Karsten Michael

Impact of multi-purpose aquifer utilisation on a variable-density groundwater flow system in the Gippsland Basin, Australia

The Latrobe aquifer in the Gippsland Basin in southeastern Australia is a prime example for emerging resource conflicts in Australian sedimentary basins. The Latrobe Group forms a major freshwater aquifer in the onshore Gippsland Basin, and is an important reservoir for oil and gas in both onshore and offshore parts of the basin. The Latrobe Group and overlying formations contain substantial coal resources that are being mined in the onshore part of the basin. These may have coal-seam-gas potential and, in addition, the basin is considered prospective for its geothermal energy and CO2 storage potential. The impacts of groundwater extraction related to coal-mine dewatering, public water supply, and petroleum production on the flow of variable-density formation water has been assessed using freshwater hydraulic heads and impelling force vectors. Groundwater flows from the northern and western edges towards the central part of the basin. Groundwater discharge occurs mainly offshore along the southern margin. Post-stress hydraulic heads show significant declines near the petroleum fields and in the coal mining areas. A hydrodynamic model of the Latrobe aquifer was used to simulate groundwater recovery in the Latrobe aquifer from different scenarios of cessation of groundwater and other fluid extractions.RésuméLe Latrobe aquifer dans le Gippsland Basin, Sud de l’Australie, est un exemple de premier ordre des conflits émergeants relatifs à une ressource. Le Latrobe Group forme un aquifère d’eau douce côtier majeur du Gippsland Basin, lequel est aussi un important réservoir d’huile et de gaz, à fois terrestre et marin. Le Latrobe Group et les formations sus-jacentes contiennent de substantielles ressources de charbon, qui sont en cours d’exploitation dans la partie terrestre du bassin. Celles-ci peuvent avoir un potentiel en gaz de houille et, de plus, le bassin est considéré comme future source d’énergie géothermique et réservoir potentiel de stockage de CO2. Les impacts du pompage de l’eau de nappe en relation avec l’exhaure de la mine de charbon, l’alimentation du réseau de distribution public, et la production de pétrole sur le flux d’eau de densité variable de la formation ont été estimés en utilisant potentiels hydrauliques eau douce et vecteurs force motrice. L’eau de nappe s’écoule des bordures Nord et Ouest vers la partie centrale du bassin. La décharge a principalement lieu en mer, le long de la bordure Sud. Les potentiels hydrauliques post-stress montrent des diminutions significatives près des champs pétroliers et dans les zones d’extraction houillère. Un modèle hydrodynamique du Latrobe aquifer a été utilisé pour simuler la remontée de la nappe suivant différents scénarios d’arrêt d’extraction de l’eau et autres fluides.ResumenEl acuífero Latrobe en la cuenca de Gippsland en el sudeste de Australia es un excelente ejemplo del surgimiento de conflictos en los recursos en cuenca sedimentarias australianas. El Grupo Latrobe forma un gran acuífero de agua dulce en la zona costera terrestre de la cuenca Gippsland, y es un reservorio importante de petróleo y gas tanto costa adentro como como costa afuera de la cuenca. El Grupo Latrobe y las formaciones suprayacentes contienen sustanciales recursos de carbón que están siendo explotados en la parte continental de la cuenca. Estos pueden tener vetas potenciales gas de carbón y, en adición, la cuenca es considerada como prospectiva por su energía geotermal y potencial almacenamiento de CO2. Los impactos de la extracción de agua subterránea relacionados con el drenaje de la mina de carbón, abastecimiento de agua potable, y la producción de petróleo sobre el flujo de agua de formación de densidad variable han sido evaluados usando las cargas hidráulicas del agua dulce y los vectores de las fuerzas impulsantes. El agua subterránea fluye desde los límites norte y oeste hacia la parte central de la cuenca. La descarga de agua subterránea ocurre principalmente costa afuera a lo largo del margen sur. Las cargas hidráulicas post stress muestran una disminución significativa cerca de los campos de petróleo y en el área de minas de carbón. Se usó un modelo hidrodinámico del acuífero Latrobe para simular la recuperación del agua subterránea a partir de diferentes escenarios de cesación de las extracciones de agua subterránea y otros fluidos.摘要澳大利亚东南部Gippsland盆地Latrobe含水层是澳大利亚沉积盆地新兴资源争论的首要例子。Latrobe Group在岸上的Gippsland盆地内形成了一个较大的淡水含水层,对盆地岸上和近海部分的油气是重要的储库。Latrobe Group以及上覆的地层包含大量的煤炭资源,盆地岸上部分的煤炭正在开采。此处还有煤层天然气的潜力,此外,盆地也被认为具有未来的地热能开采和CO2封存的潜力。抽取地下水对变密度地层水的水流的影响与煤矿脱水、公共给水和采油相关,并利用淡水水头和驱动力矢量进行估算。地下水从北侧和西侧边缘朝盆地中心运移。地下水排泄主要发生在沿南部边缘的近海。靠近采油和采矿点的应激后水头显著下降。Latrobe含水层的水动力模型是用于模拟Latrobe含水层从停止地下水和其它液体抽取的不同场景中的地下水恢复。ResumoO aquífero Latrobe, na Bacia de Gippsland, sudeste da Austrália, é um excelente exemplo de conflitos na gestão dos recursos hídricos em bacias sedimentares australianas. O Grupo Latrobe forma um importante aquífero de água doce na parte terrestre da Bacia Gippsland e é um importante reservatório de petróleo e gás em partes terrestres e submarinas da bacia. O Grupo Latrobe e as formações sobrejacentes contêm substanciais recursos de carvão, os quais se encontram em exploração na parte terrestre da bacia. Estes podem ter potencialmente gás de hulha. Além disso, a bacia é considerada uma reserva potencial de energia geotérmica e tem potencial para armazenamento de CO2. Os impactes da extração de águas subterrâneas relacionados com a drenagem na mineração de carvão, com o abastecimento público de água e com a produção de petróleo no fluxo de água subterrânea de formação com densidade variável foram avaliados usando potenciais de água doce e respectivos gradientes (forças impulsionadoras). A água subterrânea flui a partir das fronteiras norte e oeste em direcção à parte central da bacia. A descarga das águas subterrâneas ocorre principalmente no mar, ao longo da margem sul. Os gradientes pós-extração indicam rebaixamentos significativos perto dos campos de petróleo e nas áreas de mineração de carvão. Foi utilizado um modelo hidrodinâmico do aquífero Latrobe para simular a recuperação das águas subterrâneas nesse aquífero a partir de diferentes cenários de cessação da exploração das águas subterrâneas e de outros fluidos.

