Rock Physics Modeling and Reservoir Characterization to Estimate Hydrocarbon Zone of Cretaceous and Paleocene Strata and Subsurface Stratigraphic Correlation of Sulaiman Fold Belt to Sulaiman Depression

Doklady Earth Sciences - The research work involves rock physics modeling and reservoir characterization of Suliman fold belt to sulamain fold depression. This area is a brighter zone for...     

Criteria of Acceptance for Constant Rate of Strain Consolidation Test for Tropical Cohesive Soil

In this study, the rapid consolidation equipment (RACE) was developed as an alternative device to the conventional consolidation test using Oedometer, consuming merely a few hours for the whole precedure to determine the consolidation characteristics of cohesive soil. RACE operates based on the constant rate of strain (CRS) consolidation theory, which is a continuous loading method of testing, requiring a good estimation of the loading rate such that it is ideal for the achievement of steady state condition during testing. The steady state condition is achieved when the c _v values from drained and undrained face of CRS converged with the c_v from Oedometer test. A slightly modification has been made on the normal constant rate of strain (CRS) test by proposing a direct back pressure system to the specimen using a tube to saturate the soil sample. This research has produced a set of criteria for determining the suitable rate for the rapid consolidation test based on the ratio of normalized strain rate, β, and proposed a new coefficient in terms of a ratio of β to clay fraction (CF), as a part of new criteria for testing a fine soil. Four types of sample were tested with different rates of strain using the RACE and their results were compared with those conducted using the Oedometer on the same soil type, from which fairly good agreements were evident in many specimens. It was found from the study that the minimum value of normalized strain rate, β, for the CRS test is 0.005 and for the u _a /σ _v ratio is suggested as 0.01. Also, the maximum β/CF for soils with clay friction lower and higher than 50 % are 0.008 and 0.001, respectively. The minimum β/CF value for both conditions is 0.0001.     

Geological environment of a methane-rich Recent sedimentary basin in the Gulf of St. Lawrence

Two sediment cores collected in Chaleur Trough, Gulf of St. Lawrence are compared in terms of organic geochemistry, sediment texture and foraminifera. One of the cores was collected from a depression and contained methane in the range of 5,970–14,230 ppm, in comparison to 42–106 ppm in the core of open environment. The sediments of the methanerich core are finer, higher in organic carbon, extractable organic matter, plant pigments and contained more diverse foraminiferal assemblages. The results of these geological investigations tend to suggest a relatively fast rate of sedimentation in the depression. This results in the preservation of organic compounds and development of anaerobic subsurface conditions, consequently giving rise to high concentrations of methane through fermentative processes. No other gaseous hydrocarbons were detected hence the possibility of seepage of petroleum gases appears to be remote.     

Trace elements in groundwater of Hindon-Yamuna interfluve region, Baghpat district, Western Uttar Pradesh

The present study was carried out in parts of Hindon-Yamuna interfluve region to evaluate the concentration of trace elements (Al, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Cd, B and Pb) in groundwater. Pre-monsoon groundwater samples were collected in 2007 from 22 locations distributed throughout the study area, and were analyzed using Inductive Coupled Plasma Mass-Spectrophotometer (ICPMS). Trace element analyses show high concentration levels for Al and Cr in almost all groundwater samples. Relatively high values are also reported for Pb, Se, Fe and Mn (as per B.I.S (1991) standard for drinking water) in few samples. These high concentrations of metal ions in groundwater were probably due to discharge of untreated effluents from Textile, dyeing and other industries. As far as Al is concerned, its source is rather enigmatic.     

Reservoir Quality Assessment of the Upper Permian Chhidru Formation,Salt and Surghar Ranges,Pakistan

