Class / Patent application number | Description | Number of patent applications / Date published |
175051000 | WITH SELF-ACTING CYCLIC ADVANCE AND RETRACTION OF TOOL OR TOOL SHAFT | 9 |
20080217059 | TRACTOR WITH IMPROVED VALVE SYSTEM - A hydraulically powered tractor includes an elongated body, two gripper assemblies, at least one pair of aft and forward propulsion cylinders and pistons, and a valve system. The valve system comprises an inlet control valve, a two-position propulsion control valve, a two-position gripper control valve, two cycle valves, and two pressure reduction valves. The inlet control valve spool includes a hydraulically controlled deactivation cam that locks the valve in a closed position, rendering the tractor non-operational. The propulsion control valve is piloted on both ends by fluid pressure in the gripper assemblies. The propulsion control valve controls the distribution of operating fluid to and from the propulsion cylinders, such that one cylinder performs a power stroke while the other cylinder performs a reset stroke. Each end of the gripper control valve is piloted by a source of high-pressure fluid selectively admitted by one of the cycle valves. The gripper control valve controls the distribution of operating fluid to and from the gripper assemblies. The cycle valves are spring-biased and piloted by fluid pressure in the propulsion cylinders, so that the gripper control valve shifts only after the cylinders complete their strokes. The pressure reduction valves limit the pressure within the gripper assemblies. These valves are spring-biased and piloted by the pressure of fluid flowing into the gripper assemblies. Some or all of the valves include centering grooves on the landings of the spools, which reduce leakage and produce more efficient operation. The propulsion control and gripper control valves include spring-assisted detents to prevent inadvertent shifting. | 09-11-2008 |
20080223616 | TRACTOR WITH IMPROVED VALVE SYSTEM - A hydraulically powered tractor adapted for advancement through a borehole including an elongate body, aft and forward gripper assemblies, and a valve control assembly housed within the elongate body. The aft and forward gripper assemblies are adapted for selective engagement with the inner surface of the borehole. The valve control assembly includes a gripper control valve for directing pressurized fluid to the aft and forward gripper assemblies. The valve control assembly also includes a propulsion control valve for directing fluid to an aft or forward power chamber for advancing the body relative to the actuated gripper assembly. Aft and forward mechanically actuated valves may be provided for controlling the position of the gripper control valve by detecting and signaling when the body has completed an advancement stroke relative to an actuated gripper assembly. Aft and forward sequence valves may be provided for controlling the propulsion control valve by detecting when the gripper assemblies become fully actuated. Furthermore, a pressure relief valve is preferably provided along an input supply line for limiting the pressure of the fluid entering the valve control assembly. | 09-18-2008 |
20080308318 | ELECTRICALLY POWERED TRACTOR - An electrically powered and controlled tractor system includes one or more electric gripper assemblies and one or more electric power train assemblies. Power and control signals for the gripper assemblies and power train assemblies can be delivered from a ground surface via a wireline. The gripper assembly employs a motor-activated lead screw and nut combination to expand passage-gripping elements, preferably by pushing the gripping elements radially outward from locations between opposing ends of the gripping elements. A failsafe mechanism can retract the gripping elements during a power interruption. The power train assembly employs a motor-activated lead screw and nut combination to expand and contract two ore more telescoping members. The tractor system can include multiple tractor units that each includes one gripper assembly and one power train assembly. A tractor can include one power train assembly and two gripper assemblies. | 12-18-2008 |
20080314639 | Dual Tractor Drilling System - The invention provides a drilling system for use in a borehole through an underground formation, comprising: | 12-25-2008 |
20100038138 | TRACTOR WITH IMPROVED VALVE SYSTEM - A hydraulically powered tractor adapted for advancement through a borehole including an elongate body, aft and forward gripper assemblies, and a valve control assembly housed within the elongate body. The aft and forward gripper assemblies are adapted for selective engagement with the inner surface of the borehole. The valve control assembly includes a gripper control valve for directing pressurized fluid to the aft and forward gripper assemblies. The valve control assembly also includes a propulsion control valve for directing fluid to an aft or forward power chamber for advancing the body relative to the actuated gripper assembly. Aft and forward mechanically actuated valves may be provided for controlling the position of the gripper control valve by detecting and signaling when the body has completed an advancement stroke relative to an actuated gripper assembly. Aft and forward sequence valves may be provided for controlling the propulsion control valve by detecting when the gripper assemblies become fully actuated. Furthermore, a pressure relief valve is preferably provided along an input supply line for limiting the pressure of the fluid entering the valve control assembly. | 02-18-2010 |
