Eight shallow seismic refraction profiles were conducted at the proposed KACST expansion site, northwest of Riyadh, to estimate the near-surface geotechnical parameters for construction purposes. Both compressional (P) and shear (S) waves were acquired, processed, and interpreted using "time-term" technique which is a combination of linear least squares and delay time analysis to invert the first arrivals for a velocity section. The most important geotechnical near-surface parameters such as stress ratio, Poisson's ratio, material index, concentration index, N value, and foundation material-bearing capacity are calculated. The results of these seismic measurements were compared with the results of borehole report in the project area in terms of number of layers, the lithological content, thicknesses, and N values of rock quality designation. A good matching between the results was observed particularly at the sites of boreholes.

During December 2002 and January 2003, Montana Tech in collaboration with Ain Shams University, Cairo, collected Ground Penetrating Radar (GPR) and seismic data at Saqqara, Egypt. The purpose of this study was to see if GPR and seismic methods could detect manmade structures in the subsurface at Saqqara. In particular, land streamer aided, seismic diving-wave tomography was tested as a method to detect archaeological features. Saqqara was one of the principal necropolises of Memphis, an ancient capital of Egypt. The research site was near the 3rd Dynasty pharaoh Djoser’s Step Pyramid—the first monumental structure built entirely of stone. A preliminary GPR study of our site yielded numerous, possibly manmade features in the subsurface with a [Formula: see text] depth of penetration using [Formula: see text] antennas. A follow-up three-dimensional (3-D) GPR survey over one of the more interesting features showed a broad trench underneath the flat-lying sand that is seen at the surface. This feature is most likely manmade because the horizontally layered limestone rocks of Saqqara are inconsistent with the shape of this feature. Seismic diving-wave tomograms show that this probable manmade feature extends to a depth of [Formula: see text] into the subsurface. Moreover, we were able to complete the seismic survey faster using a land streamer consisting of gimbaled geophones than could be done using conventional planted geophones. This site has potential for further investigation and possible excavation.

Pre-drill prediction of formation pore pressure from surface seismic survey is very important for drilling, production, and reservoir engineering because it affects drilling operations and well-planning processes. If it is not properly evaluated, it can lead to numerous drilling problems such as dangerous well kicks, lost circulation, blowouts, stuck pipe, excessive costs, and borehole instability. Pre-drill pore pressure estimation has been obtained from transform models using seismic interval velocities. However, the accuracy of this estimate of pore pressure is directly related to the reliability of these interval velocities. Bulk density was estimated from seismic interval velocity and transit time. Normal pore pressure gradient is estimated from the slope of a trendline that is generated from logarithm transit times versus depth. Overburden pressure at any depth was calculated from the integration of the average interval bulk densities and thicknesses above that depth. Pore pressure has been obtained from overburden pressure and observed interval velocities using modified Eaton's equation. 154 CDPs were used along 28 seismic lines at Beni Suef basin, Western Desert, Egypt, to accomplish the purpose of this study. Two velocity reversal zones showing abnormally high pore pressure were detected and correlated to Abu Roash and Bahariya Formations. Moreover, pore pressure gradient maps were established for these two zones to predict the possible horizontal fluid flow (migration paths) for the proposal of prospects with lower pressures and less drilling risks.Finally, it is possible to calculate and recommend the required heavier mud weight to drill.

Pore pressure prediction is one of the most critical steps while planning new well delivery activity in exploration fields in order to achieve the well target by delivering a safe well. It is very important to understand the structural and stratigraphic complexity that may influence formation pressure differences in the study area. Also, it is critical to have a range of uncertainty in prediction to mitigate any kind of drilling problems and operational risks. In this case study, the target is to predict the pore pressure gradient for four proposed exploration wells in West Nile Delta Raven field. The workflow has been applied utilizing tilted transverse isotropic seismic velocity and a high-resolution full waveform seismic inverted velocity. It is important as well to compare different methodologies where each one will have its own limitations. A manually picked normal compaction trend with the conventional Eaton pressure transform method was applied and compared with a BP internal normal compaction trend with a modified Eaton (Presgraf) pressure transform method in the Predrill prediction. The pre-drill pore pressure is finally compared with the actual measured pore pressure data that yields a good match.

We collected seismic data at a site near Djozer's Step Pyramid, Saqqara, Egypt, in order to test diving wave tomography as a method to evaluate archaeological sites. A preliminary Ground-Penetrating Radar (GPR) study of this site yielded numerous, possibly man-made features in the subsurface.Unfortunately, the maximum depth of penetration of the GPR when using 100 MHz antennas was about 4 m. We selected an area above one of the GPR anomalies as a test location for our seismic study. A land streamer sped up data collection by allowing us to move our 24-channel spread in approximately one minute. The data were inverted by using Wavepath Eikonal Traveltime (WET) tomography to build an image of subsurface velocity. A roughly triangular-shaped seismic velocity anomaly is evident in the middle of the imaged section. The horizontally layered limestone rocks of Saqqara are inconsistent with the shape of this feature. Consequently, we suspect that the observed feature is caused by a manmade artifact and should be considered for future investigation and possible excavation. Moreover, we recommend using this method to evaluate other archaeological sites where other geophysical techniques are of limited use.