The Late Permian succession of the Upper Indus Basin in northeastern Pakistan is represented by the carbonate-dominated Zaluch Group, which consists of the Amb, Wargal and Chhidru formations, which accumulated on the southwestern shelf of the Paleo-Tethys Ocean, north of the hydrocarbon-producing Permian strata of the Arabian Peninsula. The reservoir properties of the mixed clastic-carbonate Chhidru Formation (CFm) are evaluated based on petrography, using scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX) and x-ray diffraction (XRD) techniques. The diagenetic features are recognized, ranging from marine (isopachous fibrous calcite, micrite), through meteoric (blocky calcite-I, neomorphism and dissolution) to burial (poikilotopic cement, blocky calcite-II-III, fractures, fracture-filling, and stylolites). Major porosity types include fracture and moldic, while inter- and intra-particle porosities also exist. Observed visual porosity ranges from 1.5%–7.14% with an average of 5.15%. The sandstone facies (CMF-4) has the highest average porosity of 10.7%, whereas the siliciclastic grainstone microfacies (CMF-3) shows an average porosity of 5.3%. The siliciclastic mudstone microfacies (CMF-1) and siliciclastic wacke-packestone microfacies (CMF-2) show the lowest porosities of 4.8% and 5.0%, respectively. Diagenetic processes like cementation, neomorphism, stylolitization and compaction have reduced the primary porosities; however, processes of dissolution and fracturing have produced secondary porosity. On average, the CFm in the Nammal Gorge, Salt Range shows promise and at Gula Khel Gorge, Trans-Indus, the lowest porosity.     

Particulate matter dispersion and haze occurrence potential studies at a local palm oil mill

The emissions from palm oil industry through incineration and open burning are the major sources of air pollutions contribution in Malaysia. The consequence of increasing the particulate concentration, the particulate matter dissolves with vapour and grows into droplets when the humidity exceeds approximately 70% and causing opaque situation known as haze. This work focuses on the dispersion particulate matter from palm oil mill. Gaussian Plume Model from a point source, subject to various atmospheric conditions is used to calculate particulate matter concentration then display the distribution of plume dispersion using geographic information system. Atmospheric Stability, mixing height, wind direction, wind speed, natural and artificial features play an important role in dispersion process. Study on the dispersion of particulate matters and the haze potential are presented as a case study in this paper. The data obtained will be served as the purpose of modeling the transport of particulate matter for obtaining permits and prevention of significant deterioration to the environment.     

Artificial neural network prediction of sulfate and SAR in an unconfined aquifer in southeastern Turkey

In many rural communities, groundwater is used to meet the water demand of the community and for the irrigation of cultivating areas. The quality of groundwater can be adversely affected by agricultural activities and finally groundwater quality may become unsuitable for human consumption and irrigation, as in the Harran Plain. Hence, monitoring groundwater quality by cost-effective techniques is necessary, as especially unconfined aquifers are vulnerable to contamination. This study presents an artificial neural network model predicting sodium adsorption ratio (SAR) and sulfate concentration in the unconfined aquifer of the Harran Plain. Samples from 24 observation wells were analyzed monthly for 1?year. Electrical conductivity, pH, groundwater level, temperature, total hardness and chloride were used as input parameters in the predictions. The best back-propagation (BP) algorithm and neuron numbers were determined for the optimization of the model architecture. The Levenberg?CMarquardt algorithm was selected as the best of 12 BP algorithms and optimal neuron number was determined as 20 for both parameters. The model tracked the experimental data very closely both for SAR (R?=?0.96) and sulfate (R?=?0.98). Hence, it is possible to manage groundwater resources in a more cost-effective and easier way with the proposed model application.     

The influence of a salt dome on the diagenesis of organic matter in the Jeanne d'Arc Subbasin of the northeast Grand Banks of Newfoundland

This study elucidates the geothermal influence of a salt dome on the diagenesis of organic matter present in sedimentary sequences directly overlying the salt strata. Despite similarities in geological setting, geochemical characteristics in sedimentary column and proximity of location (～3 km), the exploratory wells Adolphus 2-k-41 and D-50 drilled on the crest and flank of a salt dome respectively, show considerable differences in the quantitative and qualitative distribution of hydrocarbons. The well drilled on the crest of the salt dome tested oil of 31°APl gravity. The concentrations of gaseous (C₁-C₄) and heavy (C₁₅⁺) hydrocarbons of this well were several times higher than those found in the corresponding sequences of a flank well. The coloration studies of isolated kerogen and gas chromatographic investigations of hydrocarbons suggest that the organic matter present in Adolphus 2-k-41 has undergone a greater degree of thermal alteration than that of D-50. The heat radiating from the salt strata is believed to be responsible for the early diagenesis of the organic matter.