Current Issue

In this article, the Editor of Geophysics provides an overview of all technical articles in this issue of the journal.

The model used to explain potential-field data is highly dependent on the constraints applied in the modeling process. Many studies demonstrate the necessity of constraining gravity and magnetic models. However, typically, they do not demonstrate ...

Gravity data are “nonunique” in that a gravity anomaly can be explained by many bodies with different properties. Similarly, in seismic data, the strength of a reflection is dependent on the product of the density and the seismic velocity, so the ...

Geologic risk assessment and prediction are vital processes preceding the design and construction of tunnels, offering crucial insights for ensuring the safe and efficient execution of tunnel projects. The geologic challenges posed by water inrush ...

Subsurface anisotropy is commonly induced by shale layers, aligned cracks, and fine bedding and has a significant impact on seismic wave propagation. Ignoring anisotropic effects during seismic migration degrades image quality. Therefore, we ...

Seismic anisotropy, characterized by direction-dependent seismic velocity and attenuation, is a fundamental property of the earth, widely observed in field and laboratory measurements. This anisotropy significantly influences seismic wavefield ...

Ray-tracing in anisotropic media is pivotal for interpreting observed seismic data and creating high-resolution images of subsurface structures, which are crucial in exploration geophysics. Elliptical anisotropy, a simplified model that ...

Computation of the ray-velocity vector is crucial in seismic ray tracing for the three body waves (qP, qSV, qSH) in viscoelastic anisotropic media. The primary challenge is dealing with the likely cusps or triplications of the qSV wavefronts, ...

Predicting permeability accurately is crucial for effective hydrocarbon extraction, but the intricate pore structures of tight carbonates resulting from sedimentation, diagenesis, and tectonic activity present significant challenges. Based on ...

Continuous integration of real-time logging-while-drilling data into a subsurface model with relevant geologic uncertainties enables strategic geosteering, a field-level optimization of the well-placement strategy. Model errors arising from ...

As the demand for nonrenewable oil and gas resources has increased, distributed acoustic sensing systems (DAS) have been widely used in the acquisition of vertical seismic profiles. Complicated subsurface conditions produce many types of noise ...

Fiber-optic sensing technologies allow petroleum engineering teams to detect hydraulic fracture interaction with boreholes during unconventional reservoir stimulation. In combination with high-repeatability seismic sources, the same distributed ...

Accurate anomaly azimuth identification is a major challenge in borehole acoustic reflection imaging. We develop an azimuth estimation method using an acoustic vector array to address this issue. This method is rigorously tested through a physical ...

Seepage is a common hydrogeologic hazard in engineering. Determining the seepage paths is vital for derisking the instability of embankment structures. With the improvement of the acquisition accuracy of magnetic sensors, the magnetometric ...

Efficient forward modeling of electromagnetic (EM) fields is the basis of interpretation and inversion of the EM data, which plays an important role in practical geophysical exploration. A novel extrapolation cascadic multigrid (EXCMG) method is ...

The semiairborne transient electromagnetic method (SATEM) is a geophysical method that combines the advantages of high-power ground-based transmitting and efficient airborne observation. In recent years, the threshold for SATEM application has ...

A total of 54 new core samples are built by mixing smectite-rich MX80-bentonite and Fontainebleau (silica) sand to study the effect of a hyperalkaline pore solution (including the presence of potassium) on the induced polarization properties of ...

Small-loop transient electromagnetic (TEM) devices, several meters in size, are increasingly applied to near-surface geophysical exploration in space-limited environments. But the transmitter (TX) coil significantly affects the early time data ...

We present a Python code that implements a novel threshold-free polarization strategy for removing random noise from 3C linearly polarized seismic data. The code, which we refer to as polarization denoising through windowing (poldw), uses closed-...

The performance of full-waveform inversion (FWI) in constructing high-resolution subsurface models is closely related to the design of mismatch functions. The least-squares norm (ℓ2) is commonly used; however, it is prone to local minima when high-...

