Abstract: The present invention includes a drive system for use in a flowing fluid, the drive system preferably having a first turbine connected to a shaft, a first gear connected to the shaft, a second turbine rotatably mounted on a pipe, a second gear rotatably mounted on the pipe and connected to the second turbine, and two or more satellite gears in fixed locations relative to the pipe and rotatably engaged, directly or indirectly, with the first gear and the second gear. The drive system may be used, for example, in a wind generator to generate electrical energy.

Abstract: An antenna structure is separately and independently formed with respect to a downhole tool. The antenna is adapted for easy and rapid deployment on the tool. An independently formed ‘partial ring section’ (or arcuate shaped member) contains an antenna coil. In one embodiment, two or more of the independently formed partial ring sections are placed in a recess on the tubular forming the downhole tool. In another embodiment, the partial ring sections can also be placed in one or more longitudinally distributed sections about the tool. Another embodiment includes partial ring sections forming an antenna with multiple coils of differing orientation to provide directional sensitivity.

Abstract: Techniques for calibrating an electromagnetic logging tool equipped with a plurality of antennas, with at least one antenna having its axis at an angle with respect to a tool axis, include disposing a test loop about the tool such that an axis of the tool and a plane on which the test loop lies form a tilt angle that is between about 0 and 90 degrees. An induced signal is measured at one of the antennas by energizing another of the antennas. Embodiments analyze the induced signal corresponding to a max or min extrema associated with a coupling effect due to the test loop. In other embodiments a corrected signal is compared with a calculated signal.

Abstract: A borehole tool, comprises: a tool body; a series of arms connected to the tool body and moveable radially relative thereto; and a series of pads mounted on the arms so as to be pivotable about a radial axis relative to the tool body. By allowing pivoting of the pads about a radial axis, elongate pads can be arranged to provide different circumferential coverage according to the orientation with respect to the longitudinal axis of the borehole.

Abstract: The invention concerns a device for measuring the speed and direction of rotation of an object (3) near to which it is placed. It comprises: a magnetic detection device (2) that delivers, in response to a rotation of the object (3) generating a magnetic field variation, signals representative of its speed and its direction of rotation, a conductor (4) intended to be connected to a power source to supply current to the magnetic detection device (2) at least, current receptor means (6) placed between the magnetic detection device (2) and the conductor (4) that create, from signals coming from said magnetic detection device (2), a modulation of the current (Iout) flowing in the conductor (4), said modulated current (Iout) reflecting both the speed and the direction of rotation of the object (3). Application particularly in the oil industry.

Abstract: A downhole tool for formation logging includes a tool body configured to move in a borehole; and at least one sensor module mounted in at least one mounting location on the tool body, wherein the at least one sensor module is interchangeable with other sensor modules that make different measurements. A downhole tool may further comprise a measurement system disposed in the tool body, wherein the measurement system is operatively coupled to the at least one sensor module.

Abstract: A method is disclosed for interpretation of multi-dimensional nuclear magnetic resonance data taken on a sample of an earth formation. Specifically, a set of NMR data is acquired for a fluid sample located either in a borehole or in a laboratory environment. From the set of NMR data, a multi-dimensional distribution is calculated using a mathematical inversion that is independent of prior knowledge of fluid sample properties. The multi-dimensional distribution is graphically displayed on a multi-dimensional map. Each fluid instance or artifact visible on the graph is identified as representing a probable existence of a detected fluid. One or more quantitative formation evaluation answers for one or more fluid instances is computed based on the multi-dimensional distribution associated with the respective fluid instance.

Abstract: An apparatus for investigating the wall of a borehole in a geological formation. The pad having shielding means which are arranged between a source electrode and a set of measurement electrodes and between the measurement electrodes and a return electrode. The shielding means being flush with or almost flush with the outside face of the pad and extending along the length of the outside face of the pad so that the electric field generated by the current and return electrodes is substantially eliminated in the pad and in the vicinity of the measurement electrodes.

Abstract: A novel on-the-fly data processing technique is useful for extracting signals from the azimuthal variation of the directional measurements acquired by a logging tool within a borehole. The relevant boundary, anisotropy and fracture signals are extracted from the formation response through fitting of the azimuthal variation of the measured voltages to some sinusoidal functions. The orientation of the bedding is also obtained as a result. The extracted directional signals are useful for obtaining boundary distances and making geosteering decisions. Two techniques involving inversion and cross-plotting may be employed, depending on the nature of the boundary. A Graphical User Interface (GUI) is part of a system to facilitate flexible definition of inversion objectives, for improving the inversion results, and for visualization of the formation model as well as inversion measurements.

