Abstract: The present application relates to energy harvesting. More particularly, the present application relates to harvesting energy from non-stationary, multi-frequency mechanical vibrations using a tunable electrical circuit.

Abstract: Actuators, pumps, clutches, brakes and other assemblies may utilize field-responsive fluids that include a plurality of particles suspended in a base fluid. A positive displacement pump is provided by causing particles to align into chains and walls which inhibit traversal by fluid within a fluid enclosure. The field which aligns the particles is moved, thereby causing the walls of aligned particles to move. Because traversal of the walls by the fluid is inhibited, fluid is displaced by movement of the walls of aligned particles. A reciprocating positive displacement pump can be provided by ceasing particle alignment and returning the particles to a starting position. Objects may also be moved in response to collision with chains or walls of aligned particles that move in response to field movement. Fluid circulation features are provided for preventing agglomeration of particles when translating torque between plates in relative rotational movement.

Abstract: Apparatus and method comprising a plurality of particles which are magnetically attracted to one another in response to exposure to a magnetic field, and which maintain attraction to one another after removal of the magnetic field, the attraction being disabled when the particles are demagnetized, whereby the particles operate to alter the rheological properties of a fluid in which the particles are mixed when the attraction is enabled or disabled is disclosed.

Abstract: A mechanism for moving elements in a fluid filled housing using a pump with the element to be moved attached rigidly to the pump or to a port assembly connected to the pump. The pump assembly or port assembly moves as a result of differential pressure created between a first and a second chamber separated from each other by the pump assembly or port assembly. Movement of the fluid in one direction increases or decreases pressure, the pressure change resulting in a net force in one direction or the other.

Abstract: A field-responsive fluid which enters a semi-solid state in the presence of an energy field is improved by use of a plurality of energy field responsive particles which form chains in response to the energy field. The particles can be (a) composite particles in which at least one field-responsive member having a first density is attached to at least one member having a second density that is lower than the first density, (b) shaped particles in which at least one field-responsive member has one or more inclusions, and (c) combinations thereof. The particles improve the field-responsive fluid by reducing density without eliminating field-responsive properties which afford utility. Further, a multi-phase base fluid including a mixture of two or more substances, at least two of which are immiscible, may be used.

Abstract: Techniques are described for axial vibration control of wireline tools and cables during logging operations. In undesirable cases the axial vibrations may lead to or exasperate the stick-slip problems of the logging tool. Control systems and strategies to minimize vibrations are described. Techniques are also described for identifying and inhibiting the sticking of the cable. A described system includes a surface actuator and a sensor. The actuator generates an axial wave on the wireline cable which travels down the cable. If there is sticking of the cable, a reflection can also occur at the location of sticking. This shift in the transmission of the wave on the wireline cable is used to identify the onset and/or presence of sticking.

Abstract: The subject disclosure relates to energy harvesting. More particularly, the subject disclosure relates to harvesting energy from the relative motion between a rotary stabilizer and the drill string. In further embodiments, the subject disclosure relates to harvesting energy from vibrations in the drill string.

Abstract: The subject disclosure relates to methods of generating magnetic particles in a wellbore. More particularly, the subject disclosure relates to a fluid system which comprises two or more fluids which react chemically to generate magnetic particles in a wellbore.

Abstract: An actuator is disclosed which operates on the principle of the variable magnetic properties of materials with respect to temperature. As temperature is raised past Curie temperature, magnetic permeability of certain materials drops significantly to a value close to free space permeability. However, depending on the material selection, magnetic permeability may be significantly higher below Curie temperature. This principle is used to cause magnetic attractive force to move an actuator at one temperature, while permitting a return spring force to move the actuator at another temperature by changing the pathway traversed by most magnetic lines of flux from a magnetic source. The actuator may be employed to provide a temperature activated electrical switch or fluid valve. The temperature activated valves are suited to use in high temperature environments, such as SAGD wells.

Abstract: A mechanism for selectively activating a plurality of downhole pathways including a) a valve having: i) a sleeve coupled for movement between an open and normally closed position; and ii) a valve magnet set mounted to the sleeve; and b) a dart for pumping in hole including a dart magnet set matched to the valve magnet set such that the dart couples to the valve when in close proximity and, in turn, the sleeve moves from the closed position to the open position.

