Since the earliest gas wells, uncontrolled migration of hydrocarbos to the surface has challenged the oil and gas industry. Gas migration, also known as annular flow, can lead to sustained casing pressure (SCP), sometimes called sustained annular pressure (SAP). Sustained casing pressure can be characterized as the developmen t of annular pressure at the surface that can be bled to zero, but then builds up again. The presence of SCP indicates that there is communication to the annulus from a sustainable pressure source because of inadequate zonaql isolation. Annular flow and SCP are significan problems affecting wells in many hydrocarbon-producing regions of the world.
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...The presence of SCP appears to be related to well age; older wells are generally more likely to experience SCP. By the time the well is 15 years old, there is a 50% probability that it will have measurable SCP in one or more of its casing annuli. However, SCP may be present in wells of any age.
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Authors: Robert W. Howarth & Renee Santoro &
Anthony Ingraffea
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Source: https://link.springer.com/article/10.1007/s10584-012-0401-0
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Date: 12/10/11
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Abstract:
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In April 2011, we published the first comprehensive analysis of greenhouse gas (GHG) emissions from shale gas obtained by hydraulic fracturing, with a focus on methane emissions. Our analysis was challenged by Cathles et al. (2012). Here, we respond to those criticisms. We stand by our approach and findings. The latest EPA estimate for methane emissions from shale gas falls within the range of our estimates but not those of Cathles et al. which are substantially lower. Cathles et al. believe the focus should be just on electricity generation, and the global warming potential of methane should be considered only on a 100-year time scale. Our analysis covered both electricity (30% of US usage) and heat generation (the largest usage), and we evaluated both 20- and 100-year integrated time frames for methane. Both time frames are important, but the decadal scale is critical, given the urgent need to avoid climate-system tipping points. Using all available information and the latest climate science, we conclude that for most uses, the GHG footprint of shale gas is greater than that of other fossil fuels on time scales of up to 100 years. When used to generate electricity, the shale-gas footprint is still significantly greater than that of coal at decadal time scales but is less at the century scale. We reiterate our conclusion from our April 2011 paper that shale gas is not a suitable bridge fuel for the 21st Century.
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Authors: Anne Johnson, Solmaz Spence, Katie Thomas, Lauren Everett and designed by Jay Christian.
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Date:
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Source:https://www.creativesciencewriting.com/arctic-matters-booklet/
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Introduction
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Wherever you are, you are connected to the
Arctic through Earth itself.
The Arctic region includes the Arctic Ocean and
parts of Alaska, Canada, Finland, Greenland,
Iceland, Norway, Russia, and Sweden. Although
remote to most of Earth’s inhabitants, the Arctic is
tied to every point on the globe through land, sea,
or air. Our daily weather, what we eat, and coastal
flooding are all tied to the future of the Arctic.
Wherever you are, you are connected to the
Arctic through the ecosystems that sustain life.
Plants and animals observe no borders. As the
Arctic changes, the availability of many of the
resources on which we depend will also change.
The physical, ecological, and human realms of the
Arctic are inextricably linked. And in all three
dimensions, what happens in the Arctic affects
the rest of the world.
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Finally, wherever you are, you are connected to
the Arctic through human beings.
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People have lived in the Arctic for millennia, and
today the region is home to some four million
people. These people contribute to society’s
cultural heritage diversity, and provide a historical
record of the region. Increasingly, the Arctic
serves as a source of natural resources and a place
to visit, study, and travel through.
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This booklet is intended to introduce the Arctic
to those unfamiliar with the importance of this
remarkable place in the past, present, and future
of our planet. It draws from a collection of peer-reviewed
reports of the National Research Council,
the operational arm of the non-profit U.S.
National Academy of Sciences and U.S. National
Academy of Engineering that provides independent
advice on issues of science and technology,
as well as from other national and international
reports. These reports collectively represent
authoritative assessments prepared and reviewed
by independent experts, including leaders in
climate and atmospheric sciences, environmental
science, oceanography, ecology, defense, business,
anthropology, and many other fields.
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The National Research Council developed this
booklet, in recognition of the United States
becoming Chair of the Arctic Council for the
2015–2017 term, to provide a primer on the complex
ways in which the Arctic and its diverse people,
resources, and environment affect us all — in
short, why the Arctic matters.
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