THE BASIC TYPES OF SECONDARY CHANGES IN RESERVOIR ROCKS IN THE TERRITORY OF THE WEST SIBERIA PLATE

2015 ◽  
pp. 26-30
Author(s):  
A. V. Podnebesnykh ◽  
S. V. Kuznetsov ◽  
V. P. Ovchinnikov
Keyword(s):  
Oil Recovery ◽  
West Siberia ◽  
Recovery Factor ◽  
Change Processes ◽  
The West ◽  
Reservoir Rocks ◽  
Tectonically Active ◽  
Porosity And Permeability ◽  
Active Zones ◽  
Regional Character

On the example of the group of fields in the West Siberia North the basic types of secondary changes in reservoir rocks are reviewed. Some of the most common types of such changes in the West Siberian plate territory include the processes of zeolitization, carbonation and leaching. These processes have, as a rule, a regional character of distribution and are confined to the tectonically active zones of the earth's crust. Due to formation of different mineral paragenesises the secondary processes differently affect the reservoir rocks porosity and permeability: thus, zeolitization and carbonization promote to reducing the porosity and permeability and leaching improvement. All this, ultimately leads to a change of the oil recovery factor and hydrocarbons production levels. Study and taking into account of the reservoir rocks secondary change processes can considerably influence on placement of operating well stock and on planning of geological and technological actions.

scholarly journals Generation of authigenic clay minerals during diagenesis and their influences on porosity and permeability of Oligocene sandstone reservoir rocks, from a well in the west of Cuu Long basin

2014 ◽  
Vol 17 (3) ◽  
pp. 21-26
Author(s):  
Toan Minh Ho ◽  
Phuong Kim Lieu ◽  
Thuy Thi Doan ◽  
Phuong Thi Ngoc Bui
Keyword(s):  
Clay Minerals ◽  
Fluid Flows ◽  
Reservoir Rock ◽  
Burial Depth ◽  
High Porosity ◽  
Pore Waters ◽  
The West ◽  
Reservoir Rocks ◽  
Porosity And Permeability ◽  
Sandstone Reservoir

Porosity and permeability play a prerequisite role for hydrocarbon reservoirs and fluid flows, especially in sandstone reservoir rocks. The rocks with high porosity decrease down to lower porosity with increasing burial depth due to compaction, cementation and precipitation of authigenic minerals in pores from over saturated solution of minerals. The detailed study of the authigenic clay mineral formation in pore spaces of sandstone reservoir rocks is therefore crucial to estimate the degree of reservoir rock quality. In this study 20 sandstone cores taken from the interval burial depths of 3,700 m - 4,200 m from Oligocene sandstone sequence of a well in the West of the Cuu Long basin, offshore Vietnam, were analyzed by SEM and thin section. Authigenic clay minerals were formed due to temperature and chemistry changes and owing to dissolution of less stable minerals in these burial depths. Authigenic chlorite mineral appears quite abundantly and illite is less frequently. Chlorite was formed from the elements Al and Si, which were released from dissolved grains and Fe and Mg supplied from breakdown of the ferromagnesian minerals of rock fragments and matrix components into pore waters in the burial stage. Illite is associated with the expense of grain dissolution of feldspar, volcanic fragment. Chlorite mostly appears as a coating or mats comprising of small pseudo-hexagonal crystals arranged perpendicular to detrital grain surfaces. Grainrimming chlorites on quartz grain are responsible for the preservation of the porosity in the sandstones because they limit the formation of quartz overgrowth. Additionally fibrous or flaky illite bridging the pores between the grains creates permeability barriers to fluid flows through the sandstones. Thus illite significantly reduces the permeability but to lesser extent affect porosity. Locally, smectite mixes with illite or chlorite and is not abundant in the studied samples. It therefore has no significant impact on the porosity and permeability as well. The variations of the porosity and the permeability of the studied sandstones depend on the generated degree and the arranged patterns of chlorite and illite in pore spaces.

New records of aphyllophoroid fungi (Basidiomycota) for the Khanty-Mansi Autonomous Area — Yugra (West Siberia)

2020 ◽  
Vol 54 (2) ◽  
pp. 387-396
Author(s):  
I. V. Stavishenko
Keyword(s):  
Animal Ecology ◽  
New Records ◽  
West Siberia ◽  
The West ◽  
First Time ◽  
Khanty Mansi Autonomous ◽  
Aphyllophoroid Fungi

The paper provides data on records of 29 species of aphyllophoroid fungi new for the the Khanty-Mansi Autonomous Area — Yugra. Among them 10 species (Amaurodon cyaneus, Amyloxenasma allantosporum, Asterostroma laxum, Byssoporia terrestris, Paullicorticium pearsonii, Pseudomerulius montanus, Sistotrema sernanderi, Skeletocutis alutacea, S. ochroalba, Tubulicrinis orientalis) are published for the first time for Siberia, and 3 species (Scytinostroma praestans, Tomentellopsis zygodesmoides, Tubulicrinis strangulatus) are new for the West Siberia. Data on their locations, habitats and substrates in region are indicated. The specimens are kept in the Museum of the Institute of Plant and Animal Ecology of the Ural Branch of the RAS (SVER).

