Heather Bedle

University of Oklahoma | ou · School of Geosciences

Methane gas hydrates are formed in the subsurface along shallow ocean basins or in permafrost settings, and are commonly identified in the seismic data by the bottom-simulating reflector (BSR). Various methods have been employed in the past to measure gas hydrates from lab analyses, well log, or velocity data, but few studies have demonstrated meth...

Seafloor hydrocarbon seepage is a natural fluid release process that occurs worldwide on continental shelves, slopes, and in deep oceanic basins. The Vestnesa sedimentary ridge in the eastern Fram Strait hosts a deep-water gas hydrate system that became charged with hydrocarbons ∼2.7 Ma and has experienced episodic seepage along the entire ridge un...

Gas hydrates that occur on many continental margins have received global attention. In reflection seismic imaging, the bottom-simulating reflector (BSR) is a common indicator of gas hydrates. However, it is difficult to identify gas hydrates and quantify their amounts through the BSR alone. For gas-hydrate characterization, it is therefore useful t...

Recently, there has been increased interest in deep sedimentary systems such as along-slope bottom currents (contourite systems) and their interaction with gravitational sedimentary processes (mixed systems) due to the high reservoir potential of the resulting deposits. In particular, the Contourite Depositional System (CDS) of the Gulf of Cádiz in...

Seismic attributes are routinely applied for interpretation tasks. Changes in amplitude and phase components reveal faults, and provide insights into hydrocarbon reservoir management. We investigate how different seismic attributes improve the recognition of faults. Data conditioning and unsupervised machine learning methods complement the analysis...

An attractive feature seen on seismic data, also known as funny-looking thing (FLT), has a wide range of interpretations, from noise patterns to amplitude anomalies. An example of an FLT is the similar faulting patterns between a volcanic intrusion and a salt intrusion from the point of view of a machine learning (ML) algorithm. Oftentimes, seismic...

“The present is the key to the past” is a foundational geologic concept that helps us contextualize buried subsurface features in current geologic analogs. As seismic interpreters, the generation of the geologic model should be unbiased, yet as humans our unconscious biases are expected, and we sometimes overlook anomalous reflection patterns in ou...

In this study, we evaluated the injectivity and storage potential variability of the Arbuckle Group at the Wellington Field, Kansas. We first defined three petrophysics-based rock types (petrofacies) from core porosity and permeability measurements using the flow-zone indicator (FZI) approach. The petrofacies correspond to argillaceous dolo-packsto...

Basin analysis experts use distinctive seismic features like pockmarks or polygonal faulting to understand subsidence histories, migrations pathways, and sedimentation patterns in frontier basins. As geoscientists need to understand migrations paths and fluid accumulations, we rely on seismic methods to image features that aid us in gaining insight...

An effective method of identifying and discriminating undersaturated gas accumulations remains unresolved, resulting in uncertainty in hydrocarbon exploration. To address this problem, an unsupervised machine learning multi-attribute analysis is performed on 3D post-stack seismic data over several blocks within the deepwater Gulf of Mexico and with...

We utilise 3D seismic data and robust rock-physics models that are combined with a well dataset to investigate the subsurface of the Mundaú sub-basin, Brazil. Seismic attributes analysis and unsupervised machine learning approaches were able to produce high-resolution images to allow the mapping of the 3D geometry of ancient geomorphological featur...

Fault identification is a critical component of seismic interpretation. During the past 25 years, coherence, curvature, and other seismic attributes sensitive to faults improved seismic interpretation, but human interaction is still required to generate a complete fault interpretation. Today, image enhancement of fault-sensitive attributes, multiat...

During the past two decades, geoscientists have used machine learning to produce a more quantitative reservoir characterization and to discover hidden patterns in their data. However, as the complexity of these models increase, the sensitivity of their results to the choice of the input data becomes more challenging. Measuring how the model uses th...

In geosciences, a variety of machine learning (ML) algorithms are currently being employed for multiple purposes, for example, facies classification, fault prediction, and reservoir characterization. Among these are two clustering methods: principal component analysis (PCA) and self-organized maps (SOMs), which provide a fast organization of data i...

