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Case studies can be instructive in the evaluation of other coalbed methane (CBM) development opportunities. The San Juan basin, located in New Mexico and Colorado in the southwestern U.S. (Figure 1), is the most prolific CBM basin in the world. It produces more than 2.5 Bscf/D from coals of the Cretaceous Fruitland formation, which is estimated to contain 43 to 49 Tscf of CBM in place. For a long time, the Fruitland formation coals were recognized only as a source of gas for adjacent sandstones. In the 1970s, after years of encountering gas kicks in these coals, operators recognized that the coal seams themselves were capable of commercial gas rates. CBM development benefited greatly from drilling and log data compiled from previous wells targeting the deeper sandstones and an extensive pipeline infrastructure that was built to transport conventional gas. These components, along with a U.S. federal tax credit and the development of new technologies such as openhole-cavity completions, fueled a drilling boom that resulted in more than 3,000 producing CBM wells by the end of 1992. The thickest Fruitland coals occur in a northwest/southeast trending belt located in the northeastern third of the basin. Total coal thickness in this belt locally exceeds 100 ft and individual coal seams can be more than 30 ft thick. The coals originated in peat swamps located landward (southwest) of northwest/southeast trending shoreline sandstones of the underlying Pictured Cliffs formation. The location of the thickest coals (Figure 1) coincides with the occurrence of overpressuring, high gas content, high coal rank, and high permeabilities in the San Juan fairway ("fairway"). The overpressuring is artesian in origin and is caused by water recharge of the coals through outcrops along the northern margin of the basin. This generates high vertical pressure gradients, ranging from 0.44 to 0.63 psi/ft, which allow a large amount of gas to be sorbed to the coal. Coal gas in the San Juan basin can contain up to 9.4% CO2 and 13.5% C2 . Chemical analyses suggest that thermogenic gases have been augmented by migrated thermogenic and secondary biogenic gas sources, resulting in gas contents ranging up to 700 ft 3 /ton. Coal rank in the fairway ranges from medium- to low-volatile bituminous and roughly coincides with those portions of the basin that were most deeply buried. Coals in the fairway typically have low ash and high vitrinite contents, resulting in large gas storage capacities and excellent permeabilities of 10 md from well-developed cleat systems. Southwest of the fairway, Fruitland coals are typically 20 to 40 ft thick and are considerably underpressured with vertical pressure gradients in some areas of less than 0.20 psi/ft.
Unlike conventional reservoirs, coal seams are the source, trap, and reservoir for CBM. A comparison of the two reservoir types shows profound differences in reservoir properties, storage mechanisms, flow mechanisms, and production profiles. CBM reservoirs are layered and contain an orthogonal fracture set called cleats, which are perpendicular to bedding. Because the coal matrix has essentially no permeability, CBM can be produced economically only if there is sufficient fracture permeability. Relative to conventional gas reservoirs, coal seam permeabilities are generally low and may vary by three orders of magnitude in wells separated by distances of less than 500 m.
In 2017, according to EIA data, Colorado was the seventh largest energy producing state in the United States. Colorado’s existing regulatory environment has proven to deliver effective and responsible oil and gas development across the state. Yet, despite having some of the most progressive and stringent development regulations within the United States, Colorado’s oil and gas industry is still confronted with substantial opposition.
Historically, the narrative of the oil and gas industry has been one of jobs, tax revenues, and other various examples of economic prosperity. Despite fact-based messaging and the defeat of a 2018 ballot initiative for 2500 ft setbacks, 2019 has seen a continued increase in opposition to development accompanied by a notable influx of additional regulatory efforts, all driven by growing public concern.
In a social environment where the predominant message is the call for the replacement of fossil fuels with alternative energies, such as wind and solar, our industry is facing an Energy Polarity Dilemma, thus further promoting a negative "us vs them" mentality between industry and the general public. There is a mentality of "not in my backyard" from the opposition that would like to see oil and gas operations driven out of the state, despite no evident reduction in energy consumption levels. As Operators in Colorado are forced to curtail operations, local energy customers will be forced to rely on energy from other States, where opposition and regulations are not as prolific. As a result, local energy costs will come at a premium to those same users opposing Colorado’s oil and gas development.
Questions that must be addressed and managed by industry include; How can we more effectively communicate to younger generations/current demographics about our environmentally responsible development in Colorado versus other locales? How do we change and challenge the "us vs them" narrative? And finally, how do we successfully promote energy clarity and the need and role of fossil fuels in daily life.
In order to change the conversation, industry needs to develop a better educational campaign for local communities. There are some groups working towards this conversation, however it’s often polarizing and confrontational. Industry is viewed as unwilling to change and not significantly addressing environmental and safety concerns. The jobs and economic prosperity positions seem self-serving and out of touch. There needs to be Catered Education, re-addressing grassroots efforts for energy clarity, and utilizing modern communication strategies to more effectively educate consumers about energy clarity, such as social media presence.
