Development Of Underground Coal Gasification Research Articles

Modelling underground coal gasification: What to start with

Underground coal gasification (UCG) is widely regarded as a clean coal technology that holds enormous potential to decarbonize the world's coal industry. It converts coal underground into combustible syngas through a set of complex physiochemical events. Experimental and numerical efforts over the past century have contributed to the development of UCG around the world; however, tapping the world's deep-situated coal resources with UCG requires substantial contributions from numerous high-quality researchers. To facilitate effective engagement, this paper will provide a background on where to start if one wishes to undertake UCG modelling. First, a brief description of the fundamental phenomena involved in UCG is given. Then, a succinct introduction of the widely used modelling software is rendered, followed by a description of UCG studies to provide insight how to tune the various software packages for modelling UCG and where their strengths lie. This paper shall serve as guidance to new UCG modellers.

A Review of Research on Cavity Growth in the Context of Underground Coal Gasification

Underground Coal Gasification (UCG) is a leading-edge technology for clean and effective utilization of coal resources, especially for deep coal seams with a depth of more than 1000 m. Since the core operation place of UCG is the cavity, mastering the cavity growth pattern is a prerequisite to ensure the efficient and economic development of UCG. At present, scholars have conducted numerous research works on cavity growth, but the simulation conditions limit the research results. Hence, it is necessary to summarize and sort out the research results of cavity growth patterns, which contribute to deepening the understanding of UCG and pointing out the direction for subsequent research. First of all, this paper summarizes the development history of UCG technology and describes the cavity growth mechanism from chemical reactions and thermo-mechanical failure. Then, the research methods of cavity growth are summarized from three aspects: a field test, laboratory experiment, and numerical simulation. The results show that the appearance of the cavity is teardrop-shaped, and its growth direction is obviously related to the gas injection method, including the injection direction and rate. Subsequently, the factors affecting the cavity growth process are expounded from the geological factors (permeability, moisture content, and coal rank) and operating factors (temperature, pressure, gasification agent’s composition, and gasification agent’s flow pattern). Finally, the existing problems and development trends in the cavity growth are discussed. The follow-up research direction should focus on clarifying the cavity growth mechanism of the controlled-retractable-injection-point (CRIP) method of UCG in the deep coal seam and ascertain the influence of the moisture content in the coal seam on cavity growth.

Underground coal gasification modelling in deep coal seams and its implications to carbon storage in a climate-conscious world

As a clean coal technology, underground coal gasification (UCG) boasts a prospect in tapping worldwide deep coal seams, with a tremendous potential to be linked with following carbon storage and sequestration. Therefore, UCG ought to play a vital role as a sustainable technological alternative in a climate-conscious world. However, the world has very limited experience in deep UCG development because most of the tests were on shallow coals. This paper aims to bridge the knowledge gap to shed light on the development of UCG cavities in deep coal seams. A large-scale 3D UCG model was constructed with an improved Controlled Retraction Injection Point (CRIP) method, which is more suitable to deep UCG. In addition, the effect of double-diffusive natural convection was included. Modelling results show that the improved method contributed to a favourable development of UCG cavities in deep coal seams with a good gas production. Compared to a shallow UCG, pore variations exhibited a similar pattern but with distinct characteristics owing to the effects of a high pressure. Furthermore, double-diffusive natural convection was revealed to play an important role in the development of cavities and the general UCG performance. The relevant findings will help enhance the knowledge base of UCG operations in world deep coal seams, promote the clean utilization of world coal resources, and if linked to carbon dioxide storage and sequestration, contribute to the reduction of carbon dioxide emissions in a climate-conscious world.