Fault identification is critical in defining the structural framework for both exploration and reservoir characterization studies. Interpreters routinely use edge-sensitive attributes such as coherence to accelerate the manual picking process, where the actual choice of a particular edge-sensitive attribute varies with the seismic data quality and...

The use of unsupervised machine learning (ML) methods such as self-organizing maps (SOMs), has gained a significant foothold within the seismic interpretation community to enhance results and help identify similar patterns in the data. Workflows for each geological setting become, however, necessary. We analyzed a series of geometrical, instantaneo...

Identifying gas hydrates in the oceanic subsurface using seismic reflection data supported by the presence of a bottom simulating reflector (BSR) is not an easy task, given the wide range of geophysical methods that have been applied to do so. Though the presence of the BSR is attributed to the attenuation response, as seismic waves transition from...

A comprehensive North American upper mantle seismic‐tomographic model, NA13, was inferred from a combination of several decades of seismic data from early North American seismic networks and USArray data. This data‐driven modeling inverted a combination of regional waveform fits, teleseismic S delay times, and point constraints on Moho depths. The...

The factors that promote stability of Archean cratons are investigated from a combined geodynamic, geological, and geophysical perspective in order to evaluate the relative importance of nature—the initial conditions of a craton—versus nurture—the subsequent tectonic processes that may modify and destabilize cratonic lithosphere. In this review stu...

A long-standing problem in the understanding of deep-water turbidite reservoirs relates to how the three-dimensional evolution of deep-water channel systems evolve in response to channel filling on spatiotemporal scales, and how depositional environments affect channel architecture. The 3-D structure and temporal evolution of late Miocene deep-wate...

Seismic interpretation is the end game to our seismic data experiment. This is where all the hard work from seismic theory, modeling, acquisition, processing, and analysis comes together at the desks of the interpreters. They now have the ultimate task of making sense of these data to create and interpret geologically sensible models; build a coher...

A long-standing problem in the understanding of deep-water turbidite reservoirs relates to how the three-dimensional evolution of deep-water channel systems evolve in response to channel filling on spatio-temporal scales, and how depositional environments affect channel architecture. The 3-D structure and temporal evolution of late Miocene deep-wat...

We analyzed a 1991 3D seismic data located offshore Florida and applied seismic attribute analysis to identify geological structures. Initially, the seismic data appears to have a high signal-to-noise-ratio, being of an older vintage of quality, and appears to reveal variable amplitude subparallel horizons. Additional geophysical analysis, includin...

Historically, Silurian pinnacle reef complexes in the Michigan Basin have been largely identified using 2D seismic with very little research on the reservoir characterization of these reefs using 3D seismic data. By incorporating a high-resolution 3D dataset constrained by a well-studied and data-rich paleoreef reservoir, the Puttygut reef, seismic...

The Taranaki Basin, located offshore New Zealand, is a Cretaceous rift basin that has well defined yet complex Miocene deepwater sedimentary systems. We analyze a pronounced anomalous seismic response in a Late Miocene to Early Pliocene deepwater channel within the 2005 Hector 3D survey located in the southern Taranaki Basin. Several seismic attrib...

he discovery of the Jubilee Field in 2007, offshore Ghana, drew attention to the whole of the equatorial Atlantic as a major hydrocarbon province. After that, a series of discoveries in the counterparts, offshore French Guiana, Brazil, Suriname and Guyana, confirmed the importance of this region as an exploration frontier. Most oil and gas discover...

The advancement of seismic attributes and visualization techniques has allowed enhancing the study of seismic geomorphology from 3D re ection data. The study of deepwater deposits de nes and characterizes architectural elements depending on their genesis, morphology, and position along the slope and basin oor. However, the geological con guration o...

Gas hydrates that exist in the subsurface are often difficult to detect with reflection seismic data if the seismic data lacks a strong bottom simulating reflection (BSR). In these cases, the imaging and detection of the gas hydrate stability zone (GHSZ) becomes particularly difficult, as hydrate detection relies heavily on the BSR, gas chimneys, o...

In the southern Taranaki Basin, a thick stratigraphic sequence of late Miocene age is well imaged by modern 3D seismic data. Within this sediment package, the evolution of multiple deepwater channel systems are preserved and interpreted. Anomalous features located between channel complexes are identified in both map-view and vertical sections. Extr...

