American Gas Research Articles

US shale gas production outlook based on well roll-out rate scenarios

This study models the uncertainty range in the future gas production output from US shale plays up to 2025. The future spread in gas output in our models follows from variations in the number of wells that will be drilled according to three distinct scenarios. Each scenario assumes a well development plan for the six major shale plays over the studied period and then quantifies the cumulative US production output from the combined shale plays. We compare the bottom-up model results with other model projections for future US shale gas output, including the top-down shale gas production forecasts by the US National Energy Modeling System (NEMS). The remarkable growth of North American gas output from unconventional resources has been highlighted in numerous industry reports and government publications, but what has remained relatively underexposed is the deterioration of economic margins due to the failure to predict the gas price decline in the North American market. The past development record of North America’s shale gas resources suggests that security of future gas supplies seems ensured, but here we develop a contrarian view. Our scenario models take into account the effect of recent declines in gas rig counts and decline in gas well completions due to the depressed gas prices. A scenario with declining shale gas output – one of three scenarios considered – cannot be excluded as being unlikely to occur, which means the future security of US gas supply that assumes a steady growth of shale gas supply cannot be ascertained at present.

Displacing Diesel: The Rising Use of Natural Gas by Onshore Operators

Natural Gas Seizing on historic margins in domestic prices, North American oil and gas companies are increasing their efforts to use more natural gas and less diesel fuel to power their field operations. Until now, oil and gas companies have been ordering natural gas-powered rigs to qualify the technology through pilot programs in the field. However, “the inflection point” may have been reached, said Brad Bodwell, senior vice president of corporate and business development at Prometheus Energy. The company is one of the largest suppliers of liquefied natural gas (LNG) to the North American oil and gas industry and is entering a stage of “rapid growth” because of economic forces and major gains in domes-tic gas production. As the technology is evolving, so is its nomenclature. Operators and service companies are using two terms to describe engines that are fueled by a simultaneous injection of natural gas and diesel: “dual fuel” and “bifuel.” Prometheus fueled up its first natural gas-powered generator sets on a drilling rig for operator EnCana in the Haynesville shale in mid-2010. “Since then, we have grown at a rate of about 80% per annum in terms of volume that we ship to our customers,” said Bodwell. In 2013, Prometheus had access to about 500,000 gal/D of LNG and was supplying seven operators in the United States and Canada. In total, North American LNG facilities produced 800,000 gal/D in 2013. New LNG facilities under construction and expansions of older facilities will bring the available supply of LNG up to 1.1 million gal/D by year-end. With several more plants already funded and expected to come online after 2014, the daily supply of LNG is projected to soar to 2.6 million gal/D after next year. Bodwell estimates that natural gas is fueling as much as 7% of North America’s 1,100 horizontal drill rig fleets, but he predicts that share to soar to 50% within the next 2 years. There are environmental drivers as well since natural gas is the cleanest burning of all fossil fuels (Table 1). “You’re getting a fuel that is going to reduce your environmental footprint and, at the same time, it saves enough money that it pays for the cost of conversion,” he said. “So we don’t need to wait to achieve some sort of scale benefit or a government injection of capital into the industry to make it work. It is all stuff we know how to do.”

Shale gas and the revival of American power: debunking decline?

The spectre of American decline is once again animating both observers and practitioners of US foreign policy. The global financial crisis, a faltering American economy and continued costly and controversial military engagements overseas have been presented as conclusive proof that American foreign policy will soon lack the resources needed to sustain its previous international hegemony. Arguments of domestic weakness have been linked to analyses of the economic vitality of America's competitors to demonstrate a seemingly watertight case for relative decline. The inexorable rise of China has been presented from various quarters as evidence that the American era will soon be drawing to a close. Yet, such declinist arguments continue to suffer from fundamental weaknesses, overestimating the likely future strength of America's rivals while concurrently downplaying the capacity of the US to rejuvenate its economy and thus revivify its liberal universalist creed. The most interesting development in this regard has been the sudden resurgence of the US energy sector. Written off less than a decade ago as being in terminal decline, the American oil and gas industry has staged a remarkable recovery. Vast reserves of shale gas and accompanying tight oil offer the potential to aid the revival of the American economy, with some forecasts pointing to US energy self-sufficiency within two decades. Notions of US relative decline may yet prove premature. The geopolitical impact of American energy self-sufficiency is likely to be very significant, making an important contribution to a reversal of the US trade deficit, a revival of America's industrial base, and the possibility of a corresponding relative decline in power for conventional fossil fuel exporters.

