scholarly journals SILLi 1.0: A 1D Numerical Tool Quantifying the Thermal Effects of Sill Intrusions

2017 ◽  
Author(s):  
Karthik Iyer ◽  
Henrik Svensen ◽  
Daniel W. Schmid
Keyword(s):  
Thermal Effects ◽  
Thermal Evolution ◽  
Thermal Structure ◽  
Sedimentary Basins ◽  
Gas Generation ◽  
Porosity Evolution ◽  
Karoo Basin ◽  
Igneous Intrusions ◽  
User Friendly ◽  
Latent Heats

Abstract. Igneous intrusions in sedimentary basins may have a profound effect on the thermal structure and physical properties of the hosting sedimentary rocks. These include mechanical effects such as deformation and uplift of sedimentary layers, generation of overpressure, mineral reactions and porosity evolution, and fracturing and vent formation following devolatilization reactions and the generation of CO2 and CH4. The gas generation and subsequent migration and venting may have contributed to several of the past climatic changes such as the end-Permian event and the Paleocene-Eocene Thermal Maximum. Additionally, the generation and expulsion of hydrocarbons and cracking of pre-existing oil reservoirs around a hot magmatic intrusion is of significant interest to the energy industry. In this paper, we present a user-friendly 1D FEM based tool, SILLi, which calculates the thermal effects of sill intrusions on the enclosing sedimentary stratigraphy. The model is accompanied by three case studies of sills emplaced in two different sedimentary basins, the Karoo Basin in South Africa and the Vøring Basin offshore Norway. Input data for the model is the present-day well log or sedimentary column with an Excel input file and includes rock parameters such as thermal conductivity, total organic carbon (TOC) content, porosity, and latent heats. The model accounts for sedimentation and burial based on a rate calculated by the sedimentary layer thickness and age. Erosion of the sedimentary column is also included to account for realistic basin evolution. Multiple sills can be emplaced within the system with varying ages. The emplacement of a sill occurs instantaneously. The model can be applied to volcanic sedimentary basins occurring globally. The model output includes the thermal evolution of the sedimentary column through time, and the changes that take place following sill emplacement such as TOC changes, thermal maturity, and the amount of organic and carbonate-derived CO2. The TOC and vitrinite results can be readily benchmarked within the tool to present-day values measured within the sedimentary column. This allows the user to determine the conditions required to obtain results that match observables and leads to a better understanding of metamorphic processes in sedimentary basins.

scholarly journals SILLi 1.0: a 1-D numerical tool quantifying the thermal effects of sill intrusions

2018 ◽  
Vol 11 (1) ◽  
pp. 43-60 ◽  
Author(s):  
Karthik Iyer ◽  
Henrik Svensen ◽  
Daniel W. Schmid
Keyword(s):  
Thermal Effects ◽  
Thermal Evolution ◽  
Thermal Structure ◽  
Sedimentary Basins ◽  
Gas Generation ◽  
Porosity Evolution ◽  
Karoo Basin ◽  
Igneous Intrusions ◽  
User Friendly ◽  
Latent Heats

Abstract. Igneous intrusions in sedimentary basins may have a profound effect on the thermal structure and physical properties of the hosting sedimentary rocks. These include mechanical effects such as deformation and uplift of sedimentary layers, generation of overpressure, mineral reactions and porosity evolution, and fracturing and vent formation following devolatilization reactions and the generation of CO2 and CH4. The gas generation and subsequent migration and venting may have contributed to several of the past climatic changes such as the end-Permian event and the Paleocene–Eocene Thermal Maximum. Additionally, the generation and expulsion of hydrocarbons and cracking of pre-existing oil reservoirs around a hot magmatic intrusion are of significant interest to the energy industry. In this paper, we present a user-friendly 1-D finite element method (FEM)-based tool, SILLi, which calculates the thermal effects of sill intrusions on the enclosing sedimentary stratigraphy. The model is accompanied by three case studies of sills emplaced in two different sedimentary basins, the Karoo Basin in South Africa and the Vøring Basin off the shore of Norway. An additional example includes emplacement of a dyke in a cooling pluton which forgoes sedimentation within a basin. Input data for the model are the present-day well log or sedimentary column with an Excel input file and include rock parameters such as thermal conductivity, total organic carbon (TOC) content, porosity and latent heats. The model accounts for sedimentation and burial based on a rate calculated by the sedimentary layer thickness and age. Erosion of the sedimentary column is also included to account for realistic basin evolution. Multiple sills can be emplaced within the system with varying ages. The emplacement of a sill occurs instantaneously. The model can be applied to volcanic sedimentary basins occurring globally. The model output includes the thermal evolution of the sedimentary column through time and the changes that take place following sill emplacement such as TOC changes, thermal maturity and the amount of organic and carbonate-derived CO2. The TOC and vitrinite results can be readily benchmarked within the tool to present-day values measured within the sedimentary column. This allows the user to determine the conditions required to obtain results that match observables and leads to a better understanding of metamorphic processes in sedimentary basins.

