scholarly journals Study of the lithological characteristics of Domanic deposits of the Pervomayskoe field

Georesursy ◽  
2018 ◽  
Vol 20 (4) ◽  
pp. 324-330
Author(s):  
A. Takhauov ◽  
A. Titov
Keyword(s):  
Organic Matter ◽  
Microscopic Analysis ◽  
Oil Field ◽  
Core Material ◽  
Sharp Change ◽  
Reservoir Properties ◽  
The Core ◽  
The North ◽  
Lithological Composition ◽  
Rock Eval

The paper presents the results of studying rocks of the domanic horizon of the Pervomayskoe oil field represented by core material of the well 467D. In tectonic terms, this well, like the entire Pervomayskoe field, is confined to the axial part of the Kama-Kinel deflection system on the territory of the North-Tatar arch. Administratively, the Pervomayskoe deposit is located on the territories of the Elabuga, Mendeleevsky and Tukaevsky districts of the Republic of Tatarstan. To study the core material presented, different studies were conducted, including a macroscopic description of the core; comparison of the studied rocks with well logging data; optical microscopic analysis; X-ray analysis; determination of reservoir properties of rocks; study of organic matter by the Rock-Eval pyrolysis method. Based on the analysis, it was found that the domanic horizon is composed of rocks containing carbonate and siliceous minerals to varying degrees, occasionally including minor mixtures of other minerals. The section of rocks is characterized by a sharp change in the lithological composition with a thickness of interlayers of several centimeters. According to Rock-Eval data, carbonate-siliceous interlayers have a high content of organic matter. Organic matter in Domanic deposits is characterized as immature and is found in rocks in the form of kerogen.

scholarly journals Types of reservoirs of the Ufa stage of the Republic of Tatarstan. Genesis and reservoir properties

Georesursy ◽  
2018 ◽  
Vol 20 (4) ◽  
pp. 331-335
Author(s):  
R. Vafin ◽  
R. R.R. Khaziev ◽  
L. Anisimova ◽  
K. Koluzaeva
Keyword(s):  
Oil Field ◽  
Core Material ◽  
Carbonate Sediments ◽  
Reservoir Properties ◽  
Fine Grained ◽  
The North ◽  
Viscous Oil ◽  
Western Border ◽  
The Republic ◽  
North And South

In this paper, we studied core material from well No. 15 of the extra-viscous oil field, geographically located within the western border of the South Tatar arch. Under laboratory conditions, reservoir properties (porosity, permeability), oil saturation and particle size distribution of Sheshmin sandstones were measured. It was established that the terrigenous reservoir belongs to class I and II according to the classification of A.A. Hanin, with high permeability. In addition, in well No. 15 , a downward trend was identified in reservoir properties downstream of the section, the reason for which is probably the migration of underlying formation waters from carbonate sediments of Sakmar age. By analyzing the grain size data distribution, the reservoir is represented by well-sorted fine-grained sandstone with a dominant fraction of 0.1-0.25 mm (about 65% of the entire sample); paleodynamic analysis was carried out using the Passega diagram; It was established that the formation of the reservoir took place under conditions of gradation suspension (P-Q-R area in the diagram), in the lower parts of fast river flows, directly at the bottom. The findings are consistent with data from previous researchers. According to the study of the cores of other wells, maps of changes in reservoir properties have also been constructed, which highlighted reservoir zones with high reservoir properties – the central parts of the North and South Uplifts.

scholarly journals A Mesoproterozoic iron formation

2018 ◽  
Vol 115 (17) ◽  
pp. E3895-E3904 ◽  
Author(s):  
Donald E. Canfield ◽  
Shuichang Zhang ◽  
Huajian Wang ◽  
Xiaomei Wang ◽  
Wenzhi Zhao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Time Window ◽  
Iron Formation ◽  
The North ◽  
Fe Oxidation ◽  
Organic Biomarkers ◽  
Rock Eval ◽  
Fe Reduction ◽  
Rule Out ◽  
Xiamaling Formation

