Certain aspects of the present disclosure provide methods and apparatus for closed-loop control of a system using one or more electron paramagnetic resonance (EPR) sensors located on-site. With such EPR sensors, a change can be applied to the system, the EPR sensors can measure the effect(s) of the change, and then adjustments can be made in real-time. This feedback process may be repeated continuously to control the system.

A system and method for evaluating a subterranean earth formation as well as a method of steering a drill bit in a subterranean earth formation. The system comprises a logging tool that is operable to measure formation data and locatable in a wellbore intersecting the subterranean earth formation. The system also comprises a processor that is in communication with the logging tool. The processor is operable to calculate multiple distance-to-bed-boundary (DTBB) solutions using the measured formation data, identify DTBB solutions that satisfy a threshold, convert the identified solutions into pixelated solutions by dividing the identified solutions into pixels, generate a formation model based on the pixelated solutions, and evaluate the formation using the generated formation model.

A system and method for evaluating a subterranean earth formation as well as a method of steering a drill bit in a subterranean earth formation. The system comprises a logging tool that is operable to measure formation data and locatable in a wellbore intersecting the subterranean earth formation. The system also comprises a processor that is in communication with the logging tool. The processor is operable to calculate multiple distance-to-bed-boundary (DTBB) solutions using the measured formation data, identify DTBB solutions that satisfy a threshold, convert the identified solutions into pixelated solutions by dividing the identified solutions into pixels, generate a formation model based on the pixelated solutions, and evaluate the formation using the generated formation model.

Disclosed are a multi-line source ground-borehole transient electromagnetic detection method and a multi-line source ground-borehole transient electromagnetic detection device. The method includes following steps: S1, constructing a multi-line source ground-borehole transient electromagnetic forward model; S2, obtaining multi-line source ground-borehole transient electromagnetic responses of an underground target layer by the multi-line source ground-borehole transient electromagnetic forward model; and S3, recognizing the underground target layer according to electromagnetic diffusion characteristics of the multi-line source ground-borehole transient electromagnetic responses. A resolution and a detection capability of the underground target by a ground-borehole transient electromagnetic method is greatly improved by adopting technical schemes.

A subterranean earth formation is evaluated by running a process with a logging tool residing in a borehole in the earth formation to collect shallow measurements of a property of the formation and deep measurements of the property of the formation. An inversion is performed on the shallow measurements to produce a group of possible formation models that fit the shallow measurements. A machine-learning algorithm is applied to estimate the shallow formation structure, using the group of possible formation models that fit the shallow measurements, to produce a shallow formation structure. An inversion is performed on the deep measurements to produce a group of possible formation models that fit the deep measurements. The shallow formation structure is expanded using the group of possible formation models that fit the deep measurements to produce a deep formation structure.

A subterranean earth formation is evaluated by running a process with a logging tool residing in a borehole in the earth formation to collect shallow measurements of a property of the formation and deep measurements of the property of the formation. An inversion is performed on the shallow measurements to produce a group of possible formation models that fit the shallow measurements. A machine-learning algorithm is applied to estimate the shallow formation structure, using the group of possible formation models that fit the shallow measurements, to produce a shallow formation structure. An inversion is performed on the deep measurements to produce a group of possible formation models that fit the deep measurements. The shallow formation structure is expanded using the group of possible formation models that fit the deep measurements to produce a deep formation structure.

A method for evaluating saturation of a kerogen bearing subterranean formation includes obtaining conductivity and permittivity values of the formation and providing an effective medium model relating the conductivity and the permittivity to a water filled porosity of the formation and an effective aspect ratio of graphitic kerogen particulate in the formation. The obtained conductivity and the permittivity values are input into the model which is in turn processed to compute the water filled porosity. The method may further optionally include evaluating the water filled porosity to estimate a hydrocarbon producibility of the formation.

A method for evaluating saturation of a kerogen bearing subterranean formation includes obtaining conductivity and permittivity values of the formation and providing an effective medium model relating the conductivity and the permittivity to a water filled porosity of the formation and an effective aspect ratio of graphitic kerogen particulate in the formation. The obtained conductivity and the permittivity values are input into the model which is in turn processed to compute the water filled porosity. The method may further optionally include evaluating the water filled porosity to estimate a hydrocarbon producibility of the formation.

A digitizing apparatus for transmitting electromagnetic telemetry signals to facilitate drilling operations comprises a local receiver and one or more remote transmitters. A method uses the remote transmitter to measure an electric potential between a pair of ground stakes that are positioned at some distance away from the local receiver. The local receiver is coupled to a surface receiver that is located at or near a drilling rig. The remote transmitter converts the electric potential into a digital signal and transmits the digital signal wirelessly to the local receiver. The local receiver then converts the digital signal into an analog signal that is provided to the surface receiver for processing. The remote transmitter and local receiver may comprise GPS clocks to synchronize the signals to maintain a constant phase shift.

A digitizing apparatus for transmitting electromagnetic telemetry signals to facilitate drilling operations comprises a local receiver and one or more remote transmitters. A method uses the remote transmitter to measure an electric potential between a pair of ground stakes that are positioned at some distance away from the local receiver. The local receiver is coupled to a surface receiver that is located at or near a drilling rig. The remote transmitter converts the electric potential into a digital signal and transmits the digital signal wirelessly to the local receiver. The local receiver then converts the digital signal into an analog signal that is provided to the surface receiver for processing. The remote transmitter and local receiver may comprise GPS clocks to synchronize the signals to maintain a constant phase shift.