20100108387 | TRACTOR WITH IMPROVED VALVE SYSTEM - A hydraulically powered tractor includes an elongated body, two gripper assemblies, at least one pair of aft and forward propulsion cylinders and pistons, and a valve system. The valve system comprises an inlet control valve, a two-position propulsion control valve, a two-position gripper control valve, two cycle valves, and two pressure reduction valves. The inlet control valve spool includes a hydraulically controlled deactivation cam that locks the valve in a closed position, rendering the tractor non-operational. The propulsion control valve is piloted on both ends by fluid pressure in the gripper assemblies. The propulsion control valve controls the distribution of operating fluid to and from the propulsion cylinders, such that one cylinder performs a power stroke while the other cylinder performs a reset stroke. Each end of the gripper control valve is piloted by a source of high-pressure fluid selectively admitted by one of the cycle valves. The gripper control valve controls the distribution of operating fluid to and from the gripper assemblies. The cycle valves are spring-biased and piloted by fluid pressure in the propulsion cylinders, so that the gripper control valve shifts only after the cylinders complete their strokes. The pressure reduction valves limit the pressure within the gripper assemblies. These valves are spring-biased and piloted by the pressure of fluid flowing into the gripper assemblies. Some or all of the valves include centering grooves on the landings of the spools, which reduce leakage and produce more efficient operation. The propulsion control and gripper control valves include spring-assisted detents to prevent inadvertent shifting. | 05-06-2010 |
20140116779 | APPLICATION OF DOWNHOLE ROTARY TRACTOR - A towing string useful for positioning a towed assembly into a horizontal well bore includes a towed assembly coupled to a tractor assembly. The tractor assembly is operable to convert introduced energy into a pulling force that is directed downhole. The tractor assembly includes a disposable motor and a coupled rotary tractor. The rotary tractor has a rotating portion that is operable to rotate around a central axis of the rotary tractor and a rotary element that is operable to frictionally engage the well bore wall. A method for using the towing string for positioning the towed assembly in the horizontal section includes introducing the towing string into the horizontal well bore, operating the towing string such that the rotary element frictionally engages the well bore wall, and introducing energy to the towing string such that the tractor assembly provides a pulling force directed downhole. | 05-01-2014 |
20140190749 | DOWNHOLE DRILLING TOOL - A directional drilling tool includes a housing defining a central cavity for enabling the transmission of drilling fluid through the drill string. A motor contained in the housing includes a rotor-stator assembly, and produces eccentric motion of the rotor. An inverter or shock absorbing assembly disposed along the housing upstream from the motor functions to expend and contract the central cavity in response to fluid pressure changes produced by the drilling fluid flow. A valve assembly, comprising a multi-port flow head that rotates under influence of the motor and a multi-port flow restrictor, creates a varying pattern of pressure spikes in the drilling fluid as the ports of the flow head move into and out of alignment with the ports of the flow restrictor, which in turn induces a percussive effect and axial movement in the drill string. | 07-10-2014 |
20160076310 | TELESCOPIC MINI-RIG - A system and method are usable as a telescoping, small-scale oil rig, having the ability to rotate tubulars in a wellbore, pull tubulars from the wellbore, and insert tubulars into the wellbore. The system comprises a telescopic derrick section, a casing jack platform, and a base section. The telescopic derrick comprises U-shaped substructure frames that can be nested together, and is connected to an adjacent substructure through hydraulic cylinders. When pressurized, the cylinders extend to separate each substructure and raise the telescopic derrick. The casing jack platform comprises a traveling casing jack and spider for holding, inserting and removing tubulars. The base section supports the telescopic derrick and comprises a rotary floor and another spider for holding, inserting and removing tubulars into and from the wellbore. The combination of the traveling spider and stationary spider can be used for inserting tubulars into the wellbore when the well is under pressure. | 03-17-2016 |