Abstract: Various methods are disclosed for evaluating water saturation characteristics in a geological formation penetrated by a borehole, including injection fluid introduced into the formation by an external injection process performed upon the formation. In various embodiments, the total water saturation may be obtained from the relationship provided by the Triple Water Equation, and used to map saturation in the formation and making drilling decisions.

Abstract: A tool for electromagnetic logging of a formation includes a tool body configured to move in a borehole penetrating the formation; an antenna array disposed on the tool body; and an electronic unit configured to control operation of the antenna array, wherein the antenna array comprises at least one transmitter and at least one receiver, wherein at least one selected from the group consisting of the at least one transmitter and the at least one receiver comprises a printed circuit antenna.

Abstract: A method for determining a characteristic of earth formations from measurements taken on the formations, includes the following steps: producing a data base that includes a multiplicity of data points, each data point representing a stored formation characteristic output related to a stored input measurement; deriving, from the data base, a mapping function; deriving an input formation measurement value; and determining an output formation characteristic value from the data base, the mapping function, and the input formation measurement value.

Abstract: A method for estimating a concentration of a substance in a test sample of formation fluid, comprising measuring an NMR parameter of a first sample of formation fluid to obtain a first measurement, adding a known quantity of the substance to the first sample to produce a modified sample, measuring the NMR parameter of the modified sample to obtain a second measurement; and determining a relation between the concentration of the substance and a function of the NMR parameter using the first and second measurements and the NMR parameter of the substance.

Abstract: The invention provides a measuring sonde (1) for a hydrocarbon well, the sonde comprising a main body (2), a downstream arm (3), and an upstream arm (5), at least one of said arms being fitted with measurement means (6) for determining the characteristics of the fluid flowing in the well; said downstream and upstream arms being connected to the main body respectively via first and second sliding pivot links (A and E).

Abstract: It is described a logging tool 20 for underground formations surrounding a borehole 14, comprising an elongated body 21 along a major axis; a collar 22 disposed peripherally around said body 21 having a collar wall defined by an inner and an outer surface; a radiation emitting source 201 arranged to illuminate the earth formation 16 surrounding the borehole; at least one radiation detector 211 arranged to detect radiation reflected by the earth formation resulting from illumination by the source 201; at least one source collimation—window 202 and one detector collimation window 212 through which the earth formation is illuminated and radiation is detected; and characterized in that it further comprises at least one radiation shield 30 located between said inner collar surface and the outer surface of the tool, said radiation shield positioned so as to eliminate parasitic radiation that has not traversed the outer collar.

Abstract: A technique that is usable with a subterranean well that has a first string that lines a borehole includes running a second string into the well and engaging a deflecting face of a deflector to deflect the second string into a window of the first string. The technique includes performing at least one of positioning the second string and orienting the second string using a profile on the deflector downhole of the deflecting face.

Abstract: Techniques for implementing antenna configurations with substantially co-located axes are disclosed. A method for constructing co-located antennas includes winding a first antenna on a support, the first antenna having a first magnetic dipole in a first orientation; and winding a second antenna on the support through a first set of openings in the support, the second antenna having a second magnetic dipole in a second orientation, wherein the first orientation is different from the second orientation, and wherein a center of the first magnetic dipole substantially co-locates with a center of the second magnetic dipole.

Abstract: A method for reducing stand-off effects of a downhole tool includes disposing the downhole tool in a borehole, wherein the downhole tool comprises at least one moveable section disposed between an energy source and a receiver on the downhole tool; and activating the at least one moveable section to reduce a thickness of at least one selected from a mud layer and a mudcake between the downhole tool and a wall of the borehole. A downhole tool includes an energy source and a receiver disposed on the downhole tool; at least one moveable section disposed between the energy source and the receiver; and an activation mechanism for reducing a thickness of at least one selected from a mud layer and a mudcake between the downhole tool and a wall of a borehole.

Abstract: By breaking the calibration into two parts—one calibration offset being associated with a first portion, and the other calibration offset being associated with a second portion, it is possible to combine the various calibration offsets for a particular first portion mated with a particular second portion. Thus, any one of a number of downhole first portions can be combined, on a session-by-session basis, with any number of second portions. In one embodiment, the second portion calibration is specific to the particular second portion, and in another embodiment the calibration for a second portion is a fixed calibration offset that is based on a second portion type, such as the second portion size.

Abstract: A method to determine water saturation of laminated sand-shale formations based on measurements of formation and shale resistivity anisotropy, the fraction of shale, and the porosity.