Nonlinear simultaneous inversion of pore structure and physical parameters based on elastic impedance

2021 ◽  
Author(s):  
Hongbing Li ◽  
Jiajia Zhang ◽  
Haojie Pan ◽  
Qiang Gao
Keyword(s):  
Pore Structure ◽  
Physical Parameters ◽  
Simultaneous Inversion ◽  
Elastic Impedance

Application of extended elastic impedance in seismic geomechanics

Geophysics ◽  
2019 ◽  
Vol 84 (3) ◽  
pp. R429-R446 ◽  
Author(s):  
Javad Sharifi ◽  
Naser Hafezi Moghaddas ◽  
Gholam Reza Lashkaripour ◽  
Abdolrahim Javaherian ◽  
Marzieh Mirzakhanian
Keyword(s):  
Carbonate Reservoir ◽  
Reservoir Rock ◽  
Earth Model ◽  
Physical Parameters ◽  
Simultaneous Inversion ◽  
Geomechanical Parameters ◽  
Mechanical Earth Model ◽  
Well Data ◽  
Southwest Of Iran ◽  
Elastic Impedance

We have evaluated an innovative application of extended elastic impedance (EEI) to integrate seismic and geomechanics for geomechanical interpretation of hydrocarbon reservoirs. EEI analysis is used to extract geomechanical parameters. To verify and assess the capabilities of EEI analysis for extracting geomechanical parameters, we selected a jointed, oil-bearing, shale carbonate reservoir in the southwest of Iran, and we used petrophysical data and core analysis to estimate static and dynamic moduli of the reservoir rock. We calculated the corresponding EEI curve to different intercept-gradient coordinate rotation angles (the chi angle, [Formula: see text]), and we selected the angles of the maximum correlation for the corresponding geomechanical parameters. Then, combining the intercept and gradient, we generated 3D reflectivity patterns of EEI at different angles. To obtain a cube of geomechanical parameters, we performed model-based inversion on the EEI reflectivity pattern. A comparison between the modeling results and well data indicated that the geomechanical parameters estimated by our method were well-correlated to the observed data. Accordingly, we extracted the geomechanical and rock-physical parameters from the EEI cube. We further found that EEI analysis was capable of giving a 3D mechanical earth model of the reservoir with the appropriate accuracy. Finally, we verified the proposed methodology on a blind well and compared the results with those of the simultaneous inversion, indicating comparable levels of accuracy. Therefore, application of this method in seismic geomechanics can bring about significant progress in the future.

Analysis of the Hidrocarbon Sandstone Distribution Using Rock Physics and Petrophysic Calculations, Simultaneous Inversion, Extended Elastic Impedance (EEI) and Curved Pseudo-Elastic Impedance (CPEI) in X Field Bonaparte Basin

2020 ◽  
Author(s):  
A., H. Kusuma
Keyword(s):  
Gamma Ray ◽  
Water Saturation ◽  
Rock Physics ◽  
Fluid Distribution ◽  
Elastic Parameters ◽  
Angular Rotation ◽  
Simultaneous Inversion ◽  
A Value ◽  
Seismic Volumes ◽  
Elastic Impedance

To analyze the distribution of hydrocarbon reservoirs in an area, appropriate methods and parameters can be used to map sediments in the area. In this study, the research was conducted on the X Field located in the Bonaparte Basin. The EEI and CPEI methods are used. The Extended Elastic Impedance (EEI) method is a method that can be used to connect seismic data with elastic parameters by applying the principle of angular rotation. From this method, seismic volumes of various elastic parameters and reservoir parameters will be obtained. The Curved Pseudo-elastic Impedance (CPEI which is able to answer the problem in describing the distribution of fluid in the study area) is also carried out. Gamma Ray (GR) is used to detect lithology and fluid distribution, while from the results of CPEI inversion, the water saturation volume is obtained to see the hydrocarbon distribution in the study area. The results show that the two inversions are able to differentiate the distribution of tight sand lithology, shale, wet sand, gas sand and porous sand. The presence of gas sand distribution can be identified by the value of GR = 20-40 API, λρ = 0-50 GPA*gr/cc, μρ > 80 GPA*g/cc, σ = 0.05-0.24 unitless and the value of Sw = 0-40%, lithology tight sand has a value of GR = 40-70 API, λρ = 70-80 GPA*gr/cc, σ>0.4 unitless, shale lithology has a value of GR > 90 API , μρ <30 GPA*gr/cc, and wet sand is shown with the value GR = 20-40 API, λρ = 50-80 GPA*gr/cc, σ = 0.25-0.35 unitless and Sw> 70%. Based on the results of these interpretations, a sandstone distribution map in X Field was generated and it consists of 2 reservoir layers in the research target zone.