Arabs and the future of oil

The discovery of shale oil and gas in North America (the United States and Canada) is considered a ‘game changer’ in the global petroleum industry. It provides an opportunity for the United States to achieve the energy self-reliance it has sought since the 1970s. It is also expected to allow the United States, the largest petroleum consumer and importer globally, to focus its attention on maximizing the economic benefits and comparative advantages of becoming a self-reliant energy state. It could also enable the United States to reprioritize its strategic interests, sharing responsibility for the security of the oil export routes in the Gulf with its European and Asian allies, rather than shouldering that task almost single-handedly, as is presently the case. However, realization of the advantages that North American shale oil and gas discoveries are purported to bring about will depend on whether the depletion rate can be slowed down and minimized and on whether the cost of production can remain competitive compared with that of conventional hydrocarbons. It will also depend on whether the United States will allow a large percentage of its shale petroleum to be exported, rather than be consumed domestically.

Middle East/North Africa Region Focuses on Tight Gas

Conference review As the era of the easy extraction of conventional hydrocarbon is over, energy companies across the world are tapping into difficult resources and developing unconventional reserves, such as shale gas and tight gas. In the Middle East and North Africa region, results from recent gas exploration and appraisal activities indicate that the region holds substantial resources of unconventional gas, especially tight gas. Regardless of the existence of highly productive conventional gas fields in this region, tight gas-related exploration and appraisal activities in several countries in the region have increased and are expected to pick up pace going forward. With this background, the SPE Middle East Unconventional Gas Conference and Exhibition (UGAS) was held in Oman to address the best practices and techniques used for the development of unconventional resources in the region. Under the theme “Unconventional and Tight Gas: Bridging the Gap for Sustainable Economic Development,” the conference highlighted the latest developments related to tight gas and shared success stories about the development of tight wells from regions all over the world. The 3-day conference highlighted the criteria, challenges, and environment required for successful unconventional gas production and how it implicates the long-term global supply of natural gas. Thirteen technical sessions along with poster and e-poster stations offered 90 presentations from more than 35 companies and 18 countries. Delivering the keynote speech, Zaid bin Khamis al Siyabi, director general of oil and gas exploration and production at the Ministry of Oil and Gas in the Sultanate of Oman, said the Sultanate recently began searching for and exploring unconventional gas resources, and needs to make more natural gas available to local industries. “The importance of unconventional resources for the sultanate is really huge,” al Siyabi said. Al Siyabi revealed that oil companies operating in Oman—such as Petroleum Development Oman, Shell, and BP—have drilled approximately 50 wells to explore unconventional gas resources using the latest technologies. Darryl Willis, vice president resources, North American Gas, BP, said in his presentation titled “Development of Unconventional Resources: Past, Present and Future” that unconventional gas continues to be a journey of discovery and challenge. “The future of our industry is increasingly unconventional. In the US, about 40% of the gas comes mainly from shale gas,” Willis said. The industry is now capable of producing gas from difficult geological structures at reasonable cost, making such resources economically viable, Willis said. “Among the success factors is the application of conventional techniques to unconventional, including the sweet-spot identification, integrated reservoir description, as well as the long-term development,” he said.

