Reservoir and Production Engineering Challenges for Geothermal Systems Hosted in Australian Sedimentary Basins

2016 ◽  
Author(s):  
Ludovic P. Ricard ◽  
Cameron R. Huddlestone-Holmes ◽  
Martin Pujol
Keyword(s):  
Sedimentary Basins ◽  
Geothermal Systems ◽  
Production Engineering

Defining structural permeability in Australian sedimentary basins

2015 ◽  
Vol 55 (1) ◽  
pp. 119 ◽  
Author(s):  
Adam Bailey ◽  
Rosalind King ◽  
Simon Holford ◽  
Joshua Sage ◽  
Martin Hand ◽  
...  
Keyword(s):  
Regional Scale ◽  
Sedimentary Basins ◽  
In Situ Stress ◽  
Natural Fracture ◽  
Enhanced Geothermal Systems ◽  
Structural Development ◽  
Geothermal Systems ◽  
Stress Regime ◽  
Orientation Data

Declining conventional hydrocarbon reserves have triggered exploration towards unconventional energy, such as CSG, shale gas and enhanced geothermal systems. Unconventional play viability is often heavily dependent on the presence of secondary permeability in the form of interconnected natural fracture networks that commonly exert a prime control over permeability due to low primary permeabiliy of in situ rock units. Structural permeability in the Northern Perth, SA Otway, and Northern Carnarvon basins is characterised using an integrated geophysical and geological approach combining wellbore logs, seismic attribute analysis and detailed structural geology. Integration of these methods allows for the identification of faults and fractures across a range of scales (millimetre to kilometre), providing crucial permeability information. New stress orientation data is also interpreted, allowing for stress-based predictions of fracture reactivation. Otway Basin core shows open fractures are rarer than image logs indicate; this is due to the presence of fracture-filling siderite, an electrically conductive cement that may cause fractures to appear hydraulically conductive in image logs. Although the majority of fractures detected are favourably oriented for reactivation under in situ stresses, fracture fill primarily controls which fractures are open, demonstrating that lithological data is often essential for understanding potential structural permeability networks. The Carnarvon Basin is shown to host distinct variations in fracture orientation attributable to the in situ stress regime, regional tectonic development and local structure. A detailed understanding of the structural development, from regional-scale (hundreds of kilometres) down to local-scale (kilometres), is demonstrated to be of importance when attempting to understand structural permeability.

Geothermometry

1996 ◽  
Author(s):  
Craig M. Bethke
Keyword(s):  
Geochemical Modeling ◽  
Equilibrium Points ◽  
Sedimentary Basins ◽  
Equilibrium Composition ◽  
Equilibrium Temperature ◽  
Silica Content ◽  
Ore Deposits ◽  
Correct Result ◽  
Geothermal Systems ◽  
Silica Geothermometer

Geothermometry is the use of a fluid’s (or, although not discussed here, a rock’s) chemical composition to estimate the temperature at which it equilibrated in the subsurface. The specialty is important, for example, in exploring for and exploiting geothermal fields, characterizing deep groundwater flow systems, and understanding the genesis of ore deposits. Several chemical geothermometers are in widespread use. The silica geothermometer (Fournier and Rowe, 1966) works because the solubilities of the various silica minerals (e.g., quartz and chalcedony, SiO2) increase monotonically with temperature. The concentration of dissolved silica, therefore, defines a unique equilibrium temperature for each silica mineral. The Na-K (White, 1970) and Na-K-Ca (Fournier and Truesdell, 1973) geothermometers take advantage of the fact that the equilibrium points of cation exchange reactions among various minerals (principally, the feldspars) vary with temperature. In applying these methods, it is necessary to make a number of assumptions or corrections (e.g., Fournier, 1977). First, the minerals with which the fluid reacted must be known. Applying the silica geothermometer assuming equilibrium with quartz, for example, would not give the correct result if the fluid’s silica content is controlled by reaction with chalcedony. Second, the fluid must have attained equilibrium with these minerals. Many studies have suggested that equilibrium is commonly approached in geothermal systems, especially for ancient waters at high temperature, but this may not be the case in young sedimentary basins like the Gulf of Mexico basin (Land and Macpherson, 1992). Third, the fluid’s composition must not have been altered by separation of a gas phase, mineral precipitation, or mixing with other fluids. Finally, corrections may be needed to account for the influence of certain dissolved components, including CO2 and Mg++, which affect the equilibrium composition (Paces, 1975; Fournier and Potter, 1979; Giggenbach, 1988). Using geochemical modeling, we can apply chemical geothermometry in a more generalized manner. By utilizing the entire chemical analysis rather than just a portion of it, we avoid some of the restricting assumptions mentioned in the preceding paragraph (see Michard et al., 1981; Michard and Roekens, 1983; and especially Reed and Spycher, 1984). Having constructed a theoretical model of the fluid in question, we can calculate the saturation state of each mineral in the database, noting the temperature at which each is in equilibrium with the fluid.