We describe a 1,400 million-year old (Ma) iron formation (IF) from the Xiamaling Formation of the North China Craton. We estimate this IF to have contained at least 520 gigatons of authigenic Fe, comparable in size to many IFs of the Paleoproterozoic Era (2,500–1,600 Ma). Therefore, substantial IFs formed in the time window between 1,800 and 800 Ma, where they are generally believed to have been absent. The Xiamaling IF is of exceptionally low thermal maturity, allowing the preservation of organic biomarkers and an unprecedented view of iron-cycle dynamics during IF emplacement. We identify tetramethyl aryl isoprenoid (TMAI) biomarkers linked to anoxygenic photosynthetic bacteria and thus phototrophic Fe oxidation. Although we cannot rule out other pathways of Fe oxidation, iron and organic matter likely deposited to the sediment in a ratio similar to that expected for anoxygenic photosynthesis. Fe reduction was likely a dominant and efficient pathway of organic matter mineralization, as indicated by organic matter maturation by Rock Eval pyrolysis combined with carbon isotope analyses: Indeed, Fe reduction was seemingly as efficient as oxic respiration. Overall, this Mesoproterozoic-aged IF shows many similarities to Archean-aged (>2,500 Ma) banded IFs (BIFs), but with an exceptional state of preservation, allowing an unprecedented exploration of Fe-cycle dynamics in IF deposition.

scholarly journals The Evaluation of Reservoir Quality of Mishrif Formation in South and North Domes of Buzurgan Oil Field

2019 ◽  
Vol 9 (4) ◽  
pp. 89-106
Author(s):  
Ali Duair Jaafar ◽  
Dr. Medhat E. Nasser
Keyword(s):  
Physical Properties ◽  
Water Saturation ◽  
Oil Field ◽  
Reservoir Quality ◽  
Petrophysical Properties ◽  
The South ◽  
Reservoir Properties ◽  
Formation Evaluation ◽  
The North

Buzurgan field in the most cases regards important Iraqi oilfield, and Mishrif Formation is the main producing reservoir in this field, the necessary of so modern geophysical studies is necessity for description and interpret the petrophysical properties in this field. Formation evaluation has been carried out for Mishrif Formation of the Buzurgan oilfield depending on logs data. The available logs data were digitized by using Neuralog software. A computer processed interpretation (CPI) was done for each one of the studied wells from south and north domes using Techlog software V2015.3 in which the porosity, water saturation, and shale content were calculated. And they show that MB21 reservoir unit has the highest thickness, which ranges between (69) m in north dome to (83) m in south dome, and the highest porosity, between (0.06 - 0.16) in the north dome to (0.05 -0.21) in the south dome. The water saturation of this unit ranges between (25% -60%) in MB21 of north dome. It also appeared that the water saturation in the unit MB21 of south dome has the low value, which is between (16% - 25%). From correlation, the thickness of reservoir unit MB21 increases towards the south dome, while the thickness of the uppermost barrier of Mishrif Formation increases towards the north dome. The reservoir unit MB21 was divided into 9 layers due to its large thickness and its important petrophysical characterization. The distribution of petro physical properties (porosity and water saturation) has shown that MB 21 has good reservoir properties.

GEOCHEMICAL CHARACTERISTIC OF THE SILURIAN ROCKS FROM THE EASTERN PART OF MOLDAVIAN PLATFORM (ROMANIA)

2021 ◽  
Vol 16 (1) ◽  
pp. 17-30
Author(s):  
Octavian COLŢOI ◽  
◽  
Flori CULESCU ◽  
Gilles NICOLAS
Keyword(s):  
Organic Matter ◽  
Geochemical Characteristic ◽  
Petroleum Potential ◽  
The North ◽  
North Eastern ◽  
High Maturity ◽  
Cap Rock ◽  
Rock Eval ◽  
Part Thickness ◽  
North Eastern Part

The scope of this paper is to assess the hydrocarbon potential of Silurian, respectively, the maturity of this stratigraphical interval, based, especially, of the geological and geophysical data derived from eight boreholes located in the north-eastern part of Moldavian Platform - Romania. The main conclusion is that the organic matter contents measured in the core and cutting samples of the different wells are low with the Organic Carbon (TOC) (residual) mainly clearly lower than 1%. Due to the poorness of the sample and the high maturity the petroleum potential and organic matter cannot be assessed. Estimation of the initial TOC allows to differentiate a richer interval at 24 – 27m thick below the top of Silurian. It shows higher TOC with estimated initial TOC reaching 3.6 % weight at the most. The maturity is high and shows a rapid increase with depth between around 2% at 200m and 4% eq. VRr at 1100m. An estimation of the eroded cap-rock is of around 3000m. Mineral carbon content obtained from Rock Eval permits to separate two lithological intervals: carbonated in the upper part (thickness of 250-300m), argillaceous in the lower part.

