India at crossroads for energy

As one of the fastest growing economies and further larger consumer of energy in the world, there has been a paradigm shift in India’s energy demand. Here we evaluate the growth of Indian economy its, diversification of agriculture-based economy to industrial production, service and digital-technology based economy and deepening of income sources, although the dependence on foreign sources for energy demands has not markedly improved.This situation has placed India at the crossroads for energy sufficiency, especially under the highly fluid and changing geopolitical, strategic, environmental and economic scenarios of the World order. We attempt to understand the issue from geological perspective and address some of the impediments.

3-D seismic interpretation of stratigraphic and structural features in the Upper Jurassic to Lower Cretaceous sequence of the Gullfaks Field,Norwegian North Sea:A case study of reservoir development

The 3-D seismic dataset is a key tool to analyze and understand the mechanism of structural and stratigraphic hydrocarbon(HC)trapping in the subsurface.Conventionally used subsurface seismic characterization methods for fractures are based on the theory of effective anisotropy medium.The aim of this work is to improve the structural images with dense sampling of 3-D survey to evaluate structural and stratigraphic models for reservoir development to predict reservoir quality.The present study of the Gullfaks Field,located in the Norwegian North Sea Gullfaks sector,identifies the shallowest structural elements.The steepness of westward structural dip decreases eastward during the Upper Jurassic to Lower Cretaceous deposition.Reservoir sands consist of the Middle Jurassic deltaic deposits and Lower Jurassic fluvial channel and delta plain deposits.Sediment supply steadily prevails on sea-level rise and the succession displays a regressive trend indicated by a good continuous stacking pattern.The key factor for the development of reservoirs in the Gullfaks Field is fault transmissibility with spatially distributed pressure.The majority of mapped faults with sand-to-sand contacts are non-sealing,which provide restriction for the HC flow between the fault blocks.The traps for HC accumulation occur between the post-rift and syn-rift strata,i.e.antiform set by extensional system,unconformity trap at the top of syndeposition,and structural trap due to normal faults.Overall reservoir quality in the studied area is generally excellent with average 35%porosity and permeability in the Darcy range.Our findings are useful to better understand the development of siliciclastic reservoirs in similar geological settings worldwide.

Episodic dolomitization of Paleozoic limestones in the Kinta Valley,Malaysia:Implications on porosity evolution and reservoir properties

Carbonates undergo a variety of physical,mineralogical,chemical changes during depositional and postdepositional stages that are of interest to exploration geologists and sedimentologists.World over,about 60%of hydrocarbon reserves occur in carbonates with the dominant proportion associated with dolomitic reservoirs,in particular fault-associated dolomites which appear to be proven hydrocarbon reservoirs.Dolomitization as the critical diagenetic process thus plays an important role in determining reservoir characteristics and in designing exploration strategies.The buried Paleozoic dolomites exhibit relatively higher porosity than their counterparts,Paleozoic limestones.Fault-associated dolomites are usually targets of hydrocarbon exploration due to their good reservoir quality.High heterogeneity in carbonate reservoirs due to varied porosity types and distribution makes reservoir characterization a daunting task.However,the key elements that control porosity development and evolution in these dolomites remain debatable.Studying the influence of multiphase dolomitization,associated diagenetic events,hydrothermal alteration and their causative thermo-tectonic events on porosity evolution and reservoir quality is essential to understanding the critical processes and controlling factors that result in diverse impacts on reservoir quality.In this paper,an attempt is made to characterize dolomitization in homogeneous carbonate mud and its relationship with porosity evolution and reservoir property.In the field,six facies types excluding host limestone are recognized,which are in turn characterized into seven petrographically recognizable phases,namely the host limestone,early replacement dolomite,sucrosic dolomite,metamorphosed dolomite,late replacement dolomite,brecciated limestone and dolomite and late stage calcite.Mineralogical analyses reveal the dominance of stoichiometric dolomites,followed by calcareous dolomites and magnesium calcites.Among all the field-based facies and petrographic phases,the sucrosic dolomites show appreciable porosity within a range from 4%to 8%,whereas the other phases show either nil or insignificant porosity under megascopic and petrographic observations.Our study confirms that in the process of dolomitization that substantially modifies porosity,dolomitic crystal morphologies play a significant role in enhancing or reducing the porosity.

Hydrocarbon reserves of the South China Sea:Implications for regional energy security

The countries such as China,Vietnam,Philippines,Malaysia,Indonesia and Brunei that border South China Sea region have immense stakes in exploring and exploiting the natural resources of the region including hydrocarbon.More than the hydrocarbon reserves,the South China Sea is home to World’s high-networth trade route that brings the interests of non-geographic entities to this region.Further,the purported reserves of hydrocarbon in the region are in the orders of Persian Gulf but are not yet properly explored and the reserves recovered owing to territorial and non-claimant stakeholder’s influences/interventions.This paper is a synopsis of information on the hydrocarbon reserves of the South China Sea region,and evaluates the territorial and extra-territorial interests in the light of energy security and equitable development and utilization of natural resources from a geological perspective.We also suggest several measures for future consideration and implementation.

Removal notice to“Hydrocarbon reserves of the south China sea:Implications for regional energy security”[Energy Geosci.1/1-2(2020)1-7]

Available online<Date>This article has been removed:please see Elsevier Policy on Article Withdrawal(https://www.elsevier.com/about/our-business/policies/article-withdrawal).This article has been removed at the request of all the Authors,the Editor-in-Chief and the owner of the journal.