Implementing the Calculations and Characterization of Underground Coal Gasification using Data Analytic Method

Indonesian coal production nowadays has reached 63% of total production, which means this high demand will also produce a lot of data. This high demand needs to be innovated as a new alternative energy based on coal production, Underground Coal Gasification (UCG). The coal in this alternative energy source is used to turn the solid coal into gas. Coal mining data has a lot of variables that might be difficult to process manually. Our automatic system will help the users, especially the geologists, identify which coal seams have the potential to be developed as the UCG. We developed the system using a python-based coding system and required data standardization to ease the built-in code reading and process all the required steps to identify the UCG. We implemented the calculation and characterization regarding the calorific value (ADB), proximate, and ultimate analysis from the provided data to find the needed variables for the UCG analytics system. The automatic system will allow the user to choose the interesting borehole that they want to identify. Our system then shows the initial UCG recommendation layer for the next analysis. From our experiment, our system finally found that at the depth of 260 meters, Borehole MJ02 has the potential as the initial guest of the recommendation layer of the UCG development. Doi: 10.28991/CEJ-SP2021-07-012 Full Text: PDF

Screening criteria of underground coal gasification (UCG): a case study from Mangunjaya Area, South Sumatra Basin, Indonesia

Underground coal gasification (UCG) is a technology that can increase the value of coal. This technology turns coal into gas below the surface through the gasification process. UCG offers many applications for power generation, heating, and the chemical industry. The Mangunjaya area is one prospecting area, located in the South Sumatra Basin, which has been actively producing coal for a long time. This study focused on determining the potential location of UCG in Mangunjaya. Screening criteria were extracted from previous studies including coal thickness, depth of the coal seam, depth and thickness ratio, coal rank, the dip of a coal seam, roof and floor rock type and thickness, and geological structure. Thirteen boreholes were examined to determine their potential, namely MJ1 to MJ13. The evaluation results show that the Mangus coal seam at a depth of 260,4 meters in the MJ2 borehole and the surrounding area in 15 km2, matches the criteria and has the most potential coal for UCG development.

Assessment of Coal Permeability using Injection Falloff Test and Effect of Temperature and Skin Factor on It: A Case Study for Coal Seams of Jamalganj Coalfield, Bangladesh

The Jamalganj coalfield with the coal deposits of the Permian Gondwana Group in the halfgraben basin was discovered in Joypurhat District, Northwestern Bangladesh, sometime in 1962. Individual coalbed thickness ranges from 0.60 m to 42 m and seams were encountered between the depth ranges of 640 m and 1158 m. Since mining has not yet begun due to the greater depth of the coal seams, several researchers have proposed a Coalbed Methane (CBM) exploration in this region. This research focuses on the permeability of the Jamalganj coal derived from the in-situ Injection Falloff Test (IFT), which is an important reservoir parameter and one of the key factors in CBM exploration and Underground Coal Gasification (UCG). In addition to that, the relationship of temperature and skin factor with permeability is one of the key findings of this research, permeability obtained from the IFT ranges from 2.57 to 121.16 mD while the skin factor ranges from - 6.11 to 50.85 and a higher temperature gradient as of about 4°C per 100 m depths was observed. The study shows that temperature has an inverse relationship with the permeability that decreases with depth and temperature increases, which is analogous with the other CBM producing reservoirs around the world. The negative skin factor denotes flow enhancement near the wellbore and a well-stimulated reservoir, and the positive skin factor indicates increased flow resistance near the wellbore, which reduces permeability. The permeability data suggest that the analyzed coal seams of the Jamalganj Coalfield are suitable for unconventional gas production by either CBM or UCG development. The Dhaka University Journal of Earth and Environmental Sciences, Centennial Special Volume June 2022: 103-112

SAUCGA: The potential, role, and development of underground coal gasification in South Africa

SAUCGA: The potential, role, and development of underground coal gasification in South Africa

Global Development of Commercial Underground Coal Gasification

Global development of Underground Coal Gasification (UCG) is considered here in light of latest trends of energy markets and environmental regulations in the countries that have been traditional proponents of UCG. The latest period of UCG development triggered by initial success of the Chinchilla UCG project (1997-2006) has been characterized by preponderance of privately and share-market funded developments. The deceleration of UCG commercialization has been in part caused by recent significant decrease of world oil, gas and coal prices. Another substantial factor was lack of necessary regulations governing extraction and conversion of coal by UCG method in the jurisdictions where the UCG projects were proposed and developed. Along with these objective causes there seem to have been more subjective and technical reasons for a slowdown or cancelation of several significant UCG projects, including low efficiency, poor environmental performance, and inability to demonstrate technology at a sufficient scale and/or at a competitive cost. Latest proposals for UCG projects are briefly reviewed.

