Colorado water law and ramifications

Abstract
Surface waves decay less rapidly than body waves, because their energy spreads over only two dimensions as they propagate along a surface, while body waves spread spherically. This makes surface waves tractable over relatively large times and distances. Often obscuring
body waves for land exploration geophysics, surface waves (ground roll) are generally treated as noise, with ongoing efforts in Industry to remove their presence. I will discuss some of the issues of ground-roll removal.

But on the other hand, surface waves contain a wealth of information about any medium being probed: they can detect flaws in composites for engineering applications (I will show some of this so-called nondestructive testing at PAL), but at larger scales Rayleigh waves circumvent the Sun, Moon and Earth. Over the last 100+ years, surface waves have taught us a lot about the subsurface, both at the global scale, as well as the geotechnical scale. I will present results of projects in the Physical Acoustics Lab that focus on the pitfalls and possible improvements in subsurface imaging with surface waves.

In addition to addressing practical issues in surface-wave propagation, we study surface waves to answer fundamental questions about wave propagation in complex media regarding topics such as localization, and seismic interferometry. Because surface waves travel -- as their name suggests -- along the surface of a solid, it makes them available to measure as they propagate, as opposed to body waves that typically can only be detected after transmission or reflection. Secondly, to make surface waves scatter, patterns at the surface are easily constructed and described.

Biography

Kasper van Wijk is an assistant research professor in the Department
of Geophysics at Colorado School of Mines, and co-director of the Physical Acoustics Lab (PAL). He received his MS on data and model uncertainty analysis in Inverse Theory from Utrecht University and his PhD in surface wave multiple scattering from Colorado School of Mines. His current projects fall into the categories of wave propagation in disordered media, near-surface geophysics, land-mine detection, noncontacting (microwave and laser) geophysical sensor development, laboratory ultrasonics, physical and numerical modeling of issues related to exploration and global seismology, and geophysical inversion theory. His favorite color is green.

Abstract
It has been demonstrated experimentally that an estimate of the Green's tensor between two seismic stations can be obtained from the long-time average of the cross-correlation of ambient noise at the two stations. This result provides a means to image Earth structure using the ambient noise field only, without the use of active seismic sources or earthquakes. The theoretical relationship between the Green’s function and noise correlation function will be discussed. Results from the correlation function of seismic noise recordings among pairs of stations will be presented for both small scale area using the Parkfield Network, California, and large scale area using the Southern California Seismic Network.

A record section of the noise correlation function (NCF) waveforms as a function of increasing receiver separation shows clearly that the recovered signals are propagating wavetrains, similarly to a passive analog to a shot gather made with active sources. For distances below 11km, both a P-wave and a Rayleigh wave are observed in the NCF. A time-frequency analysis allows us to separate the two wave packets that are further identified through their polarization. Arrival times were estimated from the NCF and they compared favorably with predictions using ray tracing in a regional velocity model and with the velocity gradient across the San Andreas Fault.

Over larger scale (from 30km to 500km), ambient noise (originating from ocean microseisms) propagating over long distances is typically dominated by surface waves in this frequency band 0.1-0.2Hz. Seismic noise data from 148 broadband seismic stations in Southern California were used to extract the surface wave arrival-times between all station pairs in the network. The seismic data were then used in a simple, but densely sampled tomographic procedure to estimate the surface wave velocity structure for a region in Southern California. The result compares favorably with previous estimates obtained using more conventional and elaborate inversion procedures. This demonstrates that coherent ambient noise between station pairs can be used for seismic imaging purposes.

Biography

Karim G. Sabra received his Ph.D. degree in April 2003 from the Mechanical Engineering Department at the University of Michigan, Ann Arbor. His thesis research investigated the broadband performance of an acoustic Time-Reversing Array retrofocusing in a shallow-water sound channel, as well as application of time-reversal signal processing to the blind deconvolution problem. From June 2003 to June 2005, he held a Post-Doctoral appointment at the Marine Physical Laboratory, Scripps Institution of Oceanography, San-Diego, California. His research activities were in ultrasonic experiments to study multipath propagation in scattering environments, and the applications of ambient noise cross-correlation techniques for passive sensing and passive tomography using both ocean noise and seismic noise. Presently he is a project scientist at the Marine Physical Laboratory. His research interests include time-reversal acoustics, underwater acoustics and target detection, coherent processing of ambient noise and seismology.

Abstract
Have you wondered how your hydrogeology-related research might be applicable to water law and policy? I will give a brief introduction to Colorado water law and water resources and will suggest some ways in which engineers might become more involved in legal and political water projects.