Fracture Height Containment in the Stimulation of Oriskany Formation

The Oriskany sandstone formation has been a prolific producer of natural gas in the Appalachian basin since 1930s. Lot of production wells have been converted to gas storage wells for the ease of operation. Natural gas storage industry is a vital part of North American energy driven economy because of the fluctuation in seasonal demand and in maintaining the reliability of supply needed to meet the demands of the consumer. However, the storage wells suffer from an annual deliverability loss of 5% owing to the various damage mechanisms. A lot of work pertaining to the issue of identification of damage mechanisms and subsequent development of stimulation technology in order to mitigate the damage and restore the wells deliverability have been done in a joint effort between The Gas Research Institute, Department of Energy, American Gas Association and the various other operator companies involved in the storage industry. Operators mostly rely on traditional methods such as blowing, washing, reperforating, acidizing, infill drilling to restore wells deliverability. These traditional methods do provide short term benefits, but the longevity is not sustained and the overall situation remains same. Hydraulic fracturing is not preferred in terms of legitimate concerns over excessive vertical height growth, long fracture fluid cleanup times, lack of expertise and cost. This research study was carried out to understand the various damage mechanisms affecting the Oriskany wells, with a focus on gas storage wells. We then developed a dataset of reservoir properties, rock properties and fracture treatment data for Oriskany based on a complete literature review and calculations from a sonic log. Parametrical studies were carried out to investigate the effect of type of fracture fluids, injection rate, types of proppant, treatment volume, reservoir pressure and treatment schedule on fracture geometries in the Oriskany formation. Based on the results, we developed new stimulation methods that lead to increased well deliverability, fracture height containment, and higher average fracture conductivity. This new understanding and knowledge help in practicing engineers design better treatments in stimulating Oriskany wells.

The Second Unconventional Gas Wave

Guest editorial Gas exploration activity in North America looks like it is in the doldrums. In the past 12 months, gas-directed North American rig counts have fallen by almost half. This is easy to understand. Since the beginning of 2010, front-month gas futures prices have fallen from USD 5.60/MMBtu to their current level of USD 3.60/MMBtu. I have a bullish view on the long-term future of natural gas. When accounting for all of the upside influences—environmental imperatives, relentless demand growth in the developing world, the potential of the domestic power sector, revitalization of the US industrial base, and downstream innovations such as gas to liquids (GTLs)—the picture looks positive. At the same time, I have a firm belief that continuing innovation will drive efficiency, making gas an even more attractive alternative and leading to more exploration and development. These indicators lead me to believe a second wave in the development of the North American gas business is on the way. The first wave has been quite a ride. Only a few years ago, gas industry pundits assumed that new gas demand could only be met with imports. An entire subindustry was developed around the regasification, storage, and transport to market of imported liquefied natural gas (LNG). Today, LNG regasification facilities are largely idle. Instead of increasing, gas imports have fallen dramatically—from 12.6 Bcf/D in 2007 to less than 9 Bcf/D in the most recent 12 months. Although gas production has increased dramatically, from just under 55 Bcf/D in 2007 to a current rate of 69 Bcf/D, the increases in production have been absorbed incrementally, without long-term structural adjustments in the US energy economy or significant investments in infrastructure. Existing gas plants displacing coal in the power sector and reductions in imports have absorbed more than 70% of the increase in gas production. The United States is still a net gas importer, but the industry is now focused on developing export markets. Those markets are there. Demand growth in China is almost certain for a generation. If Japan follows up on its commitment to step away from nuclear power, new supplies will need to be found there. Exporting gas will require us to adopt workable regulations, develop infrastructure, and change a mind-set. The United States is accustomed to thinking as an energy importer. As new sources are developed, we tend to guard them jealously and reserve them for domestic use. The Federal Energy Regulatory Commission approves the construction of LNG liquefaction facilities and the Department of Energy grants export licenses based on a “public interest” standard.

