Secondary dolomitization as a factor determining the reservoir properties of the Lower Devonian deposits in Eastern edge of the Khoreyver depression (Timan-Pechora basin)

2020 ◽  
pp. 47-56
Author(s):  
V. A. Zhemchugova ◽  
E. E. Maslova
Keyword(s):  
Exposure Time ◽  
Carbonate Rock ◽  
Lower Devonian ◽  
Pore Space ◽  
Key Factors ◽  
Reservoir Properties ◽  
Pechora Basin ◽  
Eastern Edge

The Lower Devonian deposits were characterized in terms of their composition, texture and secondary transformations, the distribution of various types of pore space was analyzed and several types of dolomite textures were identified. The analysis showed that permeability, solubility and primary texture of carbonate rock or sediment, as well as temperature, volume and exposure time of dolomitizing fluids are key factors for dolomitization and depending on these factors dolomitization can lead to not only increase but also decrease of porosity.

Investigation on On-Board High-Pressure Composite Tanks Subjected to Localized and Engulfing Fire

2012 ◽  
Author(s):  
Kesheng Ou ◽  
Jinyang Zheng ◽  
Yongzhi Zhao
Keyword(s):  
High Pressure ◽  
Exposure Time ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Fire Exposure ◽  
Key Factors ◽  
Activation Time ◽  
Thermally Activated ◽  
Tank Pressure ◽  
Composite Tank

Safety performance of on-board high-pressure composite tanks under fire exposure has drawn extensive attention. Vehicle fires usually lead to such tanks experiencing a term of localized and engulfing fire. During this period, the composite tank would be degraded and even burst before pressure relief device (PRD) opens to release internal high-pressure gas. In this paper, experimental investigation for the tanks subjected to localized and engulfing fire was conducted on an Aluminum liner composite tank filled with hydrogen. Based on the temperature distribution and pressure rise measured in the experiment, a three-dimensional computational fluid dynamics model is developed to study the key factors influencing PRD activation time. The effects of filling medium, tank pressure and localized fire exposure time are analyzed in detail. The experimental results showed that pressure and temperature of internal gas changed little during the localized fire. In addition, filling medium and tank pressure have weak influence on the activation time of thermally-activated PRD (TPRD), but have significant effect on the activation time of pressure-activated PRD. TPRD can respond more quickly to protect the hydrogen composite tank than pressure-activated PRD. PRD activation time increases as the localized fire exposure time extends.

Effets de la texture petrographique sur les proprietes petrophysiques d'un calcaire en zone de diagenese meteorique (calcaire oligocene d'Aquitaine, France)

2000 ◽  
Vol 171 (4) ◽  
pp. 419-430 ◽  
Author(s):  
Adrian Cerepi ◽  
Louis Humbert ◽  
Rene Burlot
Keyword(s):  
Porous Medium ◽  
Specific Surface ◽  
Pore Space ◽  
Space Complexity ◽  
Petrophysical Properties ◽  
Chemical Analyses ◽  
Reservoir Properties

Abstract 120 samples of three quarries of the Oligocene Aquitaine limestone were subjected to petrographic, petrophysical and chemical analyses. Strong variations of depositional and diagenetic textures were observed. Four main depositional textures characterize this limestone: mudstone-wackestone, packstone, packstone-grainstone and grainstone. The diagenetic transformations recognized and specially meteoric leaching increases the heterogeneity of porous medium. The "Pierre de Bordeaux" shows a high variation of porosity (12,8 % to 42,51%), permeability (4,27 to 4755 mD), specific surface (0,78 to 3,73 m 2 /g) and distribution of pore throats (from monomodal to three modal distribution). Petrophysical properties depend strongly on depositional and diagenetic patterns. Textures with two and three modal distribution of porous medium, packstone-grainstone and grainstone have the best reservoir properties. The meteoric dissolution associated to microfracturing improves strongly both the macroporosity, permeability in mudstone-wackestone and packstone and increases the pore space complexity in all textures.

scholarly journals Silurian and Lower Devonian petroleum source rocks of the Chernov Ridge (Timan-Pechora Basin, Russia)

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
I.S. Kotik ◽  
◽  
O.S. Kotik ◽  
O.V. Valyaeva ◽  
L.V. Sokolova ◽  
...  
Keyword(s):  
Lower Devonian ◽  
Source Rocks ◽  
Pechora Basin

scholarly journals Refinement of the petrophysical model of the Achimov formation based on facial analysis of sedimentation conditions