Biography
Wendy Wempe received a PhD from Stanford University in 2000, focusing on using geophysical data to improve aquifer characterization. She has co-taught a course that she developed called Groundwater Law and Hydrology as an adjunct professor at the University of Colorado Boulder School of Law. This year, Wendy started a hydrology education consulting company called Hydro Info (www.hydro-info.com) through which she teaches groundwater hydrology to water lawyers, policy makers and resource managers. As a 2005 Kinship Conservation Institute Fellow, Wempe worked on developing market incentives to control the spread of tamarisk, which is a non-native, woody, noxious weed that has invaded most arid and semiarid riparian areas of the western United States and has considerable adverse hydrologic economic and environmental implications. Wempe’s long-term goal is to be at the forefront of water issues backed by experience in hydrogeology, water law, and water policy.

Abstract
Groundwater-surface water interactions, the exchange of water between streams and connected aquifers, has been an important hydrologic research focus for the last 25 years. However, there has been little advance in the techniques that are employed in this work. Here I will report on a current research project in arctic Alaska, in which we are assessing sub-stream thaw bulbs using ground-penetrating radar. We are coupling this work with more traditional hydrologic methods to determine whether these thaw bulbs are important to arctic stream ecosystems. Our working hypothesis is that these thaw bulbs, which extend more than 1 m below the streambed in many locations, may provide a large volume of potential exchange with the stream. Our findlings so far suggest that only a small, but biogeochemically active, portion of these subsurface thaw bulbs actually exchange with the stream.

Biography

Dr. Michael Gooseff joined the faculty at Colorado School of Mines in December 2004 in the Geology and Geological Engineering Department. His research focuses on hydrologic and biogeochemical processes in stream and near-stream environments, with a particular interest in transport and fate of nutrients in streams. He received his Ph.D. from the Department of Civil, Environmental and Architectural Engineering at the University of Colorado in 2001, and then took on a postdoctoral position at Oregon State University in the Department of Geosciences before moving on to Utah State University where he was an assistant professor from 2002- 2004 in the Department of Aquatic, Watershed, and Earth Resources.

Abstract
Sparse and/or low-resolution subsurface data introduce significant geologic uncertainty in petroleum reservoir modeling. Model parameters need to be assigned in a realistic and consistent manner to define multiple geologic scenarios that can be used to identify, rank and manage uncertainty. To investigate this process and improve submarine channel reservoir modeling workflows a model was built from outcrops of the middle Brushy Canyon Formation (MBC). The model is 3D, honors the outcrop data and incorporates multiple scales and types of geologic heterogeneity.

Sand-rich, MBC lower slope submarine channels are reproduced in a 10.6 km by 2.75 km by 150 m model. The long axis of the continuous and moderately 3D outcrop belt is oriented oblique to depositional strike. Three channel fairways intersect the outcrop, with major fairways in the north and south separated by a minor central fairway. Nine channel trend maps of 20m thick, sandstone-rich, 6 th-order cycles were tied to 70 measured sections and 31 km of photopanel data to delineate a three-fold stratigraphic hierarchy. The MBC 4 th-order cycle contains three 5th-order stratigraphic cycles. The oldest MBC, 5 th-order cycle (fan 4) is dominated by freely-migrating channel complexes encased in sandstone sheets, whereas the overlying 5 th-order cycle (fan 5) consists of large confined channel complexes that show a greater lateral change in facies and lithology. The youngest 5 th-order cycle (40 ft siltstone marker) is a regional fan abandonment zone that provides topseal for the model.

The outcrop model was constructed using a combination of cell- and deterministic object-based methods. Deterministic channel grids (197) were modeled individually. Each channel object contains discontinuous “bar” regions and varies in drape and fill style related to position in a channel hierarchy. These channel objects were placed in a background layer populated using Sequential Indicator Simulation with external drift. Paleogeographic facies trends were imposed using channel fairway and interfairway regions, and high and low-gradient longitudinal regions, built from 6 th-order channel maps. The regions define areas of confined, partially confined and unconfined flow conditions that are used to constrain facies probability cubes and control lithology, correlation range and azimuth, body type, arrangement and connectivity. Stratigraphic patterns were modeled by changing 6 th-order layer parameters with regard to position in 5 th- and 4 th-order depositional cycles. The stratigraphic framework describes phases of fan initiation, growth and retreat that record changes in slope depositional system energy. There is a strong link between stratigraphic phase, channel type, and fairway-to-interfairway lithology trends.

