Abstract: Methods and apparatus according to which a first valve is opened, or kept open, the first valve being part of a wellhead including a flow component above the first valve. The method may further include detecting a state of the first valve and, in response to detecting the state of the first valve, metering an amount of grease to the first valve. In addition, or instead, the method may further include opening, or keeping open, a second valve, the second valve being operably coupled to the wellhead and positioned above the flow component, and, after opening, or keeping open, each of the first and second valves, detecting whether the second valve is open or closed, in response to detecting that the second valve is open, preventing the first valve from being closed, and in response to detecting that the second valve is closed, allowing the first valve to be closed.

Abstract: Methods and apparatus according to which a first valve is opened, or kept open, the first valve being part of a wellhead including a flow component above the first valve. The method may further include detecting a state of the first valve and, in response to detecting the state of the first valve, metering an amount of grease to the first valve. In addition, or instead, the method may further include opening, or keeping open, a second valve, the second valve being operably coupled to the wellhead and positioned above the flow component, and, after opening, or keeping open, each of the first and second valves, detecting whether the second valve is open or closed, in response to detecting that the second valve is open, preventing the first valve from being closed, and in response to detecting that the second valve is closed, allowing the first valve to be closed.

Abstract: Apparatus, systems, and methods according to which a launcher defines a central passageway and is adapted to launch an object into the central passageway so that the object enters an oil and gas wellbore. The launcher includes a cylinder rotatable about an axis between first and second angular positions, the cylinder defining a chamber into which the object is loadable when the cylinder is in the first angular position, and from which the loaded object is launchable when the cylinder is in the second angular position. A lubricator is extendable through, and retractable from, the central passageway of the launcher.

Abstract: A well stack connector has the following features. A drive ring is carried by a housing and is rotatable relative to the housing. A clamp is within the housing. The clamp is moveable between an engaged position and a disengaged position. In the engaged position, the clamp engages the first well device to the second well device. In the disengaged position, the clamp allows the first well device to become unrestrained from the second well device. A linkage is coupled to the drive ring, the housing and the clamp. The linkage is moveable, by rotation of the drive ring, between a first position supporting the clamp in the engaged position and a second position supporting the clamp in the disengaged position.

Abstract: A valve apparatus that includes a first containment area having a fluid disposed therein at a first fluid pressure and a second containment area disposed below the first containment area having a fluid disposed therein at a selective fluid pressure where the selective fluid pressure can be increased and decreased, the second containment area in fluid communication with the first containment area. The valve apparatus also includes a valve disposed between the fluid in the second containment area at the selective fluid pressure and the fluid in the first containment area at the first fluid pressure. The valve apparatus includes a third containment area disposed below the second containment area having a fluid disposed therein at a third fluid pressure wherein the third fluid pressure is higher than the first fluid pressure, the second containment area in fluid communication with the third containment area.

Abstract: Apparatus and methods for launching objects into a wellbore. The apparatus generally includes a first object container and a container actuator. The first object container includes first compartments. The container actuator is adapted to displace the first object container so that respective ones of the first compartments are sequentially aligned with an opening. When the respective ones of the first compartments are sequentially aligned with the opening, objects loaded into the respective ones of the first compartments are sequentially launchable through the opening and into the wellbore. In some embodiments, the apparatus further includes a second object container including second compartments and being positionable above the first object container so that the respective second compartments are aligned with the respective first compartments.

Abstract: While a fracturing stack on a well is at fracturing pressure, receiving a perforating string in a section of the center bore of the fracturing stack. The section is a section above a fracturing head of the fracturing stack. While the fracturing stack is at fracturing pressure, sealing the section of the center bore to maintain a fracturing pressure in and below the fracturing head. Equalizing pressure in the section to atmospheric pressure. Receiving, at atmospheric pressure, a well drop in the section. Equalizing pressure in the section to pressure in the fracturing stack below the section. Releasing the well drop into the center bore of the fracturing head and to the well.

Abstract: Apparatus and methods for launching objects into a wellbore. The apparatus generally includes a first object container and a container actuator. The first object container includes first compartments. The container actuator is adapted to displace the first object container so that respective ones of the first compartments are sequentially aligned with an opening. When the respective ones of the first compartments are sequentially aligned with the opening, objects loaded into the respective ones of the first compartments are sequentially launchable through the opening and into the wellbore. In some embodiments, the apparatus further includes a second object container including second compartments and being positionable above the first object container so that the respective second compartments are aligned with the respective first compartments.

Abstract: Apparatus, systems, and methods according to which a launcher defines a central passageway and is adapted to launch an object into the central passageway so that the object enters an oil and gas wellbore. The launcher includes a cylinder rotatable about an axis between first and second angular positions, the cylinder defining a chamber into which the object is loadable when the cylinder is in the first angular position, and from which the loaded object is launchable when the cylinder is in the second angular position. A lubricator is extendable through, and retractable from, the central passageway of the launcher.