scholarly journals X-ray CT analysis of pore structure in sand

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 929-942 ◽  
Author(s):  
Toshifumi Mukunoki ◽  
Yoshihisa Miyata ◽  
Kazuaki Mikami ◽  
Erika Shiota
Keyword(s):  
Image Analysis ◽  
Pore Structure ◽  
Pore Diameter ◽  
Pore Space ◽  
Soil Mechanics ◽  
Image Data ◽  
Petroleum Engineering ◽  
Physical Parameters ◽  
X Ray ◽  
Definition Of

Abstract. The development of microfocused X-ray computed tomography (CT) devices enables digital imaging analysis at the pore scale. The applications of these devices are diverse in soil mechanics, geotechnical and geoenvironmental engineering, petroleum engineering, and agricultural engineering. In particular, the imaging of the pore space in porous media has contributed to numerical simulations for single-phase and multiphase flows or contaminant transport through the pore structure as three-dimensional image data. These obtained results are affected by the pore diameter; therefore, it is necessary to verify the image preprocessing for the image analysis and to validate the pore diameters obtained from the CT image data. Moreover, it is meaningful to produce the physical parameters in a representative element volume (REV) and significant to define the dimension of the REV. This paper describes the underlying method of image processing and analysis and discusses the physical properties of Toyoura sand for the verification of the image analysis based on the definition of the REV. On the basis of the obtained verification results, a pore-diameter analysis can be conducted and validated by a comparison with the experimental work and image analysis. The pore diameter is deduced from Young–Laplace's law and a water retention test for the drainage process. The results from previous study and perforated-pore diameter originally proposed in this study, called the voxel-percolation method (VPM), are compared in this paper. In addition, the limitations of the REV, the definition of the pore diameter, and the effectiveness of the VPM for an assessment of the pore diameter are discussed.

scholarly journals Hydrocarbon reservoir delineation using simultaneous and elastic impedance inversions in a Niger Delta field

2021 ◽  
Author(s):  
Oluwakemi Y. Adesanya ◽  
Lukumon Adeoti ◽  
Kayode F. Oyedele ◽  
Itsemode P. Afinotan ◽  
Taiwo Oyeniran ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Wave Velocity ◽  
Seismic Data ◽  
Niger Delta ◽  
Low Frequency ◽  
Hydrocarbon Reservoirs ◽  
Well Test ◽  
Simultaneous Inversion ◽  
Hydrocarbon Reservoir ◽  
Elastic Impedance

