scholarly journals Multi-physics evaluation of carbonate-rich source rocks from high-resolution images

2021 ◽  
Author(s):  
Shannon L. Eichmann ◽  
Mita Sengupta ◽  
Abdelrahman Kotb
Keyword(s):  
High Resolution ◽  
Effective Medium Theory ◽  
Pore Space ◽  
Ion Beam ◽  
Rock Physics ◽  
Rich Source ◽  
Hydrocarbon Exploration ◽  
Source Rocks ◽  
Unconventional Reservoirs ◽  
Empirical Equations

AbstractIn unconventional reservoirs, the pore space is hosted by a heterogeneous matrix with various minerals and organic components. This heterogeneity complicates petrophysical interpretation during hydrocarbon exploration. A digital rock physics study of thermal and electrical conductivity was conducted using high-resolution focused ion beam scanning electron microscopy images of carbonate-rich source rocks. Finite-volume simulation results are discussed in context of the sample heterogeneity and anisotropy and supported by comparisons to empirical equations and effective medium theory. The results show how the presence of organic matter, pyrite, and pore constrictions impacts application of empirical equations and simplified models to unconventional reservoirs. Graphic abstract

Rock-physics analysis of clay-rich source rocks on the Norwegian Shelf

2015 ◽  
Vol 34 (11) ◽  
pp. 1340-1348 ◽  
Author(s):  
Per Avseth ◽  
José M. Carcione
Keyword(s):  
Rock Physics ◽  
Rich Source ◽  
Source Rocks

Computing elastic properties of organic-rich source rocks using digital images

2021 ◽  
Vol 40 (9) ◽  
pp. 662-666
Author(s):  
Mita Sengupta ◽  
Shannon L. Eichmann
Keyword(s):  
Organic Matter ◽  
Elastic Properties ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Rock Physics ◽  
Flow Property ◽  
Source Rocks ◽  
Digital Rock ◽  
Rock Structure ◽  
Imaging Resolution

Digital rocks are 3D image-based representations of pore-scale geometries that reside in virtual laboratories. High-resolution 3D images that capture microstructural details of the real rock are used to build a digital rock. The digital rock, which is a data-driven model, is used to simulate physical processes such as fluid flow, heat flow, electricity, and elastic deformation through basic laws of physics and numerical simulations. Unconventional reservoirs are chemically heterogeneous where the rock matrix is composed of inorganic minerals, and hydrocarbons are held in the pores of thermally matured organic matter, all of which vary spatially at the nanoscale. This nanoscale heterogeneity poses challenges in measuring the petrophysical properties of source rocks and interpreting the data with reference to the changing rock structure. Focused ion beam scanning electron microscopy is a powerful 3D imaging technique used to study source rock structure where significant micro- and nanoscale heterogeneity exists. Compared to conventional rocks, the imaging resolution required to image source rocks is much higher due to the nanoscale pores, while the field of view becomes smaller. Moreover, pore connectivity and resulting permeability are extremely low, making flow property computations much more challenging than in conventional rocks. Elastic properties of source rocks are significantly more anisotropic than those of conventional reservoirs. However, one advantage of unconventional rocks is that the soft organic matter can be captured at the same imaging resolution as the stiff inorganic matrix, making digital elasticity computations feasible. Physical measurement of kerogen elastic properties is difficult because of the tiny sample size. Digital rock physics provides a unique and powerful tool in the elastic characterization of kerogen.

Rock-physics templates for clay-rich source rocks

Geophysics ◽  
2015 ◽  
Vol 80 (5) ◽  
pp. D481-D500 ◽  
Author(s):  
José M. Carcione ◽  
Per Avseth
Keyword(s):  
Rock Physics ◽  
Rich Source ◽  
Source Rocks

Nanopore Imaging in Vaca Muerta Mudrocks To Evaluate Controls on Complex Resistivity Spectra in Unconventional Reservoirs

2017 ◽  
Vol 20 (04) ◽  
pp. 1028-1044 ◽  
Author(s):  
Jan H. Norbisrath ◽  
G. Michael Grammer ◽  
Beth Vanden Berg ◽  
Max Tenaglia ◽  
Gregor P. Eberli ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Ion Beam ◽  
Low Frequency ◽  
Hydrocarbon Exploration ◽  
Unconventional Reservoirs ◽  
Rock Properties ◽  
Pore Geometry ◽  
Carbonate Content ◽  
Complex Resistivity ◽  
Vaca Muerta

