New Experimental Approach to Measure Petrophysical Properties of Organic-rich Shales
Author : Mehrdad Zamirian
Publisher :
Page : 124 pages
File Size : 38,75 MB
Release : 2015
Category :
ISBN :
Characterization of Petrophysical Properties of Organic-rich Shales by Experiments, Lab Measurements and Machine Learning Analysis
Author : Han Jiang (Ph. D.)
Publisher :
Page : 0 pages
File Size : 47,7 MB
Release : 2018
Category :
ISBN :
Book Description
The increasing significance of shale plays leads to the need for deeper understanding of shale behavior. Laboratory characterization of petrophysical properties is an important part of shale resource evaluation. The characterization, however, remains challenging due to the complicated nature of shale. This work aims at better characterization of shale using experiments, lab measurements, and machine leaning analysis. During hydraulic fracturing, besides tensile failure, the adjacent shale matrix is subjected to massive shear deformation. The interaction of shale pore system and shear deformation, and impacts on production remains unknown. This work investigates the response of shale nanoscale pore system to shear deformation using gas sorption and scanning electron microscope (SEM) imaging. Shale samples are deformed by confined compressive strength tests. After failure, fractures in nanoscale are observed to follow coarser grain boundaries and laminae of OM and matrix materials. Most samples display increases in pore structural parameters. Results suggest that the hydrocarbon mobility may be enhanced by the interaction of the OM laminae and the shear fracturing. Past studied show that the evolution of pore structure of shale is associated with thermal maturation. However, the evolution of shale transport propreties related to thermal maturation is unclear due to the difficulty of conducting permeability measurement for shale. This work studies evolution of permeability and pore structure measurements using heat treatment. Samples are heated from 110°C to 650°C. Gas sorption and GRI (Gas Research Institute) permeability measurements are performed. Results show that those petrophysical parameters, especially permeability, are sensitive to drying temperature. Multiscale pore network features of shale are also revealed in this study. Characterizing fluids in shale using nuclear magnetic resonance (NMR) T1-T2 maps is often done manually, which is difficult and subjected to human decisions. This work proposes a new approach based on Gaussian mixture model (GMM) clustering analysis. Six clustering algorithms are performed on T11-T2 maps. To select the optimal cluster number and best algorithm, two cluster validity indices are proposed. Results validate the two indices, and GMM is found to be the best algorithm. A general fluid partition pattern is obtained by GMM, which is less sensitive to rock lithology. In addition, the clustering performance can be enhanced by drying the sample
Recueil factice d'art. de presse sur le film tiré de "L'Ange du foyer" de Caillavet et de Flers
Author :
Publisher :
Page : 4 pages
File Size : 11,28 MB
Release :
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Book Description
Gravimetric Measurement of Spontaneous Imbibition of Water in Organic-rich Shales
Author : Evan Daniel Gilmore
Publisher :
Page : 318 pages
File Size : 24,75 MB
Release : 2013
Category :
ISBN :
Book Description
Organic-rich shales in the last decade have become a focus of the oil and gas industry, and currently are the primary source of oil and gas production from Unconventional resources. These resources will be in need of a method of enhanced recovery to maximize lifetime production from each well. Spontaneous imbibition, or the adsorption of a fluid into a porous media due to capillary forces and consequent displacement of non-wetting fluids is a good potential enhanced recovery method. Measuring the amount of spontaneous imbibition in an organic-rich shale is complicated by several challenges compared to traditional oil reservoir rocks, such as the ultra-low permeability and the high clay content. This clay content can often lead to swelling, which can affect imbibition measurements. In this study, a new gravimetric method for measuring spontaneous imbibition is developed that can measure the rate, and volume of spontaneous imbibition as well as the degree of shale swelling. Two organic-rich shales, the Bakken and the Utica were examined and compared to establish the viability of the experimental method. The results of this work suggest that this method is a promising and viable method for measuring the volume and rate of spontaneous imbibition in organic-rich shale. The exposure of organic-rich shales to atmospheric conditions can significantly modify the properties of the shale through drying or hydration of the samples. All of the shales used in experiments in the following study were carefully maintained at their native state before exposure to the imbibition fluids. Additionally, the shale samples were exposed to several surfactant mixtures to measure the effect of these surfactants on the rate of imbibition.