Study on the Forming Conditions of Shale Gas in Coal Measure of Wuli Area, Qinghai Province, China

2013 ◽  
Vol 295-298 ◽  
pp. 2770-2773 ◽  
Author(s):  
Dai Yong Cao ◽  
Jing Li ◽  
Ying Chun Wei ◽  
Xiao Yu Zhang ◽  
Chong Jing Wang
Keyword(s):  
Shale Gas ◽  
Thermal Evolution ◽  
Organic Matter Content ◽  
Gas Production ◽  
Matter Content ◽  
Source Rocks ◽  
Coal Measure ◽  
Gas Generation ◽  
Qinghai Province ◽  
Coal Measures

Besides coal seam, the source rocks including dark mudstone, carbon mudstone and so on account for a large proportion in the coal measures. Based on the complex geothermal evolution history, the majority of coal measure organic matters with the peak of gas generation have a good potential of gas. Therefore, shale gas in coal measure is an important part of the shale gas resources. There are good conditions including the thickness of coal measures, high proportion of shale rocks, rich in organic matter content, high degree of thermal evolution, high content of brittle mineral and good conditions of the porosity and permeability for the generation of shale gas in Wuli area, the south of Qinghai province. Also the direct evidence of the gas production has been obtained from the borehole. The evaluation of shale gas in coal measure resources could broaden the understanding of the shale gas resources and promote the comprehensive development of the coal resources.

scholarly journals EFFECTS OF IGNEOUS INTRUSION ON THE MINERALOGICAL CONTENT OF IRATI FORMATION, PARANÁ BASIN, IN SAPOPEMA (PR), SOUTHERN BRAZIL

2019 ◽  
Vol 4 (3) ◽  
pp. 350-360
Author(s):  
Werlem Holanda ◽  
Anderson Costa dos Santos ◽  
Camila Cardoso Nogueira ◽  
Luiz Carlos Bertolino ◽  
Sérgio Bergamaschi ◽  
...  
Keyword(s):  
Host Rock ◽  
Mineral Assemblage ◽  
Sedimentary Basins ◽  
Southern Brazil ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineralogical Association ◽  
Irati Formation ◽  
Igneous Intrusions ◽  
Rock Association

Igneous intrusions in sedimentary basins are commonly related with mineralogical association changes in host-rock. At Sapopema region (Paraná State, southern Brazil), an extensive diabase sill (associated to Serra Geral Formation) was emplaced in pelitic-carbonate succession during post-Triassic. The sedimentary host-rock association includes mostly shale, siltstone and carbonate of the Permian Irati Formation. X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) data revealed that heat transfer was not enough to cause modifications in mineral assemblage of the Taquaral Member (quartz + albite + muscovite + illite + kaolinite + chlorite). However, mineralogical content from Assistência Member presented changes probably caused by the intrusion of diabase sill (talc + pyrophyllite + calcite). Talc and calcite were formed due to the reaction between dolomite and quartz, while pyrophyllite was the product of reaction between kaolinite and quartz. EFEITOS DA INTRUSÃO IGNEA NA COMPOSIÇÃO MINERALÓGICA DA FORMAÇÃO IRATI, BACIA DO PARANÁ, SAPOPEMA (PR), SUL DO BRASIL ResumoAs intrusões ígneas em bacias sedimentares dão origem em geral a alterações mineralógicas da rocha hospedeira. Na região de Sapopema (Estado do Paraná, sul do Brasil), uma extensa soleira de diabásio (associada à Formação Serra Geral) pós-Triássica, foi intrudida numa sucessão sedimentar constituída por pelitos e carbonatos. A associação de rochas sedimentares hospedeiras, era principalmente constituída por folhelho, siltito e carbonato da Formação Irati, do Permiano. Dados de difração de raios X (DRX), microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS) revelaram que a transferência de calor não foi suficiente para causar modificações na composição mineralógica do membro Taquaral (quartzo + albita + moscovita + ilita + caulinita + clorita). No entanto, o conteúdo mineralógico do Membro Assistência apresentou alterações, provavelmente causadas pela intrusão do diabásio (talco + pirofilita + calcita). O talco e a calcita foram formados devido à reação entre dolomita e quartzo, enquanto a pirofilita foi o produto da reação entre a caulinita e o quartzo. Palavras-chave: Bacia Sedimentar. Intrusões Ígneas. Metamorfização de sedimentos. Reações mineralógicas. XRD. SEM / EDS.