The parameters that had greatest impact on reproducing trends recognized in outcrop, in decreasing order of importance, are: 1) statigraphic framework (layer thickness and parameters trends), 2) deterministic channel placement (trends, size, type and hierarchy), 3) areal regions (facies maps, vertical proportion cubes and correlation azimuth maps), 4) channel fill patterns, 5) global facies proportions and 6) variogram structure. Factors to closely consider for retaining geologic accuracy include: 1) sparse and biased well data, 2) cell thickness, 3) grid design and orientation and 4) facies grouping schemes.

Jim Borer
Jim is a recent PhD graduate from CSM in the Department of Geology and Geological Engineering.

Abstract

Inference of earth medium structure and properties is based on multidisciplinary data and information. Commonly, geophysics, petrophysics and geology need to be integrated to produce a realistic description of reservoirs, basins or other earth structures. To achieve a quantitative combination of such different types of information we use a statistical approach that begins with defining a common model jointly describing structural, petrophysical and physical properties of the medium. This prior statistical model represents the knowledge of the medium structure and properties before taking into account the information provided by the geophysical surveys. By inverting the geophysical data onto the common model, we further constraint the model to jointly explain the geophysical observations and comply with the petrophysical and geological information. The related calculations are developed using sampling ( Monte Carlo) techniques or optimisation techniques based on iterative linearization.

The geostatistical inversion approach is useful in many exploration situations. We have used it to improve a seismic velocity model, via travel time inversion combined with well log and structural information. In this case, we developed an iterative Newton´s algorithm for optimising model parameters. We have developed methods for joint estimation of porosity and impedance from seismic waveform data. In this case the link between the elastic parameters and the material rock parameters (porosity) is given by an statistical relationship based on Wyllie’s petrophysical transform, and could be based on ad-hoc transforms adapted to the specific area. In another application of the geostatistical inversion approach, we infer basin structure in 3D from joint inversion of gravity and magnetic data. The statistical model in this case constraints the structure of the basin and the rock properties using information obtained from the geology, seismic surveys and rock sample measurements. We used a Monte Carlo approach obtaining a full description of probabilities for the basin structure and properties.

Our present work involves estimating reservoir properties from multi-component pre-stack seismic data, and linking geophysical data with medium mechanics for the estimation of the lithospheric structure.

Biography

Miguel Bosch is an Associate Professor at the Applied Physics Department, Faculty of Engineering, Universidad Central de Venezuela, where he is presently the head of the department. Since 2003 he formed and directs the Geophysical Simulation and Inversion Laboratory of the university. He has been visiting fellow at the Department of Earth Sciences, University of Cambridge (2000-2001) and obtained his Doctoral degree in Geophysics at the Institut de Physique du Globe de Paris (1998). He started his academic career in the Universidad Central of Venezuela, where he enrolled in 1990 as Instructor, after working in the seismic processing industry (1984-1988).

Dr. Bosch's research interests have been in the fields of inverse problems, their applications at different exploration scales, geostatistics and seismic tomography. Particularly, he has been working in the development of techniques to combine geophysical information with multidisciplinary information under a statistical framework. He is interested in the integrated description of resource’s reservoirs, sedimentary basins, lithospheric and mantle structure.

Abstract

Azerbaijan has been linked with oil for centuries, even for millennia. Medieval travelers to the region remarked on its abundant supply of oil, noting that this resource was an integral part of daily life there. By the 19 th century, Azerbaijan was by far the frontrunner in the world's oil and gas industry. In 1846, more than a decade before Drake made his famous discovery of oil in Pennsylvania, Azerbaijan drilled its first oil well in Bibi-Heybat (offshore field near Apsheron peninsula). By the beginning of the 20 th century, Azerbaijan was producing more than half of the world's supply of oil 60 million barrels per year.

During the 20 th century and for more that 70 years Azerbaijan was a part of the Soviet Union and was site of active production during the Soviet era. Today, after independence and the start of the 21 st century, the Caspian basin is still one of the largest and most attractive petroleum basins in the world. There are numerous rich oil and gas fields in the Caspian and the potential for further exploration and development exists. Most wells drilled in the past were on oil seeps, now are on structure, and my research suggests that there is considerable stratigraphic potential. Seismic attributes including amplitudes and spectral decomposition were applied to interpret 3-D seismic data, which leads to an understanding of the reservoir components and serves as a guide for future exploration and development. The integrated interpretation of seismic and well log data has shown the possibility of stratigraphic traps. Valleys and channels have been interpreted to represent feeder systems to downslope turbidite lobes with perhaps better down structure reservoir quality. High amplitude anomalies off the structure are indicative of turbidite lobes. Lobes that are faulted and isolated in some cases may exhibit better seal capacity.

Biography

Firuz Salamov received a BS degree (2001) and a MS (2003) in geophysics from the State Oil Academy in Azerbaijan.

