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With readily available wide-azimuth, onshore, 3D seismic data, the search for attributes utilizing the azimuthal information is ongoing. Theoretically, in the presence of ordered fracturing, the seismic wavefront shape changes from spherical to nonspherical with the propagation velocity being faster parallel to the fracturing and slower perpendicular to the fracture direction. This concept has been adopted and is used to map fracture direction and density within unconventional reservoirs. More specifically, azimuthal variations in normal moveout velocity or migration velocity are often used to infer natural fracture orientation. Analyses of recent results have called into question whether azimuthal velocity linked to intrinsic azimuthal velocity variations can actually be detected from seismic data. By use of 3D orthorhombic anisotropic elastic simulation, we test whether fracture orientation and intensity can be detected from seismic data. We construct two subsurface models based on interpreted subsurface layer structure of the Anadarko Basin in Oklahoma. For the first model, the material parameters in the layers are constant vertically transverse isotropic (VTI) in all intervals. The second model was constructed the same way as the base model for all layers above the Woodford Shale Formation. For the shale layer, orthorhombic properties were introduced. In addition, a thicker wedge layer was added below the shale layer. Using the constructed model, synthetic seismic data were produced by means of 3D anisotropic elastic simulation resulting in two data sets: VTI and orthorhombic. The simulated data set was depth migrated using the VTI subsurface model. After migration, the residual moveouts on the migrated gathers were analyzed. The analysis of the depth-migrated model data indicates that for the typical layer thicknesses of the Woodford Shale layer in the Anadarko Basin, observed and modeled percentage of anisotropy and target depth, the effect of intrinsic anisotropy is too small to be detected in real seismic data.

Hydraulic fracturing operations in unconventional reservoirs are typically monitored using geophones located either at the surface or in the adjacent wellbores. A new approach to record hydraulic stimulations uses fiber-optic distributed acoustic sensing (DAS). A fiber-optic cable was installed in a treatment well in the Meramec formation to monitor the hydraulic fracture stimulation of an unconventional reservoir. A variety of physical effects, such as temperature, strain, and microseismicity are measured and correlated with the treatment program during hydraulic fracturing of the well containing the fiber and also an adjacent well. The analysis of this DAS data set demonstrates that current fiber-optic technology provides enough sensitivity to detect a considerable number of microseismic events and that these events can be integrated with temperature and strain measurements for comprehensive hydraulic fracture monitoring.

Hydraulic fracturing operations in unconventional reservoirs are monitored using distributed fiber-optic sensing through which physical effects such as temperature, strain, and microseismic activity can be measured. When combined with treatment curves and other reservoir information, these measurements give engineers more data to understand the effectiveness of a treatment program and make future reservoir management decisions. Distributed fiber-optic data are acquired within a borehole that is actively being fractured and is subsequently used as an observation well for treatments of a neighboring well. The large-aperture and finely sampled data acquisition provides a variety of measurements at different resolution scales as changes are induced in the reservoir. Distributed acoustic sensing microseismic events are observed with magnitudes above −2. The spatial distribution of events, up to 500 m from the observation well, allows us to estimate diffusivity and fracturing trends for nearby treatment wells. Microseismic events acquired using a standard three-component borehole tool provide insight into the type of events that can be observed only on one system or simultaneously on both systems. We correlate very low frequency (well below 1 Hz) strain-front behavior with the onset of microseismic events, as they are triggered by pore pressure and fracturing progress throughout the reservoir.