scholarly journals New data on lithology, organic geochemistry and accumulation conditions of the Bazhenov formation in Western Siberia

Georesursy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Vika G. Eder ◽  
Elena A. Kostyreva ◽  
Anna Yu. Yurchenko ◽  
Natalia S. Balushkina ◽  
Inga S. Sotnich ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbonate Rocks ◽  
Western Siberia ◽  
Organic Geochemistry ◽  
Carbonate Content ◽  
Reservoir Properties ◽  
Bottom Part ◽  
Bazhenov Formation ◽  
Lithological Composition ◽  
Transformation Of Organic Matter

This paper presents data on lithological composition, distribution, reservoir properties, geochemistry of organic matter and genesis of carbonate rocks of the Bazhenov formation within the central part of Western Siberia (the region of the Khantei hemianteclise). The following types of carbonates are distinguished: a) primary biogenic – shell rock interlayers and residues of coccolith; b) dia- and catagenetic – in varying degrees, recrystallized rocks with coccoliths, nodules and aporadiolarites; c) catagenetic – cracks healed with calcite in limestone of the foot of the Bazhenov formation. It was determined that the crystallization of the carbonate material of nodules took place in various conditions: in the bottom part of the sediments and in the later stages of diagenesis. The source of calcite for nodules was calcareous nanoplankton or bivalve shells. The carbonate content of the cuts decreases in the following sequence: Yuzhno-Yagunsky → Povkhovsky → Novortyagunsky → Druzhny areas, which are associated both with facial features and various physicochemical conditions of diagenesis and catagenesis. Transformation of organic matter increases in the northeast direction from South Yagunsky to Povkhovsky area, which is confirmed by molecular parameters of catagenesis. The carbonate rocks of the bottom part of the Bazhenov formation in the South Yagunsky area are similar in structure to the main oil-bearing reservoirs of the Salym and Krasnoleninsky fields.

scholarly journals NEW DATA ON PROMISING OIL AND GAS OBJECTS IN THE SANDSTONES OF THE YAMNA SUITE OF THE PALEOCENE IN THE NORTHWEST OF THE SKIBA ZONE OF THE UKRAINIAN CARPATHIANS

2021 ◽  
pp. 90-110
Author(s):  
V.Ye. Shlapinskiy ◽  
H.Ya. Havryshkiv ◽  
Yu.P. Haievska
Keyword(s):  
Oil And Gas ◽  
Gas Production ◽  
Oil Field ◽  
Distribution Area ◽  
Total Production ◽  
Reservoir Properties ◽  
Oil And Gas Production ◽  
The North ◽  
Natural Oil ◽  
Porosity And Permeability

More than 6 million tons of the oil have been extracted in the Skybа Zone of the Ukrainian Carpathians. In particular, 4.2 million tons of oil (85.7% of total production) were obtained from the Yamna sandstones of Paleocene, which are characterized by satisfactory physical properties. Most of the areas of fields that exploited them are located in the Boryslav oil and gas production area. Among them are such oil fields as Skhidnytsko-Urytske (more than 3.8 million tons of oil extracted), Violeta, Faustina, MEP, Miriam and Ropne. Outside this area, oil was extracted in Strilbychi and Staraya Sol. At most of these fields, oil horizons are at a depth of only 100-800 m. The gas and condensate are extracted at the field of Tanyavа in the wing of the Vytvytska Luska of the Berehova Skyba, which has been torn off by the thrust. In addition, a very large number of natural oil and gas manifestations - direct signs of oil and gas potential - have been recorded in the Skyba Zone. All this indicates the potential prospects of structures within the Skyba Zone, including shallow ones. The distribution area of Yamna sandstones is much larger than the area of these deposits. The distribution area of sandstones of Yamna is much larger than the area of these deposits. It occupies about half of the area of Skyba Zone. Part of it can be considered promising, removing areas where of Yamna sandstones are present on the day surface, although, even in such conditions, they are in some cases industrially oil-bearing (Strelbychi oil field). Sandstones of Yamna are characterized by satisfactory reservoir properties., The calculated porosity and permeability reach the maximum values at known deposits: 0.182 and 130 ∙ 10–3 microns2 respectively, and the estimated thickness of 13.5 m. In the Folded Carpathians and, especially, within the north-eastern fragments (Beregova, Oriv, Skoliv) in different years performed a large amount of field seismic surveys. On the basis of the obtained materials, for the first time in the Carpathian region structural constructions were made on the reflecting horizons in the Paleocene (Yamna Formation) and in the Stryi Formation of the Upper Cretaceous. This article evaluates the prospects of these research objects. The Khodkiv and Osichnyanska structures of Berehova Skyba are recommended for conducting search works.

