Oil tool release joint

A release tool for coupling pipe string segments within a subsurface hole comprising:

• (a) a top sub for coupling to a first string segment, the top sub having a longitudinal axis and a bore substantially along the longitudinal axis;
• (b) a bottom sub for coupling to a second downhole string segment, the bottom sub having a longitudinal axis and a bore substantially along the longitudinal axis, the bottom sub being connectable to the top sub so that the top and bottom sub bores are substantially aligned;
• (c) means on each sub for transmitting motion rotational about the longitudinal axis from the top sub to the bottom sub;
• and
• (d) means for retaining the subs in connection with each other and capable of releasing the subs from each other upon the application of a first force pulling the subs apart in the absence of a substantial increase in fluid pressure within said bore.

A release tool comprising:

• (a) a top sub having a longitudinal axis, a bore substantially along the axis, and means for coupling the top sub to a drill string at one end of the axial bore, the other end of the bore comprising a pin;
• (b) a bottom sub having a longitudinal axis, a bore substantially along the axis, means for coupling the bottom sub to a downhole tool at one end of the bore, and an opening opposite the coupling means for receiving the pin end of he top sub opposite the coupling so that the axial bores of the subs are substantially aligned;
• (c) means for retaining the top sub pin end within the opening and capable of releasing the top sub pin end in response to hydraulic pressure in the bore and an axial force independent of said hydraulic pressure;
• (d) a plurality of axial splines on the bottom sub outside and proximate the opening and extending away from the coupling means;
• and
• (e) a plurality of axial slots on the top sub pin end for receiving the splines when the top sub pin end is within the bottom sub opening and for transmitting motion rotational about the longitudinal axis between the subs.

A method of running in a liner in a well comprising:

• (a) attaching a liner to a release sub of a setting and release tool and attaching the setting assembly of the setting and release tool to a drill pipe string forming a work string;
• (b) running the liner into position in the well by rotating the work string and providing a force generally aligned along a well axis direction;
• (c) after the liner is in the desired position anchoring the liner in the well;
• and
• (d) releasing the release sub from the setting assembly by increasing the hydraulic pressure and applying an upwell force independent of said hydraulic pressure in the pipe string to separate the release sub away from the setting assembly.

A release tool for releasably coupling duct segments during insertion of coupled duct segments into a subsurface hole, said tool comprising:

• a top sub and a bottom sub, each of said subs having a bore substantially along a longitudinal axis when the subs are coupled;
• means for attaching a top bore end of said top sub to a first duct segment;
• means for attaching a bottom bore end of said bottom sub to a second duct segment;
• means for coupling unattached ends of said subs;
• wherein said coupling means, when coupled, is capable of transmitting from said top end to said bottom end a rotational force and up to a pulling apart longitudinal force, wherein a majority of said pulling-apart force is substantially independent of said rotational force;
• and
• wherein said coupling means is capable of releasing said subs from each other when said pulling-apart longitudinal force is applied to said subs in the absence of an increased fluid pressure in said bore.

A method of inserting a first duct segment into a hole using a releasably coupled tool having a bore along a longitudinal axis and also using a second duct segment, said method comprising:

• (a) attaching a first duct segment end to a coupled tool end and a second segment end to a generally distal end of said coupled tool, said coupled tool bore and duct segments forming a fluid passageway;
• (b) inserting said coupled segments into said hole;
• (c) applying a tensile or compressive force to said coupled tool along said longitudinal axis during at least a portion of said inserting step, wherein said tensile force is less than a tensile limit value and said compressive force is less than a compressive limit value;
• (d) applying a rotating force and rotating said coupled segments in a first rotational direction during at least a portion of said inserting step, wherein said rotating force is less than a rotating limit value;
• and
• (e) after said inserting step, uncoupling said tool by applying a tensile force sufficient to longitudinally uncouple said segments, wherein the magnitude of said compressive limit value is larger than said tensile limit value and a majority of said tensile force is substantially independent of said rotating force and independent of fluid pressure in said fluid passageway.

A release tool comprising:

• (a) a top sub having a fluid passageway passing therethrough;
• (b) a bottom sub having a fluid passageway passing therethrough;
• (c) releasable coupling means for coupling the two subs together and allowing fluid at a first pressure in one of the two passageways to communicate with the other passageway, said coupling means being capable of transmitting axial forces between the two subs and being capable of uncoupling in the absence of a change in said first fluid pressure;
• and
• (d) transmitting means for transmitting rotational forces when said subs are coupled, wherein said transmitting means is substantially independent of said coupling means.