46 Background: Genetic susceptibility to colorectal cancer (CRC) include well-defined hereditary syndromes such as Lynch Syndrome, Familial Adenomatous Polyposis syndrome (FAP), MUTYH-Associated Polyposis syndrome (MAP) and other less common syndromes. National Comprehensive Cancer Network (NCCN) guidelines recommend that individuals meeting certain criteria have detailed risk assessment and potential genetic testing. Here, we describe the clinical and molecular characteristics of patients with personal history of CRC evaluated by cancer genetics counseling services. Methods: This is an IRB-approved retrospective chart-review study. Between 2016 and 2020, 1011 unique genetic counseling visits were conducted. Germline testing was recommended by a certified genetic counselor if medically necessary. All patients with a personal history of CRC were identified (N = 52) and their clinical and molecular characteristics were summarized. Results: The median age is 50 years-old (29-82). Thirty-five (67%) patients were females. Caucasians, African Americans and other ethnic backgrounds represented 75%, 19% and 6% respectively. The primary tumor location was in the right colon, left colon and rectum in 29%, 37% and 27% of our cohort respectively. In 7%, the primary location of the tumor was not available. In our cohort, 11 out of 52 (21%) patients had a pathogenic germline mutation and 9 patients (17%) had a germline variant of unknown significance (VUS). Among patients with pathogenic germline mutations (N = 11), 4 patients had MSH2 mutations (MSH2 c.1759+1G > A, MSH2 c. 1687dupT, MSH2 c.1861C > T and MSH2 c.811_814delTCTG), 1 patient had a MSH6 mutation (MSH6 c.1012A > T), 1 patient had a PMS2 mutation (PMS2 c.2182_2184delACTinsG), 3 patients had CHEK2 mutations (CHEK2 c.1100delC and CHEK2 c.470T > C (p.I157T)), 2 patients had MUTYH mutations (MUTYH c.1187G > A and MUTYH c.536A > G) and 1 patient had a BRCA2 mutation (BRCA2 c.2808_2811delACAA). One patient had a CHEK2 and a MUTYH mutation. The VUS mutations in our cohort were POLE c.1645T > C, POLE c.5480C > T, c.2999G > A, MLH1 c.1628A > G, CTNNA1 c.503G > A, MSH2 c.128A > G, NBN c.16C > T, ATM c.6537T > G and AXIN2, BRCA1, NTHL1 mutations. Conclusions: In our cohort of patients with personal history of CRC, the majority of patients (62%) had negative germline testing. An underlying pathogenic germline mutation and VUS were identified in 21% and 17% of the patients respectively. Lynch Syndrome was the most commonly diagnosed hereditary CRC syndrome with 6 out of 11 patients found to have MMR germline mutations. Other pathogenic mutations were identified in the CHEK2, MUTYH and BRCA2 genes.

47 Background: National Comprehensive Cancer Network (NCCN) guidelines recommend that individuals with >10 adenomatous polyps, ≥2 hamartomatous polyps, or ≥5 serrated polyps proximal to the sigmoid colon have detailed risk assessment and potential genetic testing to rule out polyposis syndrome. Here, we describe germline testing of patients with a personal history of colorectal polyposis by Cancer Genetics Counseling Services. Methods: This is an IRB-approved retrospective chart-review study. Between 2016 and 2020, 1011 unique genetic counseling visits were conducted. Germline testing was recommended by a certified genetic counselor if medically necessary. All patients with a personal history of colorectal polyposis were identified (N=20) and their germline testing results were summarized. Results: The reasons for referral to the Cancer Genetics Counseling Services were personal history of >10 adenomatous polyps (N=13), personal and family history of colorectal polyposis (N=3), personal history of juvenile colorectal polyps (N=3) or personal history of ≥2 hamartomatous polyps (N=1). The median age is 58 years-old (1-84). Ten (50%) patients were females. Caucasians, African Americans and other ethnic backgrounds represented 80%, 10% and 10% respectively. In our cohort, 6 out of 20 (30%) patients had a pathogenic germline mutation, 5 (25%) patients had variant of unknown significance (VUS) and 9 (45%) patients had negative testing. Among patients with pathogenic germline mutations, 3 patients had a pathogenic APC mutation (APC c.1659G>A, APC c.2802C>A and APC c.1643dupT) and were diagnosed with Familial Adenomatous Polyposis (FAP). One patient had 2 pathogenic MUTYH mutations (MUTYH c.536A>G and MUTYH c.1187G>A) and was diagnosed with One patient had a pathogenic PTEN c.634+5G>A mutation and was diagnosed with PTEN Hamartoma Tumor Syndrome. Among the 3 patients with a personal history of juvenile colorectal polyps, one patient had a CHEK2 c.190G>A mutation while the other two had negative genetic test results. The VUS mutations in our cohort were MRE11A c.826C>T, BLM c.3478T>C, BRCA2 c.2519T>C, CHEK2 p.V395L and CTNNA1 c.392dupT. Conclusions: In our cohort of patients with personal history of colorectal polyposis, the majority of patients (45%) had negative germline testing. An underlying pathogenic germline mutation and VUS were identified in 30% and 25% of the patients, respectively. FAP Syndrome was the most commonly diagnosed hereditary polyposis syndrome with 3 patients found to have APC germline mutations. Other pathogenic mutations were identified in the MUTYH, PTEN and CHEK2 genes. Patients with MUTYH and PTEN mutations were diagnosed with MAP and PTEN Hamartoma Tumor Syndromes respectively.