scholarly journals Emplacement of the Little Minch Sill Complex, Sea of Hebrides Basin, NW Scotland

2021 ◽  
pp. jgs2020-177
Author(s):  
Laura-Jane C. Fyfe ◽  
Nick Schofield ◽  
Simon P. Holford ◽  
Dougal A. Jerram ◽  
Adrian Hartley
Keyword(s):  
Large Scale ◽  
Sedimentary Basins ◽  
Geothermal Systems ◽  
Magma Flow ◽  
Magma Transport ◽  
Combining Data ◽  
Emplacement Processes ◽  
Using Data ◽  
Atlantic Margin ◽  
Isle Of Skye

The Little Minch Sill Complex is comprised of a series of stacked, multi-leaved Paleocene aged dolerite sills, which have been primarily intruded into Mesozoic sedimentary rocks and Paleocene tuffs/?hyaloclastites within the Sea of Hebrides Basin, situated on the NE Atlantic margin. Two previously proposed models for the emplacement of the sill complex have opposing ideas for the location of magma input and emplacement mechanisms. Both models have been constructed using data primarily from onshore outcrops, located on the Isle of Skye, Raasay and the Shiant Isles. However, onshore outcrops only represent a quarter (1040 km2) of the entire extent of the sill complex, which is largely situated offshore. In order to understand how the sill complex as a whole was emplaced within the basin, both onshore and offshore magma transport needs to be considered. Using high resolution multibeam bathymetry data (up to 2m resolution) obtained between 2008 and 2011 along with supporting seismic reflection, sparker and pinger data, a new assessment of the offshore extent and character of the sill complex has been constructed. Mapping of large-scale relationships between intrusions and the host rock, along with morphological features such as magma lobes, magma fingers, transgressive wings, en-echelon feeder dykes and the axis of saucer/half-saucer shaped intrusions, has indicated magma flow directions within the intrusive network. Assessing the flow kinematics of the sills has provided insights into magma transport and emplacement processes offshore. Combining data from previously mapped onshore sills with data from our newly constructed model for magma emplacement offshore has allowed us to construct a new model for the emplacement of the Little Minch Sill Complex. This model demonstrates that major basin bounding faults may play a lesser role in channelling magma through sedimentary basins than previously thought. Applying the knowledge obtained from this study could further progress understanding of the effect of sill emplacement on fluid flow within volcanic rift basin worldwide, with direct impacts on the exploitation of petroleum and geothermal systems.

A general inverse method for modelling extensional sedimentary basins

2000 ◽  
Vol 12 (3-4) ◽  
pp. 219-226 ◽  
Author(s):  
P. Bellingham ◽  
N. White
Keyword(s):  
Inverse Method ◽  
Sedimentary Basins

Production engineering at Imperial College

1959 ◽  
Vol 38 (7) ◽  
pp. 351 ◽  
Author(s):  
O.A. Saunders ◽  
J.M. Alexander ◽  
R.C. Brewer
Keyword(s):  
Imperial College ◽  
Production Engineering

Discussion Group ‘G’: How to apply in industry the knowledge gained from production engineering research

1951 ◽  
Vol 30 (10) ◽  
pp. 632
Author(s):  
W.P. Kirkwood ◽  
F.T. Nurrish ◽  
A.L. Stuchbery ◽  
D.H. Turnbull ◽  
H. Schofield ◽  
...  
Keyword(s):  
Discussion Group ◽  
Production Engineering ◽  
Engineering Research

The relationship between research and production engineering

1948 ◽  
Vol 27 (6) ◽  
pp. 285
Author(s):  
W. Armstrong ◽  
C.L. David ◽  
R.J. Mitchell
Keyword(s):  
Production Engineering ◽  
The Relationship
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