Summary Nanopore geometry and mineralogy are key parameters for effective hydrocarbon exploration and production in unconventional reservoirs. This study describes an approach to evaluate relationships between low-frequency complex resistivity spectra (CRS), nanopore geometry, and mineralogy to use CRS to provide estimates of reservoir parameters concerning hydrocarbon saturation, storage, and producibility. For this purpose, the frequency dispersion of CRS was analyzed in 56 mudrock core plugs from the Vaca Muerta Formation (VMF) (Jurassic/Cretaceous) in Argentina, along with cementation factors (m), carbonate content (CO3), and total organic carbon (TOC). To quantify the nanoporosity, a subset of 23 samples was milled with broad ion beam (BIB) and imaged with scanning electron microscopy (SEM); the image grids of these samples were stitched together into high-resolution BIB-SEM mosaics and analyzed with digital image analysis (DIA) techniques. Results show that porosity is the dominant control on electrical properties in the mudrocks analyzed as part of this study. There is no conclusive evidence that pore geometry influences the electrical properties in the analyzed mudrocks. Pore-geometry parameters [dominant pore size (DOMsize) and perimeter over area (PoA)] do not correlate with electrical properties. Instead, mineralogy shows a first-order correlation with electrical properties, where cementation exponents are higher in rocks with high TOC and low CO3 content. CRS can be used to estimate porosity and cementation factors with high correlation coefficients of R2 = 0.71 and R2 = 0.95, respectively. Estimates of the 2D interfacial surface area (ISA2D), which is a function of both pore geometry and porosity, achieve an R2 = 0.59. The results of this study suggest that low-frequency dielectric rock properties, if measured downhole, could be useful to identify primary producing intervals in unconventional reservoirs, and to accurately determine cementation factors independent of formation fluids and porosity.

scholarly journals Synchrotron-based X-ray tomographic microscopy for rock physics investigations

Geophysics ◽  
2013 ◽  
Vol 78 (1) ◽  
pp. D53-D64 ◽  
Author(s):  
Claudio Madonna ◽  
Beatriz Quintal ◽  
Marcel Frehner ◽  
Bjarne S. G. Almqvist ◽  
Nicola Tisato ◽  
...  
Keyword(s):  
High Resolution ◽  
Pore Space ◽  
Laboratory Data ◽  
Image Data ◽  
Rock Physics ◽  
Nondestructive Method ◽  
Rock Properties ◽  
Data Sets ◽  
X Ray ◽  
Rock Types

Synchrotron radiation X-ray tomographic microscopy is a nondestructive method providing ultra-high-resolution 3D digital images of rock microstructures. We describe this method and, to demonstrate its wide applicability, we present 3D images of very different rock types: Berea sandstone, Fontainebleau sandstone, dolomite, calcitic dolomite, and three-phase magmatic glasses. For some samples, full and partial saturation scenarios are considered using oil, water, and air. The rock images precisely reveal the 3D rock microstructure, the pore space morphology, and the interfaces between fluids saturating the same pore. We provide the raw image data sets as online supplementary material, along with laboratory data describing the rock properties. By making these data sets available to other research groups, we aim to stimulate work based on digital rock images of high quality and high resolution. We also discuss and suggest possible applications and research directions that can be pursued on the basis of our data.

Oil to Source Rock Correlation Using Biomarker Data Through Pattern Matching and Fingerprinting Analysis in “Kitkat” Field, Jabung Block, South Sumatra Basin

2020 ◽  
Author(s):  
S., R. Muthasyabiha
Keyword(s):  
Pattern Matching ◽  
Source Rock ◽  
Vitrinite Reflectance ◽  
Hydrocarbon Exploration ◽  
Source Rocks ◽  
Maturity Level ◽  
Fingerprinting Analysis ◽  
Kerogen Type ◽  
Oil Characteristics ◽  
Biomarker Data

Geochemical analysis is necessary to enable the optimization of hydrocarbon exploration. In this research, it is used to determine the oil characteristics and the type of source rock candidates that produces hydrocarbon in the “KITKAT” Field and also to understand the quality, quantity and maturity of proven source rocks. The evaluation of source rock was obtained from Rock-Eval Pyrolysis (REP) to determine the hydrocarbon type and analysis of the value of Total Organic Carbon (TOC) was performed to know the quantity of its organic content. Analysis of Tmax value and Vitrinite Reflectance (Ro) was also performed to know the maturity level of the source rock samples. Then the oil characteristics such as the depositional environment of source rock candidate and where the oil sample develops were obtained from pattern matching and fingerprinting analysis of Biomarker data GC/GCMS. Moreover, these data are used to know the correlation of oil to source rock. The result of source rock evaluation shows that the Talangakar Formation (TAF) has all these parameters as a source rock. Organic material from Upper Talangakar Formation (UTAF) comes from kerogen type II/III that is capable of producing oil and gas (Espitalie, 1985) and Lower Talangakar Formation (LTAF) comes from kerogen type III that is capable of producing gas. All intervals of TAF have a quantity value from very good–excellent considerable from the amount of TOC > 1% (Peters and Cassa, 1994). Source rock maturity level (Ro > 0.6) in UTAF is mature–late mature and LTAF is late mature–over mature (Peters and Cassa, 1994). Source rock from UTAF has deposited in the transition environment, and source rock from LTAF has deposited in the terrestrial environment. The correlation of oil to source rock shows that oil sample is positively correlated with the UTAF.

FIB Enhancement of Mechanically Polished Cross-sections

2019 ◽  
Author(s):  
Becky Holdford
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Scanning Electron Microscope ◽  
Cross Sections ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
High Resolution Imaging ◽  
Chemical Attack ◽  
Resolution Imaging ◽  
Scanning Electron

Abstract On mechanically polished cross-sections, getting a surface adequate for high-resolution imaging is sometimes beyond the analyst’s ability, due to material smearing, chipping, polishing media chemical attack, etc.. A method has been developed to enable the focused ion beam (FIB) to re-face the section block and achieve a surface that can be imaged at high resolution in the scanning electron microscope (SEM).

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