Gas permeability of sedimentary rocks of the upper carboniferous strata (in German)

1980 ◽  
Vol 17 (5) ◽  
pp. 83
Keyword(s):  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Upper Carboniferous

Deep fluids and their role in hydrocarbon migration and oil deposit formation exemplified by supercritical СO2

2021 ◽  
pp. 1-11
Author(s):  
Sara LIFSHITS
Keyword(s):  
Supercritical Fluid ◽  
Oil And Gas ◽  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Source Rocks ◽  
Reservoir Properties ◽  
Hydrocarbon Migration ◽  
Geological Processes ◽  
Before And After ◽  
Oil Source

ABSTRACT Hydrocarbon migration mechanism into a reservoir is one of the most controversial in oil and gas geology. The research aimed to study the effect of supercritical carbon dioxide (СО2) on the permeability of sedimentary rocks (carbonates, argillite, oil shale), which was assessed by the yield of chloroform extracts and gas permeability (carbonate, argillite) before and after the treatment of rocks with supercritical СО2. An increase in the permeability of dense potentially oil-source rocks has been noted, which is explained by the dissolution of carbonates to bicarbonates due to the high chemical activity of supercritical СО2 and water dissolved in it. Similarly, in geological processes, the introduction of deep supercritical fluid into sedimentary rocks can increase the permeability and, possibly, the porosity of rocks, which will facilitate the primary migration of hydrocarbons and improve the reservoir properties of the rocks. The considered mechanism of hydrocarbon migration in the flow of deep supercritical fluid makes it possible to revise the time and duration of the formation of gas–oil deposits decreasingly, as well as to explain features in the formation of various sources of hydrocarbons and observed inflow of oil into operating and exhausted wells.

scholarly journals IV.—On the Denudation of Western Brittany

1869 ◽  
Vol 6 (64) ◽  
pp. 442-446
Author(s):  
G. A. Lebour
Keyword(s):  
Sedimentary Rocks ◽  
The South ◽  
Upper Carboniferous ◽  
The North ◽  
Upper Silurian ◽  
East And West

Geology.—Stated roughly, the geology of the Department of Finistère may be said to consist of two masses of granite, one to the north and one to the south, enclosing between them nearly the whole of the sedimentary rocks of the district. These consist of Cambrian slates and gneiss, Lower, Middle, and Upper Silurian slates and grits, and very small and unimportant patches of Upper Carboniferous shales. The entire mass of these deposits has an east and west direction, and occupies the central part of the Department.

scholarly journals Radon over Kimberlite Pipes: Surface Field Experiments and Calculations of Vertical Diffusion (Arkhangelsk Diamondiferous Province, NW Russia)

2021 ◽  
Vol 11 (24) ◽  
pp. 11765
Author(s):  
Evgeny Yakovlev ◽  
Andrey Puchkov
Keyword(s):  
Field Experiments ◽  
Gas Permeability ◽  
Sedimentary Rocks ◽  
Experimental Studies ◽  
Physical Parameters ◽  
Vertical Diffusion ◽  
Diffusion Transfer ◽  
Emanation Method ◽  
Kimberlite Field ◽  
Made In

We present the results of field and experimental studies to assess the influence on the formation of the radon field over the kimberlite pipes of the Arkhangelsk diamondiferous province. Measurements were made in the field to establish the radon radiation in the soil air and the gas permeability of soils in the area of the Chidvinskaya pipe. Experimental work was aimed at determining the radiation and physical parameters of the rocks occurring within the kimberlite field. Based on a set of field and experimental data, a model of the diffusion transfer of radon in the area of the Chidvinskaya pipe was calculated for three profiles, represented by the rocks of the pipe, sedimentary rocks of the exocontacts of the pipe, and host sandy and clay sedimentary rocks. The results of the calculations show that the rocks of the exocontacts of the pipe have the greatest potential for increased radon radiation. The calculated values of the radon radiation produced by these rocks exceeded 9000 Bq·m−3. The diatreme kimberlites produced the lowest radon radiation. We showed that the source of the increased values of radon radiation is the rocks of the pipe’s exocontacts. This fact will make it possible to use the emanation method as an additional one for the search for kimberlite pipes.

scholarly journals Klinkenberg effect for gas permeability and its comparison to water permeability for porous sedimentary rocks

2006 ◽  
Vol 3 (4) ◽  
pp. 1315-1338 ◽  
Author(s):  
W. Tanikawa ◽  
T. Shimamoto
Keyword(s):  
Pore Pressure ◽  
Water Permeability ◽  
Gas Flow ◽  
Gas Permeability ◽  
Slip Flow ◽  
Sedimentary Rocks ◽  
Water Film ◽  
Klinkenberg Effect ◽  
Two Phase ◽  
Order Of Magnitude

Abstract. The difference between gas and water permeabilities is significant not only for solving gas-water two-phase flow problems, but also for quick measurements of permeability using gas as pore fluid. We have measured intrinsic permeability of sedimentary rocks from the Western Foothills of Taiwan, using nitrogen gas and distilled water as pore fluids, during several effective-pressure cycling tests at room temperature. The observed difference in gas and water permeabilities has been analyzed in view of the Klinkenberg effect. This effect is due to slip flow of gas at pore walls which enhances gas flow when pore sizes are very small. Experimental results show (1) that gas permeability is larger than water permeability by several times to one order of magnitude, (2) that gas permeability increases with increasing pore pressure, and (3) that water permeability slightly increases with increasing pore-pressure gradient across the specimen. The results (1) and (2) can be explained by Klinkenberg effect quantitatively with an empirical power law for Klinkenberg constant. Thus water permeability can be estimated from gas permeability. The Klinkenberg effect is important when permeability is lower than 10−18 m2 and at low differential pore pressures, and its correction is essential for estimating water permeability from the measurement of gas permeability. A simple Bingham-flow model of pore water can explain the overall trend of the result (3) above. More sophisticated models with a pore-size distribution and with realistic rheology of water film is needed to account for the observed deviation from Darcy's law.

Chemistry and prehnite–pumpellyite facies metamorphism of calc-alkaline Carboniferous volcanic rocks of southeastern New Brunswick

1979 ◽  
Vol 16 (5) ◽  
pp. 1071-1085 ◽  
Author(s):  
D. F. Strong ◽  
W. L. Dickson ◽  
R. K. Pickerill
Keyword(s):  
New Brunswick ◽  
Volcanic Rocks ◽  
Sedimentary Rocks ◽  
Calc Alkaline ◽  
Upper Carboniferous ◽  
Geological Setting ◽  
Quantitative Estimates ◽  
Chemical Transfer ◽  
Facies Metamorphism ◽  
The City

Mafic pillowed and massive lavas of the Upper Carboniferous West Beach Formation, as exposed in the city of Saint John, southeastern New Brunswick, were metamorphosed under prehnite–pumpellyite facies conditions, possibly between 315 and 370 °C and 1 and 2.5 kbar (105 and 2.5 × 105 kPa). Petrographic and chemical data for 32 samples indicate that this metamorphism was accompanied by significant silicification of some samples and variable chloritization of most. These processes caused relatively minor chemical transfer of most elements other than silica, and calculations from averages assuming constant Al indicate that TiO2, P2O5, Zr, Rb, Nb, Ga, and Y are relatively immobile. However, ratio diagrams show anomalous concentrations of these elements in a few samples and illustrate the inherent flaws of quantitative estimates based on averages. Classifications using these elements in a variety of diagrams clearly and consistently indicate a primitive calc-alkaline nature for the lavas, contrary to what might be expected from their geological setting interbedded with plant-bearing paralic or continental sedimentary rocks.

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