In 2003 Firuz joined BP Caspian Sea Exploration Company in Sunbury (UK) and Baku ( Azerbaijan). BP offers a MS scholarship program for schools in Europe or the United States, and Firuz decided that it would be useful for his professional growth to study for another MS in the USA. He chose the Department of Geophysics at Colorado School of Mines and is now certain that it was the right decision. Upon graduation, Firuz plans to work with BP in London (UK).

Abstract

GPR is a high-resolution shallow geophysical technique that is used by many industries such as utility detection, NDT of infrastructure, hydro-geophysics, archeology, and law enforcement. These industries have a need for higher resolution imaging and better locations of sub-surface objects. These needs are more pressing in conductive soils where GPR penetration is limited and the image resolution is poorer. To provide better imaging, we need to characterize and quantify the subsurface wave fields. For GPR, this requires a better understanding of the response of the antennas. Since ground-coupled antennas are preferred for conductive soils, and since the response of ground-coupled antennas depends on the soil properties, the soil properties directly under the antenna are needed to predict the antenna response and the subsurface wave fields.

The response of a GPR system has been characterized so that a quantitative interpretation of field measurements can be made. Part of this characterization involved a large number of numerical simulations of the antenna response for different soil properties. This characterization facilitates the construction of an inversion algorithm for estimating the soil properties under the antennas based on the early waveform arrivals. These early waveforms arrive before the subsurface reflections. The forward operator for the inversion is based on a compilation of these early arrivals from many numerical simulations of the antenna response. The non-linear inversion finds many acceptable solutions, and the estimated soils properties are obtained from a statistical description of these solutions. These statistical results suggest that the technique can be applied in many field situations. Armed with the knowledge of the soil properties and the antenna response, many techniques become available for extracting more subsurface information and increasing image resolution.

Biography

Chuck Oden received B.S. degrees in Geology and Electrical Engineering from the University of Nebraska in 1989 and 1991. He spent 13 years with Mt. Sopris Instrument Company developing borehole geophysical instruments for the mining, groundwater, and geo-technical industries. As their lead engineer, he conceived and directed the development of many types of instruments. In 2002, he started a small software company called Mercury Geophysics, which produces software for well log analysis and interpretation. He left Mt. Sopris Instruments in 2004 to return to school. Currently, he is a student researcher at the USGS working on his doctorate in geophysics. He is studying GPR under Dr. Gary Olhoeft.

Abstract

BP has been very effective in developing and deploying repeat and 4D seismic technologies, especially to its offshore fields in the North Sea and the Gulf of Mexico. 4D seismic has become the newest class of reservoir surveillance data. In combination with the more traditional static and dynamic well logs and production data, it has become a very effective tool for reservoir management. Taken on its own, 4D seismic can teach us about changes in reservoir saturation and reservoir pressure. It is sensitive to the influx of an acquifer, to the sweep of a waterflood flood front, to the development of a gas phase as pressure drops and to changes in reservoir pressure, e.g., associated with reservoir compartmentalization. However, it is sensitive to all of these potential changes all at the same time. To understand what changes are occuring in a specific reservoir, and in what combinations, it is necessary to combine the 4D response with other sources of surveillance data and well logs, and with our models of the reservoir. These data types may have higher spatial and temporal resolution than the 4D, or may represent an averaged response of the reservoir up to the producers.

We will report on recent developmental work, in conjunction with Dynamic Graphics, Inc., on how best to combine the 4D seismic volumes with traditional sources of surveillance data. We will exemplify these developments with several case studies from the North Sea. We will demonstrate a progression from fairly static map and cross-sectional based interpretations to our current dynamic volumetric approach which combines three dimensional spatial data and models in a shared temporal context, exhibiting the improved understanding of reservoir performance that can be obtained in this fashion.

Biography
Mike received his PhD in 1980 from Syracuse University, and joined the oil industry (SOHIO) in 1982 after two years of post-doctoral studies in nuclear and particle physics. His early work involved pore to core scale mechanistic studies, laboratory coreflood and centrifuge analysis, numerical methods, and viscous fingering, both as an individual contributor and as a team leader. His expertise in heterogeneity modeling and upscaling of geologic models was gained after transferring to the BP laboratory at Sunbury-on-Thames. Since then he has worked as a senior reservoir engineer in BP assets in the North Sea and in North America. He rejoined BP’s Exploration & Production technology group in 1999 during the BP Amoco merger. As a technology network leader, technology Advisor, and R&D project manager he has shaped BP’s global reservoir modeling strategy. He continues active research in this area, including the current development work on the integration of 4D seismic with other sources of reservoir surveillance data.

