Improving the carbonate reservoirs development efficiency on the example of the Tournaisian stage deposits

The article deals with the issue of carbonate strata of complex geological structure development efficiency improving. Such facilities, as a rule, have deteriorated reservoir properties, parameter anisotropy and are complicated by secondary cavernosity. All of these factors affect the recovery efficiency and are often reflected in development indicators. On the example of Tournaisian stage deposits an example of a methodological approach to the development analysis which takes into consideration various geological factors is presented. As a result, various dependencies were obtained, which when taken into account determin the most promising areas in terms of development efficiency. The issues of the waterflooding system efficiency and the ways of its efficiency increasing are considered separately. Keywords: oil fields development; carbonate reservoirs; development efficiency; waterflooding system.

Comprehensive study of the geological structure Verkhneyakovlev deposits of the Tagul field in the process of justifications for operational drilling

Currently, most of the fields being put into development are characterized by a complex geological structure, both in terms of section and in terms of plan. The solution of all geological tasks, including such important ones as the preparation of exploration projects, operation and effective development management, is impossible without creating models that reflect the main features of the variability of target parameters. The construction of adequate models of objects with a complex structure requires the involvement of all available information. The accuracy of the geological model is mostly determined by the accuracy of the well correlation. Paleosols are a new marker for the complex-built layers of the VAk-2 and VAk-3(1) of the Tagul field, which contributes to the validity of the correlation of the section of these layers. The reliability of the model was also improved by the use of the results of facies analysis. This analysis showed that the sedimentation of the studied objects includes channel and floodplain facies. Reservoir rock properties of these facies differ significantly. The updated model is characterized by a reduction in the oil-bearing area and the amount of reserves. The implementation of the model will optimize the project fund of wells and reduce the cost of well intervention. Economically, this means reducing capital costs and increasing the profitability of the project.

ANALYSIS OF FRACTION CONTENTS IN ROCK SCRATCH TESTS FOR ESTIMATING THE ANGLE OF INTERNAL FRICTION FOR THE SEDIMENTARY COVER OF THE KOVYKTA FIELD

The article describes the possibility of using the granulometric analysis of rock cuttings formed in controlled core scratching tests to estimate the angle of internal friction.The study object is the Kovykta gas-condensate field (GCF) that occupies a wide area in the southeastern part of the Irkutsk amphitheater of the Siberian platform. This uniquely complex geological structure holds significant reserves of hydrocarbons. Its sedimentary cover is composed of the Vendian – lower Paleozoic and partly Riphean formations. Their total thickness exceeds 6000 m, as estimated from the new seismic survey data [Vakhromeev et al., 2019].The sedimentary cover of the Kovykta GCF has been studied by surface and borehole geophysical techniques, remote sensing and geostructural methods, in combination with the tectonophysical approach [Seminsky et al., 2018] based on drilling data, including standard and special core sampling data.

Explosive Fragmentation of Rock Masses with Heterogeneous Structure

A method to optimize drilling and blasting parameters with account of the physical and technical properties of rocks within the blasted block is proposed to improve the quality of blasting in open pit mines characterized by complex geological settings. The results of laboratory tests are provided that confirm improvement in the quality of rock sample crushing by blasting charges with variable delays and locations, depending on the strength properties of the samples, relative to blasting charges with unchanged parameters. The proposed method can be used in combination with GPR surveys of the rock mass. Explosive fragmentation of the rock masses with complex structures is characterized with a number of features caused by changes in the strength properties within the blasted block. In order to optimize the fragmentation efficiency of rock masses with complex geological structure, it is required to assess physical and technical properties of rocks and to determine their location and variations of the strength properties within the blasted block. It is possible to quickly assess the physical and technical properties of the blasted rocks using the surface georadar method. The outcome of this method is georeferencing of the reoradar data to the location and properties of the rocks to be blasted, along with the methodology of applying the georadar surveys, selection of the areal assembly type depending on the size and properties of detected jointing, and economic justification of applying this method. The novelty consists in linking the georadar data on the rocks to be blasted with drilling and blasting parameters.

Analisis Parameter Gempabumi Dengan Struktur Geologi Di Daerah Asparaga, Gorontalo

Gorontalo is an area located in the North Arm of Sulawesi which has a complex geological structure as a result of the submergence of the Sulawesi Sea and East Sangihe so that this area is considered an earthquake-prone area. The existence of the regional structure and the mapping of the earthquake point distribution is interesting to be studied more deeply because it affects seismic activity in the area. The purpose of this study is to analyze earthquakes in the Asparaga area based on their depth and magnitude and to relate them to the geological structures found in the study area. The earthquake data used were obtained from USGS. Satellite image data used is the SRTM satellite image. Earthquake data is mapped to produce depth maps, magnitude maps, and earthquake zoning maps. Lineament data were processed using a rosette diagram. Lineament can reflect the morphology observed on the earth's surface as a result of the activity of geological forces. The results showed that the Asparaga area had shallow earthquake depths and moderate to large magnitudes. The focus of the earthquake was right on the path traversed by the geological structure and its relatively northwest-southeast direction. The geological structure in the research location is the epicenter of the earthquake because it is crossed by regional geological structures.

