Abstract: This disclosure provides methods, systems and devices that may be used to measure, calculate, and orient a device such as a drill bit in a downhole environment. To that end, disclosed are fiber optic gyroscopes, wherein the fiber optic gyroscopes comprise elliptical fiber optic cable coils in a mutually orthogonal arrangement that is tilted relative to a longitudinal axis of a supporting shaft, e.g., tube. Light travels in opposite directions within each of the elliptical fiber optic cable coils, and, subsequently, sensors detect differences in time for each light path of the light that traveled in opposite directions within each one of the elliptical fiber optic cable coils. The elliptical nature of the fiber optic cable coils minimizes the cross-sectional area of the mutually orthogonal arrangement, and thereby makes it well-suited for use in downhole environments where space is at a premium. This disclosure also may provide an inertial measurement unit.

Abstract: This disclosure provides methods, systems and devices that may be used to measure, calculate, and orient a device such as a drill bit in a downhole environment. To that end, disclosed are fiber optic gyroscopes, wherein the fiber optic gyroscopes comprise elliptical fiber optic cable coils in a mutually orthogonal arrangement that is tilted relative to a length of a supporting shaft, e.g., tube. Light travels in opposite directions within each of the elliptical fiber optic cable coils, and, subsequently, sensors detect differences in time for each light path of the light that traveled in opposite directions within each one of the elliptical fiber optic cable coils. The elliptical nature of the fiber optic cable coils minimizes the cross-sectional area of the mutually orthogonal arrangement, and thereby makes it well-suited for use in downhole environments where space is at a premium. This disclosure also may provide an inertial measurement unit.

Abstract: Methods of monitoring various downhole conditions are described, including a system for determining and/or identifying the flow of fluid in a well, determining sand production in a well, identifying localized events in a well, determining the apparent flow velocity of fluid flowing through a downhole conduit, and/or monitoring the strain in downhole tubulars. These determinations may be made by monitoring signals received from one or more sensors located in a well and analysing the signals, such as their frequency and timing.

Abstract: A head member having a piston provided thereon is connected to an elongate tube such as a micro-tube. The micro-tube contains one or more optical fibres, preferably suspended therein by a protective fluid such as a scavenging gel. The head member is preferably inserted into an already-deployed downhole tubular and fluid is pumped down that already deployed tubular behind the piston such that the head member and attached micro-tube and optical fiber(s) are pumped downhole. A sealing means such as a resin material may be pumped downhole in the annulus between the outer circumference of the micro-tube and the inner circumference of the already-deployed tubular downhole in low viscosity form and which may be adapted to cure or harden after a passage of time and/or under application of heat.