We need to help consumers understand the
US energy-related carbon dioxide (CO2) emissions declined by 2.8% in 2019 to 5,130 million metric tons (MMmt), according to data in the US Energy Information Administration’s (EIA) Monthly Energy Review. CO2 emissions had increased by 2.9% in 2018, the only annual increase in the past 5 years. Because of continuing trends in how much energy the US economy uses and how much CO2 that energy use generates, energy-related CO2 emissions in 2019 fell more than energy consumption, which declined by 0.9% in 2019, and gross domestic product, which increased by 2.3% in 2019. The changes in US energy-related CO2 emissions in 2019 offset the increase in 2018. The increase in 2018 was largely caused by increased energy use as a result of weather and was the largest increase in CO2 emissions since 2010, when the US economy was recovering from an economic recession.
To ensure continued access to JPT's content, please Sign In, JOIN SPE, or Subscribe to JPT The crash in the oil price during March, caused by oversupply coinciding with an expected large drop in short-term demand because of the COVID-19 pandemic, will cause severe disruption to the industry for at least the next 12–18 months. Whether the low price spurs greater demand for oil when the pandemic subsides, or whether demand for oil continues to drop for the next few years, does not really affect the longer-term trends that we examine in this article. There are numerous views of what the future energy landscape will look like in the next decade and beyond. A common theme throughout is that energy use could switch quite rapidly, from fossil fuels to electrical energy. Although a pivot to gas is widely talked about, none of the major oil companies have yet to significantly alter the ratio of gas vs. oil produced.
Unlike conventional reservoirs, coal seams are the source, trap, and reservoir for coalbed methane (CBM). A comparison of the two reservoir types shows profound differences in reservoir properties, storage mechanisms, flow mechanisms, and production profiles. Understanding the reservoir differences is key to successful evaluation and operation of a CBM project. Coal is a chemically complex, combustible solid consisting of a mixture of altered plant remains. Organic matter constitutes more than 50% of coal by weight and more than 70% by volume. Type refers to the variety of organic constituents.
Activists of the environmental organization Greenpeace project a slogan that reads "No Future in Fossil Fuels" on the cooling tower of RWE coal power plant, one of Europe's biggest electricity companies in Neurath, northwest of Cologne, Germany, on 10 November 2017. The world’s major fossil fuel producers are set to bust global environmental goals with excessive coal, oil and gas extraction in the next decade, the United Nations and research groups said in the latest warning over climate crisis. The report reviewed specific plans from 10 countries, including superpowers China and the United States, as well as trends for the rest of the world, and estimated that global fossil fuel production by 2030 would be at levels between 50 and 120% over Paris Agreement targets. Under that 2015 global pact, nations committed to a long-term goal of limiting the average temperature increase to within 1.5 to 2°C above preindustrial levels. But by 2030, global planned production would lead to 39 gigatonnes (Gt) of carbon dioxide emissions, 53% higher than what is needed to reduce temperature rises to 2°C and 21 Gt, or 120%, more than is needed for 1.5°C, the report said.
There are approximately ten thousand coal bed methane (known locally as coal seam gas or CSG) wells in the Surat and Bowen Basins of Australia. It is estimated that a third of these wells experience significant levels of solids production. This is a notable problem for CSG operators, which requires some form of corrective action. Believed to be caused by deterioration of interburden clays, a measurement of how the well bore outside of the casing has changed since openhole logging, such as caliper, would enable a more intelligent approach to any remedial workover. Research into such a ‘caliper behind casing’ measurement is relatively unexplored. This paper introduces and investigates the use of wireline nuclear logging tools for this unique problem.
Using nuclear simulation software, the relationship between borehole diameter and detector count rate was characterised for standard completions found in Queensland CSG wells. A range of typical formation properties were then simulated to develop a correction algorithm which was able to compensate for the variations in formations found in these environments, the input to be provided by pre-casing openhole logging. These variations are normally the variables of interest in conventional logging, but for a caliper behind casing measurement, they represent sources of error. Testing of this measurement was done with controlled lab logging of well characterised blocks in addition to field-based testing on mature and recently drilled wells.
In this paper we show how nuclear logging tools can provide a caliper behind casing measurement of up to eighteen inches when logged through casing. Therefore, estimations of hole volume are calculated more accurately by taking into account the unknown rugosity. Identification of potentially problematic features such as bridges is made possible. Excellent verification of the modelling provided by the lab-based benchmarking is seen. Finally, example logs from case studies show measurement repeatability and improve understanding of the fundamental problem of formation deterioration in the CSG wells which were included in this study.
The application of this new solution provides significant potential for improvements in operational efficiency in Queensland CSG.