GEOLOGICAL STRUCTURE OF A SEGMENT IN THE CHORNA TYSA RIVER BASIN (UKRAINIAN CARPATHIANS), A HIGH-POTENTIAL SITE FOR RECREATION AND TOURISM

The segment has a rather complex geological structure. The Svydovets massif is characterized by a complex division of structural overthrust sheets – Dukliansky, Porkuletsky and Chornohirsky overthrusts. The northern part of the site is located in the Slavsko-Verkhovynsky subzone of the Krosno zone. The Dukliansky overthrust represents Svydivets and Blyznytsia subzones, the Porkuletsky overthrust represents the Luzhansky subzone, and Chornohirsky – Yalovychorsky or Hoverliansky subzones. Each overthrust sheet shows the presence of ridgelike anticlinal folds that are deformed by thrusts and faults in fold parts. The Krosno zone is blocked by the thrusts of the Dukliansky and Chornohirsky overthrust sheets. A significant area within the study segment is occupied by the Inner Gorgans (near the water divide), which are confined to the raised base of the Silesian sheet, where the Gorgan folds were formed. The main morphostructural element is the massive Bratkivsky ridge, whose structure is dominated by resistant rocks of the Paleocene and Eocene, in particular the sandstones of the Yamna and Vyhodsky suites. The territory of the Chorna Tysa basin upper part is located in a seismic zone where resonant earthquakes of magnitude 4-6 periodically occur. Slow tectonic movements in this area are +1.5 –2.0 mm per year. Apart from analyzing the geological structure of the Chorna Tysa basin segment, which is a promising area for recreation and touristic development, this paper aims to outline the possibilities of using the geological structure and relief to develop educational forms of tourism, including geotourism. It is most often the geological structure (tectonics, diversity of rocks, long history of geological development, formation of mountain relief, etc.) that creates attractive sites – picturesque landscapes, outcrops of rocks, peaks, relict landforms, waterfalls, gregots, i.e., massive rock stream accumulation, and others). It can thus be concluded that the geological structure is crucial in forming promising tourism and recreation proposals and in the development of prospective infrastructure. Therefore, it is imperative to keep in mind the geological structure and landforms, when planning the development of recreation and tourism. Key words: geological structure (tectonics and lithology); landform, recreation and tourism; geotourism; geotourism attractions; Chorna Tysa; Ukrainian Carpathians.

Productivity Criteria for Complex Reservoirs Based on the Study of Deep-Adsorbed Gases

The work is devoted to the development of geochemical criteria for determining the nature of saturation for deep-adsorbed gases in the core. As the object of investigation used the core material selected in the fields in the Nadym-Pyrskoy oil and gas field. In each sample, 72 components were determined, namely, hydrocarbons of different material groups: normal, branched, polycyclic, and aromatic compounds from butane to dodecane. With respect to the quantitative distribution and correlation among the components, qualitative geochemical indicators of sediment productivity have been developed. The saturation character established by the criteria of deep-adsorbed gases was confirmed by the test results. In this regard, this research method significantly increases the effectiveness of diagnostics of prospective deposits, the application of which is relevant in the territory of the West Siberian oil and gas basin, especially when studying deep-submerged deposits of complex geological structure.

APPLICATION OF A MULTIDIMENSIONAL DETERMINISTIC-STATISTICAL NUMERICAL CORRELATION MODEL TO REFINE THE STRUCTURE OF THE AS11 HORIZON OF THE ZAPADNO-KAMYNSKOYE FIELD

One of the primary and significant tasks in the construction of geological models of oil and gas reservoirs and development facilities is the problem of correlation of productive layers. This task, as a rule, is reduced to the identification and areal tracing of presumably even-aged oil and gas strata, horizons, and layers characterized by clear boundaries between sand strata and clay layers overlapping them. The practice of work related to modeling the structure of oil and gas horizons, layers and strata indicates that the correlation is not always unambiguous. The ambiguity is especially noticeable when correlating strata characterized by a clinoform structure, one of the examples is the Achimov strata. The most reliable basis for well correlation is GIS materials and lithological features of the interlayers forming individual layers. Clay interlayers and clay strata separating productive deposits provide valuable information when choosing a correlation model in sedimentary sections. These interlayers are characterized by the greatest consistency in area and are most clearly displayed on geophysical diagrams by the nature of the drawings of GIS curves. However, even in this case, i. e. when using the entire accumulated volume of the most diverse lithological and field-geophysical information, the correlation models of the sections turn out to be different and often even opposite. In this paper, the authors had to face a similar situation when correlating the horizon AS11 of the Zapadno-Kamynskoye field. The paper describes a method for clarifying the position of the chops of the productive horizon of oil and gas deposits using a multidimensional deterministic-statistical numerical model of the correlation of sedimentary strata. The proposed approach allows us to uniquely determine the positions of the chops in the conditions of a complex geological structure of the object, high thin-layered heterogeneity. A concrete example shows the advantages of the proposed approach in comparison with the traditional one.

GEOLOGICAL AND GEOMORPHOLOGICAL RESEARCH METHODOLOGY FOR METALLOGENIC PURPOSES

The basic questions of the methodology of geological and geomorphological study (ore geomorphology, morphostructural analysis, morphotectonics, neotectonics) of ore-bearing territories are considered. The concepts of "geomorphologic systems organization element" as the smallest particle of matter preserving the structure and properties of a mineral, as well as "objectives", "objects" and "subjects" of morphostructural and morphotectonic studies for solving problems of metallogeny have been formulated. In areas with complex geological structure, it is recommended to carry out complex of morphostructural and morphotectonic works with repeated solution of direct and inverse problems: relief and geological environment, geological environment relief. This will make it possible to establish the totality of available deterministic and chronological relations between landforms and structural elements of the lithosphere. Along with the solution of traditional problems of ore geomorphology, it is proposed to use the developed original complex of morphostructural and morphotectonic studies.