scholarly journals Transient Thermal Effects in Sedimentary Basins with Normal Faults and Magmatic Sill Intrusions—A Sensitivity Study

Geosciences ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 160 ◽  
Author(s):  
Magnhild Sydnes ◽  
Willy Fjeldskaar ◽  
Ivar Grunnaleite ◽  
Ingrid Fjeldskaar Løtveit ◽  
Rolf Mjelde
Keyword(s):  
Physical Properties ◽  
Thermal Effects ◽  
Sedimentary Basins ◽  
Sensitivity Study ◽  
Fault Slip ◽  
Structural Development ◽  
Potential Source Rock ◽  
Magmatic Intrusions ◽  
Transient Thermal ◽  
Magmatic Sill

Magmatic intrusions affect the basin temperature in their vicinity. Faulting and physical properties of the basin may influence the magnitudes of their thermal effects and the potential source rock maturation. We present results from a sensitivity study of the most important factors affecting the thermal history in structurally complex sedimentary basins with magmatic sill intrusions. These factors are related to faulting, physical properties, and restoration methods: (1) fault displacement, (2) time span of faulting and deposition, (3) fault angle, (4) thermal conductivity and specific heat capacity, (5) basal heat flow and (6) restoration method. All modeling is performed on the same constructed clastic sedimentary profile containing one normal listric fault with one faulting event. Sills are modeled to intrude into either side of the fault zone with a temperature of 1000 °C. The results show that transient thermal effects may last up to several million years after fault slip. Thermal differences up to 40 °C could occur for sills intruding at time of fault slip, to sills intruding 10 million years later. We have shown that omitting the transient thermal effects of structural development in basins with magmatic intrusions may lead to over- or underestimation of the thermal effects of magmatic intrusions and ultimately the estimated maturation.

COAL AS A SOURCE OF OIL AND GAS: A CASE STUDY FROM THE BASS BASIN, AUSTRALIA

2003 ◽  
Vol 43 (1) ◽  
pp. 117 ◽  
Author(s):  
C.J. Boreham ◽  
J.E. Blevin ◽  
A.P. Radlinski ◽  
K.R. Trigg
Keyword(s):  
Organic Matter ◽  
Oil And Gas ◽  
Middle Eocene ◽  
Vitrinite Reflectance ◽  
Mineral Resources ◽  
Sedimentary Basins ◽  
Source Rocks ◽  
Gas Generation ◽  
Australian Context ◽  
Effective Source