The perforation strategy for a hydraulic fracture completion for an unconventional reservoir can have a very large influence on the overall success of the injection program at effectively stimulating that network. To evaluate differences in perf clustering methodologies, operators are frequently in need of observational evidence to suggest which strategy is most efficient. We present a paper where we look at a detailed analysis of microseismicity for different stages with different completion programs.While event distributions tend to be the first and most frequently examined aspect of a microseismic monitoring effort, because the generation of a microseismic event is not immediately diagnostic of fluid-induced fracturing, the event clouds tend to overestimate the effective area of fracturing. In order to gain further insight into how microseismic events describe effective fracture growth, a deeper look at the waveforms through techniques like Seismic Moment Tensor Inversion (SMTI) and subsequent stress inversion can be effective. These steps are necessary to describe the discrete network of cracks, from the microseismic data. Using a fracture network topology approach, the network can then be characterized in terms of its ability to percolate fluids.We compare how cracks behave for a regular geometric shot cluster (GSC) and a variable shot cluster (VSC) and assess variations in the stimulations. Both shot clusters were completed in consecutive stages of the same lateral. The mechanisms from the GSC stages show shear-dominant mechanisms with opening and closing components in roughly equal proportions, while the VSC stages have a higher concentration of shear-tensile opening failures. Furthermore, the GSC stages showed modest connectivity around the treatment well relative to the VSC stages, which showed significant growth of connected fractures away from the treatment well. Since the VSC stages also showed relatively more stable stress behaviour than the GSC stages, these observations suggest that stability in stresses allows for steady growth of the fracture network across the reservoir.This type of higher-order analysis of microseismic data is critical to establishing value from this data stream in terms of completion evaluation. The recognition that each microseismic event is tied to the rupture of a crack in the reservoir allows for these types of comparisons to be made in a robust fashion and be tied to the underlying geomechanics that governs the type of response from one type of completion to the other.

The role of the geophysicist in resource plays has been hard to define. There is obvious benefit to seismic structural interpretation for hazard avoidance and model building for geosteering applications, but when it comes to predicting optimal well placement, much of the industry still is struggling. Common applications of seismic attributes search for deterministic predictions using attributes such as rock strength and anisotropy. However, even with many claims of success and a rich base of literature, the value and use of these approaches are lacking in practice. A simple case study shows the value added by using a single seismic attribute, curvature, in the Barnett Shale. The key to understanding this value is the use of Bayesian statistics. For this case, controlling for just one seismic attribute is seen to increase the probability of a successful well by 10% or more, also leading to substantial increases in rate of return of 10 percentage points or more.

A number of years ago, there was an appeal to microseismic service providers and end users to go ‘beyond the dots’ in terms of the types of analysis that can be performed to relate the microseismic waveforms to problems in terms of drilling, completion, and field development. While this call to arms has often been interpreted rather specifically, in terms of moment tensor inversion, this is just one aspect of how microseismic data can be looked at beyond the rather limited information afforded to by their locations. Even in terms of determining the moment tensors of microseismic events, the question of how to use this information to affect business decisions is not intuitively obvious. In this paper, we describe a number of analyses that aim to make use of microseismic data, from moment tensors to other source parameters, in the context of a completion in the STACK play in Kingfisher County, Oklahoma. Key to extracting information from these data is the concept that a single microseismic event does not afford a lot of information in of itself. The critical idea is that it is the interaction of different microseismic events which captures processes that are not elucidated in the consideration of events individually. Using the example of seismic moment tensor inversion (SMTI) data, we describe an approach for obtaining a picture of a connected fracture network that can further be described in terms of the percolation properties of the network. This allows for the moment tensor data to be linked to where the hydraulic stimulation fractures connect to the treatment well and therefore the volumes where we may expect production. Further consideration of microseismic event clusters can identify the different deformation processes that accompany the microseismicity. By clustering events of similar character, and considering both how they are distributed in time and space, as well as the insights into their failure processes from a detailed study of their source mechanics, the deformation in the reservoir can be mapped. Characterizing the deformation by the degree of co-seismic (anelastic) deformation allows the processes in the reservoir to be described in terms of different deformation indexes, ‘dynamic parameters’: plasticity index (PI) corresponding to anelastic deformation; stress index (SI) as related to the localized stress behaviour/conditions leading to seismicity; and diffusion index (DI) which describes the rate of stress transfer as it results in seismicity throughout the volume of interest. We introduce the site and give an overview to the microseimsic data acquisition for a lateral well completion in the STACK play (Sooner Trend Anadarko basin Canadian and Kingfisher counties). We then describe an approach for processing these data, through moment tensor inversion, into a picture of the Discrete Fracture Network (DFN). This requires a methodology to group events occurring under like stress conditions to invert for the stress ratio and the principal stress axes, such that the fracture planes may be deterministically derived from the moment tensor data. We also discuss the methodology to determine the cluster-based dynamic parameters. We then illustrate how we can use these tools to arrive at an integrated interpretation of processes occurring during the hydraulic completion, and how these data can be used to affect design decisions for completion and field development.

