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Borehole instability issues account for approximately 18% of the non-productive time during drilling. The data needed for the planning of optimized wellbore trajectories and mud weight windows can come from multiple sources, notably Logging-While-Drilling (LWD) and wireline measurements. In particular, in-situ tectonic stresses can be inferred from the identification and characterization of breakouts (some of the most common processes that infringe upon the stability of boreholes). Two techniques can help to distinguish the breakouts: (1) determining borehole ovalization and (2) identifying the breakouts on borehole geophysical images. Multi-arm caliper logs from wireline imaging tools provide a direct measure of the borehole size but are not always available. Borehole shape can, however, be inferred from LWD geophysical imaging logs, notably from acoustic and density logs, which are very sensitive to standoff. Synthetic caliper curves can be computed from the standoff curves and converted into an oriented caliper image, displayed as a borehole wireframe. Sections through this borehole wireframe provide ovalization information and eliminate the uncertainty of breakouts direction estimation from resistivity images, which may show sometimes artifacts related to the presence of bad hole conditions or to very high formations true resistivity / mud resistivity ratios. This paper presents the application of LWD imaging data for better characterization of a borehole cross-section and easier breakouts detection in hostile environments (borehole excavations and rugosity, resistivity image artifacts, presence of fractures and faults). The proposed method enables detecting breakouts in real time or in memory mode. Determining the magnitude and orientation of borehole breakouts enables the validation or adjustment of geomechanical models and the selection of optimal parameters for the drilling mud. [ABSTRACT FROM AUTHOR]

Integrating conventional well log interpretation with high-resolution borehole electrical image analysis enables a complex understanding of the geological formations intercepted by exploration wells. Whereas conventional geophysical well logs allow the determination of the main reservoir parameters and the fluids distribution, borehole imaging serves as a valuable tool in sedimentary features identification and interpretation, regional dip determination, structural and tectonic elements identification, as well as the analysis of borehole failures (such as breakouts and natural or drilling-induced fractures) related to tectonic stress in a particular area. In addition to conventional well log interpretation, we have carried out a detailed analysis of the borehole electrical imaging data for a gas exploration well drilled in Sarmatian (late Middle Miocene) deltaic deposits from north-western Moldavian Platform, Romania. 1100 borehole features were picked and interpreted across a 196 m interval (386 – 582 m depth) covered by the borehole image. The number of picks provided a satisfactory statistical dataset to carry out a dip analysis, faults and fractures characterization and present day stress analysis. The features identified on the borehole image include bedding and soft-sediment deformations (in shales), cross-bedding (in sands and silty sands), faults, open fractures, borehole breakouts and unconformable surfaces. A statistical analysis of 775 low-angle planar features picked in shale intervals and representing bedding revealed two dominant dip directions towards SSW (200 – 220 degrees dip azimuth, 3.1 degrees dip angle modal value) and SSE (150 degrees dip azimuth, 7.2 degrees dip angle modal value), with subordinate preferential dip directions towards ENE or east (60 – 100 degrees azimuth). The dominant directions are consistent with the general structure of the Moldavian Platform, which dips from NE to SW and, also, towards south or SSE. Two high-angle faults (55 – 58 degrees formation dip angles) were recognized on the borehole image and they might have provided pathways for biogenic gas migration from deeper levels up to shallower Sarmatian sand reservoirs. Borehole breakouts were found on various intervals and they show a counterclockwise rotation of their azimuth (from 155 to 116 degrees) along with increasing depth, attributable to localized stress field perturbations resulted from faulting. [ABSTRACT FROM AUTHOR]

The identification of fluid contacts (gas-water contact – GWC, oil-water contact – OWC and gas-oil contact – GOC) is essential for field reserve estimates and field development and, also, for detailed formation evaluation. For the accurate calculation of some petrophysical parameters, such as porosity, the reservoir interval has to be zoned by fluid type, to account for differences in fluid saturations and fluid properties (e.g., hydrogen index, density, sonic transit time) in the various intervals: gas cap, oil column and aquifer zone. The fluid contacts may vary over a reservoir either because of faults, semipermeable barriers, rock quality variations / reservoir heterogeneity, hydrocarbonfilling history or a hydrodynamic activity. Horizontal contacts are typically taken into consideration, although irregular or tilted contacts occur in some reservoirs. The methods used for determining the fluid contacts include fluid sampling, water and hydrocarbons saturation estimation from geophysical well logs, analyses of conventional or sidewall cores, and formation pressure measurements. The pressure profiles obtained with various formation testing tools over reservoir intervals are, frequently, the primary source of data for defining the fluid contacts. When good quality pressure data can be collected, the fluid contacts can be determined by identifying the depths at which the pressure gradients (pressure versus depth trends) change. This study addresses some issues related to the identification of GWC for two gas fields of Early Pliocene age (Dacian stage), belonging to the biogenic hydrocarbon system of western Black Sea basin - Romanian continental shelf. We show that the identification of these contacts based exclusively on pressure gradients analysis is uncertain or may be inaccurate. The pressure gradients approach should be checked against the results of the conventional interpretation of geophysical well logs (e.g. changes in the computed fluid saturations as a function of depth) and, if available, the results of nuclear magnetic resonance (NMR) log investigations, which are able to indicate the intervals with claybound water, capillary-bound water and movable fluids. [ABSTRACT FROM AUTHOR]

