Differential Strain Index-Based Multiphysics Model for Coal Seam Gas Production

The Queensland Government has developed an associated water management policy that, among other things, strives to maximise the beneficial use of associated water derived from Queensland’s burgeoning coal seam gas industry. The Department of Infrastructure and Planning reports that domestic gas production alone (i.e. without an export LNG market) will produce on average 25 GL per annum in the next 25 years. Most of this water has sufficiently high total dissolved solids and other water quality issues to require some form of treatment prior to use. Clearly, the relatively large volumes of water present both challenges and opportunities to the communities in which the CSG industry is developing. In line with the philosophy of beneficial use of associated water, Santos has developed a portfolio of options within its associated water management strategy and plans for its Arcadia Valley, Fairview and Roma tenements. The strategy seeks to: provide enduring value for the community; maximise benefits while minimising the environmental footprint; provide a range of alternatives to avoid single-mode failure; use scalable options in response to uncertainty; deploy demonstrated technologies; and, meet and exceed all regulatory requirements. This paper will set some context around the broader CSG industry’s associated water challenges, and identify what parameters must be considered in arriving at beneficial uses for the water. The paper then explores some of Santos’ approaches to associated water management.

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Determining the impacts of coal seam gas extraction on water-dependent assets

The APPEA Journal ◽

10.1071/aj15051 ◽

2016 ◽

Vol 56 (2) ◽

pp. 545

Author(s):

David Post ◽

Peter Baker ◽

Damian Barrett

Keyword(s):

Coal Seam ◽

Indigenous Peoples ◽

Rural Areas ◽

Scientific Information ◽

Gas Production ◽

Specific Reference ◽

Catchment Management ◽

State Governments ◽

Coal Seam Gas ◽

Coal Resource

Many Australians, particularly in rural areas, are seeking clear scientific information about the potential impacts of coal seam gas production on groundwater and surface water across the country. In response to the resultant community concern, the Australian Government commissioned an ambitious multi-disciplinary program of bioregional assessments to improve understanding of the potential impacts of coal seam gas (and large coal mining) activities on water-dependent assets across six bioregions in eastern and central Australia. Delivered through a collaboration between the Department of the Environment, the Bureau of Meteorology, CSIRO, and Geoscience Australia—and including close engagement with natural resource management and catchment management organisations, coal resource companies, Indigenous peoples and state governments—the results will allow coal resource companies, governments, and the community to focus on the areas where impacts may occur so that these can be minimised. Key findings of the program will be presented with specific reference to the potential impacts on water-dependent assets due to CSG development by Metgasco and AGL in the Clarence-Moreton and Gloucester regions, respectively.

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Modelling the Contribution of Individual Seams to Coal Seam Gas Production

Proceedings of the SPE/AAPG/SEG Asia Pacific Unconventional Resources Technology Conference ◽

10.15530/ap-urtec-2019-198241 ◽

2019 ◽

Author(s):

Vanessa Santiago ◽

Ayrton Ribeiro ◽

Suzanne Hurter

Keyword(s):

Coal Seam ◽

Gas Production ◽

Coal Seam Gas

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Mathematical modelling of gas production and compositional shift of a CSG (coal seam gas) field: Local model development

Energy ◽

10.1016/j.energy.2015.05.107 ◽

2015 ◽

Vol 88 ◽

pp. 621-635 ◽

Cited By ~ 4

Author(s):

Steven Psaltis ◽

Troy Farrell ◽

Kevin Burrage ◽

Pamela Burrage ◽

Peter McCabe ◽

...

Keyword(s):

Coal Seam ◽

Mathematical Modelling ◽

Model Development ◽

Gas Production ◽

Local Model ◽

Coal Seam Gas ◽

Gas Field

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Stochastic forecasting of production potential using customised type curves in coal seam gas

The APPEA Journal ◽

10.1071/aj09082 ◽

2010 ◽

Vol 50 (2) ◽

pp. 718 ◽

Cited By ~ 1

Author(s):

Georg Zangl ◽

Shripad Biniwale ◽

Andreas Al-Kinani ◽

Vikram Sharma ◽

Rajesh Trivedi

Keyword(s):

