scholarly journals Geologic characterization of nonconformities using outcrop and core analogs: hydrologic implications for injection-induced seismicity

Solid Earth ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 1803-1821
Author(s):  
Elizabeth S. Petrie ◽  
Kelly K. Bradbury ◽  
Laura Cuccio ◽  
Kayla Smith ◽  
James P. Evans ◽  
...  

Abstract. The occurrence of induced earthquakes in crystalline rocks kilometers from deep wastewater injection wells poses questions about the influence nonconformity contacts have on the downward and lateral transmission of pore-fluid pressure and poroelastic stresses. We hypothesize that structural and mineralogical heterogeneities at the sedimentary–crystalline rock nonconformity control the degree to which fluids, fluid pressure, and associated poroelastic stresses are transmitted over long distances across and along the nonconformity boundary. We examined the spatial distribution of physical and chemical heterogeneities in outcrops and core samples of the Great Unconformity in the midcontinent of the United States, capturing a range of tectonic settings and rock properties that we use to characterize the degree of past fluid communication and the potential for future communication. We identify three end-member nonconformity types that represent a range of properties that will influence direct fluid pressure transmission and poroelastic responses far from the injection site. These nonconformity types vary depending on whether the contact is sharp and minimally altered (Type 0), dominated by phyllosilicates (Type I), or secondary non-phyllosilicate mineralization (Type II). Our observations provide geologic constraints for modeling fluid migration and the associated pressure communication and poroelastic effects at large-scale disposal projects by providing relevant subsurface properties and much needed data regarding common alteration minerals that may interact readily with brines or reactive fluids.

2020 ◽  
Author(s):  
Elizabeth S. Petrie ◽  
Kelly K. Bradbury ◽  
Laura Cuccio ◽  
Kayla Smith ◽  
James P. Evans ◽  
...  

Abstract. The occurrence of induced earthquakes in crystalline rocks kilometres from deep wastewater injection wells poses questions about the influence nonconformity contacts have on the downward and lateral transmission of pore fluid pressure and poroelastic stresses. We hypothesize that structural and mineralogical heterogeneities at the sedimentary-crystalline rock nonconformity control the degree to which fluids, fluid pressure, and associated poroelastic stresses are transmitted over long distances across and along the nonconformity boundary. We examined the spatial distribution of physical and chemical heterogeneities in outcrops and whole-rock core samples of the great nonconformity in the midcontinent of the United States, capturing a range of tectonic settings and rock properties that we use to characterize the degree of historical fluid communication and the potential for future communication. We identify three end-member nonconformity types that represent a range of properties that will influence direct fluid pressure transmission and poroelastic responses far from the injection site. These nonconformity types vary depending on whether the contact is sharp and minimally altered, or if it is dominated by phyllosilicates or secondary non-phyllosilicate mineralization. We expect the rock properties associated with the presence or absence of secondary non-phyllosilicate mineralization and phyllosilicates to either allow or inhibit fractures to cross the nonconformity, thus impacting the permeability of the nonconformity zone. Our observations provide geologic constraints for modelling fluid migration and the associated pressure communication and poroelastic effects at large-scale disposal projects by providing relevant subsurface properties and much needed data regarding common alteration minerals that may interact readily with brines or reactive fluids.


2020 ◽  
Author(s):  
Lisa Johann ◽  
Serge A. Shapiro

<p>It is understood that the recent acceleration of seismic event occurrences in Kansas and Oklahoma, U.S., can be connected to the large-volume disposal of wastewater. These highly saline fluids are co-produced with oil and gas and are re-injected under gravity into the highly porous Arbuckle aquifer. Since 2015, injection rates have been decreasing. However, the seismic hazard in that region remains elevated. Furthermore, it has been noticed that some events in Kansas occur far from disposal wells.</p><p>To analyse spatio-temporal patterns between the fluid injection and earthquake locations, we applied a time-dependent 2D cross-correlation technique. This reveals a vectorial migration pattern of the seismic events. Whereas early events occur towards the east-sourtheast, later events are located preferably in northeastern direction of large volume injectors. With time, event locations migrate further in that direction. We explain this observation as well as measured Arbuckle pore pressures by a directional pore-fluid pressure diffusion and poroelastic stress propagation. This also follows from our principal two-dimension poroelastic finite element model which is of predictive power and identifies controlling parameters of the observations. These are mainly the permeability of the target injection formation and the seismogenic basement as well as the anisotropic permeability and the critical fault strength distribution. Our results lead to the conclusion that remote locations are destabilised also when injection rates are declining.</p><p>Thus, volume reductions may only provide a direct effect to lower earthquake rates locally. However, a state-wide decrease of the seismicity may require longer times such that the seismic hazard due to wastewater disposal induced seismicity may remain for decades. </p>


