Geochemical Evaluation of Formation Water, Mauddud Reservoir, Khabbaz Oilfield, Kirkuk Area, Northern Iraq

In this study, formation-water samples were collected by NOC Staff, during drilling time, from the Mauddud Formation reservoir of the Khabbaz Oilfield, for this reason four samples from four wells; Kz-3, Kz-4, Kz-7, and Kz-23 were selected to geochemical analysis. Analyzed geochemical parameters include TDS and the concentrations of the different dissolved cations and anions present in brines (Ca+2, Mg+2, Na+1, SO4-2, Cl-1, HCO3-1, and NaCl). Variations among the resulted data are discussed by comparison with other Cretaceous Brines. Geochemical ratios of Na/Cl, (Na-Cl)/SO4) and (Cl-Na)/Mg+2 was calculated for formation water classification following Bojarski, (1970). The calculated geochemical ratios of the studied samples in the studied four wells indicate that all of these waters are "chloride calcium" type under subsurface conditions, this type reflect closed system isolated associations reservoir, which are becoming high hydrostatic in deeper zones without influence by infiltration waters. A major transversal fault cutting the structure at its SE plunge had participated in the dilution of the Mauddud reservoir brine effectively.

Geochemical evaluation of soils, surface and groundwater from natural protected areas from Romania. Case studies.

The purpose of this article was to present an assessment of the soil and water quality in some protected areas from Romania in order to establish a series of geochemical thresholds on a spatial and temporal scale. The activities and results presented in this article are based on extensive monitoring, being stage results because the monitoring activities will continue, the project is ongoing. Two protected areas, Cheile Nerei -Beusnita National Park and Piatra Craiului National Park were selected. Surface water, groundwater samples, and soil samples were collected in 2019, respectively 2021 from 16 sampling sites situated in both locations. For each sample, twenty quality parameters/indicators were analyzed and the values were compared with in-force legislations. For Arsenic, Copper, and Nitrates parameters have plotted the distribution of the values in each site. In future monitoring activities, the evolution of the parameters will be followed.

Organic Petrographic and Geochemical Evaluation of the Black Shale of the Duwi Formation, El Sebaiya, Nile Valley, Egypt

This study evaluates the palynologic, organic, inorganic, and petrographic properties of organic-rich black shale (Mahamid Mine) in the El Sebaiya area, Nile Valley, Egypt. Black shale is composed of quartz (50%), calcite (10%), kaolinite (25%) and montmorillonite (15%). Organic and inorganic analyses revealed that this shale was deposited under oxic to anoxic marine conditions during strong chemical weathering. Black shale has poor to very good organic richness, and poor to fair hydrocarbon potential. Organic petrography indicates that the kerogen is mixed types II/III and III and is immature to marginally mature (%VRo is 0.44 and 0.53). Liptinite macerals consist of alginite, cutinite, and bituminite. The hydrocarbon products to be generated at higher maturity are expected to be oil and gas.

Geochemical evaluation of the in-situ regolith of Madengi hills of Dodoma, Tanzania. Implication on bedrock mapping and delineating gold mineralization target

Successful gold exploration projects depend on a piece of clear information on the association between gold, trace elements, and mineralization controlling factors. The use of soil geochemistry has been an important tool in pinpointing exploration targets during the early stage of exploration. This study aimed to establish the gold distribution, the elemental association between gold and its pathfinder elements such as Cu, Zn, Ag, Ni, Co, Mn, Fe, Cd, V, Cr, Ti, Sc, In, and Se and identify lithologies contributing to the overlying residual soils. From cluster analysis, a high similarity level of 53.93% has been shown with Ag, Cd, and Se at a distance level of 0.92. Au and Se have a similarity level of 65.87% and a distance level of 0.68, hence is proposed to be the most promising pathfinder element. PCA, FA, and the Pearson's correlation matrix of transformed data of V, Cu, Ni, Fe, Mn, Cr, and Co and a stronger correlation between Pb and U, Th, Na, K, Sn, Y, Ta and Be shows that source gold mineralization might be associated with both hornblende gneisses interlayered with quartzite, tonalite, and tonalitic orthogneiss. From the contour map and gridded map of Au and its pathfinder elements, it has been noted that their anomalies and target generated are localized in the Northern part of the area. The targets trend ESE to WNW nearly parallel to the shear zones as a controlling factor of Au mineralization emplacement.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5721965

Biogenic and Thermogenic Gas Potential of The Underexplored Southern Kutai Basin, Offshore East Kalimantan: A Case Study from South Sesulu Block

The Southern Kutai Basin is currently less explored than the Mahakam area and others in the northern part of this Basin. Therefore, this research focuses on knowing the potential of active source rocks that can produce hydrocarbons, the volume that can be produced and its migration that can encourage exploration activities in this area. The method of this research is to conduct a geochemical evaluation as a screening of source rock which has the potential to generate biogenic and thermogenic hydrocarbons. Rock - Eval Pyrolysis, biomarker analysis in the form of Gas Chromatography - Mass Spectrometry (GC-MS) evaluated from eight exploration wells was used to determine the quantity, quality, maturity and environment of organic material deposition. 1D and 3D basin modelling using geochemical and geological evaluations to determine the presence of thermogenic hydrocarbon shows accumulations around the study area through migration analysis. Isotope analysis, thermal gradient and sedimentation rates are used to determine the environment and activity of anaerobic micro-organisms in generating biogenic gases. Geophysical analysis including interpretation and mapping of subsurface structures using 2D and 3D seismic are used to determine the distribution of potential source rock and its migration history. Geochemical data indicate that biogenic gas have been generated from within the Late Miocene tol recent sedimentary section where the quantity of organic matter is fair to excellent (0.51 – 7.31 %wt TOC) which represents the results of micro-organism activities where sedimentation rates avg 6,2 x 107 ton/year. Thermogenic gas; however, is estimated from the Late Oligocene to Early Miocene series of post rift sediment throughout the Kutai Basin.