Perm Journal of Petroleum and Mining Engineering

On the basis of the study of crystalline basement in axis zone of the Talysh-Vandam gravity maximum in the central part of the Kurinskaya depression the Saatlin uplift of the brachiform profile in the area of the junction of the Kura and Arax rivers was identified. The results of analysis of the data obtained by deep seismic sounding, refraction correlation method, gravimetry showed that a crustal architecture of that area may be represented as a lifted basement block with bedding of crystalline rock surface at the depth of 7-8 km and boundary velocity ranging from 6.0 to 7.3 km/s. A thickness of the sedimentation mass was found to be decreased. Physical properties of porphyrites, andesites, diabases and other rocks from different stratigraphic units and in different conditions were studied. The experiments showed that in the area of the Talysh-Vandam gravitation maximum the lifted crustal block in terms of material constitution at the depth of 8-10 km may be characterized by andesite porphyrites without any transformation undergone. The Talysh-Vandam gravitation maximum has been mainly examined using the data taken from the Saatlin super-deep well on the basis of complex investigations of the core material retained during the drilling process down to 8,267 m. The study has confirmed that andesite porphyrites of the crystalline basement at the Talysh-Vandam gravitation maximum at the 8-10 km are metamorphic.

The study is focused on improving efficiency of well cleanout in permafrost conditions using cleaning agents of low thermal conductivity. At present drilling in hard conditions, e.g. abnormal reservoir pressures (low or high), unstable rock, rock of higher hardness, permafrosts and so on, gains momentum. Permafrost areas are common in Russia, covering 10 million km2 in different regions and thus totaling more than 50 % of the whole territory of Russia. Large parts of Alaska (USA) and Canada also contain permafrost. A big number of oil and gas fields are located in these areas; that is why developing technologies of well drilling in hard conditions draws much attention. In doing so a depth of permafrost can reach 1400 m (for instance, the Markhinskaya well in the northwestern part of Yakutia) but usually it is 600-700 m. The permafrost temperature can make -8 °C though it mainly fluctuates between 0 and -2,5 °С. The paper offers the analysis of the Russian and foreign experience related to well drilling including cleanout by different agents and technologies of their cooling. The Russian practice based on traditional technologies tells us that defrosting, destruction of permafrost leads to a number of complications, particularly in the wellhead area resulting in poor well performance. The cleaning agents investigated include cooled air, gas-liquid disperse systems and flushing fluids.

Topicality of the theoretical study results is determined by a need to develop, correct and improve the methods to forecast changes in air distribution and parameters of mine air in case of emergency. An analysis is made of relation between aerological and thermalphysic processes in mine workings. It is shown that the link between them is in thermal drop of ventilation pressure which influence on ventilation grows during mine emergency leading to fire and the main fan unit failure. Alteration of thermodynamic properties of air flow under gravitational contraction and stack effect in shafts was modeled. A solution is given to the problem of coupled heat transfer of ventilation air with rock mass using the short-time approximation, allowing forecast of thermal drops of ventilation pressure during the fire. The results of numerical simulation of air movement evolution inside the inclined shafts during the fire of different scale are presented. The results of mathematical simulation of aero- and thermal-gas-dynamic processes occurring in emergency ventilation mode lay foundation for development of a complex of measures aimed at emergency prevention and real-time emergency ventilation control.

The Zhaman-Aibat cupriferous sandstone deposit is developed by the Zhomart Mine which reserves are nearly depleted. The paper suggests the method and the results of the research of natural stress field at the Zhomart mine. Stress measurements were carried out by fissure relief in the walls of single development openings located outside the extraction influence area. Evaluation of the rock stressed-deformed state was performed by mathematical simulation in accord with in-situ measurements made. Data input for the calculations performed included strength and deformation characteristics of gray sand following the laboratory uniaxial tension tests of the core samples retained from the exploratory sites. The field studies and numerical simulation established that the maximum horizontal stresses in the investigated area of the virgin rock at the Zhomart mine reach 27.7 MPa and are directed perpendicularly to the ore-body strike. Accordingly, the minimal main horizontal stresses of 16.2 MPa trend along the ore-body strike. Vertical stresses generated by the rock weight above make up 17.5 MPa. The research results are meant to adjust parameters of the mining system implemented in some tracts under development at the Zhaman-Aibat deposit.

The research deals with the process of formation of various plastic microdeformations in the Donets Basin sandstone quartz at different catagenesis substages. The aim is to verify whether analysis of microdeformations may be applied to forecast the properties of the sandstone studied, in particular outburst hazard, hardness, stability, reservoir features. The research revealed a number of plastic deformations of all types in sandstone’s detrital quartz, that were previously found in rocks and minerals in other regions. In outburst-prone sandstones the total number of plastic deformations significantly surpasses that in nonhazardous sandstones. Besides those deformations described previously two new types were investigated, i.e. tabular quartz and translation glide lines. These two types may serve as an indicator of the stressed rock state. The results obtained confirm the opinion of many authors that a matter structure is a fine indicator of external conditions impact, reflect the influence of temperature and pressure in the form of physical and chemical modifications occurring during catagenetic transformations. Quantitative values of microdeformation were patented as two techniques to determine rock outburst hazard. Deformation factor as an indicator of rock stresses state is included in the complex method of rock outburst hazard forecast.