scholarly journals Static and Dynamic Mechanical Properties of Organic-Rich Gas Shale

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hui Li ◽  
Chi Dong ◽  
Hongwei Yu ◽  
Xin Zhao ◽  
Yan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamic Properties ◽  
Confining Pressure ◽  
Dynamic Mechanical Properties ◽  
Eagle Ford Shale ◽  
Eagle Ford ◽  
Dynamic Mechanical ◽  
Rock Mechanical Properties

Rock mechanical properties are critical for drilling, wellbore stability, and well stimulation. There are usually two laboratory methods to determine rock mechanical properties: static compression tests and acoustic velocity measurements. Rocks are heterogeneous, so there are significant differences between static elastic constants and the corresponding dynamic ones. Usually, static test results are more representative than dynamic methods but the static tests are time consuming and costly. Dynamic methods are nondestructive and less expensive, which are practical in the laboratory and field. In this paper, we compare the static and dynamic elastic properties of Eagle Ford Shale by triaxial compressive tests and ultrasonic velocity tests. Correlations between static and dynamic elastic properties are developed. Conversion from dynamic mechanical properties to static mechanical properties is established for better estimating reservoir mechanical properties. To better understand the relationship of static and dynamic mechanical properties, 30 Eagle Ford Shale samples were tested. According to the test results, the dynamic properties are considerably different from the static counterparts. For all tested samples, static Young’s modulus is lower than dynamic Young’s modulus, ranging from 55% to 90%. The difference of the static and dynamic Young’s moduli decreases with the increasing of confining pressure. The reason may be because the microcracks closed in high confining pressure. Correlations between static and dynamic Young’s modulus are developed by regression analysis, which are crucial to understand the rock mechanical properties and forecast reservoir performance when direct measurement of static mechanical properties is not available or expensive. There are no strong correlations between static and dynamic Poisson’s ratios observed for the tested samples. Two potentially major reasons for the discrepancy of the static and dynamic properties of Eagle Ford Shale are discussed. Lithology and heterogeneity may be the inherent reasons, and external causes are probably the difference in strain amplitude and frequency.

Young's Modulus and Dynamic Mechanical Properties of San Resins Modified with Ethylene-Propylene Rubber

1978 ◽  
Vol 51 (4) ◽  
pp. 655-667 ◽  
Author(s):  
A. Brancaccio ◽  
L. Gargani ◽  
G. P. Giuliani
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Dynamic Mechanical Properties ◽  
Ethylene Propylene ◽  
Dynamic Mechanical ◽  
Styrene Copolymer ◽  
Wide Range ◽  
Main Transition ◽  
The Relationship

Abstract The dependence of Young's modulus and dynamic mechanical properties of a new high impact resin, ATS (acrylonitrile-styrene copolymer polymerized in the presence of ethylene-propylene-triene terpolymer), on the composition and morphology of the dispersed phase is examined and compared to that of ABS resins (acrylonitrile-styrene copolymer polymerized in presence of polybutadiene). The relationship between modulus and composition is different for the two resins because of the different morphology of the rubbery phases. The experimental results are compared to the predictions of several mathematical models. This analysis is extended to the dynamic moduli E′ and E″, measured over a wide range of temperatures covering the main transition of the rubbery phases.

Manuscript Title: Mechanical and Microstructural Studies of Volcanic Ash Beds in Unconventional Reservoirs

2021 ◽  
Author(s):  
Juan C Acosta ◽  
Mark E Curtis ◽  
Carl H Sondergeld ◽  
Chandra S Rai
Keyword(s):  
Mechanical Properties ◽  
Hydraulic Fracturing ◽  
Young’S Modulus ◽  
Volcanic Ash ◽  
Young's Modulus ◽  
Microstructural Analysis ◽  
Thin Layers ◽  
Ion Milling ◽  
Eagle Ford ◽  
Diagenetic Alteration

