Indications of the Potential of Shale Gas for Non-Conventional Energy Sources in Indonesia

Shale Gas is a potential non-conventional energy source to be developed. However, currently shale gas has not been developed optimally in Indonesia. Therefore, the authors aim to help develop the potential of shale gas by indicating the potential for distribution in Indonesia. The research study was conducted by reviewing literature sourced from literature such as journals, articles and books. Based on the research conducted, potential shale gas reserves are found in the North Sumatra Basin, Central Sumatra Basin and South Sumatra Basin. Geochemical method which includes parameters of Total Organic Carbon (TOC), type of kerogen and maturity level (Ro) used to develop shale gas potential in an area. Shale gas can be a substitute for conventional fossil fuels, so further studies are needed so that it can be produced commercially

Theoretical and methodological aspects regarding the evaluation of a super-resource product

The subject of the study is the value of geological objects investigated for the needs of defining a number of concepts related to economic and fiscal geology. The purpose of this article is to substantiate the nature of resource-resource fiscalization of subsoil use and methods of estimated calculation of its indicators. Methodology of work – the method of monographic analysis (in determining the cost-resource approach); method of abstract-logical analysis (in defining the system of concepts of economic and fiscal geology); method of generalization (when forming conclusions and suggestions). Methodology of work – method of abstract-logical analysis (in defining the system of concepts of fiscal geology, in particular, fiscal subsoil-resource product); monographic analysis (when using the resource-cost approach), volumetric- geochemical method (to quantify the estimated and prospective resources by the results of geochemical studies); comparison and generalization (when forming conclusions and proposals). Results of work. According to the results of the conducted researches of the essence, content, processes of subsoil use and methods of determining its cost indicators, according to literature sources and official documents, certain fiscal concepts of fiscal geology are substantiated. The essence of resource-based fiscalisation in subsoil use is defined as the conduct of certain studies of subsoil objects, the allocation of subsoil products, the determination of their resource indicators, and the establishment using official and non-official methods of value of these objects.The value-for-money approach to the evaluation of the subsoil resource product (required) is substantiated. This approach first distinguishes the explorable geological object, further distinguishes it from subsoil resources, then provides these products with specific methods of value estimation. These estimates determine the expected sale price of the property, the cost of renting the property, permanent ownership, permanent use, etc., as well as payments to the state treasury. Conclusions and suggestions. Cost and resource fiscalisation is interpreted as the determination of the fiscal value of subsoil resources products, on the basis of which the fiscal payments are calculated. The methodologies for calculating the cost of mining are necessary with certain additions and practical calculations combined into a recommendation document, discuss it, check it in practice, make certain adjustments and officially approve it for use in determining the fiscal value. Keywords: subsoil, minerals, resources, costs, expenses, extraction, payment.

Characterization of Tertiary Flints by geochemistry; application to the French territory

In present-day France, tertiary flints have played an important part in the supply of prehistoric populations, due to their abundance, quality and presence in areas without marine flint. From the Upper Paleolithic until the end of the use of flint, they were transported over far distances, especially in the center of the Central Massif. In this article the geochemical method is preferred for attributing of precise geographical origin to an archaeological artifact. To form the geological repository, a very large geographical field was taken, encompassing a large part of France, from the Marne county to the Gard county, and most of the major French sedimentary basins (Bassin Parisien, Cantal, Gard). The archaeological corpus includes pieces from sites of the Upper Paleolithic and the Epipaleolithic of Auvergne. The geochemical study does not provide a comprehensive answer to the question of the geographical origin of tertiary flints, but nevertheless allows for certain and significant advances in knowledge. Keywords: Flint raw materials, Palaeolithic age, Magdalenian, Raw materials, Geochemistry.

An Integrated Geophysical and Geochemical Investigation of an Open Dumpsite in a Sedimentary Formation

The extents of migration of leachate plumes and the probabilistic assessment of human health risks were carried out on Oke-Diya dumpsite, Sagamu, Southwestern Nigeria. Geophysical methods involving Very Low Frequency-Electromagnetic (VLF-EM) and Electrical Resistivity Topography (ERT) techniques, and Atomic Absorption Spectrometric (AAS) geochemical method were used to map and detect the presence and extent of leachate migration. The VLFEM pseudo-sections revealed conductive zones of responses 25 - 50 to a depth of about 15 m and approximated distance 50 m from the study area. The 2D and 3D ERT models delineated high conductive zones with very low resistivity values ranging from 0.551-6.54 and 2.4respectively. These conductive regions were observed to depths above 13.4 m and approximated distance 60 m from the study area in the 2D models. The 3D sections comprising of the horizontal depth slices, vertical planes and volumetric displays revealed regions with higher conductivity to a depth of about 21.9 m and approximated distance 50 m from the dumpsite. The mean concentrations of heavy metals Pb, Ni, Cd, Zn, Fe and Cu in the soil samples were higher than the concentrations in the control samples. The human health risk assessment indicated unacceptable values for non-carcinogenic adverse effects for both children and adults. The probabilistic cancer risks were within the acceptable range for Pb and unacceptable for Cd for both the children and adults. Generally, this study had identified areas of concentrated plumes accumulation and migration pathways, which were in agreement with earlier studies in sedimentary terrain.