A least-square-driven functional networks type-2 fuzzy logic hybrid model for efficient petroleum reservoir properties prediction

Various computational intelligence techniques have been used in the prediction of petroleum reservoir properties. However, each of them has its limitations depending on different conditions such as data size and dimensionality. Hybrid computational intelligence has been introduced as a new paradigm to complement the weaknesses of one technique with the strengths of another or others. This paper presents a computational intelligence hybrid model to overcome some of the limitations of the standalone type-2 fuzzy logic system (T2FLS) model by using a least-square-fitting-based model selection algorithm to reduce the dimensionality of the input data while selecting the best variables. This novel feature selection procedure resulted in the improvement of the performance of T2FLS whose complexity is usually increased and performance degraded with increased dimensionality of input data. The iterative least-square-fitting algorithm part of functional networks (FN) and T2FLS techniques were combined in a hybrid manner to predict the porosity and permeability of North American and Middle Eastern oil and gas reservoirs. Training and testing the T2FLS block of the hybrid model with the best and dimensionally reduced input variables caused the hybrid model to perform better with higher correlation coefficients, lower root mean square errors, and less execution times than the standalone T2FLS model. This work has demonstrated the promising capability of hybrid modelling and has given more insight into the possibility of more robust hybrid models with better functionality and capability indices.

Factors Affecting Hydraulically Fractured Well Performance in the Marcellus Shale Gas Reservoirs

Development of shale gas reservoirs has become an integral part of the North American gas supply. The Marcellus shale reservoir contains large untapped natural gas resources and its proximity to high demand markets along the East Coast of the United State makes it an attractive target for energy development. The economic viability of such unconventional gas development hinges on the effective stimulation of extremely low permeability reservoir rocks. Horizontal wells with multistage hydraulic fracturing technique are the stimulation method of choice and have been successful in shale gas reservoirs. However, the fundamental science and engineering of the process are yet to be fully understood and hence the protocol that needs to be followed in the stimulation process needs to be optimized. There are several factors affecting the hydraulic fracture treatment and the postfracture gas production in shale gas reservoirs. In this paper, we used numerical reservoir simulation techniques and quantified the effect of the following pertinent factors: multiphase flow, proppant crushing, proppant diagenesis, reservoir compaction, and operating conditions on the performance of the designed multistage hydraulic fracturing process. The knowledge generated in this study is expected to enable engineers to better design fracture treatments and operators to better manage the wells in the Marcellus shale gas reservoir.

The Thinking of Shale Gas Development in China According to the US Shale Gas Development Experiments

This paper introduces American shale gas resource development experience and technique. The author also discusses China's shale gas resource potential and current states of exploration and development. Based on this information, this paper puts forward some strategic concepts of accelerating shale gas development in China.

Experimental research on performance response of domestic gas cookers to variable natural gas constituents

In China, the imported Liquefied Natural Gas (LNG) has been steadily increased in past years, with its constituents different from those of traditional pipeline natural gases (PNG) to various extents. In this paper several natural gases to be delivered to Guangdong provinces in China were selected as test gases to measure performance response of 17 sets of domestic gas cookers. Heat input rating, CO and NOx emission, and thermal efficiency was measured according to related national standards. American Gas Association indexes and Weaver indexes were used to predict combustion stability and emission under different gas constituents. Experiment results were compared with prediction to analyze the applicability of the two well-established indexes systems. It was concluded that Wobbe Index can predict heat input rating quite accurately, and CO and NOx emissions can be remained with reasonable limits for the changing constituents discussed. For combustion stability prediction, judgment criteria should be adjusted as follows: Weaver lifting index from JL ≥ 0.64 to JL ≥ 0.95, Weaver incomplete combustion index from JI ≤ 0.05 to JI ≤ 0.04, and AGA lifting index from IL ≤ 1.10 to IL ≤ 1.05.