Evaluation Of Petrophysical Properties Of Gas Shale And Their Change Due To Interaction With Water
Author : Levent Yildirim
Publisher :
Page : pages
File Size : 48,16 MB
Release : 2014
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ISBN :
Book Description
Gas shale is a fine grained clastic, fissile sedimentary rock of gray/black color formed by consolidation of clays and silts. Successful petrophysical evaluation and stimulation treatments with horizontal drilling and hydraulic fracturing enable economic shale gas production. Shale gas development has contributed about 35 % of natural gas supply in US in 2013.Detailed evaluation of gas shales before and after stimulation treatments is a prerequisite to optimize gas production. Complex pore network in gas shales may result in inaccurate evaluation of petrophysical properties with traditional petrophysical models. Therefore, in this research we proposed a new methodology comprising a new understanding of evaluation of porosity, maturity analysis, geomechanical properties and initial gas in place calculations of gas shale via well logs and core analysis based on a new petrophysical model. We applied the methodology in a case study to investigate a Marcellus shale well in evaluating maturity, porosity and geomechanical properties to calculate initial gas in place and reserves and optimize stimulation designs. In the second part of this study, we conducted acoustic travel time measurements of Green River shale samples parallel and perpendicular to bedding plane before and after interaction with water to observe how shale interacts with water at different interaction times and bedding planes by analyzing change in acoustic velocity and mechanical properties before and after treatment to optimize stimulation designs. X-Ray diffraction analysis, scanning electron microscope imaging and horizontal and vertical permeability measurements of Green River shale samples using helium are conducted to characterize the samples by observing mineralogy, pore network and how permeability changes at different in-situ conditions. Therefore, the first and second parts of this research relate with utilization of well logs and core analysis to evaluate petrophysical properties of different gas shale formations.Maturity analysis, porosity evaluation and initial gas in place results of field case study of Marcellus shale show that total organic carbon content directly relates with porosity and adsorbed gas in place occupied in organic matter. Comparison of young's modulus and minimum in-situ stress values between Marcellus shale zone and adjacent boundaries are used for determination of stimulation interval in Marcellus Formation. An effective hydraulic fracturing treatment can be applied within the upper Marcellus Formation because of relatively higher minimum in-situ stress contrast between Stafford Limestone and upper Marcellus Formation. Closer porosity results of Marcellus shale when compared to that in literature and sufficient reserves suggest that density/resistivity separation method is more reliable than sonic/resistivity separation method. X-Ray diffraction and SEM images suggest that Green River Formation samples are dominantly comprised of carbonate minerals. Permeability measurements indicate that Green River Formation samples having very low permeability at various confining stresses needs to be stimulated effectively. Acoustic travel time measurements of Green River shale before and after interaction with water show that compressional and shear velocities increase as confining stress increases. Shear, young's and bulk modulus of Green River shale increase resulting in more rigid samples having more fracture conductivity as confining stress increases. Compressional and shear velocities decrease as Green River shale is exposed to water since minerals are dissolved by water solution and salinity of the samples decrease so that shear, young's and bulk modulus of the samples slightly decrease resulting in less rigid samples having lower fracture conductivity.The new methodology of petrophysical evaluation of gas shale based on the new petrophysical model serves a new understanding of evaluation of maturity analysis, porosity and mechanical properties and initial gas in place calculations of gas shale by utilizing well logs in field and core analysis in laboratory.