2020 ◽  
Vol 110 (5) ◽  
pp. 2295-2307
Author(s):  
Lisa Johann ◽  
Serge A. Shapiro

ABSTRACT The recent surge of earthquakes in the central United States is linked to the disposal of large volumes of wastewater. Even if injection rates have been decreasing since 2015, the seismic hazard remains elevated. Moreover, some events in Kansas occur far from disposal wells. We applied a multidimensional cross-correlation technique to analyze the spatiotemporal relation between fluid injection and earthquakes. While a strong correlation is observed in east-northeastern direction of the disposal wells for the majority of events, some earthquakes occur in northeastern direction far from the disposal wells. We explain this pattern and the large-scale evolution of borehole pressure observations by directional migration of poroelastic stresses and pore pressure diffusion. This follows from our principal 2D poroelastic finite-element model that has a predicting power and identifies controlling parameters of the process. These are the permeability of the basement and its anisotropic character as well as the distribution of critical fault strengths. Our results suggest that remote locations may be destabilized even when injection rates are declining. Thus, a volume reduction may only provide an immediate effect to lower the seismicity locally. It follows that a state-wide reduction in earthquakes may require longer waiting times and that the hazard of induced seismicity may remain elevated for tens of years.


2019 ◽  
Vol 7 (4) ◽  
pp. SJ7-SJ22
Author(s):  
Asm Kamruzzaman ◽  
Manika Prasad ◽  
Stephen Sonnenberg

Production from organic-rich shale petroleum systems is extremely challenging due to the complex rock and flow characteristics. An accurate characterization of shale reservoir rock properties would positively impact hydrocarbon exploration and production planning. We integrate large-scale geologic components with small-scale petrophysical rock properties to categorize distinct rock types in low-porosity and low-permeability shales. We then use this workflow to distinguish three rock types in the reservoir interval of the Niobrara Shale in the Denver Basin of the United States: the Upper Chalks (A, B, and C Chalk), the Marls (A, B, and C Marl), and the Lower Chalks (D Chalk and Fort Hays Limestone). In our study area, we find that the Upper Chalk has better reservoir-rock quality, moderate source-rock potential, stiffer rocks, and a higher fraction of compliant micro- and nanopores. On the other hand, the Marls have moderate reservoir-rock quality and a higher source-rock potential. The Upper Chalks and the Marls should have major economic potential. The Lower Chalk has higher porosity and a higher fraction of micro- and nanopores; however, it exhibits poor source-rock potential. The measured core data indicate large mineralogy, organic richness, and porosity heterogeneities throughout the Niobrara interval at all scales.


1966 ◽  
Vol 05 (02) ◽  
pp. 67-74 ◽  
Author(s):  
W. I. Lourie ◽  
W. Haenszeland

Quality control of data collected in the United States by the Cancer End Results Program utilizing punchcards prepared by participating registries in accordance with a Uniform Punchcard Code is discussed. Existing arrangements decentralize responsibility for editing and related data processing to the local registries with centralization of tabulating and statistical services in the End Results Section, National Cancer Institute. The most recent deck of punchcards represented over 600,000 cancer patients; approximately 50,000 newly diagnosed cases are added annually.Mechanical editing and inspection of punchcards and field audits are the principal tools for quality control. Mechanical editing of the punchcards includes testing for blank entries and detection of in-admissable or inconsistent codes. Highly improbable codes are subjected to special scrutiny. Field audits include the drawing of a 1-10 percent random sample of punchcards submitted by a registry; the charts are .then reabstracted and recoded by a NCI staff member and differences between the punchcard and the results of independent review are noted.