scholarly journals The Hydrocarbon Genesis of pre-Jurassic Complex of Khanty-Mansiyskoe Oil Field

2020 ◽  
Vol 6 (10) ◽  
pp. 95-110
Author(s):  
Yu. Korzhov ◽  
G. Lobova ◽  
A. Starikov ◽  
M. Kuzina
Keyword(s):  
Organic Matter ◽  
Molecular Mass Distribution ◽  
Lower Jurassic ◽  
Oil Field ◽  
Tectonic Block ◽  
The Core ◽  
Complex Source ◽  
Parent Rocks ◽  
Paleozoic Rocks ◽  
Hydrocarbon Deposits

The origin of hydrocarbon deposits in Jurassic and pre-Jurassic complexes of the Khanty-Mansiysk area, located within the Frolov depression, in the local compression zone of the West Siberian plate — the suture zone, is established. The core and crude oil of Jurassic and pre-Jurassic complexes from prospecting wells of the Khanty-Mansiyskoe field is studied. The content and molecular mass distribution of hydrocarbons, including n-alkanes, n-alkylbenzenes, naphthalene’s and phenanthrenes, is determined in bitumen of rocks and oils by chromatography-mass spectrometry. Lithological and petrographic characteristics of rocks is determined by optical microscopy. For oil deposits of the pre-Jurassic complex “source of hydrocarbons” is not reliably established, the parent rocks were not clearly identified in this research. In the lower horizons of the Jurassic section, there is a layer of highly permeable gritstone of the Gorely formation, in which organic matter is localized, presumably making the main contribution to the hydrocarbon deposits of the lower Jurassic and pre-Jurassic complexes. As a possible “source of Paleozoic oil”, it is proposed to collect hydrocarbons from scattered organic matter of Paleozoic rocks at a significant depth (not covered by core drilling) in the areas of tectonic block crushing of foundation.

scholarly journals LITHOLOGICAL AND MINERALOGICAL PECULIARITIES OF CARBONATE ROCKS IN THE UPPER TOURNAISIAN SUBSTAGE AT THE ALEKSEEVSKY OIL FIELD

2018 ◽  
pp. 57-62
Author(s):  
I. P. Zinatulluna ◽  
L. B. Kadyrova
Keyword(s):  
Carbonate Rocks ◽  
Genetic Differences ◽  
Oil Field ◽  
Core Material ◽  
Present Stage ◽  
The Core ◽  
Microscopic Studies ◽  
Geological Sciences

At the present stage of the development of geological sciences more detailed lithological and petrographic studies become more important. Microscopic studies of core material in the Upper Taurus substage made it possible to isolate the lithotypes of carbonates characteristic of the investigated field. There are cloddy, clot-detrital, clay-detrital, and foraminifera-clotting lithotypes.The collectors are only limestones lumpy and clotty-detritus of the isolated structural-genetic differences. The study of the core material of the Upper Taurus substage of the Alekseevsky oil field allowed to conclude that the Kizel and Cherepets horizons are separate development objects.