Wide azimuth seismic data acquisition has become standard in many plays where azimuthal characterization of fractures or stress is important for fully understanding reservoir behavior. Usually, the desire is to image preexisting fracture networks, but, in artificially stimulated reservoirs, it is also desirable to understand the fracture state after completion. To characterize the induced fractures in a heavily drilled area of the Barnett Shale, a wide azimuth survey was acquired and processed to generate four separate azimuthal stacks. Attributes exploiting variations in amplitude and waveform were independently calculated for each azimuthal stack. Azimuthal variations in the attributes were then quantified through ellipse fitting. The attributes with the most statistical significance in azimuthal variability were those related to frequency such as the wavelet dominant frequency. These attributes were consistent with each other but show a wide distribution over azimuths across the survey. In addition, random distribution of orientations within the Barnett shale compared to the over and underlying Marble Falls and Viola Limestones indicate a difference in orientation for the induced as opposed to preexisting fractures. With the ability to map the induced fractures, it becomes feasible to take an intelligent approach to planning infill locations to avoid the previously fractured areas.

Many authors have posited that agricultural education curriculum in middle schools may enhance student performance in science. To determine the effect that agricultural education curriculum has upon Georgia middle schools’ student performance in science, this descriptive study compared science knowledge among middle school students in Georgia who were enrolled in schools with and without agricultural education programs. To quantify the science knowledge and skills of students, the researchers used the state’s annual Criterion-Referenced Competency Test (CRCT) (science), mandatory for all students in middle schools. The scores of students in the 51 middle schools in the state with agricultural education programs were compared to the scores of students in 51 similar schools that did not have an agricultural education program. The percentage of students meeting or exceeding the standards in the CRCT test were consistently higher (and sometimes significantly higher) in schools with agricultural education programs over two consecutive school years. Although the researchers cannot conclude that the difference is due solely to the agricultural education programs, the results of this study open a myriad of opportunities for further research.

Diffraction tomography imaging has been applied to data acquired with two different measurement geometries at a buried waste disposal site. The experimental scale is quite small, having a horizontal extent on the order of 10 m and considering features at depths (most importantly, a layer of buried waste) of less than 10 m. Both a 3D reflection and a pseudo-3D offset vertical seismic profiling (VSP) geometry were used. The use of these two different geometries allows for a comparison of the results and limitations of each method. Images derived from both techniques must be interpreted with a knowledge of the theoretical resolution and limitations imposed by each measurement geometry and imaging algorithm. The reflection algorithm leads to images that contain hollow objects, a consequence of the reflection geometry and linearized theory; this algorithm is unable to image the sides of objects because of a lack of information at oblique reflection angles. Offset VSP experiences a blurring of objects along a line between the source and receiver because information is integrated over transmission raypaths. The two techniques provide images which are consistent with each other and the expectations based on theoretical considerations.

Summary Accurate automatic seismic event identification is a fundamental problem for passive microseismic monitoring. Simply stated, more accurate picks provide more accurate location of microseismic events. This paper introduces a new approach carrying out precise seismic event determination based on high-order statistics (HOS). Short term kurtosis to long term kurtosis ratio (S/L-Kurt) is a simple, accurate and fast event identification method. By measuring kurtosis, we are able to identify the transition from Gaussian to non-Gaussian behavior that coincides with the onset of the microseismic event in the presence of noise. We test the reliability and robustness of the proposed algorithm on synthetic and real field data and find our method provides accurate picks even in noisy microseismograms. The simplicity of the proposed method makes it an attractive candidate for the analysis of huge seismic data sets.

