Manika Prasad is a Professor of Petroleum Engineering at the Colorado School of Mines. She directs the DHI/Fluids and the OCLASSH (Organic, Clay, Sand, Shale) research consortia and is the director of the Center for Rock Abuse. Manika received a BS (Honors) in Geology (with distinction), an MS (Diplom) in Geology with Marine Geology and Geophysics as minors, and a PhD (magna cum laude) in Geophysics, from the Christian-Albrechts-Universität at Kiel in Germany. Manika won the Merit Scholarship Award from the University of Bombay for her BS achievements and the Friedrich-Ebert-Stiftung Scholarship for PhD research at Kiel University. She has worked at the Mineral Physics Laboratory at University of Hawaii, Stanford Rock Physics Laboratory at Stanford University, and at the Center for Rock Abuse at the Petroleum Engineering and Geophysics departments at Colorado School of Mines. Her students have won student paper awards. She was an advisor for Native American Students at Stanford and was named Outstanding Mentor to Native American Students during 2002 - 2003. Manika was the Fall 2012 SEG-AAPG Distinguished Lecturer and received the SEG Outstanding Educator Award in 2015.
Manika's main interests lie in understanding the basic principles governing the physical properties of rocks, fluids, and rocks with fluids. She is also interested in understanding how ant-sized phenomena control elephant-sized features. She has published widely in geophysical, geological, petroleum engineering, and nondestructive testing journals.
Physics and Mechanics of Rocks: A Practical Approach
Rock physics is an interdisciplinary branch of geophysics that explains geophysical remote sensing data, such as seismic wave velocities and electrical conductivity, in the context of mineralogy, fluid content, and environmental conditions. Thus, rock physics interpretations often require inputs from physics, geology, chemistry, chemical engineering, and other fields. For example, seismic waves travel faster in cemented rocks than in loose sediments. Since the physical behavior of rocks controls their seismic response, rock physics brings key knowledge that helps with the interpretation of rock properties such as porosity, permeability, texture, and pressure. Rock physics combines indirect geophysical data (such as seismic impedance, sonic log velocities, and laboratory measurements) with petrophysical information about porosity, fluid type, and saturation for use in reservoir characterization, evaluation, and monitoring. Typically, rock physics is used by petroleum engineers doing reservoir simulations, geologists evaluating over-pressures and making basin models, and anyone doing a monitoring survey to map fluids from 4D seismic. For all such purposes, an understanding of wave propagation is required to relate seismic properties (e.g. velocity and attenuation) to the physical properties of rocks and to evaluate seismic data in terms of subsurface petrophysical parameters. For example, an application of rock physics is seen in 4D seismic data (i.e. repeated seismic data acquired from the same field), where fluid saturation changes are evaluated from changes in velocity using fluid substitution models. Another rock physics application is to understand and predict the effect of clay minerals on the load-bearing capacity and strength of rocks using fundamental knowledge about the properties of clay minerals (e.g. CEC, surface area, dispersability, charge, sorption, plasticity, etc.), the clay water content, as well as the effects of their distribution within the rock. Thus, an effective prediction of rock properties from indirect measurements requires a solid understanding of the physical behavior of rocks under in situ conditions of pore and confining pressures and fluid saturations.
During this one-day short course, I will provide the earth scientist and engineer with a foundation in rock physics to describe the physical processes that govern the response of rocks to the external stresses essential for reservoir characterization. The course will also offer practical guidance to help better analyze existing data. A major goal of this course is to offer practical instruction and provide working knowledge in the areas of rock physics and rock mechanics for rock characterization.
Fall 2012 SEG/AAPG Distinguished Lecturer
Shales and imposters: Understanding shales, organics, and self-resourcing rocks
Shales are very commonly occurring sedimentary rocks. They are alternatively described by their grain size (less than 2 micrometers), by their mineralogy (hydrous aluminosilicates), or by an assemblage of sedimentary features (fissile, fine-grained, and clay-rich). Generally, rocks with clay contents larger than 50% are termed as shales. The presence of clay minerals, hydrous aluminosilicates that are smaller than 2 µm can alter the elastic and plastic behavior of materials significantly. Load-bearing clays form weak links between the stronger mineral components. Knowledge about the elastic properties of clay is therefore essential for the interpretation and modeling of the seismic response of clay-bearing formations. However, due to the layered structure, small grain sizes, and reactive nature of clay minerals, it has proved very difficult to investigate their elastic properties. Precise measurements of the static and elastic properties of clay minerals are rare with little agreement between theoretically derived and measured values of clay moduli. For example, elastic moduli values reported in the literature range between 10 GPa and 400 GPa. This discrepancy is mainly due to various amounts of water adsorption by the clay minerals: The nano-sized clay minerals are very reactive and reactions with free radicals, such as hydroxyls, can alter their physical properties.
