Perm Journal of Petroleum and Mining Engineering

Clays are complex polymineral formations. The properties of clays, including sorption ones, are largely determined by the structure of their crystal lattice, mineral and granulometric composition, and environmental conditions. The mineral composition of clays is realized in the form of energy on the surface of the particles, and the granulometric composition in the form of the area of the active particles surface. These two complex indicators mainly determine the sorption clays activity. To change the sorption clays activity, mechanical treatment, thermal modification and chemical activation are carried out using chemical reagents, such as acids, alkalis, salts, with different duration of exposure. In this regard, a study of the regularities of changes in the structure and sorption properties of clays subjected to pressure was carried out. Experimental studies have shown that during the treatment of kaolin by pressure, defects are formed in the structural package of the kaolinite mineral due to the removal of Al3+, Fe3+/2+, Mg2+, Si4+ ions from it. In this case, the pressure has the maximum effect on the removal of Al3+ ions from the packet. The formation of defects during the removal of ions entails deformation of the crystal lattice of kaolinite. The obtained data on IR spectroscopy confirm an increase in the defectiveness (disorder) of the kaolinite structure. It was found that at kaolin treatment pressures of 0-150 MPa the greatest influence on the sorption activity of kaolin was exerted by the pH of the solution of the particles diffuse layer Z рН = 73 % and the degree of crystallite defectiveness Z Мc = 24 %. The specific surface area of particles Z Ssp = 1 % and the defectiveness of the kaolinite mineral package Z k = 2 % had no significant effect on sorption. At kaolin processing pressures of 150-800 MPa the greatest influence on the kaolin sorption activity was exerted by the defectiveness of the mineral kaolinite package Z k = 74 % and crystallite Z Mc = 19 %. The specific surface area of the particles Z Ssp = 3 % and the pH of the solution of the diffuse layer of the particles Z рН = 4 % had no significant effect on sorption.

An assessment of the influence of lithological-facies zones on the development of the Permo-Carboniferous deposits of the Usinskoye field was carried out. To achieve this goal, the tasks of determining the filtration-capacity characteristics for each lithological-facies zone were solved, the influence of facies zoning on the degree of oil recovery for the Permo-Carboniferous reservoir of the Usinskoye field was analyzed, and the productivity was evaluated after the steam-cyclic treatments. The object of the study was the Permo-Carboniferous deposit of the Usinskoye field located in the Komi Republic. According to the developed format, a database was formed based on the results of petrophysical analysis of the core, as well as database on the effectiveness of cyclic steam treatments for a five-year period. In determining the facies, the classification of carbonate rocks according to Robert J. Dunham with the additions of Embry and Klovan (according to the predominance of structural components in limestone, the type of cementing substance, as well as their relationship in the rock). On the basis of the material composition of the rock and the structural parameter, three main facies zones were distinguished: carbonate shelf (zone of the inner ramp); organogenic structure (middle ramp zone); shallow shelf plain (middle ramp zone, partly outer ramp zone). In addition, a moderate-deep-sea shelf plain (outer ramp zone) can also be distinguished as facies. As a result of the studies, the graphs of the distribution of the displacement coefficient versus the porosity of the rocks were built, recommendations were given for determining the priority drilling areas by area. According to the core study in the eastern part of the deposit, a zone of organogenic structures is well distinguished, the formation of which occurred mainly in the Middle-Late Carboniferous and Early Permian time. In the northwestern part of the field, an internal ramp with carbonate bar facies was assumed. The placement of the priority drilling wells was selected taking into account that each production drilling cluster exposes the facies of organogenic structures with the best filtration-reservoir properties and oil displacement coefficient.

Uncertainties in the initial data when creating a geological and hydrodynamic model of a reservoir can lead to inaccuracies in the modeling results and, therefore, to an incorrect economic assessment and the perspective of an oil or gas field. In order to improve predictive reliability, an assessment of the influence of the hydrodynamic model initial parameters on the forecast of the main technological development indicators was carried out on the example of the Tournaisian object of the Soldatovskoye field. The study presents an approximate algorithm that allows to reduce uncertainties and increase the forecast reliability of the technological development indicators, obtained using a geological and hydrodynamic reservoir model. The algorithm includes a reasonable choice of initial parameters of uncertainty, assessment of the degree of initial parameters influence on the reservoir hydrodynamic model using sensitivity analysis, optimal range selection of uncertainty parameters variation as a result of multivariate adaptation of the hydrodynamic model, calculation and analysis of multivariate forecast for the reservoir hydrodynamic model. The result of the work is to clarify the design technological indicators of development, assess the risks of non-confirmation of the hydrodynamic model forecast, as well as recommendations and proposals for the study of those uncertainty parameters that had the greatest impact on the calculated technological indicators of the object development. As a result, a block diagram of the applied approach is presented in order to generalize and replicate on promising and significant oil and gas fields. The described approach to adapting the model and calculating forecast options in conditions of uncertainty of the model initial parameters would allow obtaining a more reliable and less subjective hydrodynamic model of the formation, which, in turn, would reduce the likelihood of an incorrect assessment of the prospects of a "young" field or a field developed at an early stage.

At the present stage of the oil industry development, characterized by an increase in the share of unconventional reserves, the number of complicated wells, the cost of oil production and, as a consequence, an increase in requirements for the accuracy of production accounting and the use of energy and resource-efficient technologies for development and production, in conditions of the need for a multifactorial assessment of development prospects assets, the task of intellectualization of the field comes to the fore, within the framework of which the issues of automation of processes and the introduction of integrated approaches to optimize production, prevention and control of complications, effective management of the development of assets both at the operational and long-term levels are being worked out. An integrated and effective tool for solving the assigned tasks today is an integrated model, which is understood as a model of the well products production (oil, gas, water), which includes all the elements of the production chain in the form of sequentially related component models. Integrated modeling is effectively used in the operational activities of LLC LUKOIL-PERM and is an optimal tool for solving multidisciplinary problems in the field of development and technologies for production, transportation and treatment of oil and gas (using Petroleum Experts software). The experience of using integrated models allows us to talk about a synergistic effect associated with the need to develop related areas and manifested in the growth of specialists' competencies, improving the quality and increasing the volume of initial data, improving the quality of individual components during their integration. A set of measures developed and substantiated using integrated models and their individual components made it possible to obtain additional oil production of more than 21.9 thousand tons.