摘要:
Well tools including valves operable by low electrical input. One well tool includes a valve which controls fluid communication between pressure regions in a well, the valve including a rotatable member which is biased to rotate, and a brake or clutch which prevents rotation of the member. Another valve includes a barrier which separates reactants, with the valve being operable in response to the barrier being opened and the reactants thereby reacting with each other. Yet another valve includes a barrier which separates the pressure regions, and a control circuit which heats the barrier to a weakened state. Another valve includes a member displaceable between open and closed positions, a restraining device which resists displacement of the member, and a control device which degrades or deactivates the restraining device and thereby permits the member to displace between its open and closed positions, in response to receipt of a predetermined signal.
摘要:
A method for filling an annular area within a wellbore penetrated by a subterranean formation is provided. The method includes the steps of: (a) introducing a proppant into a wellbore to form a gravel pack of the proppant, wherein a specimen of the proppant has a non-globular and non-fibrous shape, and wherein the shape is further selected to provide the proppant the ability to bridge together such that the proppant has a maximum bridging span of at least 3 times larger than a largest overall dimension of the proppant specimen, where the maximum bridging span is the largest outlet hole diameter that the proppant can bridge under the weight of gravity; and (b) passing fluid through the gravel pack.
摘要:
Structures can be formed downhole by accumulating already existing materials and/or materials introduced into a well to perform a specified function. The formed structures may be used to obstruct fluid flow of production or injection fluids, carry mechanical loads, control electrical or magnetic properties of components, mechanically actuate a component, as well as others. The materials may be induced to form the specified structure, such as by application of a potential downhole. For example, electrical, magnetic, sonic, biological potentials, or a combination thereof may be established downhole to form specified structures in specified locations to perform specified functions.
摘要:
The invention provides a proppant for treating a subterranean formation penetrated by a wellbore, wherein a typical specimen of the proppant has a non-globular and non-fibrous shape. The invention also provides a method for stimulating a subterranean formation penetrated by a wellbore, the method comprising the steps of forming the treatment fluid and introducing the treatment fluid through the wellbore and into the subterranean formation at a sufficient pressure to fracture the formation.
摘要:
In some embodiments, an apparatus includes a tool to operate downhole. The tool includes a heater. The tool also includes a cooler. The tool includes a controller to control allocation of power between the heater and the cooler based on a temperature downhole, power usage, a time delay or a pressure downhole.
摘要:
The disclosure describes a method and apparatus for effectively communicating data along an acoustic transmission path. The method comprises driving an acoustic transmitter to send a data signal along the acoustic transmission path, where the signal is distorted by ambient noise. The distorted signal is input to a spaced apart plurality of sensors so that consequent time-delayed signals provide reinforcement of the basic signal and attenuation of the ambient noise component when combined.
摘要:
A downhole seal (50) includes an elastomeric element (98) operably to provide a seal between two downhole components. A strain sensor (102) is embedded in the elastomeric element (98). The strain sensor (102) has a mechanical flexibility that is substantially matched to the mechanical flexibility of the elastomeric element (98). The strain sensor (102) is operably connected to circuitry that is operable to identify changes in a property of the strain sensor (98) indicative of the strain being experienced by the strain sensor (98), which is representative of the strain experienced by the elastomeric element (98).
摘要:
An energy storage device for powering a downhole tool may be heated to an effective temperature to improve the operability of the energy storage device. The energy storage device may comprise, for example, a primary battery, a secondary battery, a fuel cell, a capacitor, or combinations thereof. The effective temperature to which the energy storage device is heated may be greater than an ambient temperature in the wellbore near the energy storage device. The energy storage device may be heated using various heat sources such as an ohmic resistive heater, a heat pump, an exothermic reaction, a power generator, a heat transfer medium, the energy storage device itself, a downhole tool, or combinations thereof. A thermal conductor may extend between the heat source and the energy storage device. Further, a thermal insulator may at least partially surround the heat source and the energy storage device.
摘要:
A system and method of damping fluid pressure waves in a subterranean well. In a described embodiment, pressure waves are damped by positioning a dampener in the well during a perforating operation. The dampener may attenuate the pressure waves by absorbing the pressure waves, flowing the pressure waves through viscously damping material, generating complementary pressure waves, changing a material phase, or by a combination of these methods.
摘要:
An electromechanical transducer formed by an electrical and mechanical combination of a piezoelectric device and a magnetostrictive device. The two devices are electrically coupled so that their capacitive and inductive reactances approach a balance to provide an essentially resistive combined input at a selected frequency. Efficiency of circuits driving the transducer is improved. The devices are mechanically coupled so that the mechanical outputs add or reinforce each other. Two transducer pairs may be used in a two frequency telemetry system with each pair tuned to one of the frequencies for optimal reactance balancing and transduction efficiency.