Abstract: A technique facilitates automatic shut-in of a well and disconnect of a corresponding landing string. The landing string is employed in a well application and comprises a landing string module which measures a parameter or a variety of parameters. Those parameters may be used to determine the occurrence of an event which initiates shut-in of the well and disconnect of the landing string. The subsea landing string system is constructed to enable autonomous shut-in and disconnect.

Abstract: A technique facilitates valve operations in many applications including well related applications. A valve utilizes a piston which moves along an arc. The valve has an outer housing and an inner housing spaced to create an arcuate pressure chamber which extends along the arc. A piston is mounted in the arcuate pressure chamber for movement along the arc. A hydraulic force or other force may be selectively applied directly against an end of the arcuate piston to shift the arcuate piston along the arc. In some applications, the piston comprises a cutting edge oriented to enable performance of a cutting operation.

Abstract: A technique facilitates failsafe closure of a valve used in, for example, a subsea test tree. The technique utilizes a valve combined with a cutter oriented to sever well equipment passing through an interior passage of the valve. The valve is operatively coupled with an actuation system having an actuator piston which controls cutting and valve closure. The failsafe valve and the cutter are shifted to an open position by applying pressure in a control fluid chamber to shift the actuator piston. However, the actuator piston, and thus the valve and cutter, are biased toward a closed position via pressure applied in a pressure chamber and a gas precharge chamber. The combined pressure ensures adequate force for shearing of the well equipment and closure of the valve when hydraulic control pressure is lost. In some applications, additional closing force may be selectively provided to the actuator piston.

Abstract: Systems and methods for using propellant as a force generator in component actuation are disclosed. One embodiment may take the form of a method including deploying at least one component to a subsea location, controlling operation of the at least one component using a control system, and igniting a propellant. The ignition of the propellant actuates the at least one component. Another embodiment may take the form of a subsea system including a control system, a propellant system in communication with the control system, and a component in communication with the propellant system. The propellant system is ignitable by the control system upon receipt of a ignite signal and upon losing communication with the control system after being placed in an armed state by the control system. The component is actuatable by the propellant system after ignition of the propellant system.

Abstract: A technique facilitates failsafe closure of a valve used in, for example, a subsea test tree. The technique utilizes a valve combined with a cutter oriented to sever well equipment passing through an interior passage of the valve. The valve is operatively coupled with an actuation system having an actuator piston which controls cutting and valve closure. The failsafe valve and the cutter are shifted to an open position by applying pressure in a control fluid chamber to shift the actuator piston. However, the actuator piston, and thus the valve and cutter, are biased toward a closed position via pressure applied in a pressure chamber and a gas precharge chamber. The combined pressure ensures adequate force for shearing of the well equipment and closure of the valve when hydraulic control pressure is lost. In some applications, additional closing force may be selectively provided to the actuator piston.

Abstract: A technique includes deploying an untethered object though a passageway of a string in a well; and sensing a property of an environment of the string, an electromagnetic coupling or a pressure as the object is being communicated through the passageway. The technique includes selectively autonomously operating the untethered object in response to the sensing.

Abstract: A technique facilitates fluid flow control with respect to a fluid flowing through a component of a landing string by avoiding or protecting mechanisms otherwise susceptible to debris. A valve is provided in a well component of a landing string and comprises a flexible element. The flexible element is oriented for flexing in an inward direction with respect to an internal flow passage through the landing string. The flexible element enables selective closing off of the internal flow passage without exposing certain types of mechanical mechanisms to fluid flowing through the landing string.

Abstract: A tensions compensator assembly for a slip type joint in an offshore work string. The assembly includes a chamber at the joint which is constructed in a manner to offset or minimize a pressure differential in a production channel that runs through the work string. Thus, potentially very high pressures running through the string are less apt to prematurely force actuation and expansiveness of the slip joint. Rather, the expansive movement of the joint is more properly responsive to heave, changes in offshore platform elevation and other outside forces of structural concern.

Abstract: Systems and methods for using propellant as a force generator in component actuation are disclosed. One embodiment may take the form of a method including deploying at least one component to a subsea location, controlling operation of the at least one component using a control system, and igniting a propellant. The ignition of the propellant actuates the at least one component. Another embodiment may take the form of a subsea system including a control system, a propellant system in communication with the control system, and a component in communication with the propellant system. The propellant system is ignitable by the control system upon receipt of a ignite signal and upon losing communication with the control system after being placed in an armed state by the control system. The component is actuatable by the propellant system after ignition of the propellant system.

