Method and apparatus for operations in underground subsea oil and gas wells
AssigneeBakke Technology AS
InventorStig Bakke
Life of this patent
Estimating the term…
Abstract
A method and apparatus for advancing a rotating motorized downhole tool for operations in oil/gas wells. The apparatus is adapted for drilling and milling away of casing sections in the wells, as preparation for plugging the same. The apparatus includes a rotating tool and a driving motor indirectly suspended on coiled tubing. The apparatus also includes a carriage connected to the motor adapted to absorb torques that occur during use. The carriage is connected to the coiled tubing via a swivel coupling such that a tensile force on the coiled tubing provides an advancing force for the tool and motor.
Claims17
An apparatus adapted for advancement into a well bore, the apparatus comprising;
- an advancable rotating downhole tool;
- a driving motor;
- coiled tubing having a lower end thereof indirectly connected to the driving motor wherein the coiled tubing minimally absorbs torques;
- an elongated carriage comprising a first and a second carriage sections and provided with rotatable driving wheels of fixed orientation, orientated in the longitudinal direction of the carriage, said carriage being equipped with end couplings, one for connection to a free outer end of said coiled tubing through a swivel device, and one for connection to the tool;
- and
- a pulling device connected to the coiled tubing for pulling on the coiled tubing for advancing purposes wherein each wheel is positioned and grouped in longitudinal rows within each longitudinal carriage section, the radial central plane of the wheels being in a transversal plane in the respective carriage section, dividing the circumference of the respective carriage section into two halves, and is displaceable in a transversal direction of the carriage through its direct connection to a cylinder-and-piston device in order to be carried by an adjusted/controllable compressive force into friction-creating abutment on an adjacent surrounding internal casing surface or formation wall surface defining the well bore.
A method of removing a casing structure in the interior of a well bore, the method comprising:
- attaching a generally elongate tool to a first end of a generally elongate carriage having extensible supports contained therein;
- attaching an opposite second end of the carriage to a free end of a string such that the carriage can swivel with respect to the string;
- inserting the tool and the carriage into the interior of a well at least partially lined with a casing;
- inducing the extensible supports into contact with the interior of the well bore;
- and
- applying a tensile force to the carriage via the string so as to induce the tool to dislodge the casing such that torque reactions generated by the action of the tool are transmitted via the carriage to the well bore.
Dependencies are inferred from the claim text.