Only a few published geochemical studies have demonstrated that coals have sourced significant volumes of oil, while none have clearly implicated coals in the Australian context. As part of a broader collaborative project with Mineral Resources Tasmania on the petroleum prospectivity of the Bass Basin, this geochemical study has yielded strong evidence that Paleocene–Eocene coals have sourced the oil and gas in the Yolla, Pelican and Cormorant accumulations in the Bass Basin.Potential oil-prone source rocks in the Bass Basin have Hydrogen Indices (HIs) greater than 300 mg HC/g TOC. The coals within the Early–Middle Eocene succession commonly have HIs up to 500 mg HC/g TOC, and are associated with disseminated organic matter in claystones that are more gas-prone with HIs generally less than 300 mg HC/g TOC. Maturity of the coals is sufficient for oil and gas generation, with vitrinite reflectance (VR) up to 1.8 % at the base of Pelican–5. Igneous intrusions, mainly within Paleocene, Oligocene and Miocene sediments, produced locally elevated maturity levels with VR up to 5%.The key events in the process of petroleum generation and migration from the effective coaly source rocks in the Bass Basin are:the onset of oil generation at a VR of 0.65% (e.g. 2,450 m in Pelican–5);the onset of oil expulsion (primary migration) at a VR of 0.75% (e.g. 2,700–3,200 m in the Bass Basin; 2,850 m in Pelican–5);the main oil window between VR of 0.75 and 0.95% (e.g. 2,850–3,300 m in Pelican–5); and;the main gas window at VR >1.2% (e.g. >3,650 m in Pelican–5).Oils in the Bass Basin form a single oil population, although biodegradation of the Cormorant oil has resulted in its statistical placement in a separate oil family from that of the Pelican and Yolla crudes. Oil-to-source correlations show that the Paleocene–Early Eocene coals are effective source rocks in the Bass Basin, in contrast to previous work, which favoured disseminated organic matter in claystone as the sole potential source kerogen. This result represents the first demonstrated case of significant oil from coal in the Australian context. Natural gases at White Ibis–1 and Yolla–2 are associated with the liquid hydrocarbons in their respective fields, although the former gas is generated from a more mature source rock.The application of the methodologies used in this study to other Australian sedimentary basins where commercial oil is thought to be sourced from coaly kerogens (e.g. Bowen, Cooper and Gippsland basins) may further implicate coal as an effective source rock for oil.

Gas Generation Regularities of Dissipated Soluble Organic Matter in Sichuan Basin

2014 ◽  
Vol 977 ◽  
pp. 308-311
Author(s):  
Hai Tao Xue ◽  
Guo Dong Mu ◽  
Shan Si Tian ◽  
Shuang Fang Lu
Keyword(s):  
Organic Matter ◽  
Sichuan Basin ◽  
Thermal Evolution ◽  
Parent Material ◽  
Source Rocks ◽  
Soluble Organic Matter ◽  
Gas Generation ◽  
Marine Strata ◽  
Proper Order ◽  
Gas Generation Rate

The organic matter of marine strata has high degree of thermal evolution in Sichuan Basin. The gas generation ability of kerogen is very limited, which mainly relies on the soluble organic matter as gas parent material to provide gas source for gas reservoir. In this paper, chemical kinetics method and experiments are applied to study on the history of gas generation and gas generation rate of organic matter in Sichuan marine strata. Result shows that dissipated soluble organic matter in source rocks, dissipated soluble organic matter out of source rocks and organic matter in paleo-reservoir successively generate gas in proper order. Dissipated soluble organic matter out of source rocks and the oil in paleo-reservoir belong to late gas generation.

Thermal mechanisms of basin formation

1982 ◽  
Vol 305 (1489) ◽  
pp. 283-294 ◽  
Keyword(s):  
Similarity Solution ◽  
Flexural Rigidity ◽  
Thermal Evolution ◽  
Sedimentary Basins ◽  
Relative Volume ◽  
Ocean Ridges ◽  
Wide Range ◽  
Subsequent Conversion ◽  
Basin Formation ◽  
Thermal Subsidence

Thermal subsidence of the sea floor explains the observed bathymetry of ocean ridges. A similarity solution for a one-dimensional cooling model successfully predicts bathymetry, heat flow and geoid anomalies under a wide range of conditions. This similarity solution can be modified to predict the thermal subsidence of sedimentary basins. For older sedimentary basins it is necessary to consider an input of heat to the base of the lithosphere that places a limit on subsidence. The similarity solution for thermal subsidence is in quite good agreement with the observed subsidence history of a variety of sedimentary basins. Some basins subside freely and in others the flexural rigidity of the elastic lithosphere inhibits subsidence. An empirical model is proposed for the conversion of kerogen to oil and the subsequent conversion of oil to gas. This model is then used in conjunction with the thermal evolution predicted by the similarity solution in order to determine the oil window and relative volume of oil as a function of the age of the basin.

Sign in / Sign up

Export Citation Format

Share Document