Class / Patent application number | Description | Number of patent applications / Date published |
324343000 | Using angularly spaced coils | 8 |
20080265893 | Externally Guided and Directed Field Induction Resistivity Tool - In one aspect an induction resistivity tool incorporated into a downhole tool string comprises an outer wall of a downhole component comprising an outer diameter and at least one induction transmitter assembly disposed along the outer diameter. The at least one transmitter assembly comprises at least one induction transmitter coil wound about at least one core. The at least one transmitter coil is adapted to project an induction signal outward from the outer wall when the at least one transmitter coil is carrying an electrical current. The transmitter assembly is adapted to create electromagnetic fields that originate the induction signal from outside the outer wall and substantially prevent the signal from entering the outer wall. | 10-30-2008 |
20080265894 | Externally Guided and Directed Halbach Array Field Induction Resistivity Tool - In one aspect of the invention an induction resistivity tool incorporated into a downhole tool string comprises an outer wall of a downhole component having an outer diameter. At least one induction transmitter assembly is disposed along the outer diameter. The transmitter assembly comprises at least one coil array and at least one induction transmitter coil wound about at least one core. The coil array comprises a plurality of magnetic units and each unit comprising a magnetic field orientation. The magnetic field orientations accumulatively form a Halbach array with an augmented field side and a canceled field side of the array. The transmitter assembly generates an induction signal from outside the outer wall and substantially prevents the signal from entering the outer wall when the transmitter assembly is carrying an electrical current. | 10-30-2008 |
20090015261 | DETERMINING FORMATION PARAMETERS USING ELECTROMAGNETIC COUPLING COMPONENTS - A method to determine one or more parameters of a formation traversed by a borehole, at least a portion of the formation having substantially parallel boundaries, the method comprising disposing a tool in the borehole, wherein the tool includes a transmitter having a dipole moment at an angle θ | 01-15-2009 |
20090160449 | Antennas for Deep Induction Array Tools with Increased Sensitivities - Improved receiver antennas are disclosed for long offset tensor induction army logging tools. The disclosed antennas include a bobbin which accommodates a ferromagnetic core. The outer surface of the bobbin is wrapped around a binding so that winding is thicker or includes more turns towards a center of the bobbin and is thinner or includes less turns towards the outer ends of the bobbin. The result is that the primary winding with a curved or parabolic profile that enhances the effective magnetic permeability and magnetic moment of the antenna. A secondary winding may also be utilized for flux feedback compensation. The elimination of winding turns towards the ends of the magnetic coil result in reduced DC resistance and the reduction in parasitic capacitance of the antennas. The disclosed antennas may be used in x-y-z receiver arrays. | 06-25-2009 |
20100289496 | Dipole Locator Using Multiple Measurement Points - A receiver and tracking system for identifying a location of a magnetic field source. In a preferred embodiment a plurality of tri-axial antennas are positioned at three distinct points on a receiver frame. Each antenna detects a magnetic field from a source and a processor is used to determine a location of the source relative to the frame using the antenna signals. Each tri-axial antenna comprises three windings in each of three channels defined by a support structure. The windings each define an aperture area. The windings have substantially identical aperture areas and have a common center point. The receiver may to display to the operator the relative location of the field source or may direct the operator to a spot directly above the field source. | 11-18-2010 |
20110068798 | IMAGING USING DIRECTIONAL RESISTIVITY MEASUREMENTS - The present disclosure relates to a method to produce an image of a subsurface formation using directional measurements. A downhole logging tool having one or more transmitters and one or more receivers, and being capable of making directional measurements, is used to measure the voltage in a particular receiver due to a particular transmitter for one or more transmitter/receiver pairs, at least one of those voltage measurements being a directional measurement. The complex (phasor) voltage recorded on a receiver coil is divided by the complex voltage recorded at another reference receiver coil. Alternatively, we can use the ratio of a receiver voltage at a particular rotation angle of the tool divided by the voltage on the same receiver when the tool has rotated by an angle of 180 degrees. The information in those ratios is combined to produce images of the resistivity of the subsurface formation surrounding the tool. | 03-24-2011 |
20110227578 | Induction Resistivity Tool that Generates Directed Induced Fields - In one aspect of the present invention, an induction resistivity tool includes an induction transmitter and an induction receiver located along the length of the tool. The transmitter is located adjacent at least one induction bucking coils of the tool. When activated the bucking coils are configured to direct a field transmitted by the induction transmitter away from the tool at an angle from the central axis of the tool. | 09-22-2011 |
20130027044 | IMAGING USING DIRECTIONAL RESISTIVITY MEASUREMENTS - The present disclosure relates to a method to produce an image of a subsurface formation using directional measurements. A downhole logging tool having one or more transmitters and one or more receivers, and being capable of making directional measurement, is used to measure the voltage in a particular receiver due to a particular transmitter for one or more transmitter/receiver pairs, at least one of those voltage measurements being a directional measurement. The complex (phasor) voltage recorded on a receiver coil is divided by the complex voltage recorded at another reference receiver coil. Alternatively, we can use the ratio of a receiver voltage at a particular rotation angle of the tool divided by the voltage on the same receiver when the tool has rotated by an angle of 180 degrees. The information in those ratios is combined to produce images of the resistivity of the subsurface formation surrounding the tool. | 01-31-2013 |