A geophysical data acquisition system includes at least one geophysical sensor. The at least one geophysical sensor has associated therewith a signal generator configured to generate a signal corresponding to a type of the at least one geophysical sensor. The system includes at least one signal acquisition unit having a plurality of input channels. The at least one geophysical sensor is in signal communication with one of the plurality of input channels. The plurality of input channels each includes a detector for receiving and identifying the signal generated by the signal generator. The at least one signal acquisition unit includes amplification, filtering and digitizing circuits automatically configurable in response to the type of sensor identified by the detected signal.
G01V 11/00 - Prospecting or detecting by methods combining techniques covered by two or more of main groups
G01D 3/02 - Measuring arrangements with provision for the special purposes referred to in the subgroups of this group with provision for altering or correcting the transfer function
A geophysical data acquisition system includes at least one geophysical sensor. The at least one geophysical sensor has associated therewith a signal generator configured to generate a signal corresponding to a type of the at least one geophysical sensor. The system includes at least one signal acquisition unit having a plurality of input channels. The at least one geophysical sensor is in signal communication with one of the plurality of input channels. The plurality of input channels each includes a detector for receiving and identifying the signal generated by the signal generator. The at least one signal acquisition unit includes amplification, filtering and digitizing circuits automatically configurable in response to the type of sensor identified by the detected signal.
G01V 1/16 - Receiving elements for seismic signalsArrangements or adaptations of receiving elements
G01V 1/22 - Transmitting seismic signals to recording or processing apparatus
G01D 3/02 - Measuring arrangements with provision for the special purposes referred to in the subgroups of this group with provision for altering or correcting the transfer function
3.
MARINE ELECTROMAGNETIC SIGNAL ACQUISITION APPARATUS WITH FOLDABLE SENSOR ARM ASSEMBLY
A marine electromagnetic acquisition apparatus includes a sensor module (22) having at least one sensor associated therewith. A sensor arm assembly (49) is coupled to the sensor module. The sensor arm assembly has at least one sensor arm (22A) and at least one sensor (23B) disposed along the at least one sensor arm. An actuator (50) is coupled to the sensor arm assembly for moving the sensor arm assembly between a folded position and an unfolded position.
G01V 3/12 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with electromagnetic waves
4.
SIGNAL PROCESSING METHOD FOR MARINE ELECTROMAGNETIC SIGNALS
A method for processing marine electromagnetic signal measurements includes acquiring magnetotelluric (MT) measurements from below a bottom of a body of water at a plurality of positions along the water bottom at substantially the same times at each position. Controlled source electromagnetic (CSEM) measurements are acquired from below the water bottom at substantially the same positions at substantially the same time at each position. The MT measurements and the CSEM measurements are jointly processed to obtain a model of conductivity distribution in the formations below the water bottom.
G01V 3/08 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
5.
METHOD OF TESTING ELECTRIC FIELD RECORDING OF A MARINE ELECTROMAGNETIC SENSOR CABLE
A method of testing the electric field recording of a marine electromagnetic sensor cable including electrodes is provided. The method includes causing current to flow between a pair of first electrodes disposed along the marine electromagnetic sensor cable. The flow of current generates a voltage that is impressed on a pair of second electrodes disposed along the marine electromagnetic sensor cable. A potential difference between the pair of second electrodes is measured. Accuracy of the electric field recording is inferred from the measured potential difference.
G01V 3/12 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with electromagnetic waves
6.
METHOD FOR DETERMINING ELECTROMAGNETIC SURVEY SENSOR ORIENTATION
A method for determining orientation of an electromagnetic survey sensor includes deploying the sensor at a selected position on the bottom of a body of water. An electromagnetic field is generated at a selected position in the body of water. A portion of the electromagnetic field is detected along at least two orthogonal directions at the sensor. A portion of the detected electromagnetic field is selected as having traveled only in a vertical plane which includes both source position and sensor position. The polarization direction of the selected portion of the electromagnetic field is determined from the selected portion. The determined polarization direction is used to determine the sensor orientation.
G01V 3/12 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with electromagnetic waves
7.
BUOY-BASED MARINE ELECTROMAGNETIC SIGNAL ACQUISITION SYSTEM
A sensor cable system for measuring electromagnetic response of the Earth's subsurface includes a sensor cable deployable on the bottom of a body of water. The sensor cable has a plurality of electromagnetic sensing devices thereon at spaced apart locations. A system control unit is in signal communication with the sensing elements. The system control unit includes a transceiver for communicating signals to and from a corresponding sensor cable system. The system control unit includes a global positioning system signal receiver. The system control unit includes a processor configurable to receive signals detected by sensing elements in the corresponding sensor cable system. The processor is configurable to compute stacked signals from the sensing elements in the sensor cable and from sensing elements in the corresponding system. The processor is configurable to calculate a statistical measure of the stacked signals. The system control unit is disposed in a flotation device.
A marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated with the module. The electrodes are arranged to measure electric field in a direction along the direction of the cable. The cable is arranged to form a closed pattern. Another marine electromagnetic sensor cable includes a plurality of sensor modules disposed at spaced apart locations along a cable. Each module includes at least one pair of electrodes associated therewith. The electrodes are arranged to measure electric field in a direction along the direction of the cable. A plurality of spaced apart magnetic field sensors is associated with each module and arranged to enable determining an electric field amplitude in a direction transverse to the direction of the cable from magnetic field gradient.
A method for measuring magnetotelluric response of the Earth includes measuring transient controlled source electromagnetic response of the subsurface below a body of water over a plurality of actuations of an electromagnetic transmitter. The transient response measurements are stacked. The stacked transient responses are subtracted from measurements of total electromagnetic Earth response over a time period including the plurality of transient response measurements to generate the magnetotelluric response.
G01V 3/02 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with propagation of electric current
10.
METHOD FOR ACQUIRING AND INTERPRETING SEISMOELECTRIC AND ELETROSEISMIC DATA
A method for subsurface Earth surveying includes acquiring seismic data over a selected region of the Earth's subsurface. Seismoelectric data are acquired over a selected region of the Earth's subsurface. Electroseismic data are also acquired over a selected region of the Earth's subsurface. At least one type of electromagnetic survey data is acquired over a selected region of the Earth's subsurface. Survey volumes of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data are matched, and a model of the Earth's subsurface is generated that accounts for all of the seismic data, the seismoelectric data, the electroseismic data and the electromagnetic data.
A method for interpreting transient electromagnetic survey data includes measuring transient response of a medium over a plurality of switching events. The measured transient response to a first one of the current switching events is modeled. Transient response to the model for at least one current switching event prior in time to the at least a first current switching event is calculated. The calculated transient response is summed with the first event measured response and the sum is compared to the electromagnetic survey measurements. The model is adjusted and the calculating summed transient responses is repeated until a difference between the summed calculated responses and the survey measurements falls below a selected threshold.
A method for interpreting electromagnetic survey data includes acquiring electromagnetic survey data near a top of a portion of the Earth's subsurface. An initial model of the portion of the Earth's subsurface is generated. The model includes at least spatial distribution of formation resistivity within the portion. The initial model is applied to an artificial neural network trained to generate expected electromagnetic survey instrument response to the initial model. The acquired electromagnetic survey data are compared to an output of the artificial neural network. The initial model is adjusted, and the applying the model to the artificial neural network and the comparing are repeated until differences between the output of the network and the acquired survey data fall below a selected threshold.
G05B 13/04 - Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
13.
METHOD FOR COMBINED TRANSIENT AND FREQUENCY DOMAIN ELECTROMAGNETIC MEASUREMENTS
A method for interpreting transient electromagnetic survey data includes imparting an electromagnetic field in the Earth's subsurface by passing electric current through a transmitter antenna. The electric current includes switched direct current at a selected switching frequency. Voltages induced in a receiver corresponding to electromagnetic effects induced in the Earth's subsurface are detected. Frequency domain electromagnetic response of the Earth's subsurface is determined from the detected voltages and transient electromagnetic response of the Earth's subsurface is determined from the detected voltages.
G01V 3/12 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with electromagnetic waves
14.
Method for combined transient and frequency domain electromagnetic measurements
A method for interpreting transient electromagnetic survey data includes imparting an electromagnetic field in the Earth's subsurface by passing electric current through a transmitter antenna. The electric current includes switched direct current at a selected switching frequency. Voltages induced in a receiver corresponding to electromagnetic effects induced in the Earth's subsurface are detected. Frequency domain electromagnetic response of the Earth's subsurface is determined from the detected voltages and transient electromagnetic response of the Earth's subsurface is determined from the detected voltages.