Author(s):  
Joshua Kotin

This book is a new account of utopian writing. It examines how eight writers—Henry David Thoreau, W. E. B. Du Bois, Osip and Nadezhda Mandel'shtam, Anna Akhmatova, Wallace Stevens, Ezra Pound, and J. H. Prynne—construct utopias of one within and against modernity's two large-scale attempts to harmonize individual and collective interests: liberalism and communism. The book begins in the United States between the buildup to the Civil War and the end of Jim Crow; continues in the Soviet Union between Stalinism and the late Soviet period; and concludes in England and the United States between World War I and the end of the Cold War. In this way it captures how writers from disparate geopolitical contexts resist state and normative power to construct perfect worlds—for themselves alone. The book contributes to debates about literature and politics, presenting innovative arguments about aesthetic difficulty, personal autonomy, and complicity and dissent. It models a new approach to transnational and comparative scholarship, combining original research in English and Russian to illuminate more than a century and a half of literary and political history.


2008 ◽  
Vol 6 (1) ◽  
pp. 31-42 ◽  
Author(s):  
Robyn Matloff ◽  
Angela Lee ◽  
Roland Tang ◽  
Doug Brugge

Despite nearly 12 million Asian Americans living in the United States and continued immigration, this increasingly substantial subpopulation has consistently been left out of national obesity studies. When included in national studies, Chinese-American children have been grouped together with other Asian Americans, Pacific Islanders or simply as “other,” yielding significantly lower rates of overweight and obesity compared to non-Asians. There is a failure to recognize the ethnic diversity of Asian Americans as well as the effect of acculturation. Results from smaller studies of Chinese American youth suggest that they are adopting lifestyles less Chinese and more Americans and that their share of disease burden is growing. We screened 142 children from the waiting room of a community health center that serves primarily recent Chinese immigrants for height, weight and demographic profile. Body Mass Index was calculated and evaluated using CDC growth charts. Overall, 30.1 percent of children were above the 85th we found being male and being born in the U .S. to be statistically significant for BMI > 85th percentile (p=0.039, p=0.001, respectively). Our results suggest that being overweight in this Chinese American immigrant population is associated with being born in the U.S. A change in public policy and framework for research are required to accurately assess the extent of overweight and obesity in Chinese American children. In particular, large scale data should be stratified by age, sex, birthplace and measure of acculturation to identify those at risk and construct tailored interventions.


Author(s):  
Anne Nassauer

This book provides an account of how and why routine interactions break down and how such situational breakdowns lead to protest violence and other types of surprising social outcomes. It takes a close-up look at the dynamic processes of how situations unfold and compares their role to that of motivations, strategies, and other contextual factors. The book discusses factors that can draw us into violent situations and describes how and why we make uncommon individual and collective decisions. Covering different types of surprise outcomes from protest marches and uprisings turning violent to robbers failing to rob a store at gunpoint, it shows how unfolding situations can override our motivations and strategies and how emotions and culture, as well as rational thinking, still play a part in these events. The first chapters study protest violence in Germany and the United States from 1960 until 2010, taking a detailed look at what happens between the start of a protest and the eruption of violence or its peaceful conclusion. They compare the impact of such dynamics to the role of police strategies and culture, protesters’ claims and violent motivations, the black bloc and agents provocateurs. The analysis shows how violence is triggered, what determines its intensity, and which measures can avoid its outbreak. The book explores whether we find similar situational patterns leading to surprising outcomes in other types of small- and large-scale events: uprisings turning violent, such as Ferguson in 2014 and Baltimore in 2015, and failed armed store robberies.


Author(s):  
Geoffrey Jones

This chapter examines the scaling and diffusion of green entrepreneurship between 1980 and the present. It explores how entrepreneurs and business leaders promoted the idea that business and sustainability were compatible. It then examines the rapid growth of organic foods, natural beauty, ecological architecture, and eco-tourism. Green firms sometimes grew to a large scale, such as the retailer Whole Foods Market in the United States. The chapter explores how greater mainstreaming of these businesses resulted in a new set of challenges arising from scaling. Organic food was now transported across large distances causing a negative impact on carbon emissions. More eco-tourism resulted in more air travel and bigger airports. In other industries scaling had a more positive impact. Towns were major polluters, so more ecological buildings had a positive impact.


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