Expert System ◽

Coal Seam ◽

Group Membership ◽

Gas Production ◽

Well Performance ◽

Coal Seam Gas ◽

Reservoir Properties ◽

Type Curve ◽

Probability Of Occurrence ◽

Future Production

This paper discusses a new workflow to stochastically estimate the performance of future production in coal seam gas (CSG) developments. Usually performance evaluations for CSG wells are conducted using either much-generalised statistical methods or numerical simulation. Both approaches have significant drawbacks; the former methods are quick but very often lack accuracy, while the latter is very accurate however also usually highly complex in set-up and computation. The presented workflow is a new approach to well performance prediction that combines speed and reasonable accuracy. The workflow generates a set of key performance indicators of existing wells derived from historic dynamic data (water and gas production rates, pressures, etc.), static data (initial coal and reservoir properties, etc.) and predicted data (simplified production forecasts). The wells are then grouped according to the similarity of their KPIs. The production profiles of the wells within the same group are combined to a type curve that is described by the most likely production profile and an associated uncertainty range. A data-driven expert system is used to identify and capture the correlations of the parameters such as geographic locations, well spacing, reservoir properties and the group membership (equivalent to type curve). This expert system can then be applied to any location in the field in order to determine the most likely group membership of a potential well. The classification of a new well to a group is hereby not necessarily unique; the expert system might classify a new well into several groups and assign a probability of occurrence for each of the groups. A Monte Carlo routine is then applied to forecast the performance of the new well locations honoring the respective probability of occurrence of each type curve.

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WATER AND THE COAL SEAM GAS INDUSTRY

The APPEA Journal ◽

10.1071/aj06027 ◽

2007 ◽

Vol 47 (1) ◽

pp. 369

Author(s):

G. Scott ◽

C. Ammundsen

Keyword(s):

Coal Seam ◽

Environmental Protection Agency ◽

Poor Quality ◽

Gas Production ◽

End User ◽

Protection Agency ◽

Coal Seams ◽

Coal Seam Gas ◽

Gas Industry ◽

Access To Water

Access to water is a significant issue in Queensland as much of the State continues to be affected by a prolonged drought. Coal seam gas production involves extracting water from coal seams to reduce the groundwater pressure that keeps the methane trapped in the coal. This process produces large volumes of water. Local councils, primary producers and industrial developers are potential end users of this water; however, if the water is of poor quality, it may be unsuitable for release in the environment and for other direct beneficial uses.This paper examines the complex legislative and regulatory hurdles that need to be overcome before any mutually beneficial agreement between the coal seam gas producer and end user may be completed. It also examines an operational policy recently released by the Queensland Environmental Protection Agency that proposes a framework for the regulation and management of water extracted from coal seams.

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Case study of the effects on coal seam gas well production with installation of well head compression (oil-flooded rotary screw type): early outcomes of an Australian trial of four wells in the Bowen Basin

The APPEA Journal ◽

10.1071/aj16199 ◽

2017 ◽

Vol 57 (2) ◽

pp. 629

Author(s):

Terrance Presley ◽

Evilia Kurnia ◽

Basia Wronski

Keyword(s):

Coal Seam ◽

Gas Flow ◽

Lower Surface ◽

Gas Production ◽

Coal Seam Gas ◽

Potential Wells ◽

Energy Field ◽

Operational Issues ◽

Rotary Screw

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.

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Vertical gas migration associated with coal seam gas production

The APPEA Journal ◽

10.1071/aj15108 ◽

2016 ◽

Vol 56 (2) ◽

pp. 602

Author(s):

Ludovic Ricard ◽

Julian Strand

Keyword(s):

Coal Seam ◽

Risk Evaluation ◽

Critical Role ◽

Gas Production ◽

Mitigation Strategies ◽

Gas Migration ◽

Coal Seam Gas ◽

Gas Reservoirs ◽

Gas Leakage ◽

Migration Pathways

Gas migration outside coal seam gas reservoirs has been identified as a risk associated with CSG production. While such an event has not been reported or scientifically associated with CSG production, understanding the physical mechanism of the vertical migration in the overburden involved should gas leakage occur would improve mitigation strategies and risk evaluation. In this extended abstract, a series of key modelling scenarios of gas migration above the reservoir are developed. Interpretation of the scenarios highlights that: the seal/leakage nature of the overburden strongly impacts gas migration and volume of gas leaked; when leakage does occur, the leaked volume represents a very small portion of the original gas in place and volume of gas produced; the connectivity of the overburden plays a critical role on the gas migration pathways and volume of gas leaked; and, residual gas saturation, and relative permeability hysteresis provide means to trap the mobile gas, significantly reducing the volume of gas leaked reaching shallower formations.

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