Perm Journal of Petroleum and Mining Engineering

A zonal probabilistic-statistical assessment of the generation potential of deposits that form the oil and gas potential of the territory of the Perm arch was carried out. To assess the oil and gas content, databases were used on the geochemical and bituminological characteristics of dispersed organic matter in the Upper Devonian-Tournaisian carbonate, Lower Visean terrigenous and Middle Carboniferous (Oka-Bashkirian) carbonate deposits. Statistical models were built on the basis of the following parameters: organic carbon content (CORG, %); organic matter (OM, %); composition of dispersed organic matter (content of bitumoids, %: chloroform (BCL), petroleum (BPE), alcohol-benzene (BAB), humic acids (HumA, %), insoluble residue (IR, %) and DOM conversion characteristics (ratio of concentrations of chloroform bitumoid to alcohol-benzene (BCL/BAB), bitumoid coefficient (β). To determine the information content of these characteristics in relation to oil and gas potential, Student's statistical criteria - t and Pearson's - c2 were used, which made it possible to develop one-dimensional and multidimensional linear regression models. With the help of step-by-step multidimensional regression analysis, a complex criterion was developed that took into account the influence of both each geochemical indicator separately and their combinations. This made it possible to construct a distribution scheme for the probability of oil and gas content for the Perm arch territory. The analysis of the constructed scheme showed that the most favorable geochemical conditions for the formation of oil and gas potential due to the dispersed organic matter of the studied deposits were observed in the northeastern part of the Perm arch, which limited the isoprobability to more than 0.5.

When performing research, a main indicators analysis for development of the Perm region field Tournaisian reservoir was made. It was established that the development object under consideration hads a high heterogeneity and fracturing, which was determined by interpreting the data of hydrodynamic studies. Wells of the central part of the main uplift with high values of water cut were used for the analysis. The study considered the main geological characteristics of the reservoir: porosity, permeability, oil saturation, net-to-gross ratio and reservoir thickness; technological indicators of development: oil, liquid rates and depression, as well as fracture parameters: openness, fracture permeability and proportion of fractured reservoir, calculated using the Warren-Root method. With the help of statistical methods, the relationships between the reservoir characteristics and the main development parameters were studied. In order to determine the parameters that had the maximum effect on the process of watering, regression equations were constructed, the analysis of which made it possible to establish that, depending on the value of watering, there were two groups of indicators that formed it. The obtained division was confirmed by comparing the average values of all indicators using Student's t-test and constructing a linear discriminant function. This made it possible to substantiate the need to build three multidimensional models. The first model was built for all studied wells, the second and third models - according to well data, depending on the degree of their water cut. As a result, the main parameters that affect the water cut index in each of the models were determined, in particular, the role of formation fracturing was determined. By comparing the actual and predicted water cut values, it was determined that the best forecast results were obtained using differentiated models.

Factors influencing the stability of rocks were identified, taking into account changes in saturation and physical and mechanical properties of the reservoir. Existing methods for modeling sandy rocks were considered: empirical, numerical and analytical methods, as well as laboratory modeling. It was concluded that in order to obtain the most accurate prediction of the destruction of the bottomhole formation zone with the subsequent removal of mechanical particles, it was necessary to use a combination of methods, since none of them separately allowed obtaining comprehensive data for the prediction. The input parameters for modeling sandy rocks were considered. The model should take into account a combination of geological, physical-mechanical and filtration methods, which would make it possible to create the most accurate model of sand reservoirs. The physical model of sandstone can be represented as a set of four components: sand grains, cementing clay substance, water and cracks. Within the framework of this work, geological properties were analyzed: structure, texture, mineralogical composition and type of void space. The analysis of these properties made it possible to find and determine the relationship between the properties of rocks and their strength characteristics. The mechanical properties of rocks were considered. These included strength, deformation and rheological properties. To determine the deformation properties of the rock, deformation diagrams were constructed that took into account pre-limit, limit, and beyond limits. The ability of the massif to resist destruction under long-term loading depended on the rheological properties of the rock. These included: long-term strength, creep, stress relaxation. Within the framework of this work, the prerequisites and causes of sand manifestations in wells were presented. The main ones included: non-consolidation of rocks, excess of compression forces and migration of small particles. An important role in the sanding process was played by the well completion method. Criteria for the formation of studies on natural and artificial cores were identified. The results obtained can be used to improve the efficiency of wells in sandy rocks and predict their trouble-free operation.

In the conditions of potash mines, the problem of excess moisture loss from the air entering the mine during the warm period of the year is known. Physically, the process is related to the fact that warm air saturated with moisture enters the mine workings and cools down in the process of heat exchange with relatively cold rocks. When the air is cooled, its relative humidity rises until it reaches the dew point. Further cooling of the air leads to the loss of excess moisture while maintaining the maximum relative humidity. Moisture precipitation together with salt rocks creates a corrosive-aggressive environment, worsens the stability of workings and leads to soil erosion with the ensuing difficulties for the passage of mining vehicles. The introduction of heat engineering means of air drying is an extremely costly undertaking. At the same time, heat and mass transfer processes in mine workings depend on air distribution, which is controlled by modern automatic ventilation control systems. In this regard, the study considers the option of using the means of automatic ventilation control systems, along with their traditional use, for the purpose of draining mine workings. The paper shows that the amount of condensing moisture is determined primarily by the air flow. Therefore, the elimination of excess air supply to the mine and workings, implemented by automatic ventilation control systems, makes it possible to reduce moisture loss in mine workings. In addition, moving the recirculation ventilation systems, which are part of the automatic ventilation control systems, as close as possible to the shafts allows you to include a larger volume of air supply workings and service chambers in the recirculation circuit, which also makes it possible to drain them in conditions of hygroscopic rocks.