  claim 37 , in which the tool is an adjustable stabiliser, said bars being provided with hardened wear surfaces to minimise wear of the bars, in use. 
   
   
       42 . A downhole tool as claimed in  claim 30 , in which the tool is an azimuth controller, wherein one or more bars in one or more slots are arranged asymmetrically around the longitudinal axis of the tool. 
   
   
       43 . A downhole tool as claimed in  claim 42 , further comprising one or more static blades. 
   
   
       44 . A downhole tool comprising:
 a) a body having a longitudinal axis and a body through-bore, a slot communicating the outside of the body with the body through-bore;   b) a sleeve actuator having an actuator through-bore and being axially slidable in the body through-bore between a tool actuated position and a tool deactuated position   c) a mandrel having a mandrel through-bore and being selectively axially slidable in the body through-bore between a tool actuated position, an interlock position and a sleeve-lock position;   d) a hollow bar slidable with a radial component in the slot;   e) at least two levers, each pivoted to said sleeve actuator mandrel about a first axis, and each lever extending into said hollow bar and pivoted thereto about a second axis parallel said first axis, wherein an actuation plane of movement of said hollow bar on pivoting of the levers is perpendicular said first and second axes and contains said slot.   f) first means to lock the sleeve actuator with respect to the body in said tool deactuated position and while said mandrel is between said interlock and sleeve-lock positions; and   g) second means to lock the sleeve actuator with respect to the mandrel and while said mandrel is between said interlock and tool actuated positions.   
   
   
       45 . A downhole tool as claimed in  claim 44 , in which said first and second means comprise a lock element captivated by the sleeve actuator and located in one of a groove in the body or a recess on the mandrel. 
   
   
       46 . A downhole tool as claimed in  claim 45 , in which alignment of said groove and recess occurs in said interlock position of the mandrel, which coincides with said tool deactuated position of the sleeve actuator. 
   
   
       47 . A downhole tool as claimed in  claim 44 , which said sleeve actuator has ports therethrough which align with jets in the body when the sleeve actuator is in its tool actuated position, whereupon the through-bore of the sleeve actuator is in fluid communication with said jets, and whereby drilling fluid under pressure in said body through-bore is directed into the well bore. 
   
   
       48 . A downhole tool as claimed in  claim 47 , further comprising a valve operated by the sleeve actuator to restrict drilling fluid flow through the tool past said jets. 
   
   
       49 . A downhole tool as claimed in  claim 44 , in which the levers are captivated by pivot pins forming said first and second pivots between the levers and the sleeve actuator and the hollow bar respectively. 
   
   
       50 . A downhole tool as claimed in  claim 49 , in which said pivot pins are captured in blind bores in said hollow arms, said blind bores being formed by elements inserted in said hollow arms. 
   
   
       51 . A downhole tool as claimed in  claim 44 , in which the levers are pivoted to a flange connectable to the mandrel sleeve actuator. 
   
   
       52 . A downhole tool as claimed in  claim 44 , in which there are more than two of said levers in parallel. 
   
   
       53 . A downhole tool as claimed in  claim 44 , in which there are a plurality, preferably three, of said bars and slots spaced around the longitudinal axis of the tool. 
   
   
       54 . A downhole tool as claimed in  claim 53 , in which said tool is an under-reamer and said bars are provided with cutting elements to effect under-reaming when the tool is actuated in a well bore having a pilot hole receiving the tool. 
   
   
       55 . A downhole tool as claimed in  claim 54 , in which said body is thickened in the region of said slots and bars to support said bars. 
   
   
       56 . A downhole tool as claimed in  claim 55 , in which said body has fins ahead of said slots having dimensions to match said pilot hole and bear against its surface and stabilise the tool, in use, said fins being provided with a hardened wear surface to minimise wear.