Abstract: A coring bit, including an outer hollow coring shaft, and a rotationally uncoupled internal sleeve disposed inside the outer hollow coring shaft. The rotationally uncoupled internal sleeve may be a non-rotating internal sleeve. The rotationally uncoupled internal sleeve may be a free-floating internal sleeve.

Abstract: A method for analyzing formation fluid in earth formation surrounding a borehole includes storing analytical reagent in a reagent container in a fluids analyzer in a formation tester and moving the formation tester, including the reagent, downhole. Reagent from the reagent container is injected into formation fluid in the flow-line to make a mixture of formation fluid and reagent. The mixture is moved through a spectral analyzer cell in the fluids analyzer to produce a time-series of optical density measurements at a plurality of wavelengths. A characteristic of formation fluid is determined by spectral analysis of the time-series of optical density measurements.

Abstract: A core sample retaining sleeve is provided for preventing loss of a cut core sample from the distal end of a coring bit, particularly during retraction of the coring bit to within the coring tool. Preferably, the core sample retaining sleeve is disposed concentrically within the coring bit to fit around the received core sample. The core sample retaining sleeve has one or more retaining fingers formed on the distal end of the coring bit. The retaining fingers are selectively closeable, preferably by urging the one or more retaining fingers against one or more guide members. A guide member is preferably provided as a stationary ridge on the inner, distal surface of the coring bit. The core sample is contained and protected within the closed retaining sleeve.

Abstract: The present invention provides a core sample retaining sleeve for preventing loss of a cut core sample from the distal end of a coring bit, particularly during retraction of the coring bit to within the coring tool. Preferably, the core sample retaining sleeve is disposed concentrically within the coring bit to fit around the received core sample. The core sample retaining sleeve has one or more retaining fingers formed on the distal end of the coring bit. The retaining fingers are selectively closeable, preferably by urging the one or more retaining fingers against one or more guide members. A guide member is preferably provided as a stationary ridge on the inner, distal surface of the coring bit. The core sample is contained and protected within the closed retaining sleeve.

Abstract: The present invention provides a brush bit for cutting a core sample from an unconsolidated formation with reduced fragmentation or damage to the core sample by using a plurality of stiff bristles to cut rock from around the core sample. The present invention also provides an improved method of obtaining a core sample from an unconsolidated formation.

Abstract: The present invention provides an improved coring motor for use in obtaining a core sample from the side wall of a drilled bore hole. The present invention provides controllable rotation, extension and retraction of the coring bit relative to the side wall without complicated positioning linkages and with conservation of space for use in slim tools for use downhole.

Abstract: A flow-control apparatus enables the taking of representative formation samples at sampling rates less than 10 cc/sec in typical high pressure wells, e.g., to 20,000 psi. Throttle valves are used to control pressure drawdown in the flowline and to continue that pressure control until captured in a sample chamber. Very low flow rates at high pressures are made possible by using a motor-driven, variable orifice, needle valve (throttle valve) and a downhole feedback loop on the piston position. The flow control device uses metered fluid, which is internally contained oil, which overcomes the difficulty of trying to meter "dirty" (particle laden) well fluids or dual phase gas-liquid fluids. A single probe module (or a dual packer) is coupled with a multi-sample module and the flow control module. This combination can then be used to draw a sample from the formation at a very low flowrate and, hence, a very low pressure differential which keeps the sample pressure above the bubble point (or dew point).