K-Mean Cluster Analysis for Better Determining the Sweet Spot Intervals of the Unconventional Organic-Rich Shale: A Case Study

The petrophysical analysis is the crucial task for evaluating the quality of unconventional organic-rich shale and tight gas reservoirs. The presence of organic matter and the ultra-tight with over complex pore system have remained a lack of understanding of how to evaluate the extensive parameters of porosity considering organic content, gas saturation, organic richness, brittleness index, and sweet spot interval by only using conventional log. Therefore, this study offers effectively applied techniques and better analysis for interpreting these parameters by maximizing and integrating geological, geochemical, rock mechanical and engineering data. In general, the field data used in this study are from the first dedicated well for source rock exploration in the North Sumatra Basin, Indonesia. The developed method was derived by using conventional log. All interpretation results were validated by laboratory data measurements of routine and special core analysis, petrography, total organic carbon (TOC) and organic maturation, and brittleness index (BI) calculation. Moreover, the high quality of NMR log data was used as well to ensure our developed techniques present good estimations. Briefly about the methods, we started to determine the total and effective porosity based on the density log by including the presence of organic matter and multi-mineral analysis in these estimations. Then, we used the revised water saturation-TOC of water saturation while the TOC was predicted in advance by averaging three results from the correlation of TOC-Density, modified CARBOLOG and Passey’s ΔlogR methods. Equally important, in order to obtain the reliable gas saturation prediction, we used saturation exponent (n), cementation factor (m), and the tortuosity factor (a) parameters which obtained from laboratory measurement of formation resistivity factor and resistivity index (FFRI). In addition, the brittleness index was predicted based on sonic log data. Finally, all parameters needed for determining gas shale sweet spot have been made. Then, we developed a way to evaluate the sweet spot interval by using K-mean clustering. In conclusion, this clustering result properly follows the shale quality index parameters which consist of organic richness and maturation, brittleness index, the storage capacity of porosity and gas saturation. This study shows that these petrophysical applied techniques leads us to interpret the best position of shale interval to be developed with a simple, fast, and accurate prediction way. Furthermore, as a novelty, this method can be used as rock typing method and obviously can reduce uncertainty and risks in organic-rich shale exploration.

Petrogenetic and Compositional Features of Rare Metal Pan-African Post-Collisional Pegmatites of Southwestern Nigeria; A Status Review

This research reviews the geology, petrogenesis, compositional trends and geochronology of the rare-metal pegmatite of southwestern Nigeria. The source of these pegmatites is still presently debated which have been explained as either product of highly fractionated molten material or anatexis of the local crust. However, published works of past authors have been compiled to give a detailed understanding of the formation of the mineral deposits. The basement complex of southwestern Nigeria comprises of Precambrian rocks of amphibolite, the hornblende gneiss and the granite gneisses which were formed as a result of the opening and closing of the ensialic basin with significant, extensive subduction during the Pan-African orogeny. The pegmatites in this region have shown internal zoning and a high degree of evolution from the border zone to the core zone during the crystallization and solidification of the felsic granite to pegmatite melt. The rare-metal pegmatites have distinct chemical compositions and mineralogy, containing quartz, biotite, muscovite, microcline, garnet with localized tourmaline, tantalite and columbite. These pegmatites vary significantly by their bulk-rock and mineral chemistry which indicates a more peraluminous attribute and enrichments of lithophile elements of Rb, Cs, Ta and Ba. Previous K/Ar isotopic ages (502.8±13.0 Ma and 514.5±13.2 Ma) suggest that the pegmatites are related to the post-collisional phase of intensive metasomatism. Adopted from previous studies, a five-stage conceptual model of evolution which is widely accepted have been proposed for the origin of the pegmatites.

Climate change and its impact on Forest Fire in the state of Himachal Pradesh and Uttarakhand states of India: Remote Sensing and GIS Analysis

We have examined the climate and forest fire data using Remote Sensing and GIS in the state of Himachal Pradesh and Uttarakhand states of India. The significant high forest fire events were observed in district of Pauri Garhwal (22.4%) followed by Naini Tal (16.4%), Tehri Garhwal (8.5%), Almora (7.7%), Chamoli (5.8%), Dehra Dun (4.6%), Uttarkashi (4.3%), Champawat (4.2%), Haridwar (3.6%), Una (3.4%), Bageshwar (3.1%), Udham Singh Nagar (2.9%), Sirmaur (2.7%), Solan (2.3%), Kangra (2.1%), Pithoragarh (1.7%) and Shimla (1.2%). The LULC forest category “Deciduous Broadleaf Forest” occupied 17.2% of total forest area and retain significantly high forest fire percent equivalent to 44.7% of total forest fire events. The study revealed that 79% of forest fire incidence was found in the month of April and May. The fire frequency was found highest in the month of April (among all months) whereas it was spread over the five grids (in the count) where the fire frequencies were greater than 100. The average monthly analysis (from January to June) for maximum temperature (°C), precipitation (mm), solar radiation (MJ/m^2), wind velocity (meter/sec.), wet-days frequency (number of days) and evapotranspiration (mm/day) were found to be in the range of (9.90 to 26.44), (26.06 to 134.71), (11738 to 24119), (1.397 to 2.237), (1.46 to 5.12) and (3.96 to 8.46) respectively. Rapid climate/weather severities which significantly enhance the forest fire events were observed in the month of April and May. The analysis of the Pearson Correlation Coefficient (PCC) values of climate parameters showed a significant correlation with forest fire events. The analysis of predicted (2050) climate anomalies data (RCP-6) for the month of April and annual precipitation manifest the significant rise in April temperature and reduction in annual precipitation observed over large part of high forest fire grids will certainly impact adversely to the future forest fire scenario.

