Abstract: A flow meter for measuring the velocity of surrounding fluid, comprising a rotatable member rotatably coupled to a shaft member, wherein the shaft member comprises a measuring electrical circuit comprising an AC power supply and a primary coil, the rotatable member comprising a passive non-permanent magnet marker responsive to a magnetic field, the arrangement being such that when the circuit is powered by the AC supply the coil generates a magnetic field and the marker is positioned on the rotatable member such that rotation of the rotatable member in response to fluid drag on the member causes the distance between the marker and the coil to oscillate, the marker interacting with the magnetic field at its closest approach to the coil, thereby to cause a measurable electrical response in the circuit.

Abstract: A tagged object includes a main body and a plurality of coded particles. Each coded particle may have a miniature body and be configured to provide a resolvable optical emission pattern when illuminate. The plurality of coded particles may be immobilized to the main body. A method for performing oilfield monitoring may include disposing of different types of tagged objects at different locations, wherein the different types of tagged objects each comprise a plurality of coded particles. Each of the coded particles may have a miniature body containing rare earth elements configured to produce a unique optical emission pattern when illuminated. The method may include allowing an event to trigger the release of one of the different types of tagged objects from one of the different locations. In addition, the method may include identifying the released tagged objects by unique optical emission patterns, in some cases in order to determining an occurrence location of the event.

Abstract: The present invention provides a hydraulically actuated downhole adjustable bent housing for use in directional drilling of bore holes and wells that allows adjustment of the housing from aligned to a bent configuration without raising or lowering the drillstring. The present invention also provides a method of directionally drilling a bore hole or a well using an downhole adjustable bent housing that can be operated without raising or lowering the drillstring.