Abstract
The application of seismic geomorphology to exploration and field development is a natural consequence of the advent of high-quality and increasingly more affordable and widespread 3D seismic data currently available. 3D seismic data affords plan view images of depositional elements and in some instances entire depositional systems. Analyses of such images can significantly enhance predictions of the spatial and temporal distribution of subsurface lithology (reservoir, source, and seal), compartmentalization, and stratigraphic trapping capabilities, as well as enhanced understanding of process sedimentology and sequence stratigraphy. Examples from fluvial, estuarine, shelf, deep-water, and carbonate environments will be presented.

Typical seismic geomorphologic workflow involves 1) initial reconnaissance through 3D volumes using various slicing techniques using a variety of different seismic attribute volumes including full stack reflection amplitudes, near and far stacked amplitude volumes, and coherence volumes, as well as opacity rendering. The objective to this initial analysis is to identify features that have geologic or stratigraphic significance. 2) Such features are subsequently investigated further through a combination of detailed slicing, interval attributes, horizon picking and amplitude extraction, horizon illumination, etc. 3) Integration of seismic geomorphologic analyses with seismic stratigraphic analyses is a critical part of the workflow, whereby the plan view is integrated with the section view to ensure a consistent interpretation. Calibration and ground-truthing with well logs and core is essential at this stage.

Three-dimensional images also readily lend themselves to quantitative assessment of geomorphic features. This approach lends credence to the more qualitative aspects of seismic geomorphologic analyses. Such attributes as channel sinuosity, slope, width:thickness ratios, as well as measures of channel bifurcation, internal architecture and distribution of architectural elements associated with carbonate build-ups can be readily measured.

Biography

Henry W. Posamentier is the Chief Geologist for Anadarko Petroleum Corporation. Prior to joining Anadarko in 2001, he was with Veritas Exploration Services (2000-2001), the Atlantic Richfield Co. (1991-2000), Exxon Production Research Co. and Esso Resources Canada, Ltd. (1979-1991), and at Rider University, Assistant Professor of Geology (1974-1979).

Dr. Posamentier’s research interests have been in the fields of sequence stratigraphy and depositional systems analysis, where he has published widely. Most recently, he has employed an interdisciplinary approach to geologic prediction using 3D seismic visualization integrated with borehole data to interpret depositional systems and develop basin fill histories, in particular with reference to deep-water depositional settings. His current responsibilities include coordinating the team of Anadarko’s Technical Chiefs and ensuring integration of appropriate technologies into the exploration process. In 1971-1972, Dr. Posamentier was a Fulbright Fellow to Austria. He has served as an AAPG Distinguished Lecturer to the United States (1991-1992), an AAPG Distinguished Lecturer to the former Soviet Union (1996-1997), and an AAPG Distinguished Lecturer to the Middle East (1998-1999).

Abstract
Rulison field is located in the center of Piceance basin, northwestern Colorado. This field holds an estimated 135Bcf of recoverable gas reserves. Potential gas in place within Piceance basin is estimated between 80 Tcf and 136 Tcf (Tyler et.al., 1998). Rulison field is categorized as tight gas field. This field has some unique reservoir characteristics. It has very low permeability (30 – 50 micro-Darcy). The reservoir consists of complex channel sandstones making it a very heterogeneous reservoir. There are tremendous challenges for production engineers and geoscientist to effectively produce gas from this unconventional reservoir.

To help increase production from this field, information from reservoir changes during production are important to monitor. Time lapse seismic data can provide this information. In my research, time lapse seismic was conducted using P-wave seismic data.

I have analyzed time lapse data from Rulison field using time lapse attributes and inversion. I have used this time lapse analysis in conjunction with production data to build a comprehensive characterization of the reservoir. The result of this research is information that can be used to effectively produce more gas from the reservoir at Rulison field.

Biography

Mahendra Kusuma obtained his BS degree in Geophysical Engineering from Institute of Technology Bandung (ITB) Indonesia, in 2002. After about a year of work for Development Technology Center (DTC) ITB, in 2004 he started work towards his M.Sc. in Geophysics at Colorado School of Mines with the Reservoir Characterization Project. After finishing his degree, Mahendra plans to work for Chevron Texaco Indonesia.

Abstract
Anisotropic attenuation can have a strong influence on reflection amplitudes and provide sensitive attributes for fracture detection and lithology discrimination. I will present a consistent analytic treatment of plane-wave properties for TI (transversely isotropic) media with attenuation anisotropy. To characterize TI attenuation, it is convenient to introduce a set of Thomsen-style parameters that includes two reference isotropic quantities and three dimensionless anisotropic parameters ε_Q, δ_Q, and γ_Q. Assuming weak attenuation as well as weak velocity and attenuation anisotropy helps to obtain simple attenuation coefficients linearized in the Thomsen-style parameters. The linearized approximations not only provide valuable analytic insight, they also remain accurate for the practically important range of small and moderate anisotropy parameters.