Pore-scale Numerical Modeling of Petrophysical Properties with Applications to Hydrocarbon-bearing Organic Shale
Author : Vahid Shabro
Publisher :
Page : 0 pages
File Size : 10,17 MB
Release : 2013
Category :
ISBN :
Book Description
The main objective of this dissertation is to quantify petrophysical properties of conventional and unconventional reservoirs using a mechanistic approach. Unconventional transport mechanisms are described from the pore to the reservoir scale to examine their effects on macroscopic petrophysical properties in hydrocarbon-bearing organic shale. Petrophysical properties at the pore level are quantified with a new finite-difference method. A geometrical approximation is invoked to describe the interstitial space of grid-based images of porous media. Subsequently, a generalized Laplace equation is derived and solved numerically to calculate fluid pressure and velocity distributions in the interstitial space. The resulting macroscopic permeability values are within 6% of results obtained with the Lattice-Boltzmann method after performing grid refinements. The finite-difference method is on average six times faster than the Lattice-Boltzmann method. In the next step, slip flow and Knudsen diffusion are added to the pore-scale method to take into account unconventional flow mechanisms in hydrocarbon-bearing shale. The effect of these mechanisms is appraised with a pore-scale image of Eagle Ford shale as well as with several grain packs. It is shown that neglecting slip flow in samples with pore-throat sizes in the nanometer range could result in errors as high as 2000% when estimating permeability in unconventional reservoirs. A new fluid percolation model is proposed for hydrocarbon-bearing shale. Electrical conductivity is quantified in the presence of kerogen, clay, hydrocarbon, water, and the Stern-diffuse layer in grain packs as well as in the Eagle Ford shale pore-scale image. The pore-scale model enables a critical study of the [delta]LogR evaluation method commonly used with gas-bearing shale to assess kerogen concentration. A parallel conductor model is introduced based on Archie's equation for water conductivity in pores and a parallel conductive path for the Stern-diffuse layer. Additionally, a non-destructive core analysis method is proposed for estimating input parameters of the parallel conductor model in shale formations. A modified reservoir model of single-phase, compressible fluid is also developed to take into account the following unconventional transport mechanisms: (a) slip flow and Knudsen diffusion enhancement in apparent permeability, (b) Langmuir desorption as a source of gas generation at kerogen surfaces, and (c) the diffusion mechanism in kerogen as a gas supply to adsorbed layers. The model includes an iterative verification method of surface mass balance to ensure real-time desorption-adsorption equilibrium with gas production. Gas desorption from kerogen surfaces and gas diffusion in kerogen are the main mechanisms responsible for higher-than-expected production velocities commonly observed in shale-gas reservoirs. Slip flow and Knudsen diffusion marginally enhance production rates by increasing permeability during production.
Geomechanical and Petrophysical Properties of Mudrocks
Author : E.H. Rutter
Publisher : Geological Society of London
Page : 369 pages
File Size : 12,78 MB
Release : 2017-10-09
Category : Science
ISBN : 1786203162
Book Description
A surge of interest in the geomechanical and petrophysical properties of mudrocks (shales) has taken place in recent years following the development of a shale gas industry in the United States and elsewhere, and with the prospect of similar developments in the UK. Also, these rocks are of particular importance in excavation and construction geotechnics and other rock engineering applications, such as underground natural gas storage, carbon dioxide disposal and radioactive waste storage. They may greatly influence the stability of natural and engineered slopes. Mudrocks, which make up almost three-quarters of all the sedimentary rocks on Earth, therefore impact on many areas of applied geoscience. This volume focuses on the mechanical behaviour and various physical properties of mudrocks. The 15 chapters are grouped into three themes: (i) physical properties such as porosity, permeability, fluid flow through cracks, strength and geotechnical behaviour; (ii) mineralogy and microstructure, which control geomechanical behaviour; and (iii) fracture, both in laboratory studies and in the field.