We investigate the efficacy of spatial frequency filtering in improving gravity inversion when gravity gradient data are unavailable. The technique simulates gravity gradient data from gravity readings by extracting distinct frequency components. ...

Inversion is one of the key and difficult issues in potential field data processing and interpretation, and high-precision inversion has long been a popular research topic. We develop the distance-regularized level set inversion of the magnetic ...

Enhancing accuracy remains the main challenge for the current horizon extraction algorithms. Adding more manually interpreted seeds helps to improve the accuracy of horizon extraction. We intend to generate more seeds prior to the 3D horizon ...

Fault detection from seismic data is a critical component of hydrocarbon exploration and production. In recent years, deep-learning techniques have made tremendous achievements and breakthroughs in seismic fault detection. Especially U-nets, ...

The attenuation characteristics of a medium involve the absorption of electromagnetic wave energy during its propagation and represent a crucial parameter for describing the properties of subsurface media. Due to the complex nature of signal ...

Scientific assessment of the transport channels and distribution of oil, gas, water, and other fluids is the key to enhancing oil and gas production capacity and ensuring the safe and efficient development of mineral resources. Traditional ...

The purposes of this paper are to clarify the spatial spreading characteristics of the channel sand body in the Jurassic Shaximiao Formation reservoir in central Sichuan and to improve the precision of channel characterization. Aiming at the ...

Deep-learning methods are being successfully applied to seismic inversion and reservoir characterization problems; however, the uncertainty quantification process has not been fully studied. We investigate probabilistic approaches for seismic ...

The seismic inversion method is a pivotal approach for acquiring porosity parameters. The performance of inversion depends on several factors, such as algorithm stability, the precision of the rock-physics model, and the quality of seismic data. ...

Accurate characterization of carbonate pore types is of great significance for seismic reservoir characterization. However, the existing pore-type inversion methods cannot characterize the coexistence of three main pore types (vuggy pores, matrix ...

The data assimilation process for geothermal reservoirs often relies on well data, which primarily offer insights into the immediate vicinity of the borehole. However, integrating geophysical methods can provide valuable information beyond well ...

Compared with other sedimentary rocks, the strong elastic anisotropy of shale is extremely prominent, which is mainly caused by the preferred orientation and platy nature of its clay minerals. Especially in seismic reservoir characterization, a ...

Quantitative analysis of the relationship between seismic wave velocities and fluid saturation in porous media is of great significance for any fluid injection and extraction operation in subsurface rock formations. However, seismic velocities are ...

Seismic dispersion, attenuation, and frequency-dependent anisotropy due to wave-induced fluid flow in fluid-saturated porous and fractured rocks have been widely studied. However, most of these studies do not consider the effects of background ...

The elastic anisotropy of coal formations is important for the prediction of unconventional coalbed methane reservoir performance and hydraulic fracturing. Although essential for several geophysical applications, the elastic anisotropy of coals is ...

Accurate horizon recognition within poststack seismic sections is important in seismic interpretation. Horizon picking techniques influence diverse seismic structural analyses and inversion methodologies. Despite encountering challenges such as ...

Understanding hydraulic fracturing is crucial to improving the stimulation of unconventional reservoirs and increasing fluid production. This study develops a novel seismic monitoring technology using distributed acoustic sensing (DAS) and surface ...

Seismic interferometry is widely used to image and monitor earth structures at different scales by extracting an empirical Green’s function (EGF) from the crosscorrelation of ambient noise under the assumption of diffuse wavefields or energy ...

In recent years, machine-learning (ML) approaches have gained significant attention in seismic-based subsurface property estimation problems. However, because of the data-driven nature of these methods, it is challenging to evaluate the quality of ...

Building a high-resolution acoustic-impedance (AI) model based on nonstationary seismic data plays a key role in reservoir predictions. However, the common AI inversion methods are faced with two main shortcomings. First, because of the ...

Time-lapse inversion plays an important role in monitoring applications. Uncertainties in seismic inversion mean that there are many time-lapse changes in subsurface properties consistent with a given time-lapse data set and monitor survey, ...

