A fluid control system includes a fluid control device configured to be connected to at least one of two casing elements in a well, for controlling a fluid flow between a bore of the fluid control device and a zone located outside the casing elements; and a tracer material located within an inner chamber of a body of the fluid control device, the tracer material being uniquely associated with the fluid control device. The fluid control device is configured to release, when activated, the tracer material out of the inner chamber.

A downhole tool includes a tubular, an inner valve assembly positioned in the tubular, and a body positioned radially between the inner valve assembly and the tubular, the body at least partially made from a bonding agent configured to secure the inner valve assembly in the tubular.

A frac dart including a pressure housing, a mechanical sensor disposed through the pressure housing, a contactor inside the pressure housing and in operable communication with the mechanical sensor, and an electrical counter disposed in the pressure housing and responsive in increments to movement of the mechanical sensor that closes the contactor.

A frac dart including a pressure housing, a mechanical sensor disposed through the pressure housing, a contactor inside the pressure housing and in operable communication with the mechanical sensor, and an electrical counter disposed in the pressure housing and responsive in increments to movement of the mechanical sensor that closes the contactor.

A technique facilitates pressure application downhole by locking a ball in place to prevent it from unseating even if the pressure is bled off. A ball seat is constructed with a locking feature for effectively capturing and retaining the ball once the ball is seated in the ball seat under sufficient pressure. According to an embodiment, the ball seat may be mounted at a desired position along an internal flow passage of a well string component. The ball seat comprises a throat section which is formed of a ductile material arranged in a suitable structure to enable a desired deformation upon receiving the ball under sufficient pressure. As the ball is pressed into the throat section, the material of the throat section deforms and partially springs back to resist movement of the ball in the uphole direction, thus capturing the ball in both the uphole direction and the downhole direction.

A subsea blind stab (100), comprises a stabbing part (110) for insertion into a hot stab receptacle, the stabbing part (110) including a housing, a central rod (150) slidably arranged within the housing and at least one fluid communication line from the external side of the stabbing part (110) to an internal fluid communication line (180) within the rod (150). The at least one fluid communication line is open in a first position of the rod (150) relative the housing and closed in a second position of the rod (150) relative the housing. The stab (100) further comprises a hollow body (120) attached to one end of the stabbing part (110); a piston (130) slidably arranged in the hollow body (120), with a spring element (160) arranged between the piston (130) and a spring attachment element (170) connected to the body. A first side of the piston (130) forms a fluid chamber (140) in the hollow body. The fluid chamber (140) is in fluid communication with the internal fluid communication line in the rod, and a second side of the piston (130) is exposed to a pressure of the surrounding environment.

A thermal expansion system for actuating a remote operated sleeve assembly to open and close ports in a housing for fluidly communicating between a bore of a tubular string in a wellbore to the formation utilizes actuation of a propellant charge to create expanding gas and heat in a combustion chamber to directly act on one side of a piston connected to an axially moveable sleeve supported in the housing to shift the sleeve in one direction. Ignition of another propellant charge in a combustion chamber on an opposing side of the piston is used to directly shift the sleeve in an opposing direction.

Gravity driven reverse circulator tools are provided and methods of using same. One tool has nested pipes that when fully nested close a hole in one of the pipes, but when the drillstring is lifted, the pipes partially separate under the force of gravity to expose the hole. The other embodiment is similar, but the hole is hook shaped (hook on top as in a walking cane) and a protrusion from the other pipe fits in the hole. Thus, both lifting and rotation are needed open the tool.

A downhole well tool assembly can include a perforator and a selectively openable and closable perforation plug discharge port. A method of perforating and treating multiple formation zones of a well in a single trip of a downhole well tool assembly into the well can include positioning the downhole well tool assembly at a zone, closing a perforation plug discharge port of the downhole well tool assembly, perforating the zone, treating the zone, opening the perforation plug discharge port, deploying perforation plugs into the well via the perforation plug discharge port, plugging perforations in the zone with the perforation plugs, positioning the downhole well tool assembly at a subsequent zone, closing the perforation plug discharge port, perforating the subsequent zone, and treating the subsequent zone.

A system and method of harvesting geothermal energy in a subterranean formation includes providing an injection wellbore that extends into the subterranean formation, positioning a plurality of selectively opening sleeves in the injection wellbore spaced apart the subterranean formation, providing at least one producing wellbore that extends into the subterranean formation in a predetermined location proximate to the injection wellbore, and fracturing the subterranean formation in a plurality of locations proximate to the plurality of selectively opening sleeves to enhance a fluid pathway between the injection wellbore and the at least one producing wellbore. Fluid is injected down the injection wellbore at a first temperature, and the fluid is produced from the at least one producing wellbore at a second temperature higher than said first temperature.