SATURATION EXPONENT AS A FUNCTION OF RESERVOIR HETEROGENEITY AND WETTABILITY IN THE TAMBAREDJO OIL FIELD, SURINAME

2021 ◽  
Author(s):  
Elias R. Acosta ◽  
◽  
Bhagwanpersad Nandlal ◽  
Ryan Harripersad ◽  
◽  
...  
Keyword(s):  
Oil Recovery ◽  
Water Saturation ◽  
Variable Parameter ◽  
Oil Field ◽  
High Resistivity ◽  
Reservoir Properties ◽  
Core Data ◽  
The Core ◽  
Irreducible Water Saturation ◽  
Saturation Exponent

This research proposed an alternative method for determining the saturation exponent (n) by finding the best correlations for the heterogeneity index using available core data and considering wettability changes. The log curves of the variable n were estimated, and the effect on the water saturation (Sw) calculations and the Stock Tank Oil Initially In Place (STOIIP) in the Tambaredjo (TAM) oil field was analyzed. Core data were employed to obtain the relationship between n and heterogeneity using cross-plots against several heterogeneity indices, reservoir properties, and pore throat size. After filtering the data, the clay volume (Vcl), shale volume, silt volume, basic petrophysical property index (BPPI), net reservoir index, pore grain volume ratio, and rock texture were defined as the best matches. Their modified/improved equations were applied to the log data and evaluated. The n related to Vcl was the best selection based on the criteria of depth variations and logical responses to the lithology. The Sw model in this field showed certain log readings (high resistivity [Rt] reading ≥ 500 ohm.m) that infer these intervals to be probable inverse-wet (oil-wet). The cross-plots (Rt vs. Vcl; Rt vs. density [RHOB]; Rt vs. total porosity [PHIT]) were used to discard the lithologies related to a high Rt (e.g., lignites and calcareous rocks) and to correct Sw when these resulted in values below the estimated irreducible water saturation (Swir). The Sw calculations using the Indonesian equation were updated to incorporate n as a variable (log curves), comparing it with Sw from the core data and previous calculations using a fixed average value (n = 1.82) from the core data. An integrated approach was used to determine n, which is related to the reservoir’s heterogeneity and wettability changes. The values of n for high Rt (n > 2) intervals ranged from 2.3 to 8.5, which is not close to the field average n value (1.82). Specific correlations were found by discriminating Swir (Swir < 15%), (Swir 15%–19%), and Swir (> 19%). The results showed that using n as a variable parameter improved Sw from 39.5% to 36.5% average in the T1 and T2 sands, showing a better fit than the core data average and increasing the STOIIP estimations by 6.81%. This represents now a primary oil recovery of 12.1%, closer to the expected value for these reservoirs. Although many studies have been done on n determination and its effect on Sw calculations, using average values over a whole field is still a common practice regardless of heterogeneity and wettability considerations. This study proposed a method to include the formation of heterogeneity and wettability changes in n determination, allowing a more reliable Sw determination as demonstrated in the TAM oil field in Suriname.

scholarly journals Analysis of the core microstructure of terrigenic reservoirs based on lithological-petrographic studies to support the creation of digital core model

2020 ◽  
Vol 20 (1) ◽  
pp. 37-42
Author(s):  
IP Belozerov ◽  
MG Gubaidullin ◽  
AV Yuriev
Keyword(s):  
Pore Space ◽  
Core Model ◽  
Core Material ◽  
Berea Sandstone ◽  
Reservoir Properties ◽  
Thin Sections ◽  
Digital Core ◽  
Northern Russia ◽  
Lithological Composition ◽  
Correct Understanding

The question of digital core modelling appears highly relevant due to the fact that there is not always a sufficient amount of core material available from studied wells: in some cases, it is not possible to select core material (in case of loose, weakly cemented rocks); in others, such material may be completely absent. In order to create a computer model of a digital core, it is necessary to have a correct understanding of the pore space microstructure and rock lithological composition and structure, among the most important features determining the quality of sedimentary reservoir rocks. Such information can be obtained by carrying out lithological-petrographic studies of thin sections of reference (standard) core samples. The aim of the present work is to study petrographic thin sections for their further use in creating a digital core model. The article discusses the methodology and results of laboratory lithological and petrographic studies of thin sections using the available core information. The paper presents the results of laboratory studies of thin sections of terrigenous sandstones obtained from the Berea Sandstone formation (USA). The choice of the Berea Sandstone is due to its wide recognition by specialists, as well as its homogeneity, both in terms of the grain size of constituent rocks and their filtration and reservoir properties. The work also presents the results of data analysis on lithological and petrographic studies of core material from the terrigenous deposits obtained in the Timan-Pechora province in northern Russia. The research results can be used for mathematical modelling of the pore space microstructure in a digital core model.

Sign in / Sign up

Export Citation Format

Share Document