Research of throwing areols of underground pipeline in permafrost

Study is due to the possibility of loss of stability of the pipeline in the process of pumping a product with a positive operating temperature and the formation of thawing halos. The article presents the ways of solving the thermomechanical problem of pipeline displacement due to thawing. The rate of formation of a thawing halo is investigated depending on the initial temperatures of the soil and the pumped product. The developed monitoring system makes it possible to study the rate of occurrence of thawing halos in the process of pumping the product. An experimental study on the formation of thawing halos around the pipeline was carried out on an experimental model. A thermophysical comparative calculation of temperatures around the pipeline on a model by the finite element method has been carried out. Keywords: underground pipeline; permafrost; thawing halo; monitoring; operating conditions; stress–strain state.

Methodological approaches to increasing the flooding system efficiency at the later stage of reservoir development

Based on the analysis of the efficiency of CVI.1 and CVI.2 oil reservoirs development, which partially coincide in structural terms, and the terrigenous strata of the Lower Carboniferous of one of Volga-Ural oil and gas province oil fields, an algorithm for assessing the efficiency of waterflooding was proposed, which takes into account the geological structure of the facility, the results of core and geophysical well surveys, as well as the historical performance of wells. The presented algorithm makes it possible to identify ineffective injection directions for making decisions on waterflooding system optimizing. The effect is the identified potential to cut costs by reducing inefficient injection, as well as identifying areas for the introduction of enhanced oil recovery techniques. Keywords: field development; reservoir pressure maintenance system; waterflooding efficiency; cost reduction.

Improving the efficiency of organizational design in the oil and gas business

The article discusses a number of topical issues of modern organizational design. Through the analysis of the approaches of Russian and foreign scientists, the factors that need to be taken into account in organizational design are identified. Out of a multitude of factors, we have selected those that have the greatest impact in various options for the market and technological environment for an oil and gas company. Organizational schemes which can be recommended for organizing management in different market conditions are shown. A method to reconcile the influence of the basic and other factors in the organizational design process is proposed. A mechanism for constructing an organizational structure in modern conditions in oil and gas companies is proposed. In the conclusion, recommendations on the directions for further research on the problems of building organizational structures are given. Keywords: organizational structure; building organizational structures; competitiveness factors; organizational design.

Methodological approach to optimal geological and technological characteristics determining when planning hydraulic fracturing at multilayer facilities

The paper considers the issue of increasing the hydraulic fracturing efficiency in a multilayer facility at the final stage of development with an uneven degree of reserves development along the section. Based on the results of the analysis, it was found that the upper layers, which have the worst filtration-reservoir properties, are less developed in comparison with the highly productive lower ones. When hydraulic fracturing was carried out in the upper formations, some of the operations had low success due to the breakthrough of hydraulic fractures into the lower depleted formations. On the basis of the revealed dependencies, the work determined the optimal specific loading of proppant per meter of effective power, depending on the geological conditions, and maps of the prospects for hydraulic fracturing are built. Keywords: oil fields development; hydraulic fracturing; hydraulic fracturing optimization; multilayer facilities.

Evolution of hydraulic fracturing fluid: from guar systems to synthetic gelling polymers

The paper presents the possibilities of optimizing technological approaches for performing hydraulic fracturing operations, taking into account the transition from traditionally used chemical components of the process fluid to synthetic gelling polymers. The proposed option makes it possible to reduce the unit costs of operational activities to increase oil production both for new assets of oil and gas producing companies and for assets at the stage of industrial development. The special emphasis of the proposed technological solutions is correlated with the environmental Agenda for Sustainable Development until 2030, aimed at transforming the production processes of the energy complex to reduce the ecological footprint of enterprises. A complete set of laboratory studies confirms the prospect of industrial application of synthetic polymer systems and the feasibility of replicating this approach. The subsequent stage of scale-up of pilot tests will allow to have a basis for development and implementation of standards in the oil and gas industry. Keywords: oil; well; hydraulic fracturing; chemicals; synthetic gelling polymers.