Genetic diversity and differentiation of Siberian stone pine populations at the southern range margin in the West Siberia lowland area

2015 ◽  
Vol 5 (5) ◽  
pp. 449-459
Author(s):  
E. A. Petrova ◽  
S. N. Velisevich ◽  
M. M. Belokon ◽  
Yu. S. Belokon ◽  
D. V. Politov ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
West Siberia ◽  
Stone Pine ◽  
The West ◽  
Siberian Stone Pine ◽  
Range Margin ◽  
Siberian Stone ◽  
Lowland Area

Pilot Project Evaluating WAG Efficiency for Carbonate Reservoir in Eastern Siberia

2021 ◽  
Author(s):  
Valentina Zharko ◽  
Dmitriy Burdakov
Keyword(s):  
Oil Recovery ◽  
Gas Injection ◽  
Oil Production ◽  
Pilot Project ◽  
Carbonate Reservoir ◽  
Recovery Factor ◽  
Eastern Siberia ◽  
Water Cut ◽  
Wag Injection ◽  
Injection Rates

Abstract The paper presents the results of a pilot project implementing WAG injection at the oilfield with carbonate reservoir, characterized by low efficiency of traditional waterflooding. The objective of the pilot project was to evaluate the efficiency of this enhanced oil recovery method for conditions of the specific oil field. For the initial introduction of WAG, an area of the reservoir with minimal potential risks has been identified. During the test injections of water and gas, production parameters were monitored, including the oil production rates of the reacting wells and the water and gas injection rates of injection wells, the change in the density and composition of the produced fluids. With first positive results, the pilot area of the reservoir was expanded. In accordance with the responses of the producing wells to the injection of displacing agents, the injection rates were adjusted, and the production intensified, with the aim of maximizing the effect of WAG. The results obtained in practice were reproduced in the simulation model sector in order to obtain a project curve characterizing an increase in oil recovery due to water-alternating gas injection. Practical results obtained during pilot testing of the technology show that the injection of gas and water alternately can reduce the water cut of the reacting wells and increase overall oil production, providing more efficient displacement compared to traditional waterflooding. The use of WAG after the waterflooding provides an increase in oil recovery and a decrease in residual oil saturation. The water cut of the produced liquid decreased from 98% to 80%, an increase in oil production rate of 100 tons/day was obtained. The increase in the oil recovery factor is estimated at approximately 7.5% at gas injection of 1.5 hydrocarbon pore volumes. Based on the received results, the displacement characteristic was constructed. Methods for monitoring the effectiveness of WAG have been determined, and studies are planned to be carried out when designing a full-scale WAG project at the field. This project is the first pilot project in Russia implementing WAG injection in a field with a carbonate reservoir. During the pilot project, the technical feasibility of implementing this EOR method was confirmed, as well as its efficiency in terms of increasing the oil recovery factor for the conditions of the carbonate reservoir of Eastern Siberia, characterized by high water cut and low values of oil displacement coefficients during waterflooding.

scholarly journals Numerical Simulation of Two-Phase Flows in Heterogeneous Porous Media

2020 ◽  
Vol 21 (2) ◽  
pp. 339
Author(s):  
I. Carneiro ◽  
M. Borges ◽  
S. Malta
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Flow Behavior ◽  
Water Injection ◽  
Heterogeneous Porous Media ◽  
Flow In Porous Media ◽  
High Porosity ◽  
Two Phase ◽  
Recovery Method ◽  
Porosity And Permeability

In this work,we present three-dimensional numerical simulations of water-oil flow in porous media in order to analyze the influence of the heterogeneities in the porosity and permeability fields and, mainly, their relationships upon the phenomenon known in the literature as viscous fingering. For this, typical scenarios of heterogeneous reservoirs submitted to water injection (secondary recovery method) are considered. The results show that the porosity heterogeneities have a markable influence in the flow behavior when the permeability is closely related with porosity, for example, by the Kozeny-Carman (KC) relation.This kind of positive relation leads to a larger oil recovery, as the areas of high permeability(higher flow velocities) are associated with areas of high porosity (higher volume of pores), causing a delay in the breakthrough time. On the other hand, when both fields (porosity and permeability) are heterogeneous but independent of each other the influence of the porosity heterogeneities is smaller and may be negligible.

scholarly journals Structural connections between Urals and West Siberia: the common stage on the boundary of Permian and Triassic periods

2019 ◽  
Vol 488 (3) ◽  
pp. 294-297
Author(s):  
V. N. Smirnov ◽  
K. S. Ivanov
Keyword(s):  
West Siberia ◽  
Strike Slip ◽  
Middle Urals ◽  
The Urals ◽  
The West ◽  
Open Part ◽  
The Middle Urals ◽  
Eastern Zone ◽  
Structural Connections ◽  
The Common

40Ar/39Ar-dating of the micas from the schists and blastomylonites collected from the fault which separates the Eastern zone of the Middle Urals dipped under the cover of the West Siberian plate from the open part of the geologic structures of the Urals, showed that the last phase of deformation was represented by a submeridional sinistral strike-slip faults with the age of 251 Ma. The appearance of the analyzed deformations practically exactly coincides in time with the formation of the grabens of meridional strike at the base of the West Siberian plate. 

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