The study area is located in the northern and western parts of Moldavian Platform, the oldest platform unit of the Romanian territory and representing the margin of the East European Platform. Two hydrocarbon systems are recognized in the Moldavian Platform: a thermogenic system of Paleozoic age and a biogenic system of Miocene age. The Miocene biogenic system comprises significant natural gas fields (including dry gas with more than 98% methane), reservoired especially in Sarmatian (late Middle Miocene) deposits, where suitable conditions for accumulation and sealing are encountered. The Sarmatian stage was marked by permanent changes of the sedimentary conditions, passing from a predominantly marine environment to a transitional one, of deltaic type with lacustrine - continental influences. The gas accumulations are usually hosted in sands / sandstones (observed as good seismic reflectors with continuous or discontinuous character) that pinch-out forming lithostratigraphic traps. The sand beds or sand bodies formed during the deltaic construction, especially when they overlap and alternate with pelitic sequences, offer the most favorable settings for such accumulations. The integrated analysis of recent geophysical well logs (conventional logs and highresolution electrical imaging logs) and seismic reflection surveys, together with mud logging data and well flow test results, allow a better characterization of the Sarmatian deposits, particularly the gas reservoirs, from the study area. The correlation of three exploration wells along a NW - SE profile indicates that a low-energy, fine-grained depositional environment is developing towards SE, with a prevalence of claystones and with fewer sand reservoirs, if any. This may reflect a deltaic transition from distributary channels and mouth bar sands towards prodelta offshore silts and muds. The processed electrical imaging data recorded in the northernmost exploration well show two dominant dip azimuths (142 and, subordinately, 218 degrees) in the shale intervals. Most likely, these indicate NW to SE and NE to SW sediment paleotransport directions, related to seaward delta progradation. The electrical imaging results also reveal the presence of two high-angle faults (48 - 54 degrees dip values), which might have provided pathways for gas migration from deeper levels up to shallower Sarmatian reservoirs. [ABSTRACT FROM AUTHOR]

Leather sector is an important source of materials for various industries and fields, some of them being listed as top fields. Waste from the leather industry and leather clothing can be realised by using several processing methods in different areas of interest. European tanneries produce, on average, 2.14 kg of waste per square meter of leather produced. This figure could be an apparently significant environmental value, but we must consider the overall management and final destination of waste from tanneries. Waste problem as a whole is not simple, it requires a comprehensive approach in all aspects of management - identification and inventory, the proper treatment to annihilation, recycling, reuse, which implies concern, financial and technological support, strength working properly qualified and not least the existence of a legal framework, institutional and administrative framework. [ABSTRACT FROM AUTHOR]

The article discusses studies regarding energy production from seed oil. Topics include using technology for the cultivation of sunflower and the increase in the market value of sunflower seeds, the expenses for the production of oleginous plants including fertilisers, chemical treatments and harvesting, and the use of liquid fuels in transport errands. Also mentioned are the differences between price and caloricity.

Environmental issues have been at the top of tanners' agenda for the last few decades, since dealing properly with tannery wastes is expensive. Overall, the leather industry should be able to reposition itself as a solution to environmental problems rather than a contributor, as there is no other industry that can make use of the total volume of hides and skins yielded by the livestock and meat industries. This has caused concerns about the fairness and appropriateness of demands made by governments, and about whether it will be possible for tanneries to operate on a level global playing field regarding the environment. In dealing with these challenges, the tanning industry had to come up with some environmental friendly solutions. Anaerobic digestion is a favorable technological solution that degrades a substantial part of the organic matter contained in tannery sludge and solid waste, biogas, helping to alleviate environmental problems. [ABSTRACT FROM AUTHOR]

The article presents a research that analyzes vegetable oils' dynamics while burning inside power plants in Bucharest, Romania. Researchers did an analysis on crude vegetable oils' energetic characteristics with the use of experimental and analytical methods. Moreover, the results of their research are also stated.