“Machine learning” has become a common phrase in geophysics. These methods, based on complex algorithms and statistics, allow geoscientists to speed up and improve their interpretations. However, as interpreters, we can feel intimidated and concerned about how much of our expertise can be replaced by machine learning algorithms. To better understan...

In the shallower regions of the 3D Nimitz seismic survey, there exist multiple interesting bright seismic amplitude anomalies. These anomalies, or funny looking things, occur in a confined spatial and temporal region of the seismic. They have a concave-up seismic appearance along the cross section. Bright seismic amplitudes can be a direct hydrocar...

Machine learning models have been widely used by geoscientists to accelerate their interpretation and highlight hidden patterns in their data. However, as the complexity of the model increases, the interpretation of the results can become quite challenging. The SHAP technique provides a measure of the importance of each of the input seismic attribu...

The deepwater Cenozoic strata in the North Carnarvon Basin, Australia, represent an interval of interest for stratigraphic studies in passive margins settings of mixed siliciclastic-carbonate environments. We have explored the geomorphological characteristics of a mass-transport deposit (MTD) within the Trealla Limestone Formation to describe in de...

A seismic-constrain stratigraphic characterization of Cenozoic deep-water strata in the Northern Carnarvon Basin is presented to define a sequence stratigraphic framework and asses a detailed description of the deep-water architectural elements integrating 3D seismic data, well log interpretation and biostratigraphic reports. We evaluate the use of...

A detailed seismic stratigraphy framework for the deep-water Cenozoic deposits in North Carnarvon Basin, is developed using high resolution seismic data along with machine learning techniques. The workflow allows to characterize architectural elements and relate them to a sequence stratigraphy framework for the Cenozoic sequences. We related the se...

The discrimination of low-saturation (fizz) gas reservoirs from commercial quantities of gas remains a challenging problem in petroleum exploration. A low-saturation gas reservoir will have similar seismic amplitude and rock physics responses to that of a commercial, high gas saturation reservoir. Therefore, an effective method of identifying and d...

The discoveries of the Jubilee field offshore Ghana in 2007, as well as the Pecém well in the Ceará Basin in 2012, and Pitu well in the Potiguar Basin in 2013 have attracted the attention of the oil industry to other global transform margins. However, studies on the tectonic regimes associated with transform margins and their evolution, structures,...

The discoveries of the Jubilee field offshore Ghana in 2007, as well as the Pecém well in the Ceará Basin in 2012, and Pitu well in the Potiguar Basin in 2013 have attracted the attention of the oil industry to other global transform margins. However, studies on the tectonic regimes associated with transform margins and their evolution, structures,...

The Taranaki Basin is well known for studies examining the seismic stratigraphy, depositional and erosional features, and tectonic frameworks linked to the New Zealand (NZ) continent. We have examined a “funny looking thing” (FLT) that we associate to be consistent with that of a braided channelized system. We observe this feature within the 3D Nim...

There remains a limited understanding of the controls of pre‐existing structures on the architecture of deep‐water progradational sequences. In the Northern Taranaki Basin (NTB), New Zealand, Pliocene post‐extensional sedimentary sequences overlie Miocene back‐arc volcaniclastic units. We utilize seismic reflection datasets to investigate the relat...

The Taranaki Basin lies in the western portion of New Zealand, onshore and offshore. It is a Cretaceous rift basin that is filled with up to approximately 10 km thick deposits from marine to deepwater depositional environments from the Cretaceous (approximately 93 ma) to the Neogene (approximately 15 ma). This basin underwent important tectonic eve...

The Ceará Basin is a deepwater exploration frontier basin that comprises part of the Brazilian equatorial margin. This basin has been receiving renewed attention from the petroleum industry since the discovery of important deepwater oil fields in its African counterpart. However, detailed seismic stratigraphic, depositional, and structural framewor...

In recent years, the Brazilian Equatorial Margin has drawn attention due to its similarity to areas with new hydrocarbon discoveries in the African conjugated margin, and in French Guiana. However, studies on the tectonic regimes associated with transform margins and their evolution, structures, and petroleum potential are still lacking due to the...

Gas hydrates that exist in the subsurface are often difficult to image with reflection seismic data if the seismic data lacks a strong bottom simulating reflector (BSR). In these cases, the imaging and detection of the gas hydrate stability zone (GHSZ) becomes particularly difficult, as hydrate detection relies heavily on the BSR, gas chimneys, or...

