scholarly journals Elastic-Electrical Rock-Physics Template for the Characterization of Tight-Oil Reservoir Rocks

Lithosphere ◽  
2021 ◽  
Vol 2021 (Special 3) ◽  
Author(s):  
Mengqiang Pang ◽  
Jing Ba ◽  
José M. Carcione ◽  
Erik H. Saenger
Keyword(s):  
Complex Structure ◽  
Rock Physics ◽  
Clay Content ◽  
Rock Properties ◽  
Tight Oil ◽  
Log Data ◽  
Reservoir Rocks ◽  
Porosity And Permeability ◽  
Parallel Network ◽  
Log Interpretation

Abstract Tight-oil reservoirs have low porosity and permeability, with microcracks, high clay content, and a complex structure resulting in strong heterogeneities and poor connectivity. Thus, it is a challenge to characterize this type of reservoir with a single geophysical methodology. We propose a dual-porosity-clay parallel network to establish an electrical model and the Hashin-Shtrikman and differential effective medium equations to model the elastic properties. Using these two models, we compute the rock properties as a function of saturation, clay content, and total and microcrack porosities. Moreover, a 3D elastic-electrical template, based on resistivity, acoustic impedance, and Poisson’s ratio, is built. Well-log data is used to calibrate the template. We collect rock samples and log data (from two wells) from the Songliao Basin (China) and analyze their microstructures by scanning electron microscopy. Then, we study the effects of porosity and clay content on the elastic and electrical properties and obtain a good agreement between the predictions, log interpretation, and actual production reports.

PETROPHYSICS OF THE COOPER BASIN, SOUTH AUSTRALIA

1972 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Chris R. Porter ◽  
Hugh Crocker
Keyword(s):  
Water Saturation ◽  
South Australia ◽  
Clay Content ◽  
Computer Applications ◽  
Test Results ◽  
Upper Limits ◽  
Porosity And Permeability ◽  
Log Interpretation ◽  
Logging Tool ◽  
Cooper Basin

In the Cooper Basin lithologic types can be recognised and related to logging tool response. Empirical relationships between log readings and porosity and permeability can be developed locally by comparing log readings with core data. Water saturation/porosity relationships are found to be convergently hyperbolic. The effects of clay minerals upon water saturation determination show that only in the low porosity range is correction for clay necessary.A plot of Sw versus Sxo allows prediction of probable test results and has been confirmed by actual Cooper Basin well tests.An attempt to relate clay content to permeability has been successful in estimating tentative upper limits of permeability. Computer applications to log interpretation are utilized in achieving petrophysical parameters.

Finite-difference modeling of wave propagation and diffusion in poroelastic media

Geophysics ◽  
2009 ◽  
Vol 74 (4) ◽  
pp. T55-T66 ◽  
Author(s):  
Fabian Wenzlau ◽  
Tobias M. Müller
Keyword(s):  
Numerical Modeling ◽  
Finite Difference ◽  
Diffusion Processes ◽  
Spatial Scales ◽  
Rock Physics ◽  
Seismic Attenuation ◽  
Rock Properties ◽  
Modeling Tools ◽  
Reservoir Rocks ◽  
Poroelastic Media

Numerical modeling of seismic waves in heterogeneous, porous reservoir rocks is an important tool for interpreting seismic surveys in reservoir engineering. Various theoretical studies derive effective elastic moduli and seismic attributes from complex rock properties, involving patchy saturation and fractured media. To confirm and further develop rock-physics theories for reservoir rocks, accurate numerical modeling tools are required. Our 2D velocity-stress, finite-difference scheme simulates waves within poroelastic media as described by Biot’s theory. The scheme is second order in time, contains high-order spatial derivative operators, and is parallelized using the domain-decomposition technique. A series of numerical experiments that are compared to exact analytical solutions allow us to assess the stability conditions and dispersion relations of the explicit poroelastic finite-differ-ence method. The focus of the experiments is to model wave-induced flow accurately in the vicinity of mesoscopic heterogeneities such as cracks and gas inclusions in partially saturated rocks. For that purpose, a suitable numerical setup is applied to extract seismic attenuation and dispersion from quasi-static experiments. Our results confirm that finite-difference modeling is a valuable tool to simulate wave propa-gation in heterogeneous poroelastic media, provided the temporal and spatial scales of the propagating waves and of the induced fluid-diffusion processes are resolved properly.

scholarly journals Rock Physics Based Interpretation of Seismically Derived Elastic Volumes