Curvature gradient is a third order surface property which has been shown to improve surface and fault characterization. Previous applications have been restricted to gradients calculated in the same direction as curvature and for cases of zero dip. We demonstrate the value that can be gained by considering the full 3D tensor for variation in curvature including computation of volumetric curvature gradient in arbitrary directions relative to the curvature directions.

In conventional plays the role of the geophysicist is primarily that of locating and delineating the resource. This is most commonly accomplished through the use of active source seismic exploration. In this classic case it is the responsibility of the geophysicist to identify the structures associated with the trap and migration pathways of the resource. In the last twenty years this role has been expanded through the applicability of direct hydrocarbon indicators where, particularly in the Gulf of Mexico, the resource itself can often be identified using seismic exploration. In the case of unconventional resources neither the trap nor the presence of hydrocarbons are unknowns. The source rock, reservoir and trap are continuous and well defined. As such it would be easy to dismiss the geophysicist's role as diminished to one where his primary responsibilities are secondary concerns, such as hazard avoidance through the location of faults. However, in practice, the role of the unconventional geophysicist is much more complex and multi-dimensional. Access to resource in an unconventional rock is largely controlled by exposure to the rock, i.e. how efficiently it can be hydraulically fractured. The unconventional geophysicist can contribute to the understanding of how to best access the resource by studying the finer scale heterogeneities in the rock which are manifested indirectly through various seismic attributes such as anisotropy and curvature, and directly measured through microseismic monitoring of hydraulic stimulations.

Azimuthal volumes have often been looked at in conjunction with velocity anisotropy to determine the strike of fractures or maximum stress direction. Due to variations in the directions of fractures, attributes calculated on azimuthal volumes may also provide insight into the strike and dip, location, and spatial variation of the fractures. In particular, attributes highlighting the differences in frequency, time, and amplitude can effectively isolate areas of fractures (Tod et al 2007). If these seismic experiments can detect naturally-occurring fractures in reservoirs then why not use the same principles to detect hydraulicallyinduced fractures? The techniques discussed in this paper will show how these azimuthally sectored volumes and their attributes can be used to map the hydraulicallyinduced fractures in the Barnett Shale in the Ft. Worth Basin. Areas of pre-existing hydraulic fractures are typically avoided because of the potential interference with other wells in the area. We demonstrate how prior geologic knowledge of areas of hydraulically-induced fractures will be used in conjunction with the azimuthal volumes in order to effectively map the fractures.

The use of geometrical attributes is becoming common place in modern interpretation, however in many cases the origin and actual use of these attributes is unclear. In the case of curvature there is a lack of understanding of the difference between maximum and minumum curvature and most positive and most negative curvature. A careful examination of the derivation of these two seperate sets of attibutes reveals that what are called the most positive and most megative curvatures are in general not curvature measures, but measures of the second derivative. They are found to be the eigenvalues of the Hessian matrix. Only in the special case of zero dip, when the first derivative is zero, do these second derivative measures give the curvature,at which they are equal to the maximum and minimum curvature. It is also important to recognize that while maximum and minimum curvature are orthogonal in R3, their projections on the x-y plane, are not necessarily orthogonal. Therefore, the angle between the azimuths of maximum and minimum curvature are not necessarily ninety degrees, as is commonly stated. The derivation presented here also corrects previous misrepresentations of the equation of curvature azimuth under a quadratic approximation. Through these observations it becomes apparent that in many cases the curvature attributes may be misused and that the potential exists for a more robust use of curvature azimuths with a better understanding of their meaning. A simple example of curvature as measured at varying azimuths for a series of 3D surveys demonstrates one possible application.

Helike is an area on the south‐central coast of the Gulf of Corinth. This name is derived from the lost Classical Greek city of Helike that vanished during an earthquake and subsequent tsunami in 373 BC. It was original believed that the remains of Helike were located offshore in the Gulf of Corinth; however, early searches of this area proved fruitless. More recently, boreholes developed in the coastal plain revealed marine sediments that date to the Classical Greek period suggesting that, as a result of uplift and/or sedimentation, Helike now lies onshore. This find stimulated a sequence of ongoing geophysical investigations and excavations that have revealed buried architecture and artifacts from three periods; Early Bronze Age, Classical Greek, and Roman.