Groundmetrics, Inc.

Electronic Biosciences, Inc.

Quantum Applied Science & Research, Inc.

Saudi Arabian Oil Company

Quasar Federal Systems, Inc.

Other

Electronics Biosciences, Inc.

Andrew Dennis Hibbs

Robert Matthews

Eli N Glezer

Alberto F Marsala

H Frank Morrison

Geoffrey A Barrall

Eric N Ervin

Yongming Zhang

Regina Elvira Dugan

Igor V Fridman

Eric A Duff

Michael Andrew Krupka

Daniel K Lathrop

Todor Petrov

Peter James Turner

Jamison Scott Woodward

Thomas Kurt Nielsen

Melissa Ann Poquette

Clifford J Schenkel

Konstantine V Ermolaev

Walid V Soussou

Robert Earl Grimm

Jason D Jolly

David Matthew Jabson

The invention relates to measuring and generating electrical fields downhole. In one embodiment a system is provided that includes an amplifier connected to a first electrode in electrical contact with the Earth via an operative capacitive coupling. An additional electrode and amplifier are disposed in the borehole opposite the first electrode and constitute a first pair of electrodes spaced in a direction orthogonal to the axis. A second electrode is part of a group of counter electrodes spaced from each other and disposed outside the borehole. The first pair of electrodes and the amplifiers are configured to be one of a source that generates an electrical field in a direction substantially orthogonal to the axis of the borehole and a sensor that measures an electric field substantially orthogonal to the axis of the borehole.

System and method to measure or generate an electrical field downhole

A method is provided for determining whether a change in a subsurface formation, such as fractures produced within the earth during a fracturing process, has reached and/or crossed a given boundary. The method provides near real time assessment of fracture propagation that can be used to guide a fracturing, particularly a hydrofacturing process.

Method for mapping the propagation of earth fractures

A first electrode is located at a borehole and a second electrode is located at the surface of the earth. At least one transmitter is selectively connected to one or both of the first and second electrodes to cause current to flow within a subsurface of the earth. When the at least one transmitter is connected to the first electrode, a current is caused to flow at a deep depth within the subsurface and deep source data is acquired. When the at least one transmitter is connected to the second electrode, a current is caused to flow at a shallow depth within the subsurface and shallow source data is acquired. The deep and shallow source data are then combined.

System and method for surveying a subsurface of the earth

An electromagnetic sensing system operates either in land environments or in marine environments on the floor of a body of water to measure electromagnetic fields. The sensing system has electrodes that provide capacitive coupling to the local environment where measurements are being made. A new method of deployment in water provides considerable size and weight reductions. The size and weight reductions also facilitate deployment and rapid repositioning on land. The system is particularly beneficial for surveying sites adjacent to bodies of water.

Sensor for measuring the electromagnetic fields on land and underwater

A method for efficiently calculating a subsurface distribution of electrical resistivity or conductivity generated by an electromagnetic (EM) source is provided wherein a significant fraction of the electric current produced by a source flows along a casing of a borehole. The method is comprised of two steps: calculating EM fields produced by the casing in the background lithology; and calculating EM fields caused by a resistivity anomaly in the presence of an EM field produced by the casing within a subsurface or survey model that does not include the casing.

Subsurface resistivity modeling with electromagnetic fields using a conductive casing

An underwater EM measurement system, which is substantially smaller, much simpler to use, and more robust than prior systems, is formed as a sensor package integrated into a single pressure vessel includes two magnetic sensors including induction coils disposed substantially horizontally so as to measure fields in orthogonal directions. The package also includes two electric field sensors including electric potential antennas adapted to couple to a water potential via a capacitive electrode having a conducting material and an electrically insulative layer formed of an insulating material. The capacitive electrode has a capacitance to the medium of greater than 1 mF. Preferably, the insulating material is a metal oxide.

Compact underwater electromagnetic measurement system using magnetic sensors and electrical sensors having capacitive electrodes

A system and method for improving student learning includes learning material that is presented to a student and a device that is used to acquire physiological data from the student in real time during a learning session. A cognitive assessment algorithm determines a cognitive state of the student using the physiological data, and a learning action algorithm modifies the presentation of the learning material in response to the student's cognitive state. The learning material can include lectures, questions asked of the student or problems or activities being completed by the student. In one embodiment, the device directly measures the brain activity of the student to determine the student's cognitive state. The cognitive state of the student can include the student's cognitive load, engagement or fatigue.