2021 ◽  
Vol 8 ◽  
Author(s):  
Abrar Alabbad ◽  
Jack Dvorkin ◽  
Yazeed Altowairqi ◽  
Zhou F. Duan
Keyword(s):  
Water Saturation ◽  
Rock Physics ◽  
Clay Content ◽  
Total Porosity ◽  
Pore Fluid ◽  
Oil Field ◽  
Rock Properties ◽  
Volumetric Properties ◽  
S Wave ◽  
A Site

A rock physics based seismic interpretation workflow has been developed to extract volumetric rock properties from seismically derived P- and S-wave impedances, Ip and Is. This workflow was first tested on a classic rock physics velocity-porosity model. Next, it was applied to two case studies: a carbonate and a clastic oil field. In each case study, we established rock physics models that accurately relate elastic properties to the rock’s volumetric properties, mainly the total porosity, clay content, and pore fluid. To resolve all three volumetric properties from only two inputs, Ip and Is, a site-specific geology driven relation between the pore fluid and porosity was derived as a hydrocarbon identifier. In order to apply this method at the seismic spatial scale, we created a coarse-scale elastic and volumetric variables by using mathematical upscaling at the wells. By using Ip and Is thus upscaled, we arrived at the accurate interpretation of the upscaled porosity, mineralogy, and water saturation both at the wells and in a simulated vertical impedance section generated by interpolation between the wells.

scholarly journals THE COMPOSITION AND PHYSICOCHEMICAL PROPERTIES OF RESERVOIR-ROCKS OF SPAN SERIES OF THE PRIBUG STRUCTURE OF THE PODLESSE-BREST DEPRESSION

2018 ◽  
Vol 54 (3) ◽  
pp. 349-358
Author(s):  
V. G. Levashkevich ◽  
V. P. Samodurov ◽  
S. E. Shpak
Keyword(s):  
Physical Properties ◽  
Clay Content ◽  
Data Interpretation ◽  
Gas Storage ◽  
Laboratory Studies ◽  
Rock Series ◽  
Underground Gas Storage ◽  
Reservoir Rocks ◽  
Porosity And Permeability ◽  
Well Data

The results of laboratory studies of the composition and physical properties of span series rocks of the Pribug structure within the eponymous underground gas storage (UGS), have been presented. The rocks are represented by a finegrained quartz sandstone with various sorting and grain roundness, type of cementation and clay content. The character of section suites changes for the material composition of the rocks and their physical properties have been set. The examined properties specify reservoir rocks characteristics which are widely used for integrated geophysics well data interpretation, geological and hydrogeological UGS modeling, making recommendations for increasing efficiency of pore volume usage during gas storage operation. Rock intervals with poor porosity and permeability are detected inside the examined rock series.

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 Wave Propagation Characteristics in Gas Hydrate-Bearing Sediments and Estimation of Hydrate Saturation

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 804
Author(s):  
Lin Liu ◽  
Xiumei Zhang ◽  
Xiuming Wang
Keyword(s):  
Gas Hydrate ◽  
Clay Content ◽  
Clean Energy ◽  
Compressional Wave ◽  
Physical Parameters ◽  
Well Log ◽  
Log Data ◽  
Phase Velocities ◽  
Hydrate Saturation ◽  
Hydrate Bearing Sediments

Natural gas hydrate is a new clean energy source in the 21st century, which has become a research point of the exploration and development technology. Acoustic well logs are one of the most important assets in gas hydrate studies. In this paper, an improved Carcione–Leclaire model is proposed by introducing the expressions of frame bulk modulus, shear modulus and friction coefficient between solid phases. On this basis, the sensitivities of the velocities and attenuations of the first kind of compressional (P1) and shear (S1) waves to relevant physical parameters are explored. In particular, we perform numerical modeling to investigate the effects of frequency, gas hydrate saturation and clay on the phase velocities and attenuations of the above five waves. The analyses demonstrate that, the velocities and attenuations of P1 and S1 are more sensitive to gas hydrate saturation than other parameters. The larger the gas hydrate saturation, the more reliable P1 velocity. Besides, the attenuations of P1 and S1 are more sensitive than velocity to gas hydrate saturation. Further, P1 and S1 are almost nondispersive while their phase velocities increase with the increase of gas hydrate saturation. The second compressional (P2) and shear (S2) waves and the third kind of compressional wave (P3) are dispersive in the seismic band, and the attenuations of them are significant. Moreover, in the case of clay in the solid grain frame, gas hydrate-bearing sediments exhibit lower P1 and S1 velocities. Clay decreases the attenuation of P1, and the attenuations of S1, P2, S2 and P3 exhibit little effect on clay content. We compared the velocity of P1 predicted by the model with the well log data from the Ocean Drilling Program (ODP) Leg 164 Site 995B to verify the applicability of the model. The results of the model agree well with the well log data. Finally, we estimate the hydrate layer at ODP Leg 204 Site 1247B is about 100–130 m below the seafloor, the saturation is between 0–27%, and the average saturation is 7.2%.