Application of geophysical methods in the extrapolation of sedimentological data on unmastered areas of deposits (on the example of Pennsylvanian carbonate reservoir, Akanskoye oilfield, east of Russian Platform)

A feature of the oil-bearing carbonate deposits of the lower Pennsylvanian in the east of the Russian platform is their rapid vertical and horizontal change. It is often difficult to make correlations between sections, especially in the absence of core data when using only geophysical data. In addition, not all facies are reliably identified and traceable from log data and not all have high reservoir properties. Authors made an attempt to trace the promising facies both to adjacent wells and, in general, to the entire field area using core study results and translation of these results using log and seismic data. The data showed pinching of rocks with high reservoir characteristics in the direction of the selected profile (from south to north within the field). Coastal shallow water facies, represented by Grainstones and Packstones, with high reservoir properties in the south of the field, are replaced by lagoon facies and facies of subaerial exposures, represented by Wakestones and Mudstones with low reservoir characteristics, in the north of the field. The authors suggest that this approach can be applicable for rocks both in this region and for areas with a similar structure. Keywords: pinch-out; well data; seismic data; limestone; facies; reservoir rocks.

Review of studies on plugging compositions creation with controlled rheological properties and the ability to restore fluidity for completion, workover and abandonment of oil and gas wells

The main purpose of cementing oil and gas wells is zonal isolation of the formations exposed by the wellbore. During the entire life of the well, there should be no uncontrolled hydraulic communication between the developed formations and the surface, regardless of the composition and type of fluid (water, oil or gas). During the operation of the well, in addition to constant static ones, the casing and cement stone also experience various dynamic loads. The article presents an up-to-date review of experimental studies on the modification of grouting compositions and cement composites capable of autonomous selfhealing due to the introduction of various additives and nanomaterials. Such modification technologies significantly increase the tightness and resistance of cement to the effects of dynamic loads, the integrity of the cement stone. As a replacement for traditional cement materials, the authors propose the creation of grouting compositions with controlled physical and mechanical properties and the possibility of their re-liquefaction under the influence of temperature on the basis of bitumen or bitumen composites. Keywords: well plugging and abandoning; self-healing materials; autonomous self-healing; casing durability; impermeability of the cement stone; self-healing cement; bitumen and bitumen composites.

Carbonate oil and gas source rocks wettability alteration due to influence of polymer-colloidal drilling mud

Evaluation of rock wettability is an important task, since this parameter determines the distribution of water and oil in the reservoirs and their relative and phase permeability. The reliability of evaluation the wettability of rock samples depends on the drilling-in conditions during core sampling and core sample preparation methods. The investigation of the surface properties of the core from the Orenburg oil and gas condensate field showed that using of polymer-colloidal drilling mud leads to hydrophilization of the samples' surface. To obtain information on the actual wettability values of rock samples taken from wells drilled with polymer-colloidal drilling mud a method for estimating the relative (predominant) wettability of rocks based on petrophysical and lithological studies data is proposed. The authors suggest that the extraction of oil and gas source rock samples leads to irreversible changes in surface properties that cannot be restored. Keywords: selective wettability; relative wettability; predominant wettability; polymer-colloidal drilling mud; residual gas saturation; trapped gas saturation; pore space structure; extraction.

The expansion of innovative activity on rise of oil production enterprises in Azerbaijan

The article analysis the oil and gas production condition in the Republic on basis of statistical data of many years as well as the level of investment provision. The article estimates the structure of expenses on innovative techniques, the condition of exploitation of oil and gas boreholes, the implementation of geological and technological actions, the ways of exploitation methods as well as the methods of ledge effects and influence on extra oil production. It also shows up the reserves and ways of their rational usage. Keywords: innovative activity; geological and technological actions; oil and gas; well.

Prospects for the application of proppant hydraulic fracturing at Kashiro-Verey operational facilities Volga-Ural oil and gas province

The geological structure of Kashiro-Verey carbonate deposits is considered on the example of one of the deposits of the Perm Region. By combining geophysical studies of wells, standard and tomographic studies of core, the following lithotypes of carbonate rocks were identified: highly porous cavernous, layered heterogeneous porous, heterogeneous fractured porous, dense. It was found that for heterogeneous lithotypes, the porosity estimate in the volume of the permeable part of the rocks significantly exceeds 7%. Experiments on the destruction of rocks were carried out for the selected lithotypes. As a result, it was found that cracks do not form for samples of the cavernous lithotype at a compression pressure of 20 MPa. For a compacted lithotype, already at a compression pressure of more than 10 MPa, an intensive development of fracturing occurs. As a result of multiaxial loading of cores, which can be considered as analogous fracturing of the formation, wide fractures are formed, along which filtration of fluids can occur. Keywords: proppant hydraulic fracturing; X-ray tomography of the core; porosity; permeability; fractured reservoir; oil deposit; carbonate deposits.