Abstract: Apparatus and methods comprising a plurality of particles which are magnetically attracted to one another in response to exposure to an magnetic field, and which maintain attraction to one another after removal of the magnetic field, the attraction being disabled when the particles are demagnetized, whereby the particles operate to alter the rheological properties of a fluid in which the particles are mixed when the attraction is enabled or disabled is disclosed.

Abstract: A technique is provided for pumping fluids in a subterranean wellbore. A submersible pumping system can be deployed in a wellbore for moving desired fluids within the wellbore. The pumping system energizes the desired fluid movement by reciprocating a working fluid between expandable members.

Abstract: A mechanism for moving elements in a fluid filled housing a pump with the element to be moved attached rigidly to the pump or to a port assembly connected to the pump. The pump assembly or port assembly moves as a result of differential pressure created between a first and a second chamber separated from each other by the pump assembly or port assembly. Movement of the fluid in one direction increases or decreases pressure, the pressure change resulting in a net force in one direction or the other.

Abstract: A technique is provided for pumping fluids in a subterranean wellbore. A submersible pumping system can be deployed in a wellbore for moving desired fluids within the wellbore. The pumping system energizes the desired fluid movement by reciprocating a working fluid between expandable members.

Abstract: The subject disclosure discloses an apparatus and method of conveying magnetic particles into a wellbore. A plurality of particles which are magnetically attracted to one another in response to exposure to a magnetic field are delivered downhole via a degradable material. The degradable material confines the particles and conveys the particles to a desired location downhole. The structure comprising the degradable material and the confined particles can be lowered into a subterranean well by a cable or wire, or alternatively released into the well under the influence of gravity and flow induced forces. The material degrades in response to conditions encountered in a subterranean environment thus releasing the particles.

Abstract: A mechanism for selectively activating a plurality of downhole pathways including a) a valve having: i) a sleeve coupled for movement between an open and normally closed position; and ii) a valve magnet set mounted to the sleeve; and b) a dart for pumping in hole including a dart magnet set matched to the valve magnet set such that the dart couples to the valve when in close proximity and, in turn, the sleeve moves from the closed position to the open position.

Abstract: A technique is provided for pumping fluids in a subterranean wellbore. A submersible pumping system can be deployed in a wellbore for moving desired fluids within the wellbore. The pumping system energizes the desired fluid movement by reciprocating a working fluid between expandable members.

Abstract: Apparatus and methods comprising a plurality of particles which are magnetically attracted to one another in response to exposure to an magnetic field, and which maintain attraction to one another after removal of the magnetic field, the attraction being disabled when the particles are demagnetized, whereby the particles operate to alter the rheological properties of a fluid in which the particles are mixed when the attraction is enabled or disabled is disclosed.

Abstract: An actuator is disclosed which operates on the principle of the variable magnetic properties of materials with respect to temperature. As temperature is raised past Curie temperature, magnetic permeability of certain materials drops significantly to a value close to free space permeability. However, depending on the material selection, magnetic permeability may be significantly higher below Curie temperature. This principle is used to cause magnetic attractive force to move an actuator at one temperature, while permitting a return spring force to move the actuator at another temperature by changing the pathway traversed by most magnetic lines of flux from a magnetic source. The actuator may be employed to provide a temperature activated electrical switch or fluid valve. The temperature activated valves are suited to use in high temperature environments, such as SAGD wells.

Abstract: Steerable drilling systems for facilitating drilling according to a prescribed, three-dimensional trajectory are described. Steering may be achieved using passive actuators which require little or no power. For example, damping elements which couple a drill bit to a drill collar can be used to tilt the drill bit with respect to the drill collar. Alternatively, rotary cutting elements disposed on the drill bit may be used to control the force between the drill bit and the formation at different axial locations. The passive elements used to control the tilt or rotation of the rotary cutting elements are actuated in a certain pattern, e.g., geostationary, in order to achieve a desired deviation of the well bore while drilling ahead. One way to achieve this is through the use of field-sensitive materials, e.g. magnetorheological (MR) fluids, that change viscosity in response to an applied magnetic field.