A well system includes a drilling vessel, a concentric drillstring extending from the vessel into a subterranean wellbore disposed beneath a mudline, wherein the concentric drillstring is configured to circulate a drilling fluid from the drilling vessel into the wellbore along a first passage, and to circulate the drilling fluid from the wellbore to the drilling vessel along a second passage, and a subsea pump in fluid communication with the wellbore, wherein the subsea pump is configured to manage fluid pressure in the wellbore by controlling a height of a column of hydrostatic fluid disposed in the wellbore.

A well system includes a drilling vessel, a concentric drillstring extending from the vessel into a subterranean wellbore disposed beneath a mudline, wherein the concentric drillstring is configured to circulate a drilling fluid from the drilling vessel into the wellbore along a first passage, and to circulate the drilling fluid from the wellbore to the drilling vessel along a second passage, and a subsea pump in fluid communication with the wellbore, wherein the subsea pump is configured to manage fluid pressure in the wellbore by controlling a height of a column of hydrostatic fluid disposed in the wellbore.

A downhole tool for use in a well comprising a mandrel and an outer sleeve slidably disposed about the mandrel. An inner sleeve is slidably disposed in the mandrel. A drive pin comprising a drive pin bushing connected to the outer sleeve and a shear pin connected to the inner sleeve connects the inner sleeve to the outer sleeve.

Apparatus and methods pertaining to an adapter mechanically connecting a wireless actuator to an SCSSV subassembly that includes an SCSSV. The adapter mechanically connects to the SCSSV subassembly so that the adapter is situated uphole of the SCSSV subassembly when set in a tubular of a wellbore. An actuating piston is carried by the adapter. The actuating piston transfers an opening force to the SCSSV in response to receipt by the adapter of pressurized fluid from the wireless actuator, thereby opening a flapper of the SCSSV.

A mill including a housing having a fluid bypass pathway, a milling feature at a longitudinal end of the housing, a chamber defined by the housing, and a piston disposed in communication with the chamber, the piston defining a fluid passageway initially aligned with the fluid bypass pathway, the piston responsive to pump pressure to move toward the milling feature, the movement misaligning the fluid passageway with the fluid bypass pathway.

A buoyancy assist tool and a fluid barrier in a casing string define a buoyancy chamber therebetween. The buoyancy assist tool has a housing connected in the casing string with a retaining sleeve detachably connected in the housing. The retaining sleeve is movable from a first to a second position in the housing. A flapper disk is positioned in the housing and covers an upper end of the retaining sleeve in the first position of the retaining sleeve. In the second position of the retaining sleeve the flapper disk is in a retracted position out of the flow path through the housing.

A system and method for injecting bailer content utilizing a dump bailer having an elongated, flexible bailer receptacle secured between a head assembly and an injection assembly. Disposed within the dump bailer are first and second piston assemblies, each of which includes a piston having a central fluid passage with a pressure actuated flow control mechanism in the form of a rupture disk disposed along the fluid passage of the piston. An electric, positive displacement pump within the head assembly draws wellbore fluid into the dump bailer assembly to drive the first piston assembly towards the second piston assembly so as to release bailer content into a wellbore. The elongated flexible bailer receptacle may be a hose stored on a bailer receptacle reel, which hose may be paid out by the reel to a length that corresponds with a volume of bailer content to be released into the wellbore.

A system and method for injecting bailer content utilizing a dump bailer having an elongated, flexible bailer receptacle secured between a head assembly and an injection assembly. Disposed within the dump bailer are first and second piston assemblies, each of which includes a piston having a central fluid passage with a pressure actuated flow control mechanism in the form of a rupture disk disposed along the fluid passage of the piston. An electric, positive displacement pump within the head assembly draws wellbore fluid into the dump bailer assembly to drive the first piston assembly towards the second piston assembly so as to release bailer content into a wellbore. The elongated flexible bailer receptacle may be a hose stored on a bailer receptacle reel, which hose may be paid out by the reel to a length that corresponds with a volume of bailer content to be released into the wellbore.

A valve includes a body having a wall including an outer surface, an inner surface defining a passage, an opening extending from the passage through the outer surface. The outer surface includes a recess. A valve sleeve is arranged in the passage and is selectively positioned over the opening. A valve actuator module is detachably mounted in the recess. The valve actuator module includes a housing having an inlet fluidically exposed to the passage, an outlet fluidically exposed to the valve sleeve, and a valve member arranged between the inlet and the outlet. The valve member includes an actuator delay mechanism.

Techniques for correlating changing hydraulic pressure differentials with interval control valve (ICV) movements are contemplated. In some aspects, the disclosed technology includes include methods for applying, by a surface controller, a series of differential pressure values to a hydraulic-open line, receiving, from a position sensor, a corresponding valve position for each of the differential pressure values, and calculating a lag time, a move speed and a response delay for each of the first series of differential pressure values. In some aspects, the method can further include steps for generating an ICV positioning model based at least in part on the lag time, the move speed, and the response delay calculated for each of the first series of differential pressure values. Systems and computer-readable media are also provided.