Magnetotelluric monitoring of coal seam gas depressurisation

2015 ◽  
Vol 55 (2) ◽  
pp. 466
Author(s):  
Nigel Rees ◽  
Graham Heinson ◽  
Lars Krieger ◽  
Goran Boren ◽  
Dennis Conway ◽  
...  

The depressurisation of coal seam gas (CSG) formations causes in-situ fluids to migrate through pores and fractures in the earth. The removal of large volumes of water from coal seams has the potential to affect water table levels and groundwater flow in surrounding aquifer systems. Magnetotellurics (MT) is a passive electromagnetic technique that uses the natural fluctuations of electric and magnetic fields at the Earth’s surface to determine the Earth’s conductivity structure. The bulk movement of fluids during CSG depressurisation causes a conductivity change in the subsurface and this change can be monitored using MT. An electromagnetic survey was conducted at a CSG production scientific test site. Electric and magnetic field instruments were deployed, measuring continuously at 651 Hz across three months. New processing software was developed to generate MT responses in the bandwidth of 100–0.1 Hz across the experiment. The theory of monitoring subsurface fluid movement using MT is presented, as well as instrumentation and a case study to demonstrate the potential of the magnetotelluric method. Results from this approach can provide an inexpensive means of monitoring CSG depressurisation, as well as an improved understanding of the potential impacts on the subsurface environment during CSG production.

2021 ◽  
pp. 074171362110053
Author(s):  
Tracey Ollis

This case study research examines informal adult learning in the Lock the Gate Alliance, a campaign against mining for coal seam gas in Central Gippsland, Australia. In the field of the campaign, circumstantial activists learn to think critically about the environment, they learn informally and incidentally, through socialization with experienced activists from and through nonformal workshops provided by the Environmental Nongovernment Organization Friends of the Earth. This article uses Bourdieu’s “theory of practice,” to explore the mobilization of activists within the Lock the Gate Alliance field and the practices which generate knowledge and facilitate adult learning. These practices have enabled a diverse movement to educate the public and citizenry about the serious threat fracking poses to the environment, to their land and water supply. The movements successful practices have won a landmark moratorium on fracking for coal seam gas in the State of Victoria.


2017 ◽  
Vol 131 ◽  
pp. 300-311 ◽  
Author(s):  
Anna (Anya) Phelan ◽  
Les Dawes ◽  
Robert Costanza ◽  
Ida Kubiszewski

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1802 ◽  
Author(s):  
Micucci ◽  
Mantecchini ◽  
Sangermano

The investigations on the effectiveness of the turn signal in motorcyclists understanding of motorists’ potential intentions in potentially dangerous car–motorcycle interactions and on the relationships among some variables that could influence the perception of rear and front turn signal status are examined in this paper. The investigations have been based on data pooled from the answers of a survey of 136 motorcycle riders, with special regards to the correct detection of turning indicators. Experimental videos have been realized during in-situ simulations, both in urban and suburban areas, recording vehicular interactions in three-leg road intersections, able to potentially generate crash risks, through a 360-camera mounted on a motorcyclist’s helmet. The blinkers detection rate has been combined with other factors related to motorcyclist’s characteristics and test context (e.g., age, gender, location of the test site, presence of a car behind tester vehicles and if the motorcyclist are also habitual car or bicycle drivers) in a stepwise logistic regression that modelled the odds of detecting the turn signal turned on as a function of significant factors. Within the limits of the proposed methodology, the results highlight the low percentage of correct sighting of the turn indicators and confirm the existence of a relation between the detection of the turn indicators aspect and some of the variables considered (e.g., age, being habitual cyclist or car driver and the presence of a car occluding the views), suggesting the opportunity to further investigate the phenomenon through the use of ad-hoc simulations, in order to highlight connections among the factors that can influence the perception of turning indicators in potentially dangerous contexts for cars and motorcycles.


2012 ◽  
Vol 52 (1) ◽  
pp. 545 ◽  
Author(s):  
Julian Strand ◽  
Reem Freij-Ayoub ◽  
Shakil Ahmed

Derived from a larger scale project, which studied geomechanical issues associated with coal seam gas (CSG) production, this paper investigates a hypothetical case study based on the Latrobe Valley, Gippsland Basin, Victoria. The paper focuses on examining aquifer water management associated with CSG production-related water extraction. As such, the paper limits itself to determining the volume of water production from a hypothetical case study area in the Latrobe Valley. A simplistic property model and methane production strategy has been used. The impact of extraction of this water on the hydraulic head in aquifers underlying the produced seams is quantified. The Latrobe Valley Depression contains 129,000 million tonnes of coal resources and is one of the world’s largest, and lowest cost, energy sources. Most of Victoria’s electricity is generated using coal from the Loy Yang, Morwell and Yallourn mines. In addition to these massive operations, significant additional coal resources are available and unallocated at this time. Opportunities exist for the continued usage of these resources for electricity production, gasification, liquefaction and other coal conversion processes, as well as solid fuel for industrial, domestic and other uses. The existence of data from the Victorian Department of Primary Industries 2003 coal resource model was the main reason for the selection of the case study, and their data was used to form a model of the stratigraphy of the Latrobe Valley. Aquifer models were simulated in MODFLOW, based on extraction figures modelled in the CSG simulator COMET3.


2017 ◽  
Vol 57 (2) ◽  
pp. 629
Author(s):  
Terrance Presley ◽  
Evilia Kurnia ◽  
Basia Wronski

This paper discusses the early outcomes of a trial of well head compression on coal seam gas (CSG) wells to lower surface pressure at the well head. This is a case study of four Johnson Controls Frick rotary screw compressor packages that were installed on CSG wells in an Origin Energy field in the Bowen basin and the early effects of lower well pressures on increased gas production due to the installation of compression. In mid-2016 Johnson Controls installed four compressor packages on Origin Energy wells with different characteristics (age, flow pressure), with a view of determining uplift of gas flow over the remaining life of the well, as well as operational issues with having well head compression. The expected versus actual uplift is compared for the different wells, with a view of providing some guidance on future potential wells that will benefit from this type of compression. Operational issues, such as effects on water flow, effect of oil and overall design considerations for well head compression, are also discussed.


2018 ◽  
Author(s):  
Xuejun Lin ◽  
Graham Sutherland ◽  
Duncan Cumming ◽  
Brian Thomas ◽  
Ali Sani

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