Mineralogical and morphological studies of gold-bearing arsenopyrite and pyrite minerals of Bakyrchik and Bolshevik gold black shale deposits (Eastern Kazakhstan)

Bakyrchik and Bolshevik both are sediment-hosted disseminated gold deposits. They are located in Eastern Kazakhstan (4 km in distance between deposits) and include in the Western Qalba metallogenic zone. They originated in late Paleozoic age along structured line between palaeocontinents of Kazakhstan and Altai-Mongol. The purpose of this paper is designation of typomorphic features of gold-bearing arsenopyrite and pyrite minerals, determination of chemical composition of these two sulfides minerals. The arsenopyrite and pyrite are the main objects for analytical study of gold-bearing sulfide minerals, their different textures, morphology of the crystals and aggregates. The studies of ore samples and minerals were carried out by methods of optical microscope, X-ray diffraction, X-ray fluorescence and electron microprobe analyses. The analytical study of sulphide minerals has shown that the arsenopyrite is acicular and tabular, pyrite has three varieties - globular, hexahedral and pentahedral forms in three rock samples of the carbonaceous-terrigenous formation in the deposits.

Selected technical aspects of well construction for geothermal energy utilization in Poland

Geothermal resources have been used in Poland since the 90s of the last century. Since then, several geothermal heating plants, recreation and balneological centers have been operated. Accessing geothermal resources is possible due to deep boreholes that are either brand-new wells or old but revitalized petroleum and/or exploratory wells. In this case, the construction of production and injection wells is of significant importance. The utilization of deep geothermal energy resources is strongly dependent on the binding domestic law regulations – primarily in case of acquiring the concession enabling an execution of geological and drilling works, and subsequently a proper exploitation. The paper presents the current state of development of the geothermal energy sector in Poland, indicating examples of exploitation systems based on deep boreholes. Furthermore, the constructions of existing wells are discussed extensively. The existing examples of old but reconstructed wells in Poland, are characterized. The importance of national law and its influence on the development of a geothermal investment is highlighted, as well.

Assessment of remote sensing and GIS application in identification of land suitability for agroforestry: A case study of Samastipur, Bihar, India

Agroforestry provides the foundation for climate-smart agriculture to withstand the extreme weather events. The aim of the present study was to identify the land of Samastipur, Bihar, India for agroforestry, based on GIS modeling concept utilizing various ancillary (soil fertility) and satellite data (DEM, wetness, NDVI and LULC) sets. This was achieved by integrating various thematic layers logically in GIS domain. Agroforestry suitability maps were generated for the Samastipur district of Bihar, India which showed 48.22 % as very high suitable, 22.83 % as high suitable, 23.32% as moderate suitable and 5.63% as low suitable. The cross evaluation of agroforestry suitability with LULC categories revealed that the 86.4 % (agriculture) and 30.2% (open area) of land fall into a very high agroforestry suitability category which provides the huge opportunity to harness agroforestry practices if utilized scientifically. Such analysis/results will certainly assist agroforestry policymakers and planner in the state of Bihar, India to implement and extend it to new areas. The potentiality of Remote Sensing and GIS can be exploited in accessing suitable land for agroforestry which will significantly help to rural poor people/farmers in ensuring food and ecological security, resilience in livelihoods.

Temperature Monitoring of Marsh Landscapes and Development of Exogenous Processes in the West Siberian Plain (Russia)

The research touches upon marsh landscapes in the context of temperature monitoring and in connection with exogenous processes during engineering intervention. The monitoring of temperature regimes was conducted in the mid-taiga subzone of marsh landscapes for revealing the dynamics of exogenous processes. The authors used the method of recording systems for the field measurement of the temperature of the peat and underlying soils. The measurements were conducted on a territory that belongs to the middle taiga landscapes of Western Siberia. The authors of the research analyze the data obtained from thermowells 5, 5a and 6. During the observation period of 2015-2016, the average annual temperature was 8.3 ºC for thermowell 5a (technogenic area), which is 3.8 ºC and 4.2 ºC higher than the average annual values of thermowell 5 and thermowell 6 respectively. The latter belongs to natural marsh landscapes. Observations conducted in 2016-2017 confirmed this fact with a difference of 4.8 ºC and 3.7 ºC for thermowells 5 and 6 respectively. As compared to natural marsh landscapes not affected by man-made impact, a higher temperature was observed on soils, which affects the manifestation of exogenous processes.