2021 ◽  
Vol 6 (4) ◽  
pp. 22-31
Author(s):  
Guzel R. Vahitova ◽  
Anzhela A. Kazaryan ◽  
Timur F. Khaybullin
Keyword(s):  
Oil And Gas ◽  
Facies Analysis ◽  
Pore Space ◽  
Sedimentary Cover ◽  
Clay Content ◽  
Geological Structure ◽  
Space Structure ◽  
Reservoir Properties ◽  
The Core ◽  
Promising Source

Aim. Due to the depletion of reserves of the main oil and gas complexes, the greatest interest is attributed to hard-to-recover reserves, complex-built objects of the sedimentary cover, the development of which was unprofitable until recently. One of these is the oil-bearing complex of the Achimov deposits of the Malobalykskoye field in Western Siberia. This article is devoted to the facies analysis and typification of reservoir rocks of the Achimov deposits in order to increase the reliability of determining the boundaries of the reservoirs, their interpretation and assessment of the petrophysical properties of the reservoirs. At the same time, special attention is paid to the facies analysis, which determines the characteristics of the reservoir. The Achimov deposits are a promising source of increasing resources and maintaining production at a high level. With their increasing importance, there are problems that complicate the search and assessment of deposits. Such problems include a high degree of reservoir compartmentalization, sharp facies variability, complex pore space structure, high clay content, low permeability values, etc. Materials and methods. The work is based on a comprehensive interpretation of the data of the lithological description of the core, the results of laboratory studies of the core and well logging data analysis of the Achimov deposits of the Malobalykskoye field. The methods used in the interpretation of GIS data, statistical analysis, comparison. Due to the fact that the reservoir properties of sand bodies are determined by the peculiarities of their formation in different conditions of sedimentation, it is necessary to establish a relationship between the petrophysical characteristics of rocks and their facies nature by substantiating petrofacies models. The use of the latter in geological modeling makes it possible to more effectively predict the reservoir properties (reservoir properties) of various facies lithotypes. Results. The paper presents the results of facies analysis and typification of the reservoirs of the Achimov deposits of the Malobalykskoye field, on the basis of which the boundaries of the reservoirs and the effective oilsaturated thicknesses were refined. Conclusions. Based on the results of the study, it can be concluded that it is necessary to develop refined petrophysical models for reservoirs with complex geological structure that take into account the facies features of rocks.

Petroelastic Modeling of Complex Lithology Fields: Case Study

2021 ◽  
Author(s):  
Anastasiia Spirina ◽  
Evgeniy Cherepanov
Keyword(s):  
Pore Space ◽  
Complex Structure ◽  
Geophysical Methods ◽  
Core Sample ◽  
Reservoir Properties ◽  
Production Water ◽  
High Production ◽  
Water Cut ◽  
Effective Models ◽  
Component Models

Abstract The present-day growth of petroleum reserves, maintaining and enhancing of oil production is associated with involving of complex fields into production (Uspenskaya, 2014). The complex structure of the study areas of the Urai Region (facies variability, formation replacement, fracturing, crushing and cleavage zones, complicated structure of the pore space) makes conventional forecast of reservoir properties ineffective. Moreover, the pay formations are highly exhausted with high production water cut. Therefore, the search of prospective targets is relevant in the Urai Region. The article shows generalized results of petroelastic modeling of several fields of the Urai Region for solving the following tasks: ○ Lithology, saturation and poroperm properties forecast of reservoir rocks from log and seismic data; ○ Development of 1D mechanical earth models (MEM) of horizontal well sections and their maintenance while drilling horizontal wells. The approach is based on the principles of integrating different-scale geological and geophysical studies. The lithological division of rocks was carried out, the saturation behavior and point-by-point interpretation of the data of geophysical methods of well logging (WL) were identified. 3D component models were built with taking into account the lithological features of the section using core sample studies. Effective models for the environment of sediments of interest were selected and petroelastic modeling was carried out.

scholarly journals The key factors controlling reservoir quality of the Middle CambrianDeimena Group sandstone in West Lithuania

2002 ◽  
Vol 49 ◽  
pp. 25-39
Author(s):  
Linas Kilda ◽  
Henrik Friis
Keyword(s):  
Early Stage ◽  
Clay Fraction ◽  
Oil Fields ◽  
Reservoir Quality ◽  
Key Factors ◽  
Reservoir Properties ◽  
Carbonate Cement ◽  
Commercially Important ◽  
Early Carbonate