Abstract Volcanic ash beds are thin layers commonly observed in the Eagle Ford, Niobrara and, Vaca Muerta formations. Because of their differences in composition, sedimentary structures, and diagenetic alteration, they exhibit a significant contrast in mechanical properties with respect to surrounding formation layers. This can impact hydraulic fracturing, affecting fracture propagation and fracture geometry. Quantifying the mechanical properties of ash beds becomes significant; however, it is a challenge with traditional testing methods. Common logging fails to identify the ash beds, and core plug testing is not possible because of their friability. In this study, nanoindentation was used to measure the mechanical properties (Young's modulus, creep, and anisotropy) in Eagle Ford ash beds, and to determine the contrast with the formation matrix properties. Two separate ash beds of high clay and plagioclase composition were epoxied in an aluminum tray and left for 48 hours curing time. Horizontal and vertical samples of ash beds were acquired and mounted on a metal stub, followed by polishing and broad beam ion milling. Adjacent samples were also prepared for high-resolution Scanning Electron Microscope (SEM) microstructural analysis. The Young's modulus in ash beds ranged from 12 to 24 GPa, with the horizontal direction Young's modulus being slightly greater than that of the vertical samples. The Young's modulus contrast with adjacent layers was calculated to be 1:2 with clay-rich zones and 1:4 with calcite rich zones. The creep deformation rate was three times higher for ash beds compared to other zones. Using Backus averaging, it was determined that the presence of ash beds can increase the anisotropy in the formation by 15-25%. SEM results showed a variation in microstructure between the ash beds with evidence of diagenetic conversion of rhyolitic material into clays. Key differences between the two ash beds were due to the presence of plagioclase and the occurrence of porosity within kaolinite. Overall porosity varied between the two ash beds and adjacent carbonate layers showing a significant increase in porosity. Understanding the moduli contrast between adjacent layers can improve the hydraulic fracturing design when ash beds are encountered. In addition, the presence of these beds can lead to proppant embedment and loss in fracture connectivity. These results can be used for improving geomechanical models.

scholarly journals Approximate Dynamic Programming Based Control of Proppant Concentration in Hydraulic Fracturing

Mathematics ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 132 ◽  
Author(s):  
Harwinder Singh Sidhu ◽  
Prashanth Siddhamshetty ◽  
Joseph Kwon
Keyword(s):  
Mechanical Properties ◽  
Dynamic Programming ◽  
Hydraulic Fracturing ◽  
Young’S Modulus ◽  
Large Scale ◽  
Approximate Dynamic Programming ◽  
Young's Modulus ◽  
Computational Cost ◽  
Control Technique ◽  
Rock Mechanical Properties

Hydraulic fracturing has played a crucial role in enhancing the extraction of oil and gas from deep underground sources. The two main objectives of hydraulic fracturing are to produce fractures with a desired fracture geometry and to achieve the target proppant concentration inside the fracture. Recently, some efforts have been made to accomplish these objectives by the model predictive control (MPC) theory based on the assumption that the rock mechanical properties such as the Young’s modulus are known and spatially homogenous. However, this approach may not be optimal if there is an uncertainty in the rock mechanical properties. Furthermore, the computational requirements associated with the MPC approach to calculate the control moves at each sampling time can be significantly high when the underlying process dynamics is described by a nonlinear large-scale system. To address these issues, the current work proposes an approximate dynamic programming (ADP) based approach for the closed-loop control of hydraulic fracturing to achieve the target proppant concentration at the end of pumping. ADP is a model-based control technique which combines a high-fidelity simulation and function approximator to alleviate the “curse-of-dimensionality” associated with the traditional dynamic programming (DP) approach. A series of simulations results is provided to demonstrate the performance of the ADP-based controller in achieving the target proppant concentration at the end of pumping at a fraction of the computational cost required by MPC while handling the uncertainty in the Young’s modulus of the rock formation.