The analytic results were applied to laboratory measurements of attenuation made on an anisotropic (phenolic) sample. Using the spectral-ratio method, we estimated the group (effective) attenuation coefficient of P-waves transmitted through the sample for a wide range of propagation angles with the symmetry axis. After a correction for the difference between the group and phase angles, the attenuation coefficient was inverted for the attenuation-anisotropy parameters ε_Q, and δ_Q. Whereas the symmetry axes of the angle-dependent attenuation coefficient and of the velocity function have close orientations, the magnitude of the attenuation anisotropy far exceeds that of the velocity anisotropy.

This approach to attenuation analysis was extended further to orthorhombic velocity and attenuation models that describe azimuthally varying seismic signatures recorded over naturally fractured reservoirs

Biography

Yaping graduated from Tsinghua University in Beijing in 2000 with a major in solid mechanics. He interned with WesternGeco in 2001 and ExxonMobil in2005. His thesis topic is related to attenuation anisotropy, in which he works with his advisor, Ilya Tsvankin, to develop a consistent treatment of plane-wave properties for anisotropic media with anisotropic attenuation. His interests spread from AzAVO, inversion, migration, and seismic signature of fault zones, to an ancient board game called "Go" (also called "Weiqi" in China and "Baduk" in Korea).

Abstract
Most incoming bolides are destroyed in the 95-bar Venusian atmosphere. The 1000 obvious pristine and slightly modified impact craters on Venus have rims 1.5-270 km in diameter and are conventionally assigned a maximum age of 0.5 or 1 Ga, complete planetary resurfacing by plume-driven processes at that time being assumed, but a plumeless planet with an ancient surface is more likely. Venus displays an additional 5000 or so circular basins, mostly rimmed, that may record still-older impacts. Many hundreds retain modestly degraded impact morphology—steep-inside rims 5 to 2000 km in diameter, central peaks, conical debris aprons, etc. The others form an increasingly-degraded older continuum in highlands and an increasingly-buried continuum in sedimented lowlands, and saturate much of the surface. Most of these old structures are ignored in conventional analysis. The fanciful plume origins proposed for a selected subset (“coronae” etc.) of ~500 of them cannot account for circularity, morphology, and cookie-cutter superpositions, and are contrary to known geophysics of the planet. The largest (800-2000 km) rimmed basins are among the youngest, and analogy with 3.91 Ga Imbrium (youngest large impact basin on Moon’s nearside) indicates the old structures to be mostly ³ 3.9 Ga, and hence to record the tail of main planetary accretion.

Biography

Warren Hamilton received his geology PhD from UCLA in 1951. His career was as a U.S. Geological Survey research geologist, mostly in geophysical units, plus visiting professorships at Caltech, Yale, Amsterdam, and, twice, Scripps Institution of Oceanography. He worked as a field-based structural geologist and petrologist, and also produced many broad and innovative syntheses on tectonics and crustal evolution, including wallmaps and a large book on active and past plate tectonics of onshore and offshore Indonesia and surrounding regions. He moved to Mines in 1996, and works primarily with geodynamics (plate tectonics in 3-D), changes in dynamic styles through time, and Venus. He is a member of the National Academy of Sciences, and holds the Penrose Medal of the Geological Society of America.

Abstract
From November 2003 to April 2005, Pasquale organized and led the historic 114-day Nile First Descent Expedition, the first complete descent of the Blue Nile and Nile River from its source high in the mountains of Ethiopia to the Mediterranean Sea, a distance of 3,260 miles. The expedition had to overcome enormous hurdles: suicidal rapids, crocodile attacks, gunfire from bandits and arrests by unfriendly militias. The expedition is featured in the newly released IMAX film, "Mystery of the Nile" which is the highest grossing large-format film of 2005. Pasquale will be giving a talk and slide presentation overview of the Nile and the countries it passes through, and highlights of the expedition.

Biography
Pasquale Scaturro, geophysicist, adventurer and expedition leader is one of the most successful and accomplished mountain and river expedition leaders in the world and has been exploring the far reaches of the planet for over 20 years.

Pasquale is founder and president of Exploration Specialists an international geophysical and exploration company. For the last 26 years he has managed geophysical oil and gas exploration and development projects in many of the most remote, dangerous and politically and technically challenging areas on earth, and has explored throughout North and South America, Africa, and the former Soviet Union. In 1986 he founded Seismic Specialists, a full service geophysical company and in 1988 founded US Seismic, a geophysical data acquisition company. In 1995 he founded Tricon Geophysics, a geophysical data processing company, with offices in Denver, Dallas and Houston.