Petrophysical Characterization and Fluids Transport in Unconventional Reservoirs
Author : Jianchao Cai
Publisher : Elsevier
Page : 354 pages
File Size : 34,40 MB
Release : 2019-01-24
Category : Business & Economics
ISBN : 0128172894
Book Description
Petrophysical Characterization and Fluids Transport in Unconventional Reservoirs presents a comprehensive look at these new methods and technologies for the petrophysical characterization of unconventional reservoirs, including recent theoretical advances and modeling on fluids transport in unconventional reservoirs. The book is a valuable tool for geoscientists and engineers working in academia and industry. Many novel technologies and approaches, including petrophysics, multi-scale modelling, rock reconstruction and upscaling approaches are discussed, along with the challenge of the development of unconventional reservoirs and the mechanism of multi-phase/multi-scale flow and transport in these structures. Includes both practical and theoretical research for the characterization of unconventional reservoirs Covers the basic approaches and mechanisms for enhanced recovery techniques in unconventional reservoirs Presents the latest research in the fluid transport processes in unconventional reservoirs
Understanding Petrophysical Properties of Porous Media Using Imaging and Computational Methods
Author : Mengyu Guan
Publisher :
Page : pages
File Size : 34,8 MB
Release : 2020
Category :
ISBN :
Book Description
Development of both conventional and unconventional energy resources remains a significant component in the US and world energy portfolio. From well log data at the reservoir level to nanoscale characterization, each step informs our understanding of the petrophysical behavior of the system. Due to the multiscale heterogeneity in shale reservoirs especially, characterization at various scales is necessary to capture the full physical behavior. Electron and x-ray microscopy techniques are commonly used to image and characterize the microstructure and composition of porous media. Including information about the microstructure and pore connectivity of the inorganic and organic matrix improves estimations of hydrocarbon production and storage capacity in shale reservoirs. In order to capture the effect of multiscale features on bulk properties, a combination of experimental characterization techniques must be employed. The main objective of this research is to develop a multiscale method to describe porosity, connectivity, and chemistry in complex, microporous systems. We first examine a selection of experimental techniques used to characterize complex microporous media. We combine direct measurements of the pore space with image analysis methods to create a multiscale understanding of a Texas cream carbonate and a Vaca Muerta shale sample. We show how these methods are used to obtain a more accurate representation of the pore network for systems with microporosity or features that are difficult to segment. We propose a series of methods that are used together to improve our understanding across multiple length scales. Next, we apply this workflow to study how kerogen evolution and migration during an artificial maturation process is tied to changes in the shale microstructure. We observe an increase in porosity across the shale surface, coupled with a decrease in organic matter-rich regions. This result, in addition to SEM imaging of microcrack development along intraparticle and organic-rich areas, provides important insight into the possible pathways for kerogen to escape the sample. We then investigate how imaging parameters, specifically resolution, affect the petrophysical properties that are calculated directly from the imaged pore networks of a sandstone sample. We present a workflow to downsample a high-resolution image dataset, segment the pore network, and calculate the single-phase permeability using a direct numerical method. We show directly how changes in imaging resolution affects uncertainty in the porosity and permeability of a sample. Finally, given the imaging intensive work performed above, we investigate the potential of using recently developed deep learning based methods for generating realistic pore volumes. These pore volumes are segmented and used for further petrophysical analysis without requiring additional imaging or sampling of the actual reservoir. We develop a generative flow network and apply the model to create 2D and 3D representations of the sandstone pore network with morphological and petrophysical properties that mimic those of real rock. We illustrate the advantages of using such a model for its rapid generation capability and scalability during training.
Sedimentation and Reservoirs of Marine Shale in South China
Author : Feng Yang
Publisher : Springer
Page : 0 pages
File Size : 33,65 MB
Release : 2024-09-23
Category : Science
ISBN : 9789819753604
Book Description
This book systematically investigates the depositional process and reservoir characteristics of organic-rich shales, including (1) The types and development mechanisms of organic-rich shales under ancient ocean and climatic backgrounds. Schematic models are proposed to understand the organic matter enrichment and depletion in shale systems. (2) Microstructure and petrophysical properties. The general lithofacies are recognized and linked to the depositional setting and petrophysical properties. Full-scale pores and fractures are characterized using FE-SEM, gas adsorption, nano-CT and micro-CT scanning. (3) Brittle-ductile characteristics. Rock mechanical properties and in-situ stress are determined. The brittle-ductile transformation of shales is discussed. (4) Shale gas occurrence state and differential enrichment. Gas content and dynamic dissipation over geological time are evaluated using sorption experiments and numerical simulation. Shale gas enrichment model is developed to understand the gas differential accumulation in organic-rich shales. This book can be used for reference by researchers engaged in shale oil and gas geology in both academics and industry.