Gas hydrates in the oceanic subsurface are often difficult to image with reflection seismic data, particularly when the strata run parallel to the seafloor and in regions that lack the presence of a bottom-simulating reflector (BSR). To address and understand these imaging complications, rock-physics modeling and seismic attribute analysis are perf...

A detailed study of Pliocene channel systems within the Taranaki Basin was undertaken from the Parihaka 3D seismic volume to improve our understanding of the Plio-Pleistocene channel elements in terms of structure, channel evolution, and lithology. Seismic picking parameters were chosen based on the lateral resolution for optimal mapping of the cha...

One of today's challenges is to maximize recovery from existing assets, which may require drilling horizontal wells in complex and thin reservoirs. Optimal well placement is the key technology to achieve this objective. In the past 15 years, the most effective and widely accepted technologies are borehole images (such as density, Gamma and shallow...

We construct a new three-dimensional S velocity model and Moho map by jointly inverting regional S and Rayleigh waveform fits, teleseismic S and SKS arrival times, fundamental mode Rayleigh wave group velocities, and independent Moho depth estimates for the region that extends from the mid-Atlantic ridge through northern Africa, southern Europe, an...

We estimate radial anisotropy along the Tethyan margin by jointly fitting regional S and Love waveform trains and fundamental-mode Love-wave group velocities. About 3600 wave trains with S and Love waves and 5700 Love-wave group velocity dispersion curves are jointly inverted for SH-velocity perturbations from a pre-existing, 3-D SV-velocity model....

We construct a new 3-D SV-velocity model by jointly inverting regional S and Rayleigh waveform fits, teleseismic S and SKS arrival times, fundamental-mode Rayleigh-wave group velocities, and Moho depth estimates from receiver functions, refraction/reflection lines, and gravity surveys for the region which extends from the mid-Atlantic ridge to the...

Global and regional S and surface wave tomography shows that the US interior is underlain by a relatively thick, high-velocity lithosphere. The seismic velocity and thickness of this lithosphere exhibit lateral heterogeneity to a degree that varies from model to model. Many global models do not contain much heterogeneity despite the presence of nea...

We have developed a variety of S-velocity models for the North American upper mantle through fitting regional S and Rayleigh wave trains that swathe the continent. These wave trains were extracted from seismograms from the IRIS Data Management System, covering seismicity from the years 2000 through 2006, and include waveforms from the Transportable...

We investigate S velocity variation in the upper mantle beneath North American to better understand the effects of data heterogeneity, model parameterization, and regularization. To this end, we analyzed and fit regional S and Rayleigh wave trains generated by earthquakes around North America that occurred between the years 2000 through 2006, inclu...

Seismic tomography has long been a powerful tool for inferring present-day structural variations within the mantle in three dimensions, but does not provide explicit information on the evolution of the mantle. However, in conjunction with geodynamic modeling, mineral physcis, geology, tectonophysics, and geodesy, seismic tomography can provide crit...

We construct a new 3-D S-velocity model by jointly inverting regional S and Rayleigh waveform fits, teleseismic S and SKS arrival times, fundamental-mode Rayleigh-wave group velocities, and Moho depth estimates from receiver functions, refraction/reflection lines, and gravity surveys for the region which extends from the mid-Atlantic ridge to the H...

Seismic tomography has long been a powerful tool for inferring present-day structural variations within the mantle in three dimensions, but does not provide explicit information on the evolution of the mantle. However, in conjunction with geodynamic modeling, mineral physcis, geology, tectonophysics, and geodesy, seismic tomography can provide crit...

Several surface wave tomographic studies of the upper mantle structure beneath North America are presented, which take advantage of high quality seismic data, primarily recorded in the last decade, to create better resolved S-wave tomographic models. The first study presents a regional 3D model, IL05, of the upper mantle beneath the mid-continent U...

For purposes of studying the lateral heterogeneity as well as for ultimately predicting seismograms for the region which extends from the western Mediterranean region to the Hindu Kush, we construct a new 3-D S-velocity model by jointly inverting regional waveforms, surface wave group velocity measurements, teleseismic S arrival times, and crustal...