Sequential extraction of carbonaceous siltstone rock for multi-element analysis by ICP OES

The carbonaceous siltstone rock material is a disseminated sulfide-rich sedimentary rock from a sediment-hosted gold deposit of Bakyrchik. The Bakyrchik deposit is located in Eastern Kazakhstan, which includes in Qalba gold province. The main purpose of this paper is a demonstration on chemical extraction of heavy metals from the carbonaceous siltstone rock and detection of its elemental concentrations. In the work was used a rock sample from the deposit which is a sericizited carbonaceous-siltstone rock. In sequential extraction method was selected four stages such as water soluble fraction (reaction with deionized water) for extraction of water soluble metals, reducible metal fraction (reaction with hydroxyl ammonium chloride) for extracting all reducible metals, organics and sulfides (reaction with hydrogen peroxide) for dissolution of organics and copper sulfide, and extraction of metal oxides and residual fraction (reaction with aqua regia) for extracting of all remaining metals. The paper comprises analytical methods for research outlooks. They are X-Ray Diffraction (determination of mineralogical composition), X-Ray Fluorescence (determination of chemical composition) and Inductively Coupled Plasma – Optical Emission Spectrometry (determination of heavy metal concentrations).

Relief evolution of landslide slopes in the Kamienne Mts (Central Sudetes, Poland) – analysis of a high-resolution DEM from airborne LiDAR

The aim of the study is to reconstruct the development of landslide relief in the Kamienne Mountains (Central Sudetes, SW Poland) based on a DEM from LiDAR data. Analyses of relief and geological maps in ArcGIS 10.5 and of slope cross-sections in Surfer 14 allowed to distinguish different types of landslide relief, developed in latites and trachybasalts lying above claystones and mudstones. The types vary from small, poorly visible landslides to vast landslides with complex relief. They were interpreted as consecutive stages of geomorphic evolution of hillslope-valley topography of the study area. Two main schemes have been established which explain the development of landslide slopes in the Kamienne Mts: (1) upslope, from the base of the slope towards the mountain ridge and (2) downslope, beginning on the top of the mountain ridge. The direction of landslide development depends on the thickness of volcanic rocks in relation to underlying sedimentary rocks. When the latter appear only in the lowest part of the slope, landslides develop upslope. If sedimentary rocks dominate on the slope and volcanic rocks form only its uppermost part, landslides develop downslope. The results show that landsliding leads to significant modifications of relief of the study area, including complete degradation of mountain ridges.

Assessment of Shoreline and Associated Landuse/Land cover Changes along Part of Lagos Coastline, Nigeria

The city of Lagos, Nigeria has undergone rapid increase in population due to economic and commercial activities. As a result of this, there has been a persistent change in Land use/Land cover (LULC) of the city and shoreline through the years. This observation necessitated the use of multi-temporal satellite data to characterize shoreline changes between 1984 and 2016. Therefore, the study attempts to determine the shoreline change during the study period and the coastal land use and land cover (LULC) of the study area. Satellite data was acquired andsubjected to some image processing techniques such as image enhancement, supervised classification, and shoreline extraction. The digital shoreline analysis system (DSAS) in ArcGIS environment was utilized to cast transects and calculate statistical parameters for the shoreline and spatial data used was Landsat TM, ETM and OLI for the years 1984, 1990, 2000, 2004 and 2016 respectively. The results indicate that LULC changes in builtup areas increases rapidly during the years (1984-2015) from 12.2 -36.2%, water bodies increased from (1984- 1990-2000) from 52%, 54%, 52% and reduces to 47.4% in the year 2015 while vegetation cover reduces drastically through the year range from 36%, 33%, 29%, 24% and 16%. A total of 1034 transects were generated with 100m spacing and the average rate of change was calculated for the 32 year period (1984-2016). The linear regression rate (LRR) shoreline result shows a mean of -0.59m/year where 73.1% of transect fall under erosion and 61.8% accretion respectively. The end point rate (EPR) and net shoreline movement (NSM) analysis revealed mean shoreline change of -0.57m/year and -18.1m/period respectively from 1984-2016. The EPR and NSM results both revealed that 231 transect or 22.3% experienced erosion, and 805 transect or 77.9% with accretion. It was observed that significant accretion rate recorded along most sections of the shorelines is attributed to beach nourishment activities.