Rock physics knowledge is essential to evaluate mechanical strength, fluid content, fluid flow, and recovery rates. Information about subsurface formations is generally gathered at different scales, which vary in resolution, spatial coverage, and number of parameters measured. There is a need to up- or downscale to increase reliability of prediction. I will discuss applications of rock physics and experimental data to calibrate observations made on the field. I will analyze experiments results on shales in controlled environment and show the different petrophysical controls on seismic properties, for example, on porosity, permeability, cementation, pore-filling, saturation, and compaction.
A special focus will be on "imposter" shales: organic-rich "shales" (ORS) that are gaining popularity as complete reservoir systems; they form the source, seal, and reservoirs. These rocks are erroneously termed as shale – they often do not have any clay minerals. The organic-rich "shale" (ORS) prospects of today are in reality fine-grained organic-rich rocks. The increasing importance of ORS as hydrocarbon reservoir rocks require better understanding of the processes that lead to shale maturity. Successful exploration and production programs for unconventional petroleum systems need reliable identification of their physical properties, maturity, and changes in mechanical, elastic, and flow properties through indirect methods.
The processes that generate extractable hydrocarbons from kerogen are fairly well understood. Detection of the maturity levels of kerogen in organic-rich shales is not as well known. Current methods determine kerogen content by geochemical analysis of core samples or through empirical methods. For example, the maturity of shales at in- situ conditions may be inferred from empirical relationships between shale pressures and downhole resistivity and sonic logs. The ability to determine maturity by the use of indirect measurements such as seismic is still the subject of research. The properties of kerogen are poorly understood and, so, predictions about maturity and rock-kerogen systems remain a challenge. Assessment of maturity from indirect measurements can be greatly enhanced by establishing and exploiting correlations between physical properties, microstructure, and kerogen content. Successful exploitation of the hydrocarbons also requires significant understanding of the natural fracture systems and the ambient stress conditions. This would allow improved project economics in exploration and development of shale oil fields.
SEG Virgil Kauffman Gold Medal 2017
Manika Prasad is recommended as the 2017 recipient of the Virgil Kauffman Gold Medal for her extensive experimental work in rock physics at the Colorado School of Mines. Letters from several prominent members of the profession voice support for Prasad to receive a Virgil Kauffman Gold Medal for her work in studying seismic wave propagation in complex rocks. These letter writers are particularly impressed with Prasad ’s recent work with shale rocks. They predict her experimental results in this area will be instrumental in evaluating unconventional reservoir plays with seismic data.
Biography Citation for the Virgil Kauffman Gold Medal 2017
Manika Prasad is a natural recipient of the SEG Virgil Kauffman Gold Medal for her contributions to the field of experimental rock physics and geophysics. During her active career, Manika has led key developments in conceptual and experimental geophysical observations on a broad range of rock types and rock properties. Her strongest contributions relate to understanding the elastic, transport, and storage properties of shales and unconsolidated rocks in a variety of experimental setups to address a wide range of length scales.
Her innovative research has focused on interrelating elastic measurements using atomic force acoustic microscopy, scanning electron microscope, nitrogen gas absorption techniques, nuclear magnetic resonance, and complex electrical resistivity. This approach highlights her versatility and multidisciplinary experimental approach to the hardest of problems.
Manika has contributed to the understanding of how pore-space distribution and size (micro- to mesopores) depends on mineral types such as illite and smectite. Recently, Manika developed a methodology (and obtained a patent) to extract pore size information in unconventional reservoirs by extracting surface relaxivity from combined nuclear magnetic resonance, 3D digital rock models, and focused ion beam scanning electron microprobe measurements.
Her publications include some of the first work on anisotropic attenuation on unconsolidated and fractured sandstones. On a larger scale, Manika's work on defining hydraulic units from wave velocities has had a strong impact in the interpretation of hydrogeological data, petroleum geophysical well logs, and seismic field data. Manika's scientific contributions to geophysics have led to advances in conventional and unconventional petroleum reservoir characterization, exploration, and production.
