| Patent application number | Description | Published |
|---|
| 20080284426 | WATER MAPPING USING SURFACE NMR - A method for selecting a location of a wellbore includes: using a nuclear magnetic resonance (NMR) instrument deployed on a surface of a production area, determining a location of ground water in the production area; and locating the wellbore according to the location of the ground water. A system and a computer program product are disclosed as well as a method for performing steam assisted gravity recovery. | 11-20-2008 |
| 20090084185 | ELECTROMAGNETIC ACOUSTIC TRANSDUCER WITH CROSS-TALK ELIMINATION - The electromagnetic acoustic transducer (EMAT) transducer disclosed herein is useful for the non-destructive analysis of objects. The transducer comprises a core having a winding and a coil disposed between the core and the object to be analyzed. One transducer can be used as a transmitter and another transducer as a receiver. Then selectively switching static magnetic field in either transmitter or receiver and processing data with and without static magnetic field allows for eliminating artifacts due to parasitic coupling between the transmitter/receiver pair. The switching of the static magnetic field can be implemented either by using electromagnet or a pair of permanent magnets where magnetization of one permanent magnet is reversed to provide cancellation of the static magnetic field. | 04-02-2009 |
| 20090102478 | CONFIGURABLE MAGNET ASSEMBLY FOR USING IN NMR WELL LOGGING INSTRUMENT - A magnet assembly for measuring properties of a formation from a borehole, the magnet assembly including a first device and a second device, each device adapted for insertion into the borehole, the first device producing a first magnetic field, the second device producing a second magnetic field; wherein the second magnetic field is configurable for one of reinforcing and reducing the first magnetic field; and wherein the first device comprises a permanent magnet and the second device comprises at least one of one of a switchable magnet and switching windings. | 04-23-2009 |
| 20090105955 | Sensors For Estimating Properties Of A Core - A method for estimating a property downhole is provided, which, in one aspect, may include receiving a core at a receiving end of a downhole tool while removing a portion of the received core distal from the receiving end of the tool, obtaining measurements by a sensor downhole, and processing the measurements to estimate the property of interest. | 04-23-2009 |
| 20090114022 | Electromagnetic Acoustic Transducer Using Magnetic Shielding - A combined electromagnetic acoustic transducer (EMAT) is disclosed that uses magnetic shielding to increase the efficiency (defined as the received signal per unit of excitation current). In addition, electromagnetic shielding may also be used to reduce the direct coupling between the transmit and receive coils. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. | 05-07-2009 |
| 20100033187 | METHOD FOR ELIMINATING BOREHOLE ECCENTRICITY EFFECT IN TRANSVERSAL INDUCTION SENSOR - An instrument for measuring a property of a subsurface material, the instrument including: a magnetic material surrounding a volume in at least two dimensions; and a receiver adapted for receiving energy related to the property of the subsurface material; wherein the receiver is disposed at an exterior surface of the magnetic material. | 02-11-2010 |
| 20100097065 | Method and apparatus for while-drilling transient resistivity measurements - Structure for deep MWD resistivity measurements suitable for both geo-steering and measurements ahead of the drill bit is disclosed. The structure is capable of extracting information about resistivity of formation in the presence of conductive drill. In one embodiment, ahead-of-bit sensing is achieved via transient electromagnetic measurements when current is switched off in the transmitter loop and the transient signal is measured in the receiver loops placed at some distances from the receiver. To reduce a parasitic effect of the currents in the drill three-coil bucking system with magnetic nonconductive shield in combination with a highly conductive copper shield are applied. Specifically, a short (less than 1 m) copper cover and short (less than 0.2 m) ferrite cover are placed in the vicinity of transmitting and receiving coils. A bucking operation followed by an inversion is performed on received signals to obtain data reflecting parameters of the surrounding subsurface formations. | 04-22-2010 |
| 20100125439 | Method of Deep Resistivity Transient Measurement While Drilling - A transient electromagnetic signal is recorded in an earth formation in the presence of a pipe having a finite conductivity. A portion of the signal dominated by the pipe signal is analyzed to determine a functional representation, extrapolated back to a time interval where the formation signal is present and subtracted from the recorded signal to provide a corrected signal. | 05-20-2010 |
| 20100271030 | Borehole Transient EM System for Reservoir Monitoring - A transient electromagnetic borehole system uses an arrangement of sensors deployed in a borehole for reservoir monitoring. Non-conductive casing sections may be used along with an efficient transmitter configured to provide measurements up to 300 m from the borehole. By using multiple receivers, the method can also be used without nonconductive casing. | 10-28-2010 |
| 20110012602 | Cancellation of Vibration Noise in Deep Transient Resistivity Measurements While Drilling - A transient electromagnetic (TEM) signal is recorded in an earth formation during vibration of a logging tool. Concurrently, accelerometer measurements are made. The accelerometer measurements are used to correct the TEM signal for the vibration using the accelerometer measurement and a transfer function relating the TEM signal and the accelerometer. The transfer function may be determined using measurements in a water tank or by using the tail end of the TEM measurements. | 01-20-2011 |
