A method and system for electromagnetic method (EM) signal detection based on an onshore sparker source, the method including: arranging an EM signal detection system near a sparker source; releasing, by the sparker source, an electromagnetic pulse concomitantly in a discharge and mechanical energy output process; observing an electromagnetic response generated by the earth under the excitation of the electromagnetic pulse by means of the EM signal detection system for extracting distribution information of geo-electrical parameters; when the sparker source moves, moving the electromagnetic method signal detection system to a new position along with the sparker source while keeping their positions relative to each other unchanged; and repeating the above process after the movement is completed. According to the technical solution of the present invention, fine electromagnetic detection results can be obtained while seismic detection is carried out.

The invention relates to hydroacoustic domain, notably to methods and devices of active location. The method of controlling intercarrier frequency wave efficiency with parametric radiating antenna is based on placing electroacoustic transducer with piezoelement with given resonance frequency (f.sub.1+f.sub.2)/2=f.sub.0 and pass band corresponding to intercarrier frequency wave diapason in locating area, feeding electric signals from radiating tract output to electroacoustic transducer piezoelement, forming in locating area spatial area of collinear distribution and non-linear interaction of intense ultrasound pimp waves, generation of intercarrier frequency wave with cyclic frequency Ω=2π|f.sub.1−f.sub.2|. New features are the following: multicomponent excitation signal if formed due to generating in radiating tract N oscillations with similar amplitude and with similar initial phase at the period of time t=0), with frequencies ω.sub.v, sequentially differing from each other by Ω=2πF_ and situated in pass band of piezoelement and coming from radiating tract output to piezoelement with resonance cyclic frequency ω.sub.0=2πf.sub.0 electric multicomponent signal of escitation, presented as sum of N oscillations and regulation of generation efficiency and adjusting of field parameters (N−1) of intercarrier frequency component wave with cyclical frequencies Ω, 2Ω, . . . , (N−1)Ω formed by parametric radiating antenna, implemented by switching off of antiphase switching on of given constituents set. The method is implemented due to the device that includes reference generator, delayed pulse-shaping circuit, (N−1) coincidence circuit, N frequency dividers, analog switch, adder, amplitude modulator, impulse generator, power amplifier, electroacoustic transducer, controlling and adjustment unit.

A method for characterizing a hydraulic fracture in a subsurface formation includes inducing a pressure change in a borehole drilled through the subsurface formation. At least one of pressure and a time derivative of pressure is measured in the borehole for a selected length of time. At least one physical parameter of at least one fracture is determined using the measured pressure and/or the time derivative of pressure. A method for characterizing hydraulic fracturing rate uses microseismic event count measured through the borehole and its real-time implementation.

A wave detector integrated device includes a support, protective shell and mode converter. The protective shell is installed on the support and rotates by the mode converter, and has a hollow cylindrical structure. A seismic source hammer is suspended at a protective shell central axis position. Electromagnetic accelerators are installed in a bus direction of the protective shell, and the seismic source hammer is connected with the electromagnetic accelerators. A drill bit type wireless transmission wave detector or standby flat bottom type wave detector is connected above the protective shell through a second telescopic rod having a driving device therein and driving the drill bit type wave detector to rotate. A power supply is installed inside the protective shell, and is connected with a current controller and circuit protection device. The current controller is respectively connected with the electromagnetic accelerators, drill bit type wave detector, driving device and mode converter.

A lift based acoustic source is towable in an undersea environment by a towing vessel. A controller provides a combined lift control signal and an acoustic source signal. A control cable is joined between the towing vessel and a towed depressor having an active lift control system. The combined signal is used to control the towed depressor active lift control system. The towed depressor lift fluctuates in response to the source signal to generate the undersea acoustic signal. A hydrophone or hydrophone array can be provided for measuring the generated acoustic signal for feedback and monitoring.

A method is disclosed for radiaiiy profiling shear velocities of flexural wave modes in a formation. The method includes establishing sensitivity kernels with two non-dimensionalized parameters and using said sensitivity kernels to perform an inversion for radial shear wave velocity profiles. This method may be used for LWD, MWD, or wireline logging operations.

According to an example, with respect to blast reconciliation for mines, pre blast measurement data and post blast measurement data associated with a blasting operation for a mining site may be ascertained from a pre and post blast measurer. A blast reconciliation model may be generated using existing pre blast measurement data and existing post blast measurement data, and used to analyze the ascertained pre blast measurement data and the ascertained post blast measurement data. Based on the analysis of the ascertained pre blast measurement data and the ascertained post blast measurement data, a blast material yield for the mining site may be determined as a result of the blasting operation. An alert indicative of the blast material yield may be generated.

A method for building a three dimensional (3D) model of a subsurface formation includes selecting, from a set of seismic shots, a plurality of first arrival signals representing the seismic shots. The method includes applying a quality control function to the plurality of first arrival signals to obtain a set of remaining first arrival signals. For each remaining first arrival signals, the method includes applying a velocity inversion function to obtain a depth velocity value at a common-midpoint (CMP) location in a shot gather including the seismic shot associated with that remaining first arrival signal, the CMP location representing a lateral variation of the shot gather including that seismic shot. The method includes, based on the depth velocity value for the seismic shot associated with each remaining first arrival signal, generating a velocity model representing the 3D model of the subsurface formation.

The present disclosure includes a method for combining controlled and uncontrolled seismic data. The method includes accessing one or more controlled signals, each controlled signal associated with a respective receiver of a plurality of receivers. The method also includes accessing one or more uncontrolled signals, each uncontrolled signal associated with a respective receiver of the plurality of receivers. The method also includes generating one or more reconstructed signals based on the one or more uncontrolled signals. The method also includes generating a composite image based at least on the one or more controlled signals and the one or more reconstructed signals. The present disclosure may also include associated systems and apparatuses.

A tool assembly and method are for performing formation stress testing in an openhole section of a borehole, wherein the openhole section of the borehole is to be provided with, or already have been provided with, a perforation tunnel generated by a series of electrically induced focused acoustic shock waves. The tool assembly has at least two borehole isolation means arranged with an axial distance therebetween for forming an isolated section at the openhole section of the borehole; a pump device for altering a pressure within the isolated section; a pressure sensor for measuring a pressure within the isolated section; a control unit for controlling a testing sequence; an acoustic shock wave device for generating the series of acoustic shock waves to excavate the perforation tunnel; and an acoustic shock wave sub for actuating the acoustic shock wave device.