Dynamic Mechanical Properties of Steel Fiber-Reinforced Concrete Subjected to Shock Loading

2011 ◽  
Vol 52-54 ◽  
pp. 703-708
Author(s):  
Fang Jiang ◽  
Yue Sheng Tan ◽  
Dong Zhao
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Shock Loading ◽  
Dynamic Properties ◽  
Constitutive Relations ◽  
Dynamic Mechanical Properties ◽  
Fiber Reinforced Concrete ◽  
Steel Fiber Reinforced Concrete ◽  
Specific Internal Energy ◽  
Dynamic Mechanical

One-stage light gas gun is used to study the dynamic mechanical properties of reinforced concrete (SFRC) subjected to shock loading. The material of projectile is the same as of the target. The stress-time curves are recorded by three manganin pressure transducers embedded in the targets beforehand. The data of experiment are analyzed by self-designed program using the path line principle of Lagrangian analysis method. With the stress records, complete histories of particle velocity, density (and thus strain) and specific internal energy can be obtained at any point within the gaged region of the material. Moreover, the numerical constitutive relations of RC are obtained and the strain rate ranges from 104 to 105 per second. The result of experiment indicates that the stress-strain curves of SFRC present stagnant-return properties. And some other dynamic properties can be gained, such as rate dependent, waveform dissipation etc.

scholarly journals SHPB Testing and Analysis of Bedded Shale under Active Confining Pressure

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Guoliang Yang ◽  
Jingjiu Bi ◽  
Xuguang Li ◽  
Jie Liu ◽  
Yanjie Feng
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Strain Rate ◽  
Peak Stress ◽  
Confining Pressure ◽  
Dynamic Mechanical Properties ◽  
Dynamic Elastic Modulus ◽  
Peak Strain ◽  
Dynamic Mechanical ◽  
Bedding Angle

Shale gas is the most important new energy source in the field of energy, and its exploitation is very important. The research on the dynamic mechanical properties of shale is the premise of exploitation. To study the dynamic mechanical properties of shale from the Changning-Weiyuan area of Sichuan Province, China, under confining pressure, we used a split Hopkinson pressure bar (SHPB) test system with an active containment device to carry out dynamic compression tests on shale with different bedding angles. (1) With active confining pressure, the shale experiences a high strain rate, and its stress-strain curve exhibits obvious plastic deformation. (2) For the same impact pressure, the peak stress of shale describes a U-shaped curve with an increasing bedding angle; besides, the peak stress of shale with different bedding angles increases linearly with rising confining pressure. The strain rate shows a significant confining pressure enhancement effect. With active confining pressure, the peak strain gradually decreases as the bedding angle increases. (3) As a result of the influence of different bedding angles, the dynamic elastic modulus of shale has obvious anisotropic characteristics. Shale with different bedding angles exhibits different rates of increase in the dynamic elastic modulus with rising confining pressure, which may be related to differences in the development of planes of weakness in the shale. The results of this study improve our understanding of the behavior of bedded shale under stress.

Study on Physical and Dynamic Properties of BR Based Composites Filled with Different Particle Size of Magnesia

2012 ◽  
Vol 217-219 ◽  
pp. 165-173 ◽  
Author(s):  
Nai Xiu Ding ◽  
Fu Lan Hao ◽  
Lei Li ◽  
Wen Sun ◽  
Liang Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Tensile Strength ◽  
Physical Properties ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Frequency Mode ◽  
Particle Sizes ◽  
Payne Effect ◽  
Dynamic Mechanical

BR/MgO composites were prepared with seven kinds of particle sizes of MgO filled respectively. Effects of particle sizes on dynamic mechanical properties, vulcanization characteristics and physical properties of BR/MgO composites were studied. The results showed that the tensile strength of composites filled nanoscale of MgO was nine times of pure BR, and the vulcanization time was significantly shorter than that of composites filled with micron grade filler. The RPA experiments proved that the composites filled with MgO of 20nm and 50nm have greatly higher G＇, and that the G＇of the composites increase markedly while the value of tanδ decrease sharply with given temperature above 90 °C increasing. the higher value of tanδ at the frequency mode, and the obvious Payne effect compared with the composites filled micron grade of MgO

scholarly journals Study on the Dynamic Mechanical Properties of Viscoelastic Materials Based on Asymmetrical Sandwich Beams