Geochemical, Index, and Strength Appraisals of Granite-derived Residual Soils

This research work examined the geochemical, index, and strength properties of lateritic residual soils from granitic parent rock in Akure, southwestern Nigeria. The aim is to underscore the potential use of such soils as engineering fills materials. The geochemical method involved the use of X-Ray Fluorescence (XRF). The major oxides determined from this analysis were used for the geochemical quantifications of the soils. Analysis of soil index properties involved consistency limits, grain size distribution and specific gravity tests, while the strength analysis involved compaction and unconfined compressive strength (UCS) tests. Results obtained from the index analysis classified the soil profile into behavioral groups VII and VI. These indicates that the soils are of high to intermediate plasticity and compressibility. The UCS values vary from 272.6 to 377.2 kPa while the shear strength values range from 138.8 to 188.6kPa, indicating good bearing capacity. The geochemical results revealed iron-oxide variations as the major influential constituent within the soil profile. Furthermore, the more lateriterizad zones correspond with the more competent horizons. The residual soils from the study area are found to be suitable materials in engineering construction works as Sanitary landfills and Subgrade materials.

Material Analysis Supporting Cement Industry Muara Dua Area South Oku Regency South Sumatera

Material cement industry are mostly formed by carbonate and silica. Geology of Muara Dua area was contain those material used in cement industry. Mineralogy of carbonate this area mostly formed by Calcium (Ca) contained on Calcite (CaCO3), Dolomite (CaMg(CO3)2) while Silica, Alumina, Iron Oxide element found as SiO2, Al2O3, Fe2O3, MgO on rock. Research area mostly generated by tectonically complex where the sedimentation mostly controlled the existence of material using in cement industry. Three analysis method were conducted which are Geological Mapping to describe macro petrology, Petrography analysis to determine mineralogy microscopic and Geochemical method using XRF to identified chemical mineralogy of rock. Limestone is one of lithology unit that develop on research area where known as Packstone to Wackestone (Petrography) while "Calcitic Limestone” to “Marly Limestone” classification from Geochemical analysis (XRF). Another material such as Silica and trass material are definitely found on this research area to support cement industry. Element for support cement industry that exist on Muara Dua area formed due to sedimentation process that effected by tectonic and volcanic.

Estimation of the Oil-in-Place Resources in the Liquid-Rich Shale Formations Exploiting Geochemical and Petrophysical Data in a 3D High-Resolution Geological Model Domain: Baltic Basin Case Study

The paper discusses the issue of oil-in-place estimation for liquid-saturated shales in Lower Paleozoic (Silurian and Ordovician) organic-rich formations of the Baltic Basin in North Poland. The authors adopted a geochemical method based on Rock Eval results which directly measure hydrocarbon content present in rock samples. Its application on a real data set required the implementation of correction procedures to consider also those oil compounds which were lost before Rock Eval measurements were taken or are not recorded in S1 parameter. It was accomplished through the introduction of two correction coefficients: c1—for evaporation loss and c2—for heavier compounds underestimation. The first one was approximated on the basis of published results and known properties of crude oil, while the second one was addressed with laboratory experimental procedure which combines Rock Eval pyrolysis and rock sample extraction with organic solvents. The calculation formulas were implemented in the 3D geological model of shale formations reproducing their geometry as well as the spatial variability of the petrophysical and geochemical properties. Consequently, the results of oil-in-place estimation were also available as 3D models, ready for visualization and interpretation in terms of delineation of most favorable zones or well placement. The adopted geochemical method and the results of oil-in-place estimation it produced were confronted with standard volumetric method. Although both of them are volumetric methods, the results depend on different sets of rock properties, which is an advantage for result comparison reasons. The study revealed that the geochemical method of oil-in-place estimation in liquid-rich shales after appropriate adjustment, considering shale formation and reservoir fluid dependent conditions, could provide reliable results and be implemented on the early stage of shale exploration process in a condition of production data inaccessibility.

