Browse

Approximately 110x106 m3 of oil (100x106 tons) had been recovered from 38 fields in the Croatian part of the Pannonian basin during more than 60 years of exploitation (1941-2003). Based on their cumulative production, number of reservoirs, average porosity and permeability, obtained recovery and depositional characteristics of reservoir rocks, the Croatian hydrocarbon fields may be divided into three groups (oil), or four groups (gas) (Table 1, 2). In the period 1941-1990 the production started in 38 fields, 13 of...

The paper present some result obtained by the authors in the research activity developed in the creation of a methodology to solve the environmental problems. The results presented in this paper are part of the soil moisture preservation and soil compaction prevention method, which is including in the methodology. The method is based on the soil moisture and compaction prediction in a certain geographic zone. The prediction is based on the maps of soil moisture and compaction, which is obtained starting of the GPS...

We introduce an example of a detailed study of soil texture and geochemistry with the aim of designing appropriate soil washing systems. Concretely, we have studied soils affected by the mining works of “Los Rueldos” (Asturias, Spain). After an initial characterization, composite, representative samples were taken and ICP-MS analysis was carried out. Results showed very high concentrations of As, and significant presence of heavy metals such Hg, Pb and Zn specially in silt-clay fractions obtained after wet sieving...

In this study, removal zinc from aqueous solution was studied using smectite-bearing soil. The effects of initial Zn(II) concentration, pH, adsorbent dosage, and contact time were investigated. When the initial concentration of Zn(II) was incresed from 0.7 to 3.77 mM, the Zn(II) removal efficiency decreased from 100\% to 90.7\%. To determine the effect of pH on the adsorption efficiency of Zn(II), pH was varied between 3.0 and 7.0. The sorption efficiency of Zn(II) onto soil seems to be independent of pH with in s...

The aim of this study is to provide data on biological state of soil in depth, using the comparative study of general microbiota frequency and activity. For the quantitative analysis of soil microbiota, we have used soil samples for dilutions (10-1 - 10-6). The results were expressed in colony-forming units/g soil (CFU). The soil was sampling from Calimani National Park (The Oriental Carpathians) in October 2006, June and September 2007. The soil microbiota registers quantitative variations from one sample point t...

Biogas is a part of the natural circle. Biogas is formed by the activity of anaerobic bacteria. In nature biogas is produced for example in bogs. It is also possible to produce from biological material in an environment free from air. The gas that is produced is methane (CH4), which is an excellent fuel for heat, electricity, and cars that doesn’t drain the earth’s fossil resources. The raw-material in biogas production has traditionally been waste from the food industries, and communal sewage treatment works. Bio...

The Estonian kukersite is the largest oil shale resource in the world used industrially today. The majority of mined oil shale is utilized for electricity and heat production. About 20\% of all of the oil shale extracted annually is used for retorting shale-oil and shale-gas, after which large amount of environmentally hazardous solid retort residue – semi-coke is left over. Production of 1 tonne of shale-oil is accompanied by almost 3 tonnes of semi-coke waste. During more than 80 years of operation over 110 mill...

One of technologies that can be used to increase profitability in the development of high cost off-shore operations as well as marginal or partially depleted reservoirs is so called intelligent completion. That implies such completion systems that allows monitoring, control and change of relevant data through production, by the use of remotely controlled and operated systems. Essence of the system is such way of completion that allows change of space and hydrocarbons flow conditions from the layer to the surface, ...

Recent data demonstrate a significant capacity of mushrooms to retain the pollutants from soil, so being realised the mycoremediation of soil. Nitrogen oxides are major atmospheric pollutants. The main oxides, nitrogen monoxide and dioxide, penetrated in human body cause important toxic effects: methaemoglobinemia, haemolysis, vasodilatation and even cancerogenesis. The accumulation of these oxides in mushrooms, as nitrites and nitrates, is dependent on: species, environmental conditions and chemical composition o...

Our paper presents the results of a study concerning the possibility to use mushrooms for soil remediation after mining exploitation. The samples have been harvested from Calimani Mountains (Northern Carpathians) an important site for sulphur extraction in Romania. Despite, the sulphur mines have been closed from several years, soil and vegetation are still affected and is necessary to improve theirs qualities especially by biological methods. By oxidation processes, sulphur is transformed in air to oxides especia...

The oil and gas perspectives of the Triassic rocks in the Central South Moesian Platform Margin are evaluated on the basis of a complex geological analysis. The geodynamic evolution of the region during Triassic was dominated by failed rifting phases, followed by Early Cimmerian orogeny. These events have predestined tectonic processes and sedimentation settings, leading to deposition of source rocks, reservoirs, permeable migration pathways and seals. The initial extensional stages and then compression at the end...

The introduction of positive-displacement steerable motors in directional drilling practice offers better directional control in comparison with earlier used directional drilling systems and makes directional drilling widely accepted technology. But some disadvantages of the technology as drilling the curved parts of the wellbores in sliding mode and hole cleaning connected problems, demand further development of directional drilling systems. That results in rotary steerable systems development introduced in the p...

The mushrooms are able of cumulating metals from environment depending on specie, harvesting place, type of soil, degree of development and other environment conditions. The paper presents the results of the study on levels of copper, zinc, iron, manganese, chromium and calcium in mushroom harvests from Calimani site where the soil is degraded by mining work. The mycological material (19 samples of mushrooms) was harvested from 6 places of Calimani site: Ilva Dump, Dumitrelul Dump, near Dump of Pin, Dump of Pin, P...

In this article I considered the design of a computer simulation model that approximates the exploration of a petroleum basin when exploration is conducted sequentially and according to geological hypothesis with costs and performance characteristics typical of an exploration firm. These features lead naturally to a model design in which a state of nature is created. The exploration firm initially has no knowledge of this state, only of hypothesis. In this model also, exploration decision are made according to pri...

The spoil heaps, present in the perimeter of the hydropower plants, industrial chemical complexes, groups of mining exploitation and minerals processing etc. are an important prejudice for the environment, and because of this, they need special attention (monitoring, EIA, implementation of some strategies of ecological restoration). We focused the attention on two spoil heaps categories from W. Romania (in Retezat National Park) and S.W. Romania (Moldova Noua complex), different as their provenience, morphological...