For over 20 years Pasquale has been extremely active in high altitude mountaineering and has been the leader of numerous expeditions to major mountains worldwide including three expeditions to Everest. In 1998 he summited Mt. Everest and in 2001 he conceived, organized, and led the National Federation of the Blind NFB 2001 Everest Expedition, in which blind climber Erik Weihenmayer reached the summit. The expedition was the cover feature of the June 2001 issue of TimeMagazine which called it one of the most successful Mt. Everest expeditions in history, breaking five Everest climbing records. He was recently the expedition leader for a major filming project on the North Face of the Eiger in Switzerland for Alps: Giants of Nature, the newest MacGillivray Freeman IMAX film to be released in March 2007.

Pasquale has multiple descents of major world-class rivers including the Bio Bio in Chile, rivers throughout North America, the Omo and Zambezi in Africa. In 1996 he scouted and completed the first descent of the Tekeze River in Ethiopia, the largest tributary to the Nile River and the deepest canyon in Africa. From November 2003 to April 2004 he organized and led the historic 114-day Nile First Descent Expedition, the first complete descent of the Blue Nile and Nile River from its source high in the mountains of Ethiopia to the Mediterranean Sea, a distance of 3,260 miles. The expedition had to overcome enormous hurdles: suicidal rapids, crocodile attacks, gunfire from bandits and arrests by unfriendly militias. It is featured in the newly released IMAX film Mystery of the Nile which is the highest grossing large format film of 2005. He has recently co-authored a book with Richard Bangs, Mystery of the Nile, published by Penguin Books which chronicles the expedition.

Pasquale has filmed rafting and mountaineering projects for ESPN, Turner Television, MacGillivray Freeman Films, MSNBC, MSN, PBS, Discovery Channel, National Geographic Channel, and OrbitaMax. He has appeared on the Today Show, National Public Radio, Time Magazine, Outside Magazine. National Geographic Adventure, Playboy Magazine, The Denver Post and Rocky Mountain News, LA times, Hooked on the Outdoors, Homeopathy Today, Chicago Sun-Times, Boston Globe, Paddler Magazine and many others.

Drawing upon a lifetime of experiences, Pasquale’s motivational talks have inspired audiences throughout the United States and Europe, and taught people that the realm of impossibility has no limits. Married at a very early age, serving in the U.S. military and struggling to complete a degree in geophysics and raise three children at the same time, Pasquale learned what it was to sacrifice and at the same time to strive to make his dreams materialize. His logistical expertise, hard work and enormous commitment has enabled him to lead some of the most successful mountain and river expeditions in history while at the same time combining a full time career in geophysical exploration. Leadership, persistence, planning skills, organizational ability, flexibility to overcome unexpected obstacles, and performance under pressure are all factors in Pasquale’s remarkable endeavors both in business and on the rivers and mountains of the world.

Pasquale lives in Lakewood, Colorado and online at www.explorationspecialists.com

Abstract
Invasion of mud filtrate changes reservoir properties that we measure with wireline logs. To correct log readings and estimate original reservoir properties, we need to know the shape of the invasion saturation profile. Combining density, neutron, and micro-resistivity log readings in an inversion process has proved successful in finding invasion profiles in gas-bearing formations. However, for oil-bearing formations, additional information is required that might be derived from sonic logs.

This study shows the results of modeling sonic logs to determine the effect of invasion depth, fluid compressibility, fluid type, formation porosity and permeability as well as the frequency of the emitted signal. To study these effects, full waveforms, including compressional and shear waves, were generated by a computer model called the KIAM code. This code realizes the explicit completely conservative finite-difference scheme for the Biot's equations, which were modified according to the theory of dynamic permeability and tortuosity.

The results show that a conventional sonic tool with a signal frequency of about 10 kHz is not affected by invasion up to 10 cm called the "blind zone." The verification of these modeling results was only partly successful with an analytical solution of wave propagation around a fluid-filled borehole. The blind zone is probably caused by destructive wave interference in the near field. For deeper invasion, the velocity response goes through a transition, and measures only the velocity of the invaded zone for invasion depths over 25 cm. We were able to derive a universal sonic tool response function, of which the shape only depends on the fluid compressiblity, the dry bulk modulu, and the frequency of the source signal. However, the universality of this function should be confirmed for soft formations and eccentric tools.

