Abstract: Disclosed is a fluid-driven dual-mode circulation tool which is suitable for high-temperature applications, and which is operable to switch between a flow-through mode and an annular-flow mode. Switching modes is accomplished by interrupting (or reducing) and then reinstating the flow of pressurized fluid through it. In the flow-through mode, pressurized fluid flows out of the tool into the bottom hole assembly. In the annular-flow mode, the tool diverts fluid through internal paths that access the annulus of the wellbore or casing through one or more apertures on the sidewall of the tool.

Abstract: A fluid-driven dual-mode abrasive perforation tool which is selectively operable to switch between abrasive and neutral mode is disclosed. In the abrasive mode, jets of abrasive fluid are delivered on to perforate the target site. A ratchet path having mated peaks and valleys on the surface of a J-slot piston included in the tool is engaged with guiding pins. On longitudinal sliding of the piston due to guided inflow and interruption pressurized abrasive fluid through the tool, the guiding pins cause rotation of the piston. Rotation of the piston alternately aligns a pair of flow channels included in the piston with flow paths for ejecting jets of pressurized abrasive fluid and flow paths for non-abrasive ejection of pressurized fluid. When the pair of flow channels of the piston get aligned with flow paths for ejecting jets of pressurized abrasive fluid, the tool is operated in the abrasive mode.

Abstract: A fluid-driven multi-mode extended reach vibration tool is selectively operable to control generating shock waves of different amplitudes by a downhole motor or shock-wave generating tool. Interrupting and then reinstating flow of pressurized fluid through the tool enables switching between different shock wave amplitudes, as such causes rotation of a slot piston to successive positions and enables it to unblock designated fluid ejection paths, while blocking others. Blocking different flow paths and unblocking others allows generating different internal pressures and shock wave amplitudes under the externally-applied fluid pressure downhole. There is also an “off” mode with no vibration, while maintaining well control and fluid pressure at the BHA.