Reduction of GHG emissions by geological storage of CO2

Purpose – The purpose of this paper is to identify and characterize a geological storage site at more than 800 m depth that is capable of storing large quantities of carbon dioxide (CO2) in the Alberta Basin and is close to a large CO2 supply.Design/methodology/approach – Five criteria are used to select the site: total volume of the pore space of the formation for CO2 (i.e. capacity); accessibility of the pore space in the storage site to CO2 (i.e. permeability or injectivity); ability of the storage site to retain the CO2 once the CO2 has been injected (i.e. containment); protection of other resources from contamination; and cost of the whole process: capture of the CO2, transport and storage (i.e. economics).Findings – The Heartland Redwater Leduc Reef is identified as a site that has large capacity, good injectivity, and is an excellent trap. Contamination of the oil in the oil reservoir at the top of the reef (the third largest oil reservoir in Canada) is avoided by co‐optimizing CO2 storage and oil ...

Preliminary Analysis of Containment Integrity for Geological Storage of CO2 at the South West Hub Project, Western Australia

The Mandurah Terrace in the onshore Perth Basin was proposed as a suitable site for CO2 injection. Prior investigations in the area indicate that faults affect the target storage reservoir and shale barriers. Changes in the pore pressure and stress field induced by fluid injection could alter the containment integrity by either exceeding fault capillary resistance or by triggering slip on pre-existing faults. The capillary properties of faults have been assessed using the Shale Gouge Ratio predictive algorithm which can assess the maximum fluid column height trapped by a fault without leaking. Three different scenarios were investigated, representing different juxtaposition geometries. In the south of the area, potential spots for local up and across fault fluid migration are noted. The relationship between the modelled faults and the present-day stress field has been investigated to define critically stressed fault segments most at risk of reactivation resulting from pore-pressure build-up due to injection. The likelihood of fault reactivation is low in the current day stress field with pore pressures required equivalent to a CO2 column exceeding 1000m. Preliminary geomechanical modelling also shows no likelihood of fault reactivation and potential ground uplifts of less than two centimetres at the surface.

Basin resources and carbon storage

Prospective sites for geological storage of carbon dioxide target sedimentary basins as these provide the most suitable geological settings for safe, long-term storage of greenhouse gases. Sedimentary basins can also host different natural resources including groundwater, oil and gas, unconventional gas, coal and geothermal energy.Understanding the nature of how these resources are distributed in the subsurface is fundamental to managing basin resource development and carbon dioxide storage. The underlying principal of the proposed workflow is to assess what basin resource – storage interactions are likely and to evaluate, at different scales, how they may be best managed. For regions having potential for resource conflicts a basin resource management plan may be required, and the appropriate regulator would need to decide on the priority of each resource and, if parallel development is not feasible, the order in which resources should be exploited.

ABSTRACT: Coalbed Methane Producibility in the Cretaceous Succession of the Alberta Basin as Affected by Hydrogeology and Stress Regime

Coal permeability and the hydrogeology of the coal-bearing strata are critical factors in coalbed methane (CBM) producibility. The pressure regime in the formation water affects the coal gas content and exsolution during production. Water salinity affects the amount of gas dissolved in formation waters and water disposal strategies. Permeability affects production rates of both gas and water. In the absence of direct data, the stress regime is a good regional-scale indicator of areas with enhanced permeability.