Downhole wireline tool

Abstract

The present invention relates to a downhole wireline tool for performing a machining operation, such as milling, in a well having a top, the downhole wireline tool having a longitudinal axis, a first end configured to be connected to a wireline and a second end forming a front of the tool facing away from the wireline along the longitudinal axis, the downhole wireline tool comprising a tool housing, a holding section having projectable parts configured to prevent a part of the downhole wireline tool from moving in a direction towards the top, a machining tool arranged in the front of the tool, and a rotation unit for rotating the machining tool, wherein the downhole wireline tool further comprises an oscillation device having a rotational stationary part being connected with the rotation unit and a rotational part being connected to the machining tool, the oscillation device being configured to provide an oscillating movement of the machining tool by oscillating the rotational part in relation to the rotational stationary part.

1 . A downhole wireline tool for performing a machining operation, such as milling, in a well having a top, the downhole wireline tool having a longitudinal axis, a first end configured to be connected to a wireline and a second end forming a front of the tool facing away from the wireline along the longitudinal axis, the downhole wireline tool comprising:
 a tool housing,   a holding section having projectable parts configured to prevent a part of the downhole wireline tool from moving in a direction towards the top,   a machining tool arranged in the front of the tool, and   a rotation unit for rotating the machining tool,   
       wherein the downhole wireline tool further comprises an oscillation device having a rotational stationary part being connected with the rotation unit and a rotational part being connected to the machining tool, the oscillation device being configured to provide an oscillating movement of the machining tool by oscillating the rotational part in relation to the rotational stationary part, and wherein the rotational stationary part and the rotational part of the oscillation device have serrations providing the oscillating movement. 
     
     
         2 . A downhole wireline tool according to  claim 1 , wherein the oscillation device is a mechanical oscillation device. 
     
     
         3 . A downhole wireline tool according to  claim 1 , wherein the rotational stationary part has a first end face abutting a second end face of the rotational part of the oscillation device, the first end face and/or the second end face having the serrations. 
     
     
         4 . A downhole wireline tool according to  claim 3 , wherein the first end face or the second end face has serrations, and the other of the first end face and the second end face has a cooperating part. 
     
     
         5 . A downhole wireline tool according to  claim 1 , wherein the serrations have a serration height of less than 5 mm along the longitudinal axis, preferably less than 2.5 mm. 
     
     
         6 . A downhole wireline tool according to  claim 1 , wherein the serrations have a triangular shape with an inclining face and a right face extending along the longitudinal axis. 
     
     
         7 . A downhole wireline tool according to  claim 1 , wherein the oscillation device is arranged in the tool housing. 
     
     
         8 . A downhole wireline tool according to  claim 1 , wherein the machining tool comprises bits for cutting or milling through scale or cement at least partly blocking the well. 
     
     
         9 . A downhole wireline tool according to  claim 1 , further comprising a rotational member driven by the rotation unit, the rotational member extending at least through the rotational stationary part of the oscillation device. 
     
     
         10 . A downhole wireline tool according to  claim 9 , wherein the rotational member comprises a first shaft part and a second shaft part connected via a coupling. 
     
     
         11 . A downhole wireline tool according to  claim 1 , further comprising a gearing unit arranged between the rotation unit and the machining tool. 
     
     
         12 . A downhole wireline tool according to  claim 1 , the holding section being configured to provide an axial force along the longitudinal axis away from the top. 
     
     
         13 . A downhole wireline tool according to  claim 1 , further comprising the holding section being a rolling anchor. 
     
     
         14 . A downhole wireline tool according to  claim 1 , further comprising a stroking tool providing an axial force along the longitudinal axis in relation to the holding section. 
     
     
         15 . A downhole wireline tool according to  claim 1 , wherein the holding section is a stationary anchor configured to anchor the downhole wireline tool along the longitudinal axis when the projectable parts are in a projected state engaging a wall of a borehole or a well tubular metal structure.