Seismic data acquired at different times over the same area can provide insight into changes in an oil/gas reservoir. Probabilities for pore fluid will typically change, whereas the lithology remains stable over time. This implies significant ...

Least-squares reverse time migration has emerged as a powerful tool to generate high-quality images by progressively decreasing the misfit between the observed data and the modeled data. In the construction of an inverse problem from a modeling ...

By completely solving the second-order full-acoustic wave equation, two-way/full wave equation migration generates images up to arbitrary angles in inhomogeneous media. Full wave equation depth migration (FWDM) necessitates less wavefield storage ...

In geophysical numerical models using the finite-element method or its variant, the spectral-element method, to solve seismic wave equations, a mesh is used to discretize the domain. Generating or adapting a mesh to complex geologic properties is ...

Understanding wave scattering in the earth is considered fundamental in describing seismic wave propagation and providing information on structural features of the earth’s interior. Petrophysical parameters (especially porosity and permeability) ...

Subsurface reservoirs are compressed by overburden stress resulting from the gravity of overlying masses, and the resulting stress changes significantly affect the seismic reflection responses generated at the reservoir interfaces. Several exact ...

We review five types of physics-informed machine-learning (PIML) algorithms for inversion and modeling of geophysical data. Such algorithms use the combination of a data-driven machine-learning (ML) method and the equations of physics to model or ...

Traveltime tomography, or traveltime inversion, has been one of the primary seismological tools for decades and has been used to understand the earth’s properties and dynamic processes. An accurate, preferably flexible, eikonal solver to compute ...

We adapt the one-lag-correlation (OLC) method to estimate the local dips of seismic events. The resulting local dips have extensive applications in exploration geophysics, such as seismic inversion regularization, computation of seismic attributes ...

Seismic denoising methods using supervised training normally rely on a large number of high-quality paired training data sets to obtain satisfactory results. There are two ways to generate labels for network training: one is to create synthetic ...

Understanding the orientation of geologic structures is crucial for analyzing the complexity of the earths’ subsurface. For instance, information about geologic structure orientation can be incorporated into local anisotropic regularization ...

Seismic data reconstruction has become a central focus in seismic data processing, addressing challenges posed by sparse sampling due to physical and budgetary constraints. The advent of 5D acquisition methodologies marks a significant advancement ...

Managing seismic scattering noise in geophysical surveying, especially from near-surface heterogeneity, presents significant challenges. We revisit the role of receiver arrays in mitigating such noise in regions with near-surface meter-scale ...

Compressive sensing (CS) is an alternative to regular Shannon sampling that captures similar information from reduced measurements. It relies on randomized sampling patterns and a sparse data representation to reconstruct the regularly sampled ...

Distributed acoustic sensing (DAS) is a promising technology introducing a new paradigm in the acquisition of high-resolution seismic data. However, DAS data often show weak signals compared with the background noise, especially in challenging ...

In real-world scenarios, the effectiveness of seismic denoising methods based on supervised learning (SL) is hindered by the scarcity of clean labeled data. A network trained on synthetic data often struggles to adapt to the distinct feature ...

Ocean-bottom nodes (OBNs) are widely used because of their wide azimuth, long-offset, and low-frequency advantages. However, in the vertical component of the OBN geophone, a significant amount of S-wave induced noise may be recorded. This ...

Ocean-bottom seismic plays a crucial role in resource exploration and monitoring. However, despite their undoubted potential, the use of coarse receiver geometries poses challenges to accurate wavefield redatuming. This in turn affects the quality ...

The physical and cost limitations of seismic data acquisition often result in the spatial undersampling of data, which has a detrimental impact on subsequent data processing. Seismic data reconstruction plays a crucial role in recovering missing ...

Marine seismic reflection surveys generate high-amplitude impulsive acoustic events using airgun arrays to study the geophysical characteristics of the seabed. These data can be used beyond seismic imaging, including for modeling short-range ...