2018 ◽  
Vol 8 (8) ◽  
pp. 1359 ◽  
Author(s):  
Qingqing Wu ◽  
Minqing Wang
Keyword(s):  
Mechanical Properties ◽  
Dynamic Properties ◽  
Estimation Method ◽  
Dynamic Mechanical Properties ◽  
Test Method ◽  
Core Material ◽  
Beam Specimen ◽  
Viscoelastic Materials ◽  
Dynamic Mechanical ◽  
The Core

A modified estimation method for the dynamic mechanical properties of viscoelastic materials via asymmetrical sandwich specimens is presented. In contrast to the traditional vibrating cantilever beam test method (VCBTM), the proposed method allows asymmetrical base beams in sandwich specimens. Based on the complex stiffness method, complex parameters are introduced for general sandwich configurations. Calculation formulas for loss factor and shear modulus of the core material are presented. The effectiveness of this approach is validated numerically and experimentally by analysis of one symmetrical sandwich beam specimen and two specimens with asymmetrical thicknesses and materials. It is shown that dynamic mechanical parameters of the core material can be obtained regardless of sandwiches’ symmetry. The proposed method breaks the symmetrical criteria for sandwich specimens and may provide a wider application to measure viscoelastic materials’ dynamic properties.

Improvement on Mechanical and Dynamic Properties of Palm Fiber/PLA Composites by Fiber Treatment

2015 ◽  
Vol 1087 ◽  
pp. 355-359
Author(s):  
Mohamed Nasrul Mohamed Hatta ◽  
Nagata Kenji
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Dynamic Properties ◽  
Dynamic Mechanical Properties ◽  
Palm Fiber ◽  
Dynamic Mechanical ◽  
Fiber Coating ◽  
Fiber Treatment ◽  
Hot Compress ◽  
Properties Of Composites

In this work, palm fiber reinforced polylactic acid composites were fabricated by hot-compress. The palm fibers were treated by γ-aminopropyl trimethoxysilane (APS) and coated with polylactic acid (PLA) in varied percentage (5%, 10% and 15%). The treatment reaction was analyzed by FTIR and the effect of fiber treatment on the flexural and dynamic mechanical properties of oil palm empty fruit bunch/polylactic acid (OPEFB/PL) composites were examined. The flexural properties of composites were increased with increasing of fiber coating and improved by introduction of APS. It was also observed that the APS treated fibers had improved the dynamic mechanical properties of the composites respectively.

Effect of mineralogy and organic matter on mechanical properties of shale

2015 ◽  
Vol 3 (3) ◽  
pp. SV9-SV15 ◽  
Author(s):  
Vikas Kumar ◽  
Carl Sondergeld ◽  
Chandra S. Rai
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Clay Content ◽  
Organic Content ◽  
Small Samples ◽  
Quartz Content ◽  
Eagle Ford ◽  
Young’S Moduli ◽  
Heterogeneous Samples

We report a nanoindentation study of shales on 144 samples from Barnett, Eagle Ford, Haynesville, Kimmeridge, Ordovician, and Woodford plays. Mineralogy is found to play an important role in controlling mechanical properties of shales: An increase in carbonate and quartz content is correlated with an increase in Young’s modulus, whereas an increase in total organic content, clay content, and porosity decreases Young’s modulus. We had a close agreement between indentation moduli measured on small samples (millimeter scale) and dynamic moduli calculated from velocity and density measurements made on larger samples (centimeter scale). By taking an average of a large number of indentation Young’s moduli, 100 indentations in our case, and using an appropriate penetration force, nanoindentation technology measured an acceptable average Young’s modulus even for heterogeneous samples such as shale highlighting the potential of applying this technology to plug and perhaps field-scale problems.

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