Earth models 50 (Figure 5) from survey areas are input to the artificial neural network (ANN). The result is a trained ANN 60. An initial model of the Earth's subsurface 62 in the survey area is input to the trained ANN 60. The initial model 62 may include spatial distribution of resistivity in three dimensions. The initial model 62 may be constrained by any available information such as petrophysical data. The trained ANN 60 generates a set of expected electromagnetic instrument responses 66. The expected responses 66 are compared, at 68, to the measured responses of the electromagnetic instrument. If the differences between the measured response and the expected response are not below a selected threshold, then at 70 the model is adjusted and the expected response is recalculated in the trained ANN 60. The adjustment and recalculation procedure is repeated until the differences fall below the selected threshold.
G01V 3/00 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation
G01V 3/18 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation specially adapted for well-logging
G06F 15/18 - in which a program is changed according to experience gained by the computer itself during a complete run; Learning machines (adaptive control systems G05B 13/00;artificial intelligence G06N)
G06G 7/00 - Devices in which the computing operation is performed by varying electric or magnetic quantities
16.
METHOD FOR ACQUIRING AND INTERPRETING TRANSIENT ELECTROMAGNETIC MEASUREMENTS
A method for interpreting transient electromagnetic survey data includes measuring transient response of a medium over a plurality of switching events. The measured transient response to a first one of the current switching events is modeled. Transient response to the model for at least one current switching event prior in time to the at least a first current switching event is calculated. The calculated transient response is summed with the first event measured response and the sum is compared to the electromagnetic survey measurements. The model is adjusted and the calculating summed transient responses is repeated until a difference between the summed calculated responses and the survey measurements falls below a selected threshold.
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
G01V 3/00 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation
G01V 7/00 - Measuring gravitational fields or wavesGravimetric prospecting or detecting
17.
INTEGRATED EARTH FORMATION EVALUATION METHOD USING CONTROLLED SOURCE ELECTROMAGNETIC SURVEY DATA AND SEISMIC DATA
A method for determining spatial distribution of properties of the Earth's subsurface includes obtaining seismic data over a survey area of the Earth's subsurface. Controlled source electromagnetic survey data are obtained over substantially the same survey area. An initial model of the Earth's subsurface for each of the seismic data and the electromagnetic data is generated. Further data may include gravity, magnetics, seismics any type and borehole data. Each model is optimized on at least one model parameter. Consistency is determined between the models; and the at least one model parameter is adjusted and the optimizing and determining consistency are repeated until the models are consistent. Constraints are successively derived from the data sets and also cross checked against reservoir data where available.
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
18.
Integrated earth formation evaluation method using controlled source electromagnetic survey data and seismic data
A method for determining spatial distribution of properties of the Earth's subsurface includes obtaining seismic data over a survey area of the Earth's subsurface. Controlled source electromagnetic survey data are obtained over substantially the same survey area. An initial model of the Earth's subsurface for each of the seismic data and the electromagnetic data is generated. Further data may include gravity, magnetics, seismics any type and borehole data. Each model is optimized on at least one model parameter. Consistency is determined between the models; and the at least one model parameter is adjusted and the optimizing and determining consistency are repeated until the models are consistent. Constraints are successively derived from the data sets and also cross checked against reservoir data where available.
A method for controlled source electromagnetic Earth surveying includes deploying a plurality of electromagnetic sensors in a selected pattern at the top of an area of the Earth's subsurface to be surveyed. At least one of a transient electric field and a transient magnetic field is applied to the Earth in the vicinity of the sensors at a plurality of different positions. At least one of electric field amplitude and magnetic field amplitude at each of the sensors is recorded each time the transient electric field and/or magnetic field is applied. Each recording is adjusted for acquisition geometry. An image is generated corresponding to at least one sensor position using at least two stacked, adjusted recordings.
G01V 3/08 - Electric or magnetic prospecting or detectingMeasuring magnetic field characteristics of the earth, e.g. declination or deviation operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices
20.
Method for acquiring transient electromagnetic survey data
A method for controlled source electromagnetic Earth surveying includes deploying a plurality of electromagnetic sensors in a selected pattern at the top of an area of the Earth's subsurface to be surveyed. At least one of a transient electric field and a transient magnetic field is applied to the Earth in the vicinity of the sensors at a plurality of different positions. At least one of electric field amplitude and magnetic field amplitude at each of the sensors is recorded each time the transient electric field and/or magnetic field is applied. Each recording is adjusted for acquisition geometry. An image is generated corresponding to at least one sensor position using at least two stacked, adjusted recordings.
G06F 19/00 - Digital computing or data processing equipment or methods, specially adapted for specific applications (specially adapted for specific functions G06F 17/00;data processing systems or methods specially adapted for administrative, commercial, financial, managerial, supervisory or forecasting purposes G06Q;healthcare informatics G16H)
patents