Abstract: A technique facilitates valve operations in many applications including well related applications. A valve utilizes a piston which moves along an arc. The valve has an outer housing and an inner housing spaced to create an arcuate pressure chamber which extends along the arc. A piston is mounted in the arcuate pressure chamber for movement along the arc. A hydraulic force or other force may be selectively applied directly against an end of the arcuate piston to shift the arcuate piston along the arc. In some applications, the piston comprises a cutting edge oriented to enable performance of a cutting operation.

Abstract: A technique that is usable with a well includes deploying a plurality of location markers in a passageway of the well and deploying an untethered object in the passageway such that the object travels downhole via the passageway. The technique includes using the untethered object to sense proximity of at least some of the location markers as the object travels downhole, and based on the sensing, selectively expand its size to cause the object to become lodged in the passageway near a predetermined location.

Abstract: A system and methodology facilitates utilization of a valve of a type which may be used as a subsea test tree. The valve comprises a valve element pivotably mounted in a housing having a passageway therethrough. The valve element may be actuated between an open position and a closed position blocking the passageway. A cutter is disposed along a first surface of the valve element and a seal system is positioned for engagement with a second surface of the valve element to provide separate cutting and sealing surfaces. Actuating the valve element from the open position to the closed position enables cutting of a conveyance, that may be positioned through the passageway, while simultaneously forming a seal along a separate surface to sealingly block the passageway.

Abstract: A technique provides for stimulating or otherwise treating multiple intervals/zones of a well by controlling flow of treatment fluid via a plurality of flow control devices. The flow control devices are provided with internal profiles and flow through passages. Mechanical darts are designed for engagement with the internal profiles of specific flow control devices, and each mechanical dart may be moved downhole for engagement with and activation of the specific flow control device associated with that mechanical dart.

Abstract: An explosive pellet for characterizing a fracture in a subterranean formation is provided. The pellet can include a casing having a detonation material and an explosive material disposed within the casing. The pellet can also include a nonexplosive material moveably disposed within the casing. Movement of the nonexplosive material can generate a predetermined amount of energy in the form of friction-generated heat sufficient to detonate the explosive material.

Abstract: Methods include introducing a casing into a wellbore penetrating a subterranean formation, the casing forming an annulus with the wellbore surface, where the casing is subject to a first pressure value at a distal end and a second pressure value at a proximal region within the casing, and where a shoe is positioned at the distal end of the casing. Then, placing a sealable valve within the proximal region of the casing, injecting a first cement composition into the casing, through the sealable valve and shoe, and into the annulus, and the placing a second cement composition in a medial region of the tubular formed between the distal end and the proximal region. Afterward, the sealable valve is closed.

Abstract: An apparatus usable with a well includes an explosive pellet that is adapted to be communicated into the well via a fluid and includes an explosive material that is adapted to be detonated downhole in the well. The apparatus further includes an encapsulant to encapsulate the explosive pellet to inhibit unintended detonation of the explosive material. The encapsulant is adapted to be at least partially removed from the explosive pellet in response to the explosive pellet being communicated into the well.

Abstract: A technique provides for stimulating or otherwise treating multiple intervals/zones of a well by controlling flow of treatment fluid via a plurality of flow control devices. The flow control devices are provided with internal profiles and flow through passages. Hydraulic darts are designed for selective engagement with the internal profiles of specific flow control devices, and each hydraulic dart may be moved downhole for engagement with and activation of a specific flow control device.

Abstract: Systems and methods for fracturing multiple zones in a wellbore are provided. Cement can be pumped through a work string into a first annulus formed between a liner and a wall of the wellbore. One or more first contact valves in the liner can be opened with the work string. Fluid can flow through the work string and the one or more first contact valves to fracture a first zone. One or more second contact valves in the liner can be opened with the work string. Fluid can flow through the work string and the one or more second contact valves to fracture a second zone.

Abstract: A downhole tool for generating power is provided that includes a conductive fluid disposed downhole within a tubular member, an energy harvesting apparatus, and a pressure changing apparatus. The energy harvesting apparatus includes a magnet configured to generate a magnetic field and an electrical conductor configured to move with respect to the magnet. The pressure changing apparatus is configured to supply a differential pressure across the energy harvesting apparatus, such that the electrical conductor moves with respect to the magnet.

Abstract: Compositions, apparatus incorporating a composition, and methods of use are described, one composition embodiment consisting essentially of one or more reactive metals in major proportion, and one or more alloying elements in minor proportion, with the provisos that the composition is high-strength, controllably reactive, and degradable under defined conditions. Compositions of the invention may exist in a variety of morphologies, including a reactive metal or degradable alloy processed into an alloy of crystalline, amorphous or mixed structure that may constitute the matrix of other composition, for instance a composite. Methods of using apparatus comprising a composition, particularly in oilfield operations are also described (e.g. flow and displacement control, sensors, actuators). This abstract allows a searcher or other reader to quickly ascertain the subject matter of the disclosure. It will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).