Interview: Pediatric gastroenterology

Vasundhara Tolia is currently an Adjunct Professor of Pediatrics at Michigan State University School of Medicine in Lansing (MI, USA). Prior to that, she was a Professor of Pediatrics and Director of Pediatric Gastroenterology at Wayne State University (MI, USA) and Children’s Hospital of Michigan (MI, USA), respectively. Dr Tolia attended the Medical College of Calcutta (Kolkata, India), completed a residency program and received postgraduate training in gastroenterology at Children’s Hospital in Detroit (MI, USA). Dr Tolia is board certified in Pediatrics and Pediatric Gastroenterology. She has published over 150 articles in peer-reviewed journals, reviews and book chapters. In addition to being a researcher, educator, clinician and mentor, she has been on the Best Doctors' list and is an internationally sought speaker. She has lectured extensively throughout the world and she has held several editorial board positions. Dr Tolia has been a Fellow of the American College of Gastroenterology, American Gas...

Tracking microseismic signals from the reservoir to surface

Since the launch of commercial microseismic mapping of hydraulic fracturing in the Barnett Shale in 2000, microseismic has become the de facto geophysical technique to characterize stimulated fracture networks in unconventional reservoirs. Effective stimulation of these resources through hydraulic stimulations along multiple intervals of horizontal wells is critical to economic production from tight and shale oil and gas resources. The inherent low permeability of these formations necessitates creation of permeable flow paths between the reservoir and wellbore through injection of high-pressure fluids. Microseismic observations over the last decade have led to a paradigm shift in our concept and engineering models of hydraulic fractures from simple, planar fractures to complex fracture networks controlled by the stress state and the existence of pre-existing fractures. Injected fluids in rock tend to follow the “path of least resistance” that minimizes the work done, preferentially growing into pre-existing fractures and lower stress intervals. Microseismic is the only technology that can image these fracture networks and has led to the incredible expansion of microseismic monitoring. Over the past decade, a vast microseismic database has been collected covering all North American shale oil and gas fields, in addition to key international fields. The microseismic results have demonstrated the significant variability in hydraulic fracturing responses on all scales: across a field, along the horizontal length of a well, and even between perforations of a single frac stage.

North American Oil and Gas Reserves: Prospects and Policy

Expanding estimates of North America’s supply of accessible shale gas, and more recently, shale oil, have been trumpeted in many circles as the most significant energy resource development since the oil boom in Texas in the late 1920s. How large are these resources? What challenges will need to be overcome if their potential is to be realized? How will they impact U.S. energy policy? To address these questions, the Belfer Center for Science and International Affairs and two of its programs, the Environment and Natural Resources Program and the Geopolitics of Energy Project, convened a group of experts from business, government, and academia on May 1, 2012, in Cambridge, Massachusetts. The following report summarizes the major issues discussed at this workshop. Since the discussions were off-the-record, no comments are attributed to any individual. Rather, this report attempts to summarize the arguments on all sides of the issues. The policy implications of significant additional supplies of domestic oil and gas to the United States are far ranging. Due to time constraints, many important issues were not covered in the depth that they deserved. Examples would include the impact of additional oil and gas supplies on existing U.S. efforts to reduce carbon emissions and its historical commitment to support other fuels, such as coal and nuclear power, or newer options, such as wind and solar energy. Further, as one participant pointed out, officials from industry are constrained under U.S. antitrust laws from sharing proprietary information.

Precise inversion of logged slownesses for elastic parameters in a gas shale formation

Dipole sonic log data recorded in a vertical pilot well and the associated production well are analyzed over a [Formula: see text]-ft section of a North American gas shale formation. The combination of these two wells enables angular sampling in the vertical direction and over a range of inclination angles from 54° to 90°. Dipole sonic logs from these wells show that the formation’s average properties are, to a very good approximation, explained by a transversely isotropic medium with a vertical symmetry axis and with elastic parameters satisfying [Formula: see text], but inconsistent with the additional ANNIE relation ([Formula: see text]). More importantly, these data clearly show that, at least for fast anisotropic formations such as this gas shale, sonic logs measure group slownesses for propagation with the group angle equal to the borehole inclination angle. Conversely, the data are inconsistent with an interpretation that they measure phase slownesses for propagation with the phase angle equal to the borehole inclination angle.

