A downhole system and method of performing an operational action with the downhole system. The downhole system includes a downhole string having a flow channel therethrough, a first turbine generator for generating electrical energy when a flow rate of a fluid through the flow channel is within a first flow rate range, and a second turbine generator for generating electrical energy when a flow rate of the fluid through the flow channel is within a second flow rate range. A first pulser at a downhole location in the downhole string transmits a pressure pulse communicative of data generated downhole using electrical energy generated by one of the first turbine generator and the second turbine generator. A sensor at a surface location receives the pressure pulse, and a control unit performs the operational action based on the data communicated by the pressure pulse.

The present invention provides an automatic jet breaking tool for solid fluidization exploitation of natural gas hydrate, which mainly includes an upper joint, an outer cylinder, an inner sliding sleeve, a lockup sliding sleeve, a thrust bearing, a spring, a jet joint, a telescopic jet sprinkler, a plug block and an extrusion seal ring. The present invention mainly adopts the principle of throttling control pressure to control the position of the inner sliding sleeve by controlling a flow rate of a drilling fluid, so as to turn on and turn off the jet breaking tool. The application of the present invention can realize automatic jet breaking of solid fluidization exploitation of the natural gas hydrate, reduce procedures of a round trip operation, and effectively improve the efficiency and safety of the exploitation operation of the natural gas hydrate.

Fluid flow control devices and methods to reduce overspeed of a fluid flow control device are presented. A fluid flow control device includes a port and a rotatable component that rotates about an axis in response to fluid flow from the port. The fluid flow control device also includes a mechanical component disposed on the rotatable component and configured to reduce rotational speed of the rotatable component.

A flow diverter for connecting a central bore to an outer conduit. The flow diverter defines a portion of the central bore and angled flow passages connecting the portion of the central bore to the outer conduit. Rounded edges between the central bore and angled flow passages reduce cavitation and/or turbulence. The rounded edges and an adjacent portion of the central bore may be defined by an insert. The insert may define walls extending fully around portions of the angled flow passages.

An underbalanced drilling system is provided. A bottomhole assembly includes a drill bit drilling a wellbore in a formation underbalanced. The bottomhole assembly includes a telemetry sub. A telemetry component transmits signals in real-time between the telemetry sub of the bottomhole assembly and a controller on the surface. A drill string is coupled with the bottomhole assembly, and the drill string includes a plurality of drill collars. The drill collars form a channel through which drilling fluid flows from the surface to the bottomhole assembly. The drill string is inserted into the wellbore by a hydraulic work over unit. A continuous circulation component provides continuous circulation of the drilling fluid while a new drill collar is coupled to the drill string. The continuous circulation component substantially maintains a wellbore density at a predetermined density.

A flow rate control system includes a housing and a valve assembly slidingly disposed within a housing inner bore. The housing includes bypass openings. The valve assembly includes a valve and an orifice disposed in a valve inner bore. The valve includes a plurality of valve bypass bores extending axially through a valve collar. The valve assembly slides between closed and fully open positions. A spring biases the valve assembly toward the closed position in which the valve closes the housing bypass openings. In the open position, a bypass fluid path is formed including the valve bypass bores and the housing bypass openings. The valve assembly is flow rate controlled in the closed position and pressure controlled in the open position. The valve assembly may slide within a sleeve assembly including sleeve bypass openings, which connect the valve bypass bores and housing bypass openings in the bypass fluid path.

A downhole tool having a diverter component for directing fluids in different directions within a wellbore. The diverter component has an outer pipe which forms part of the downhole string. The pipe has a through channel and holes through the wall of the pipe. Within the pipe is a sleeve which can be moved. In one position, the sleeve blocks the wall holes and allows fluid to pass through the channel of the pipe. The diverter component may be used in conjunction with packers to seal off sections of the wellbore. The diverter and packer assembly could be used to introduce acid into particular portions of the wellbore.

A rupture apparatus (50) often deployed within a wall of a casing string (53) of an oil and gas well, comprising a housing (51) defining a housing bore (54) with a bore inlet and a bore outlet; a carriage carrying a rupturable component (12) the carriage being moveable in the housing bore between a rupturable position, an open and a closed position. Thus the bore can be opened or closed or closed subject to rupture of the rupturable component (12). Moreover, after rupture the bore can still be closed. Wireless signals are normally used to for control, especially electromagnetic or acoustic signals. A pressure balancing port (6) may be defined in a wall of the housing allowing fluid communication between at least a portion of the housing bore, and an outside of the housing which can pressure-balance the carriage such that it remains stationary unless actuated.

A packoff pressure prevention system includes an internal pressure sensor to measure fluid pressure within a drillstring. The system further includes an annular vent to, when open, enable fluid to escape from within the drillstring into an annulus. The system further includes a processor coupled to receive pressure measurements from the internal pressure sensor and coupled to signal the annular vent to open if the fluid pressure within the drillstring rises a first threshold amount over a second threshold time.

A rotary valve including a port housing, a port, an axially actuated rotary sleeve disposed within the port housing, the sleeve having a plurality of apertures in fluid communication with the port; and an insert disposed within the sleeve, the insert having an opening, the sleeve being rotatable to align one of the plurality of apertures with the opening. A rotary valve including a port housing, having a port, an axially actuated rotary sleeve disposed within the port housing, the sleeve having an aperture; and an insert disposed within the sleeve, the insert having a plurality of openings of distinct size from one another, the aperture of the sleeve being selectively alignable with one of the plurality of openings.