A pressure control device for use in an oil well is described. The pressure control device comprises a support member configured to be located on a mandrel or a tubular, the support member defining at least one conduit throughbore configured to receive a conduit and a flexible cup member mounted to the support member. In use, a conduit can pass through the pressure control device intact.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

A wellbore tool includes a rod with a plurality of rod sections. The rod is configured to be placed within a wellbore casing of a low-pressure hydrocarbon well. A plurality of sealing elements are positioned at a downhole end of the rod. Each sealing element is configured to provide a gas-tight seal between the sealing element and an inner wall of the wellbore casing. A handle positioned at an uphole end of the rod provides a hand grip for a user of the wellbore tool.

A wellbore tool includes a rod with a plurality of rod sections. The rod is configured to be placed within a wellbore casing of a low-pressure hydrocarbon well. A plurality of sealing elements are positioned at a downhole end of the rod. Each sealing element is configured to provide a gas-tight seal between the sealing element and an inner wall of the wellbore casing. A handle positioned at an uphole end of the rod provides a hand grip for a user of the wellbore tool.

A well tool assembly can include a well screen configured to filter fluid flow between an interior and an exterior of a tubular string, and an outflow control section that permits the fluid flow in an outward direction and prevents the fluid flow in an inward direction, the outflow control section including at least two outflow control valves arranged in series. A method can include installing a well tool assembly including a well screen, flowing a fluid from an exterior to an interior of a tubular string through the well screen and an inflow control valve of the well tool assembly, and flowing another fluid from the interior to the exterior of the tubular string through the well screen and at least one outflow control valve of the well tool assembly.

A well tool assembly can include a well screen configured to filter fluid flow between an interior and an exterior of a tubular string, and an outflow control section that permits the fluid flow in an outward direction and prevents the fluid flow in an inward direction, the outflow control section including at least two outflow control valves arranged in series. A method can include installing a well tool assembly including a well screen, flowing a fluid from an exterior to an interior of a tubular string through the well screen and an inflow control valve of the well tool assembly, and flowing another fluid from the interior to the exterior of the tubular string through the well screen and at least one outflow control valve of the well tool assembly.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

A downhole apparatus comprises a casing string with a removable plug therein to block flow therethrough. A flow barrier is positioned in the casing below the removable plug and the removable plug and the flow barrier defining a buoyancy chamber therebetween. A debris barrier positioned above the removable plug comprises a rigid annular ring with a flexible diaphragm covering the center opening defined by the annular ring.

A method of plugging a formation fracture includes drilling, with a drill string configured to flow drilling fluid, a wellbore, where, at a downhole location, the drilling fluid is lost through a formation fracture. The method also includes deploying, through the drill string, a plugging assembly to the downhole location of the wellbore. The plugging assembly includes a flexible fiber sheet releasably coupled to a pumpable dart such that when the plugging assembly reaches the downhole location, the flexible fiber sheet is released from the dart to flow, with the drilling fluid, to the formation fracture to at least partially overlay the formation fracture. The method also includes adding, to the drilling fluid, lost circulation material configured to accumulate on a portion of the flexible fiber sheet to at least partially fluidically plug the formation fracture.