Sandstones of the Middle Cambrian Deimena Group are commercially important as they make up the largest part of the hydrocarbon-bearing reservoir in 15 oil fields discovered in West Lithuania. However, the sandstones are characterised by a very complicated spatial distribution of reservoir quality. In order to better understand the distribution of reservoir properties and their controlling parameters, eighty-two sandstone samples from twenty-one boreholes were studied by means of thin section description, scanning electron microscopy, using backscattered and cathodoluminescence modes and clay fraction analyses. Generally, the sandstones are strongly cemented by quartz, resulting in almost total destruction of porosity but porous domains with preserved early stage quartz cement occur in a complex pattern. The close location of the early and late stage overgrowth types indicates that some sandstone parts were preserved from intense authigenic quartz precipitation. We believe that early carbonate cement was such an inhibitor. Detrital quartz grains in carbonate cemented domains are mostly free of authigenic quartz and as a rule show weakly compacted fabric as compared to the quartz cemented parts. Moreover, large secondary pores are located close to the carbonate cemented domains and indicate that some carbonate cement eventually dissolved. Apparently, the best reservoir properties within the generally strongly quartz cemented Deimena Groupsandstones are found in domains where dissolution of the early carbonate cement took place.

scholarly journals Petroleum source rocks of the Silurian deposits on the Chernov swell (Timan‑Pechora basin)

Georesursy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 12-20 ◽  
Author(s):  
Ivan S. Kotik ◽  
Tatyana V. Maidl ◽  
Olga S. Kotik ◽  
Natalia V. Pronina
Keyword(s):  
Organic Matter ◽  
Shallow Water ◽  
Carbonate Rock ◽  
Source Rocks ◽  
Pechora Basin ◽  
Low Concentrations ◽  
Oil Generation ◽  
Rock Eval ◽  
Source Of Information ◽  
Carbonate Deposits

Silurian source rocks are among the least studied in the Timan-Pechora basin. This is mainly due to their occurrence at great depths (3.0–4.5 km) and the limited penetration of this stratigraphic interval by wells. Another source of information is the outcrops of the Silurian, which are known in the eastern and northeastern parts of the Timan-Pechora basin. The studied section of the Silurian deposits is exposed on the Padimeityvis River, located on the Chernov swell in the northeastern part of the basin. This article is devoted to the study of Silurian source rocks based on the results of lithological, coal petrographic studies and geochemistry of organic matter. The studied section is composed of carbonate and clay-carbonate deposits formed in shallow-water shelf conditions. Most of the section, composed of microcrystalline and microcrystalline with bioclasts limestones, is characterized by low concentrations of organic matter (Corg is generally less than 0.3 %). Elevated Corg contents (up to 1.16 %) are characteristic of clay-carbonate rock varieties, which make up about 20 % of the section. Sediments with increased concentrations of organic matter were formed in isolated and deepened areas of the bottom of the shallow-water basin as a whole. Assessment of the catagenetic transformation based on Rock-Eval pyrolysis data, coal petrographic studies, and conodont color indices showed that organic matter reached the conditions of the middle-end of the main oil generation zone (gradation MC2‑MC3). The obtained geochemical characteristics (Corg, S2, HI), taking into account a certain level of organic matter maturity, indicate that the Silurian source rocks had an average hydrocarbon potential.

scholarly journals RELATIONSHIP OF COMPLEX DIELECTRIC PERMEABILITY AND NMR CHARACTERISTICS OF DRILL CUTTINGS WITH ITS RESERVOIR PROPERTIES

2021 ◽  
Vol 2 (2) ◽  
pp. 162-167
Author(s):  
Andrey A. Mezin ◽  
Mariya Y. Shumskayte ◽  
Nikita A. Golikov
Keyword(s):  
Pore Space ◽  
Experimental Studies ◽  
Dielectric Permeability ◽  
Degree Of Saturation ◽  
Fluid Distribution ◽  
Reservoir Properties ◽  
Drill Cuttings ◽  
Relationship Of

The paper presents the results of experimental studies of the dielectric and NMR characteristics of drill cuttings. It is shown how the fluid distribution in the pore space changes at different stages of extraction and saturation. It is shown that it is possible to estimate the degree of saturation of samples by sequential interpretation the spectra of the dielectric and NMR characteristics.

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