This paper presents the subject related to the technology of creating fractures into a rock, as well as the subject related to the effect of the proppant embedment phenomenon on the effective packed fracture in a reservoir rock. This phenomenon occurs after the performed hydraulic fracturing treatment of hydrocarbon reservoirs, during closing of the rock mass. A key part of this experiment was to investigate the depth of proppant grains penetration into the fracture wall (shale rock) and size of damage to the fracture wall surface. The embedment phenomena effects on decrease in the width fracture packed with proppant. The tests were performed for shale rock initially soaked with fracturing fluid, lightweight ceramic proppant grains with a grain size of 0.600÷0.300 mm (medium diameter of proppant grains of 0.450 mm), low surface concentration of proppant of 2.44 kg/m2. Time of exposure of proppant grains to compressive stress of a value 48.3 MPa for 6 hours at 70 oC. Test results indicate that the developed testing methodology may be used for corrected evaluation of the fracturing fluid as well as proppant in hydraulic fracturing treatment of unconventional reservoirs, especially shale rocks. and Maslowski Mateusz, Kasza Piotr, Wilk Klaudia.
Based on experimental studies using the “integral velocity index of the vertical displacement of the territory” and criterion of generalized seismicity, a close functional relationship was found between two parameters of different physical nature: seismic activity and altitude displacements of the Earth’s surface in Europe. The mathematical correlation between the generalized parameters of the velocity altitude displacements on the territory and seismic activity is established according to seismic and GNSS stations for the period from 2000-2011 for the areas in Europe with close correlation between seismicity and velocity of vertical movements of the Earth’s surface. and Tretyak Kornyliy, Romaniuk Volodymyr.
For companies doing business in mining mineral deposits, ensuring safe work is one of the key tasks (Safety First!). One of the important trends in this area is prevention and endeavour to forestall risk situations. Risks need to be searched, technically described, spatially defined, evaluated and categorized by degree of risk. Complex geological and stability conditions can be one of the sources of persistent and significant risks, which are mainly landslides and rockslides threatening both mining equipment and employees. The problem described in this article and its solution concerns the Most Basin (formerly the North Bohemian Lignite Basin). This is a tertiary basin that was founded in the Oligocene. The main mineral is lignite and mining takes place on the surface. The main excavating machinery in the surface lignite quarries in Europe (Czech Republic, Germany, Poland) is the bucket wheel excavator., Roman Kapica, Dana Vrublová and Martin Vrubel., and Obsahuje bibliografii