scholarly journals SAPHYR: Swiss Atlas of Physical Properties of Rocks: the continental crust in a database

2021 ◽  
Vol 114 (1) ◽  
Author(s):  
Alba Zappone ◽  
Eduard Kissling
Keyword(s):  
Physical Properties ◽  
Laboratory Data ◽  
Rock Physics ◽  
Resource Planning ◽  
Data Representation ◽  
Common People ◽  
Rock Types ◽  
Gis Tools ◽  
Porosity And Permeability ◽  
Thermal And Electrical Properties

AbstractThe Swiss Atlas of Physical Properties of Rocks (SAPHYR) project aims at centralize, uniform, and digitize dispersed and often hardly accessible laboratory data on physical properties of rocks from Switzerland and surrounding regions. The goal of SAPHYR is to make the quality-controlled and homogenized data digitally accessible to an open public, including industrial, engineering, land and resource planning companies as well as governmental and academic institutions, or simply common people interested in rock physics. The physical properties, derived from pre-existing literature or newly measured, are density, porosity and permeability as well as seismic, magnetic, thermal and electrical properties. The data were collected on samples either from outcrops or from tunnels and boreholes. At present, data from literature have been collected extensively for density, porosity, seismic and thermal properties. In the past years, effort has been placed especially on collecting samples and measuring the physical properties of rock types that were poorly documented in literature. A workflow for quality control on reliability and completeness of the data was established. We made the attempt to quantify the variability and the uncertainty of the data. The database has been recently transferred to the Federal Office of Topography swisstopo with the aim to develop the necessary tools to query the database and open it to the public. Laboratory measurements are continuously collected, therefore the database is ongoing and in continuous development. The spatial distribution of the physical properties can be visualized as maps using simple GIS tools. Here the distribution of bulk density and velocity at room conditions are presented as examples of data representation; the methodology to produce these maps is described in detail. Moreover we also present an exemplification of the use of specific datasets, for which pressure and temperatures derivatives are available, to develop crustal models.

scholarly journals Spatial variation in porosity and permeability of the Rupel Clay Member in the Netherlands

2016 ◽  
Vol 95 (3) ◽  
pp. 253-268 ◽  
Author(s):  
Hanneke Verweij ◽  
Geert-Jan Vis ◽  
Elke Imberechts
Keyword(s):  
The Netherlands ◽  
Spatial Variation ◽  
Clay Content ◽  
Burial Depth ◽  
Southeastern Part ◽  
Boom Clay ◽  
The North ◽  
Sealing Capacity ◽  
Porosity And Permeability ◽  
Permeability Data

AbstractThe spatial distribution of porosity and permeability of the Rupel Clay Member is of key importance to evaluate the spatial variation of its sealing capacity and groundwater flow condition. There are only a limited number of measured porosity and permeability data of the Rupel Clay Member in the onshore Netherlands and these data are restricted to shallow depths in the order of tens of metres below surface. Grain sizes measured by laser diffraction and SediGraph® in samples of the Rupel Clay Member taken from boreholes spread across the country were used to generate new porosity and permeability data for the Rupel Clay Member located at greater burial depth. Effective stress and clay content are important parameters in the applied grain-size based calculations of porosity and permeability.The calculation method was first tested on measured data of the Belgian Boom Clay. The test results showed good agreement between calculated permeability and measured hydraulic conductivity for depths exceeding 200m.The spatial variation in lithology, heterogeneity and also burial depth of the Rupel Clay Member in the Netherlands are apparent in the variation of the calculated permeability. The samples from the north of the country consist almost entirely of muds and as a consequence show little lithology-related variation in permeability. The vertical variation in permeability in the more heterogeneous Rupel Clay Member in the southern and east-southeastern part of the country can reach several orders of magnitude due to increased permeability of the coarser-grained layers.

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