Reconstructing past lake water total phosphorus concentration using sediment geochemical records

<p>To understand current phosphorus (P) cycling, which encompasses disturbances caused by human activity, it is necessary to quantify the long-term natural P cycles on which modern drivers act. The shortness of monitored P records renders this difficult by only covering the post-disturbance period and therefore fail to capture pre-disturbance baselines. Target driven management of sensitive ecosystems suffering from eutrophication uses baselines for P that cannot be reliably quantified at present. Recovery will only be possible if P loadings can be brought under control and this requires an understanding of what water quality targets are both desirable and achievable on a site-specific basis. This matters because a well-functioning ecosystem will be more resilient under future climate change and increasing human pressure on the landscape.</p><p>Where lakes are present in the landscape, there is the opportunity to use the sediment archive to provide long records of past P concentration.  At present, these reconstructions rely on diatoms or related microfossil indicators. These require time and resource intensive tailored training sets and furthermore the records do not preserve in all lakes. Here we present a novel geochemical method for reconstructing water P concentrations based on lake sediment P burial fluxes, which in principle is universally applicable.</p><p>Tested at six published lake sites, the method produces results that agree very well with overlapping monitoring data for those lakes (r<sup>2 </sup>= 0.8). We want to share our method with the research community to identify additional sites to further verify the general applicability.</p><p>To illustrate the value of this approach to site-specific management, we compare past lake water total P reconstructions at Crosemere (UK) with a record of Holocene land cover change to identify the drivers of acceleration in the P cycle. Wider application of this lake sediment geochemical method will allow more critical evaluation of the human and natural drivers of the P cycle and be of benefit to ‘systems understanding’ spanning terrestrial and aquatic ecosystems.</p>

Evaluation of Filtering Methods for Hydrograph Separation in Small Agricultural Watersheds in Québec, Canada

HighlightsAgricultural hydrology is complex due to the management of surface and subsurface flow to increase productivity.This study provides an interpretation of hydrological functioning, using a geochemical tracer (electrical conductivity) as a reference method, for hydrograph separation and evaluation of filtering methods.Filtering method efficiency must be interpreted according to season, year, watershed relief, and management practices.Routine application of basic filtering concepts is not sufficient to address the heterogeneity of hydrological processes in agricultural watersheds.Abstract. Streamflow hydrographs summarize the behavior of watersheds. Their separation into quick and slow components requires hydrological knowledge of the specific drainage area. To better understand the hydrological response of 14 small agricultural watersheds in Québec, Canada, covering different physiographic attributes ranging from lowlands to hilly and steep landscapes, streamflow electrical conductivity was used as a geochemical tracer. These agricultural watersheds have undergone significant management practices, including artificial drainage. The objective of this research was to evaluate the performance of existing automated filter methods for hydrograph separation (BFLOW, UKIH, PART, FIXED, SLIDE, LOCMIN, and Eckhardt). The geochemical method was used as a reference for comparison with the filter methods. Comparison of the slow flow estimates from non-calibrated filters, using a MANOVA model, showed that the filter performance increased under conditions with high contributions of quick runoff to the stream, such as during snowmelt (spring season), during heavy precipitation, and in subwatersheds with landscape conditions more prone to quick runoff. However, filter performance decreased as hydrological processes predisposed more flow to slower pathways, typically in summer and fall, as well as in lowland landscapes generally associated with high rates of tile drainage rather than in hilly and steep relief. Underlying the filter assumptions is the classic concept of a rainfall event with quick runoff as the main source of the drainage area response. Thus, slow flow is associated with a low threshold response. Eckhardt filter simulations were in good agreement with the geochemical method after calibration, based on model statistical measures (R, NSE, and PBIAS). However, larger errors were associated with higher flow values. The slow flow overestimations were more pronounced during periods of extreme events, i.e., spring runoff and heavy precipitation. The linear concept of the Eckhardt filter yields no information on slow flow response behavior that could be useful in capturing its temporal variability. Because the routing of water has been managed to improve agricultural productivity, these hydrological modifications resulted in a more complex slow flow response. The performance of filtering methods is thus affected. Therefore, simplifications of filter assumptions are less likely to provide more effective estimates of slow flow. Furthermore, given the heterogeneity of hydrological processes due to seasonal climatic characteristics, the routine application of basic filter concepts is not sufficient to address the variable nature of the hydrological response. The variability scale of geochemical separation, from regional (agro-climatic) to local (adjacent watersheds), proved that it is always relevant to have adequate separation. However, the validation of filters without a tracer is limited and almost unsuitable for these agricultural watersheds. Keywords: Agricultural watershed, Artificial drainage, Electrical conductivity, Filtering method, Geochemical method, Hydrograph separation, MANOVA, Quick flow, Slow flow, Tile drainage.