Abstract: A valve apparatus that includes a first containment area having a fluid disposed therein at a first fluid pressure and a second containment area disposed below the first containment area having a fluid disposed therein at a selective fluid pressure where the selective fluid pressure can be increased and decreased, the second containment area in fluid communication with the first containment area. The valve apparatus also includes a valve disposed between the fluid in the second containment area at the selective fluid pressure and the fluid in the first containment area at the first fluid pressure. The valve apparatus includes a third containment area disposed below the second containment area having a fluid disposed therein at a third fluid pressure wherein the third fluid pressure is higher than the first fluid pressure, the second containment area in fluid communication with the third containment area.

Abstract: A well stack connector has the following features. A drive ring is carried by a housing and is rotatable relative to the housing. A clamp is within the housing. The clamp is moveable between an engaged position and a disengaged position. In the engaged position, the clamp engages the first well device to the second well device. In the disengaged position, the clamp allows the first well device to become unrestrained from the second well device. A linkage is coupled to the drive ring, the housing and the clamp. The linkage is moveable, by rotation of the drive ring, between a first position supporting the clamp in the engaged position and a second position supporting the clamp in the disengaged position.

Abstract: A valve apparatus that includes a first containment area having a fluid disposed therein at a first fluid pressure and a second containment area disposed below the first containment area having a fluid disposed therein at a selective fluid pressure where the selective fluid pressure can be increased and decreased, the second containment area in fluid communication with the first containment area. The valve apparatus also includes a valve disposed between the fluid in the second containment area at the selective fluid pressure and the fluid in the first containment area at the first fluid pressure. The valve apparatus includes a third containment area disposed below the second containment area having a fluid disposed therein at a third fluid pressure wherein the third fluid pressure is higher than the first fluid pressure, the second containment area in fluid communication with the third containment area.

Abstract: An apparatus may include a float member and an output line. The float member is configured in contacting adjacency to first and second liquids contained in a container. The first liquid is less dense than the second liquid such that the first liquid floats on top of the second liquid. The float member may have a specific gravity selected responsive to the first and second liquids. When the second liquid is pulled from the container through the output line to a predetermined level, the float member occludes the output line. The specific gravity of the float member may be selected based on the fluid in the container previously, currently, or in the future, or some combination of the three. The specific gravity of the float member may be adjusted by changing material within the float member or changing the float member itself from a plurality of float members.

Abstract: Apparatus and methods for launching objects into a wellbore. The apparatus generally includes a first object container and a container actuator. The first object container includes first compartments. The container actuator is adapted to displace the first object container so that respective ones of the first compartments are sequentially aligned with an opening. When the respective ones of the first compartments are sequentially aligned with the opening, objects loaded into the respective ones of the first compartments are sequentially launchable through the opening and into the wellbore. In some embodiments, the apparatus further includes a second object container including second compartments and being positionable above the first object container so that the respective second compartments are aligned with the respective first compartments.

Abstract: Apparatus and methods for launching objects into a wellbore. The apparatus generally includes a first object container and a container actuator. The first object container includes first compartments. The container actuator is adapted to displace the first object container so that respective ones of the first compartments are sequentially aligned with an opening. When the respective ones of the first compartments are sequentially aligned with the opening, objects loaded into the respective ones of the first compartments are sequentially launchable through the opening and into the wellbore. In some embodiments, the apparatus further includes a second object container including second compartments and being positionable above the first object container so that the respective second compartments are aligned with the respective first compartments.

Abstract: While a fracturing stack on a well is at fracturing pressure, receiving a perforating string in a section of the center bore of the fracturing stack. The section is a section above a fracturing head of the fracturing stack. While the fracturing stack is at fracturing pressure, sealing the section of the center bore to maintain a fracturing pressure in and below the fracturing head. Equalizing pressure in the section to atmospheric pressure. Receiving, at atmospheric pressure, a well drop in the section. Equalizing pressure in the section to pressure in the fracturing stack below the section. Releasing the well drop into the center bore of the fracturing head and to the well.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail.

Abstract: A valve apparatus that includes a first containment area having a fluid disposed therein at a first fluid pressure and a second containment area disposed below the first containment area having a fluid disposed therein at a selective fluid pressure where the selective fluid pressure can be increased and decreased, the second containment area in fluid communication with the first containment area. The valve apparatus also includes a valve disposed between the fluid in the second containment area at the selective fluid pressure and the fluid in the first containment area at the first fluid pressure. The valve apparatus includes a third containment area disposed below the second containment area having a fluid disposed therein at a third fluid pressure wherein the third fluid pressure is higher than the first fluid pressure, the second containment area in fluid communication with the third containment area.

Abstract: In accordance with some embodiments, an apparatus may include a float member and retention member. The retention member is configured to retain the float member in fluid communication with at least one fluid in an interior of a container. The float member in a first position in relation to the retention member limits the at least one fluid from leaving the interior of the container, and the float member in a different, second position in relation to the retention member promotes the at least one fluid leaving the interior of the container. The retention member is in substantially the same relative position to the container in the first position and the second position.

Abstract: A controlled aperture ball drop includes a ball cartridge that is mounted to a frac head or a high pressure fluid conduit. The ball cartridge houses a ball rail having a bottom end that forms an aperture with an inner periphery of the ball cartridge through which frac balls of a frac ball stack supported by the ball rail are sequentially dropped from the frac ball stack as a size of the aperture is increased by an aperture controller operatively connected to the ball rail.