AbstractThe global energy demand is increasing while production from mature fields is drastically reducing consequently, oil and gas industries are expanding activities into more challenging areas. The inability of the traditional seismic data to properly delineate hydrocarbon reservoirs from subtle seismic features in ‘Sandfish’ field located offshore, Niger Delta informed the use of simultaneous and elastic impedance inversion. The elastic and derived volumes from seismic inversion would reduce risk, enhance hydrocarbon discovery and optimize development plans in the study area. Four ‘Sandfish’ (Sfn) wells (Sfn-01, Sfn-02, Sfn-04 and Sfn-05), check-shots and 3D seismic data of five angle stacks (6–12°, 12–18°, 18–26°, 26–32° and 32–42°) were used in the study. Low frequency (0–2 Hz) models were generated from interpolation of high-cut-filtered compressional wave velocity log (P-sonic), shear wave velocity log (S-sonic) and density log guided by interpreted four seismic horizons. The low frequency models broaden the spectrum of the elastic volumes and also served as inversion constraints. The five partial angle stacks varying from 6–42° were simultaneously inverted using Jason’s Rock-Trace® inversion software which iterated trial inversions until the model sufficiently matched the seismic data. The near (6–12°) angle and far-far (32–42°) angle stacks were also inverted and compared with the inverted volumes from the simultaneous inversion. This was carried out to determine the effectiveness of near and far-far elastic impedance volume in delineating hydrocarbon reservoirs. The inverted elastic volumes P-impedance (ZP), S-impedance (ZS), density (ρ), near and far-far elastic and derived volumes lambda-rho (λρ), mu-rho (µρ), Poisson’s-ratio (σ) reveal vertical and lateral continuity of the reservoirs identified (K01, N01 and P01) at 2179 m, 2484 m and 3048 m, respectively. The delineated reservoirs showed good match with the sand tops away from the well control validated by a blind well test. The cross-plot of inverted ZP from simultaneous inversion and well ZP gave correlation coefficient of 86% indicative of high quality inverted volume which will reduce exploration risk. The plot of inverted ZP from simultaneous inversion and inverted far-far elastic volume reflected 82% correlation coefficient indicating that this method could be adopted in other fields with limited data and similar geological setting. Hence, the study has shown the efficacy of elastic volumes in delineating hydrocarbon reservoirs which can help locate optimum region for development wells.

scholarly journals Simultaneous Inversion of Layered Velocity and Density Profiles Using Direct Waveform Inversion (DWI): 1D Case

2022 ◽  
Vol 9 ◽  
Author(s):  
Zhonghan Liu ◽  
Yingcai Zheng ◽  
Hua-Wei Zhou
Keyword(s):  
Wave Velocity ◽  
Waveform Inversion ◽  
Seismic Inversion ◽  
P Wave ◽  
Physical Parameters ◽  
Seismic Structure ◽  
Initial Model ◽  
Density Profiles ◽  
Simultaneous Inversion ◽  
Time Space

To better interpret the subsurface structures and characterize the reservoir, a depth model quantifying P-wave velocity together with additional rock’s physical parameters such as density, the S-wave velocity, and anisotropy is always preferred by geologists and engineers. Tradeoffs among different parameters can bring extra challenges to the seismic inversion process. In this study, we propose and test the Direct Waveform Inversion (DWI) scheme to simultaneously invert for 1D layered velocity and density profiles, using reflection seismic waveforms recorded on the surface. The recorded data includes primary reflections and interbed multiples. DWI is implemented in the time-space domain then followed by a wavefield extrapolation to downward continue the source and receiver. By explicitly enforcing the wavefield time-space causality, DWI can recursively determine the subsurface seismic structure in a local layer-by-layer fashion for both sharp interfaces and the properties of the layers, from shallow to deep depths. DWI is different from the layer stripping methods in the frequency domain. By not requiring a global initial model, DWI also avoids many nonlinear optimization problems, such as the local minima or the need for an accurate initial model in most waveform inversion schemes. Two numerical tests show the validity of this DWI scheme serving as a new strategy for multi-parameter seismic inversion.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

A theory of contamination in electron microscopes by surface diffusion

1978 ◽  
Vol 36 (1) ◽  
pp. 116-117
Author(s):  
J.T. Fourie
Keyword(s):  
Electron Beam ◽  
Surface Diffusion ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Physical Parameters ◽  
Carbon Compounds ◽  
Hydrocarbon Molecules ◽  
Electron Microscopes ◽  
Primary Electrons ◽  
Long Chain

Contamination in electron microscopes can be a serious problem in STEM or in situations where a number of high resolution micrographs are required of the same area in TEM. In modern instruments the environment around the specimen can be made free of the hydrocarbon molecules, which are responsible for contamination, by means of either ultra-high vacuum or cryo-pumping techniques. However, these techniques are not effective against hydrocarbon molecules adsorbed on the specimen surface before or during its introduction into the microscope. The present paper is concerned with a theory of how certain physical parameters can influence the surface diffusion of these adsorbed molecules into the electron beam where they are deposited in the form of long chain carbon compounds by interaction with the primary electrons.

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