Your SPE: SPE Has Strong Links in New Zealand and Australia E&P Industry

President's column As I move further into my year as president, I have been refining my key message as follows: inherent in, and fundamental to, SPE's mission is the notion of and adherence to a number of values and principles. These include that SPE is a member organization, as opposed to a corporate organization, and individuals are members of SPE. These individuals belong to SPE to develop and broaden their skills as oil and gas professionals in a worldwide industry as well as to network with other individuals (technical specialists). Inevitably, each individual member brings to SPE a measure of his/her company self-interest and culture, and this adds to the diversity of SPE's international membership. Corporate culture benefits SPE directly: companies sponsor SPE initiatives and exhibit at SPE events, and they allow their employees time and funds to participate in SPE committees and activities. Thus, SPE benefits not only from an altruistic desire on the part of individuals to further technology dissemination, but also from companies wishing to be seen to engage in the Society's activities and to support its mission. Early October saw me in New Zealand and Australia. I was delighted to find that these SPE values and principles are very well understood here. Volunteerism is perceived by both individuals and companies to offer great value, and all sections have very active board members. I began this trip with a visit to New Plymouth in New Zealand. This section is small, with 82 members, including 16 young professionals. Typically, between 15 and 30 members regularly attend lunch meetings, which are organized jointly with the New Zealand Institute of Professional Engineers. No university in New Zealand offers a petroleum engineering course, so there are no student members. However, the section sponsors scholarship programs for engineering students at three New Zealand universities. I then flew to Australia, where I visited the Queensland Section in Brisbane, the South Australian Section in Adelaide, and the Western Australian Section in Perth. Membership in all six Australian sections, including New South Wales/Australian Capital Territory, Victoria and Tasmania, and Northern Territory, totals some 1,500. Australia is Huge (with a capital H indeed) and each section has a different focus. For example, 75% of the Queensland Section members work in the booming coalbed methane (CBM) business. There are plans to build four liquefaction plants to start CBM exports to Japan and China. However, the business is dominated by small and medium-sized independent companies, and they are currently finding it difficult to raise funds for further developments due to the credit crunch. Another interesting development in that region is underground coal gasification (UCG). Linc Energy, which is seeking to utilize UCG and gas-to-liquid technologies as a means of converting coal deposits into liquid fuel, is at the forefront of Australian UCG development. My next stop was Adelaide, home to the South Australian Section, founded in 1982 and thus the oldest of the Australian sections. The other five Australian sections were set up between 1983 and 1990. In addition to its monthly meetings, the South Australian Section organizes such activities as Education Day, where 70 high school students are exposed to our industry, and an annual math competition with the Math Association.

Commercial development of underground coal gasification

Underground coal gasification (UCG) is a process by which coal seams at depths uneconomic for open pit mining can be converted, using drillhole access, to a gas suitable for use as a fuel for power generation or as a chemical feedstock. Its application draws on a wide range of engineering and related disciplines including chemistry, geology, geohydrology, geotechnical engineering (including drilling techniques) and chemical engineering. This paper describes the UCG process and traces its historical development with particular reference to the vast amount of work undertaken in the former Soviet Union since the 1930s. Reference is also made to the most recent UCG tests in Australia (1999–2002), Spain (1997) and the USA (1987–1988), and to the new generation of projects that are in various stages of planning and development. The significance of the required specialist technical disciplines is discussed, and both environmental and commercial issues of specific relevance to UCG project developmen,t are reviewed.

96/01423 Evaluation of prospects for development of underground coal gasification in the Kuznetsk Basin

96/01423 Evaluation of prospects for development of underground coal gasification in the Kuznetsk Basin

Trends of Development of Underground Coal Gasification in the USSR

Trends of Development of Underground Coal Gasification in the USSR

Underground Gasification for Unrecoverable East Appalachian Coals

Underground Gasification for Unrecoverable East Appalachian Coals