Method and apparatus for milling openings in downhole structures

A milling string for use in a wellbore having a first structure, comprising:

• a support assembly having a first end and a second end;
• at least one mill supported by the support assembly between the first and second ends;
• and
• a deflection apparatus having an actuator unit attached to the support assembly to bend one portion of the support assembly with respect to another portion of the support assembly to deflect the at least one mill to engage the first structure to form an opening in the first structure.

A milling string for use in a wellbore having a first structure, comprising:

• a support assembly having a first end and a second end;
• at least one mill supported by the support assembly between the first and second ends;
• and
• a deflection apparatus attached to the support assembly to deflect the at least one mill to engage the first structure to form an opening in the first structure,
• wherein the deflection apparatus is powered by rotation of the shaft.

A milling string for use in a wellbore having a first structure, comprising:

• a support assembly having a first end and a second end;
• at least one mill supported by the support assembly between the first and second ends;
• and
• a deflection apparatus attached to the support assembly to deflect the at least one mill to engage the first structure to form an opening in the first structure,
• wherein the deflection apparatus comprises a hydraulic actuator unit including a longitudinally moveable first piston.

A milling string for use in a wellbore having a first structure, comprising:

• a support assembly having a first end and a second end;
• at least one mill supported by the support assembly between the first and second ends;
• a deflection apparatus attached to the support assembly to deflect the at least one mill to engage the first structure to form an opening in the first structure;
• and
• a feed actuator unit adapted to move the at least one mill longitudinally after engagement with the first structure.

A method for use in a wellbore lined with a liner, comprising:

• running a milling tool having at least one mill into the wellbore, the at least one mill mounted on a support assembly having a first portion and a second portion coupled by a pivot;
• deflecting the first and second portions to bend the first and second portions at the pivot with respect to each other so that the at least one mill engages the liner;
• and
• rotating the at least one mill to form an opening in the liner.

A method for use in a wellbore lined with a liner, comprising:

• running a milling tool having at least one mill into the wellbore;
• deflecting at least two portions of the milling tool with respect to each other so that the at least one mill engages the liner;
• rotating the at least one mill to form an opening in the liner;
• and
• longitudinally moving the at least one mill to cut an opening having a predetermined length.

A method for use in a wellbore lined with a liner, comprising:

• running a milling tool having at least one mill into the wellbore;
• deflecting at least two portions of the milling tool with respect to each other;
• cutting at least one slot in the liner with the at least one mill;
• and
• propagating electromagnetic waves through the at least one slot to make measurements in a formation proximal the liner.

A milling tool for use in a wellbore having a conduit therein, the tool comprising:

• a support member in the conduit;
• a shaft supported by the support member such that the axial position of the shaft is fixed by the support member;
• at least one mill mounted on the shaft;
• an actuator attached to selectively rotate the shaft;
• the support member, shaft, and mills comprising a string;
• at least one pivot point in the string, the at least one pivot point allowing rotational movement of the string;
• the string selectively rotatable between a run-in position and a deflected position in which the at least one mill is positioned for milling the conduit;
• and
• a control unit attached to the at least one mill having a feed unit adapted to axially move the at least one mill during milling.

A milling tool for milling a tubular structure in a well, comprising:

• a shaft having a support that may be set in the tubular structure;
• a mill on the shaft movable longitudinally relative to the support;
• and
• a connector coupled to the mill, the connector rotatable to enable the mill to form plural axial slots along the circumference of the tubular structure.

A milling tool for milling a conduit in a well, comprising:

• a shaft having a support that may be set in the conduit;
• and
• a mill on the shaft movable longitudinally relative to the support,
• wherein the shaft is adapted to bend in a predetermined orientation, and the mill is rotatably mounted on the shaft.

A milling tool for milling a conduit in a well, comprising:

• a shaft having a support that may be set in the conduit;
• and
• a mill on the shaft movable longitudinally relative to the support,
• wherein the mill is below the support.

Equipment for use in a wellbore, comprising:

• a conduit positioned in the wellbore;
• a milling string having at least a first portion and a second portion deflectable with respect to each other,
• at least one mill attached to the first portion,
• the milling string adapted to engage the at least one mill to the conduit to form an opening in the conduit by deflecting the first and second portions;
• and
• another mill attached to the second portion.