System and method for improving student learning by monitoring student cognitive state

System and method to measure or generate currentless electrical field downhole

A system enables a borehole casing to be used to connection with establishing electromagnetic fields within the earth at the depth of formations of interest over a significant surface area. A particular advantage is that a borehole casing can be used as an essential part of the system, without needing to open the borehole.

System and method to induce an electromagnetic field within the earth

Resistivity in subsurface earth at locations kilometers away from wells in the reservoirs is mapped and monitored. An electromagnetic source with an electrode is deployed a borehole in the reservoir, and a group of sensors at counter electrodes is deployed at a number of other locations radially spaced at some distance from the well. The source transmits a current which flows to the counter electrodes causing an electromagnetic field which is sensed at the sensors. The source is activated at different depths in the well and ratios of the electromagnetic field sensed with the source at different depths used to obtain data to map the resistivity. The sensors are capable of sensing electromagnetic fields along two orthogonal axes, and the measurements at a sensor along these axes used to reduce undesirable effects of noise and other factors on the data measurements.

Mapping resistivity distribution within the earth

Errors produced in a borehole to surface electromagnetic (BSEM) survey by near surface electrical anomalies on the estimates of formation properties are reduced. The effects of variations in subsurface electrical resistivity near the surface are separated from electrical resistivity changes at locations in the formations of interest far from the measurement region. A survey system includes one or more electrodes to inject electrical current at formation depth within a borehole, one or more counter electrodes which collect such current on the surface of the earth, and one or more electrodes to inject current on the surface. A transmitter is selectively connectable to different sets of the electrodes to cause a current to flow between the selected electrode sets. The resultant fields from the current flow are sensed and processed. The effects of near surface anomalies are detectable in the data and removable from the survey data of interest regarding the formations. The survey data more accurately indicates formation features or properties of interest.

Borehole electric field survey with improved discrimination of subsurface features

Methods, systems, and apparatuses for measuring an electric potential in the earth, which includes a first sensor are disclosed. The first sensor includes a sensing plate for placement in an environment in close proximity to the earth. The sensing plate has an operative capacitive coupling with the earth and measures the earth's electric potential. The sensor also includes a barrier providing electrochemical segregation between the sensing plate and the earth and an amplifier having at least one stage for receiving and amplifying a first signal carrying the potential measured by the sensing plate. The sensor also includes a first connection carrying the first signal from the sensing plate to the amplifier; and a reference voltage for application to the first stage of the amplifier, the reference voltage providing a reference against which the potential measured by the sensing plate is compared. Other embodiments are described and claimed.

Methods, systems and apparatuses for sensing and measuring the electric field within the earth

An apparatus and method for sensing time varying ionic current in an electrolytic system having a first fluid chamber and a second fluid chamber separated by a barrier structure is provided, wherein the barrier structure includes thick walls and a substrate having an orifice therein, with the first and second fluid chambers being in communication via the orifice. A potential is applied between electrodes in respective first and second fluid chambers, thus driving an electrical current between them and through the orifice. Total capacitance of the system is less than 10 pF. Analytes are added to one of the first and second fluid chambers and time varying ionic current that passes across the orifice is measured. An amplifier proximal to the barrier structure and electrodes amplifies the ionic current signal.

Apparatus and method for sensing a time varying ionic current in an electrolytic system

An electrolytic system includes an analyte chamber having an access port for introducing a sample containing a molecules of interest, such as DNA. Electrodes create an electric field along a length of the analyte chamber to drive molecules toward an interaction region containing a nanopore, thereby increasing the arrival rate of molecules at the nanopore. Additional electrodes may be utilized to create an electric field through the nanopore to drive a molecule into the nanopore. A current sensor may be utilized to count, discriminate or characterize the molecules as they interact with the nanopore. Advantageously, system can be utilized for unamplified DNA sequencing.

System and method for increasing polymer/nanopore interactions

A self-locating mounting apparatus for holding objects such as sensors at specific positions on a subject's head includes a central mount constituted by a plurality of inextensible elements adapted to fit over the top of a subject's head. In addition, the mounting apparatus includes an adjustable circumferential band adapted to circle the subject's head and connect the central mount to inextensible side elements via sliding joints. A plurality of biasing elements provide a force for biasing sensor mounting units on the mounting apparatus against a subject's head, allowing for long-term sensing while minimizing interference forces on the mounting units. Advantageously, the mounting apparatus holds sensors within approximately 5 mm of their desired measurement positions over a range of subject head sizes.

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La Jolla, CA, United States of America

Andrew Dennis Hibbs