Manika is the director of the successful Physics of Organics, Carbonates, Sands, and Shales Consortium at the Colorado School of Mines, showing that she excels at bridging academic questions and industry needs. After the unexpected passing of Mike Batzle, she has also taken on the leadership role in the Fluid and Direct Hydrocarbon Indicator Consortium.
Manika's capacities as a teacher were recognized by the SEG Continuing Education Lecturer on Rock Physics of Shales (2014) and the SEG Outstanding Educator Award (2015). The Virgil Kauffman Gold Medal will recognize Manika's status and record as a role model for men and women within SEG and across the greater geophysics community.
Biography citation for the SEG Outstanding Educator Award 2015
While an educator’s task is to teach, her goal and purpose are for her students to learn. Perhaps even more, it is to instill in those students an excitement about the subject she is teaching and love of further learning as a result of that teaching. Manika Prasad, selected to receive the 2015 SEG Outstanding Educator Award, is many times over a model recipient for this honor.
Not unusual for geophysicists, Manika’s career spans beyond three continents and several professional disciplines in and related to the earth sciences. Starting with a B.Sc. (honors) at the University of Bombay, India, she went on to obtain a M.Sc. and then Ph.D. (summa cum laude) at Christian-Albrechts Universität in Kiel, Germany. Her study disciplines migrated from geology (chemistry minor) to geology (minors in geophysics and marine geology) and then to geophysics (minors in marine geology and sedimentology). This brought her to an academic career that included appointments at the University of Hawaii, Stanford University, and Colorado School of Mines. This path empowered her to achieve a distinguishing perspective for multidisciplinary studies and applications as well as a very special skill to steer multiculturalism toward effective teamwork.
Manika is an educator in the most comprehensive sense of the word, from the nanoscale of the micropores in the cores she likes to study (and abuse!) to the basin scale, where her research findings are applied. A prolific and significant contributor in experimental and theoretical research into the physics of rocks and their contained fluids, she has taught courses at the undergraduate and graduate levels and to the exploration-geoscience community at large.
Remarkably, she was the 2014 SEG Continuing Education Lecturer and 2012 SEG/AAPG Fall Distinguished Lecturer, in a rare example of a woman geophysicist in a leading technical role, of which we need so many more, to inspire the young generations. One of her students told us, “Manika is known not only for excellence in research and education, but for her high moral values and humility as a person…. Manika has been much more than a teacher and an adviser. She has been a role model for many students at CSM.”
Beyond teaching in the classroom, as a keynote speaker or invited panelist in international technical events, and through an extensive number of publications, Manika’s skills as an educator include advising some 31 graduate and undergraduate students in geophysics, petroleum engineering, and chemical engineering.
In addition, she serves SEG as Associate Editor of Geophysics and as a member of several committees. She also is the technical editor of the Reservoir Evaluation and Engineering Formation Evaluation for SPE. Twice, Manika was named Outstanding Mentor to Native American Students at Stanford. This year, she was nominated for the SPE Innovative Teaching Award the Petroleum Engineering department at CSM.
But if we want to better picture why Manika deserves this year’s SEG Outstanding Educator Award, we have to listen to her students:
- “My class with Professor Manika was truly one of the most useful and enjoyable classes I took, in no small part because she clearly put the time and effort into each of the students in the class. I found in her a mentor in every sense of the word!”
- “After Mike Batzle died, Manika took care of Mike’s research group and consortium, becoming the adviser of four additional Ph.D. students and three master’s students. Without her, we all would have been left without guidance.”
- “Dr. Prasad’s research interests transcend the fields of geophysics, geology, and petroleum engineering and allow her to challenge her research students into thinking outside the box, to come up with an integrated subsurface solution to the questions they intended to answer. I am very glad to work with her.”
Here is an educator who does it all with a gracious manner, replete with warmth and, invariably, fine humor. Manika Prasad virtually defines what it means to be an outstanding educator and an outstanding person.
- Petroleum Engineering Department, Colorado School of Mines: Faculty
- Center for Rock Abuse
- (2017). ”Honors and Awards.” The Leading Edge, 36(10), 806–819. http://dx.doi.org/10.1190/tle36100806.1