This response function, which is valid for oil, water, and gas, was incorporated in the inversion process that uses the density, neutron, and micro-resistivity tools to determine the invasion saturation profile, and will be embedded as a FORTRAN code in a commercial log evaluation program.

The results of this study are expected to have a significant impact on sonic log evaluations, in particular on the fluid substitution calculation for synthetic seismic traces. It appears that for shallow invasion, sonic logs have often been erroneously corrected, while they read uninvaded conditions.

Biography
Frederic Dje Youan, is French Ivorian, born in Abidjan, Cote d'Ivoire (Ivory Coast). He was partly raised in Paris and Lausanne, where he attended elementary and junior high school. He graduated from high school in Jamaica, Queens, New York. Frederic received his bachelor's degree at Colorado School of Mines in Mathematics and Computer Science. He expects to complete his master's thesis in the Department of Geophysics in December 2005.

Abstract

The bandlimited character and directional nature of curvelets allow the wave-character of seismic data (i.e., the bandlimited nature and the directions of the recorded wavefronts) to be built into the representation of the data by using curvelets as building blocks of seismic data. Indeed, since singularities (reflections) in the data and singularities (`reflectors') in the images lie mainly along smooth curves, and because curvelets are known to provide a sparse representation of singularities (or edges) along smooth curves, it is intuitive that curvelets allow sparse representations of seismic data and their images. Moreover, since curvelets have main associated directions, it seems feasible that the imaging operator can also be sparsely represented using curvelets, based on the principle of map migration. Hence, it seems worthwhile to investigate the possibility for simultaneous sparse representation of seismic data and the imaging operator through the use of curvelets. The finite frequency nature of curvelets, together with their directional nature, provides the potential for a marriage between finite frequency methods and methods based on high-frequency asymptotics, i.e. between wave-equation-based imaging and ray-tracing-based imaging.

In this talk I present the results of seismic imaging with curvelets in the simple case of a homogeneous subsurface, to highlight the potential of seismic imaging with curvelets but at the same time explain the difficulty.

Biography

Huub Douma received a MS (1996) in geophysics from Utrecht University in the Netherlands, and was a research assistant there in the exploration geophysics group until 1997. In 1997 he joined Western Geophysical (now WesternGeco) as a field seismic analyst, where he later worked in seismic processing, was a staff geophysicist, and ended up in the research and development group in Isleworth, London. Since 2001, Huub has been working towards a PhD degree in geophysics at the Center for Wave Phenomena at the Colorado School of Mines. His research interests include seismic imaging, anisotropy and seismic interferometry. When he is not working, he can be found at his baby grand piano composing and recording his own music, in a swimming pool,or at the beach to do some windsurfing. He is a member of the SEG and the AGU. February 2006, Huub will begin a postdoc position with the seismology group at Princeton University.

Abstract
Geological outcrops and borehole images indicate that sedimentary rocks are heterogeneous. This heterogeneity is reflected in the lithostratigraphic classification system (bed, member, formation, group) used by geologists worldwide to divide the stratigraphic record in distinct units. Boundaries between these units usually mark a lithological change. Lithological change causes changes in physical properties, which can be either abrupt or gradual. In general, the entire spectrum from a step change to a smooth change in physical properties across a lithological boundary is geologically possible.

How smoothly or abruptly a physical property changes can be described mathematically by its local or pointwise regularity. This regularity then allows us not only to detect lithological transitions but also to characterize their nature with a number. In principle, this number depends only on the behavior of physical properties across these transitions. But in practice, our knowledge of physical properties is somewhat blurred because their measurement suffers from limited spatial resolution, noise, and possibly other smoothing filters. Any regularity estimated from such measurements needs to be corrected for these effects if it is to accurately describe a varying physical property.

In this presentation, I will give a brief overview of the mathematical techniques used to estimate regularity and show some results of their application to well logs. I will also show preliminary modeling results that indicate the effect of smoothing filters on regularity estimates.

Biography

Werner M. Heigl graduated in 1993 with a diploma in geology from the University of Munich, Germany. In 1995 he joined Schlumberger as a wireline field engineer. He worked in most parts of Europe including the North Sea, and had assignments as Engineer-in-Charge and Borehole Seismic Specialist. In Summer 2000 he transferred to Trinidad and Tobago, W.I., as Field Service Manager. In Spring 2002 he joined the Center for Petrophysics at the Colorado School of Mines where he is currently pursuing his PhD studies under Prof. Max Peeters. The subject of his thesis research is the estimation of regularity exponents from well logs and seismic data and their use in the characterization of lithological boundaries. His other research interests include chemical and physical rock properties, physics of well logging and formation evaluation, mud filtrate invasion, and applying mathematical analysis techniques to well logs and seismic data