The Last Gasp: The Rise and Fall of the American Gas Chamber

The Last Gasp: The Rise and Fall of the American Gas Chamber

Findings and Recommendations From the Joint NIST-AGA Workshop on Odor Masking.

Since the days of the alchemist, the observation that some substances have a smell while other substances do not has been a source of fascination. The sense of smell, or olfaction, is our least understood sense, however it is important for many human functions, including digestion, food selection and hazard avoidance. The detailed explanation of why individual chemicals (called odorants) might have a particular smell is still elusive. The situation with mixtures of odorants is even more complex and interesting. A number of distinct odorant mixture phenomena have been documented. Odorant suppression (sometimes called masking), conjugation (as described first by Zwaadermaker) and cross-adaptation are among a collection of such phenomena. They are related to the differential effects that one odorant species will have when mixed with another. Masking is a term that describes situations in which one odorant can overpower the sensation of another. There may be profound technological implications in a number of industrial sectors, most prominently in the fuel gas sector. Here, masking is suspected when the odorant that is added to natural gas can be detected by analytical instrumentation, but cannot be properly detected by an observer with a normal sense of smell. Note that this phenomenon is distinct from odor fade, which more properly describes a decrease in the concentration of an odorant rather than a decrease, disappearance or qualitative change in the perception of the odor in the absence of a change in absolute concentration. Anecdotal descriptions of masking events in the natural gas industry have persisted for over a decade, with the frequency of such events on the rise. Pursuant to the philosophy that the technological problem cannot be addressed until the basic science is understood, NIST, in collaboration with the American Gas Association (AGA), sponsored a workshop that brought together olfactory scientists and natural gas operations personnel in an effort to achieve a common understanding and identify critical research questions. This document is a summary of that workshop, and most importantly, a compendium of the findings and recommendations that resulted from the meeting.

Book Review: Scott Christianson, The Last Gasp: The Rise and Fall of the American Gas Chamber, University of California Press: Berkeley, CA, 2010; 344 pp.: 9780520255623, US$27.50

Book Review: Scott Christianson, The Last Gasp: The Rise and Fall of the American Gas Chamber, University of California Press: Berkeley, CA, 2010; 344 pp.: 9780520255623, US$27.50

The last gasp: the rise and fall of the American gas chamber

List of Illustrations Acknowledgments Introduction PART ONE THE RISE OF THE LETHAL CHAMBER 1. Envisioning the Lethal Chamber 2. Fashioning a Frightful Weapon of War 3. Devising Constructive Peacetime Uses 4. Staging the World's First Gas Execution 5. Like Watering Flowers 6. Pillar of Respectability 7. The Rising Storm 8. Adapted for Genocide PART TWO THE FALL OF THE GAS CHAMBER 9. Clouds of Abolition 10. The Battle over Capital Punishment 11 Cruel and Unusual Punishment? 12. The Last Gasp Appendix 1: Earl C. Liston's Patent Application Appendix 2: Persons Executed by Lethal Gas in the United States, by State, 1924--1999 Notes Select Bibliography Index

Note: Ultrasonic gas flowmeter based on optimized time-of-flight algorithms

A new digital signal processor based single path ultrasonic gas flowmeter is designed, constructed, and experimentally tested. To achieve high accuracy measurements, an optimized ultrasound driven method of incorporation of the amplitude modulation and the phase modulation of the transmit-receive technique is used to stimulate the transmitter. Based on the regularities among the received envelope zero-crossings, different received signal's signal-to-noise ratio situations are discriminated and optional time-of-flight algorithms are applied to take flow rate calculations. Experimental results from the dry calibration indicate that the designed flowmeter prototype can meet the zero-flow verification test requirements of the American Gas Association Report No. 9. Furthermore, the results derived from the flow calibration prove that the proposed flowmeter prototype can measure flow rate accurately in the practical experiments, and the nominal accuracies after FWME adjustment are lower than 0.8% throughout the calibration range.