Perm Journal of Petroleum and Mining Engineering

Experimental results concerning the effect of loading pressure on the electrokinetic potential of kaolinite and montmorillonite particles in aqueous suspension are presented. It has been determined that the investigated suspensions of kaolinite and montmorillonite are aggregatively and sedimentally stable. The aggregative stability is evidenced by the calculated energy of the molecular motion (10-7-10-8 J/m2). The particle size monitoring indicates sedimentation stability. It was found that the change in the electrokinetic potential of clay particles depends on the loading pressure in different ways. Three classes were distinguished: 0-125 MPa, 150-750 MPa, 800-1200 MPa. In each class, changes in the electrokinetic potential are observed, due to the nature of the clay and the fractional composition. The fractional composition of the clay is also changed while compression. Pressure load has a different effect on the change in electrokinetic potential for kaolinite and montmorillonite. To establish the influence of the particle size distribution on the conditions of formation of the zeta potential on the surface of clay particles, a statistical correlation analysis was performed. It was established that for montmorillonite in the 1st and 2nd classes, the particle size distribution and zeta-potential have statistical correlations, and in 3rd class - not, whereas for kaolinite, statistical correlations between the particle size distribution and zeta potential are observed in the 1st and 3rd classes, and in the 2nd class - not. The resulting changes in the zeta potential are associated with the processes of dispersion and aggregation, which are implemented more intensively at low pressures (P < 150 MPa).

For the formation of the technological properties of clays, various methods have been developed: thermal, chemical, ultraviolet, mechanical and others. However, the issues of changing the properties of clays and clay particles compacted with high pressures, are not well understood. Therefore, the aim of the work is to study the patterns of change in adhesion forces on the surface of particles of montmorillonite clay treated with stress pressure and shear. The adhesion force on the surface of clay particles and in the space between them was measured by atomic force microscopy on prepared samples of montmorillonite clay, compacted under different pressure (from 25 to 800 MPa). Experimental results showed that with increasing pressure on montmorillonite, adhesion forces change. So, with an increase in compaction pressure from 25 to 200 MPa, adhesion forces increase from 0.32 to 0.70 nN. When exposed to pressures above 200 MPa, adhesion forces decrease (to 0.40 nN at P = 800 MPa). To explain the dependence of the montmorillonite adhesion strength on the compaction pressure, the roughness of the samples and the amount of adsorbed water on their surface were studied. It is revealed that the roughness and thickness of the water film on the surface of the clay particle increases with increasing pressure. An increase in the thickness of the water film is probably due to the defects on the particle surface caused by pressure and shear. The presence of additional defects causes an increase in the charge density on the surface of the particles, increasing the number of adsorbed water molecules and the thickness of the water film, respectively.

The use of alternative types of motor fuel contributes to the improvement of the economic and environmental situation in open-pit mining. An analysis of the development of opencast mining in Russia indicates constant shift to the remote northern territories. In the cost of mining, the share of transport works is 40-50%, and as the mining operations go deeper for every 100 m, the cost of transporting the rock mass by tipper trucks increases by 20-30%. With an increase in the depth of the quarry, the natural ventilation of the working area deteriorates, which leads to the accumulation of exhaust gases of diesel engines in the quarry. This affects the health of miners and the economy of the enterprise, as it entails the need to stop the quarry. Currently, the global engine industry is considering the use of natural gas as a motor fuel instead of diesel fuel. The specificity of the northern regions is such that fuel must be delivered a year in advance during the navigation period, which increases its price, while gas fields are located directly in Yakutia. The cost of production of liquid natural gas (LNG) in the regions of its consumption as a motor fuel is much lower than the cost of delivery of diesel fuel. Production can be organized directly at the gas fields in Western Yakutia. LNG plants are compact and highly reliable. Tests of Cat 789C, Komatsu 830 and 930 mining trucks in gas-diesel mode showed that the efficiency and performance of the gas engine were comparable to the efficiency of a diesel engine. Diesel fuel saving was 80%, while exhaust emissions were reduced by 25%, that improve the environmental situation. Converting of tipper trucks to LNG will reduce the gas pollution of quarries and noise by 2-3 times, increase the efficiency and competitiveness of the enterprise by reducing the costs of fuel, transporting rock mass and environmental fines.

The statistics of emergency situations at pipeline transportation facilities indicates the presence of problematic issues during transportation of products. In the structure of accidents of the past decade, theft of products (“mortise terrorism”) prevailed, sabotage acts were recorded. The article presents data about the growth in the number of criminal interventions in the operation of pipelines, which pose a great danger to the health and life of the population, a threat to the environment, as they cause accidents, spills of oil and oil products, pollution of soil, rivers and water bodies, as well as associated environmental and economic losses from these criminal interventions. The total losses incurred by the owner of the pipeline system from the attacks of intruders are illustrated. The less the owner invests in ensuring the safety of the infrastructure, the greater losses should be expected during the operations. The analysis of publication activity in the field of ensuring pipeline safety and the detection of unauthorized actions in the protection zone was carried out, which showed that the research is mainly focused on creating a system of physical protection of pipelines that implements the principle of “do not miss the attacker’s contact with the shell of the pipe”. The main direction of research to counter these threats is focused on the detection of the seismic field disturbances in the security zone of the pipeline using a fiber-optic cable (sensor). In addition to distributed fiber optic systems for the preventive neutralization of terrorist threats to extended objects, the capabilities of video-analytical and thermal imaging systems were evaluated. The structure of the pipelines physical protection system for the detection and neutralization of unauthorized tie-ins into the pipe in order to minimize the level of losses during pipeline security is proposed. The effectiveness of the proposed approach to determining the requirements for systems to protect objects from terrorist threats is demonstrated.