scholarly journals Modelling igneous rock mechanics parameter based on logging data in Shunbei oil field

2021 ◽  
Vol 2076 (1) ◽  
pp. 012008
Author(s):  
Wenxia Li ◽  
Weiqiang Song ◽  
Jingtao Liu ◽  
Xiuping Chen ◽  
Huidong Mu

Abstract In order to improve the rate of penetration (ROP) in Permian igneous rock strata, the rock mechanics is modeled based on the continuous logging data (acoustic, density, caliper, resistivity and gamma logging) and confirmatory indoor experiments. The model considers the influence of well collapse and expansion on logging data in igneous rock formation to improve the calculation accuracy. Based on this model, the continuous profile of Permian compressive strength, tensile strength, mud content, internal friction angle are calculated, and then the differences of Permian strata in the north, middle and south of the oilfield are further compared and analyzed. The results can provide support for the optimization of efficient rock breaking and reservoir fracturing technology.

2021 ◽  
Vol 36 (1) ◽  
pp. 111-119
Author(s):  
Behzad Jafari Mohammadabadi ◽  
Kourosh Shahriar ◽  
Hossein Jalalifar ◽  
Kaveh Ahangari

Rocks are formed from particles and the interaction between those particles controls the behaviour of a rock’s mechanical properties. Since it is very important to conduct extensive studies about the relationship between the micro-parameters and macro-parameters of rock, this paper investigates the effects of some micro-parameters on strength properties and the behaviour of cracks in rock. This is carried out by using numerical simulation of an extensive series of Uniaxial Compressive Strength (UCS) and Brazilian Tensile Strength (BTS) tests. The micro-parameters included the particles’ contact modulus, the contact stiff ness ratio, bond cohesion, bond tensile strength, the friction coefficient and the friction angle, and the mechanical properties of chromite rock have been considered as base values of the investigation. Based on the obtained results, it was found that the most important micro-parameters on the behaviour of rock in the compressive state are bond cohesion, bond tensile strength, and the friction coefficient. Also, the bond tensile strength showed the largest effect under tensile conditions. The micro-parameter of bond tensile strength increased the rock tensile strength (up to 5 times), minimized destructive cracks and increased the corresponding strain (almost 2.5 times) during critical stress.


2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Zhibin Lin ◽  
Boyang Zhang ◽  
Xiaofei Gong ◽  
Limin Sun ◽  
Wenzhen Wang ◽  
...  

The filling material of the karst collapse column (KCC) is easy to be activated by mining. During this process, the mechanical properties of KCC fillings change, and its water resisting capacity constantly deteriorates and thus often leads to water inrush disaster. In this study, the samples of KCC fillings were taken on-site and then were remolded by the consolidation drainage method. The variation laws of the compressive strength, tensile strength, cohesive stress, internal friction angle, and permeability of the filling samples with respect to the consolidation pressure and moisture content were tested and analyzed. Based on an engineering example, the yield and activation and particle loss of the filling material of the KCC are analyzed. A mechanism for the lagging water inrush of KCC in the process of mining is proposed. The main results of the present study can be concluded concisely as follows. (1) The KCC fillings show obvious soft rock characteristics in the process of uniaxial compression and Brazilian split. The ratio of the uniaxial compressive strength to splitting tensile strength is between 12 : 1 and 8 : 1. The larger the consolidation pressure or the smaller the moisture content, the larger the ratio. (2) With the increase of consolidation pressure or the decrease of moisture content, the uniaxial compressive strength, elastic modulus, splitting tensile strength, cohesive stress, and internal friction angle of the filling material of the KCC increase linearly, while its permeability increases exponentially. (3) When the crack field of the surrounding rocks of the stope is connected with the KCC, its filling material will continue to yield, activate, and migrate under the fluid-solid coupling effect and finally result in the lagging water inrush from the KCC.


Author(s):  
Balázs Vásárhelyi ◽  
Morteza Davarpanah

The goal of this paper is to present the influence of the water saturation of the intact rock on different mechanical parameters, such as internal friction angle, cohesion, Hoek-Brown constant (mi ). Analyzing the previously published results, it was found that due to water saturation both the uniaxial compressive strength and tensile strength decrease similarly, i.e. the ratio of these two values is constant, thus the internal friction angle does not change but only the cohesion. Likewise, Hoek-Brown constant (mi ) remains constant; it is independent on the moisture content.The ratio of the elastic modulus and the uniaxial compressive strength of the intact rock is also calculated. According to the laboratory results, this ratio (namely modulus ratio) is also independent on the water content.It is shown that the mechanical parameters of the rock mass (such as compressive strength, tensile strength, deformation modulus) similarly depend on the water content than the intact rock.


2016 ◽  
Vol 50 (1) ◽  
pp. 39-50
Author(s):  
Suman Panthee ◽  
Mahesh Khanal ◽  
T. N. Singh

 Geotechnical and geomechanical properties are important to understand tunnel behaviour and they differ according to rock types. Therefore, tunnel passing through different rock types is selected for the present study. The tunnel alignment of Kulekhani III hydroelectric project crosses five stratigraphic formations which compriseing eight lithological units. The rocks of the area have most dominantly three sets of joints in which the foliation plane is prominent. In geotechnical study of intact rock, seven geotechnical properties - viz unit weight (γ), uniaxial compressive strength (σci), tensile strength (σti), young’s modulus (Ei), poison’s ratio (ν), friction angle (ci) and cohesion ( i) were measured in lab and on the basis of the intact rock properties five geotechnical properties - uniaxial compressive strength (σcm), tensile strength (σtm), young’s modulus (Em), friction angle (cm) and cohesion ( m) of rock mass were determined. RMR, Q and GSI were used for geomechanical classification and the distributions of the geomechanical class values were studied. The relationship between UCS of rock mass and geomechanical classifications RMR and Q were studied for all rock types. Quite similar results were observed with both RMR and Q systems. The trend of correlations of each rock type with both classification systems follows almost analogous order. Power type continuous equation is observed for Q and exponential type relation is obtained for RMR. The general trend of correlation of UCS rock mass with RMR and Q is calculated which has R2 more than 0.9. The observed relations were compared with empirical relations proposed by other researchers and the results of the present study lie between the upper and lower boundaries set by other researchers. Among them, harder rocks have better correlation than softer rocks. It is also observed that higher the poisson’s ratio of the rock shown higher the order of linear correlation of rock mass properties with its geomechanical properties.


2011 ◽  
Vol 250-253 ◽  
pp. 664-667 ◽  
Author(s):  
Qiao Yan Guan ◽  
Peng Zhang

A designed experimental study has been conducted to investigate the effect of clay dosage on mechanical properties of plastic concrete. The mechanical properties include compressive strength, splitting tensile strength, shear strength and elastic modulus. On the basis of the experimental results of the specimens of eight sets of mix proportions, the mechanism of action of clay on these mechanical properties has been analyzed in details. The results indicate that there is a tendency of decrease in the compressive strength, splitting tensile strength, shear strength and elastic modulus of plastic concrete with the increase of clay dosage. However, the internal friction angle of the shear specimens is increasing gradually with the increase of clay dosage. Further, the clay appears can improve the ductility of plastic concrete and this can help plastic concrete to bear larger deformation before failure.


2018 ◽  
Vol 9 (2) ◽  
pp. 67-73
Author(s):  
M Zainul Arifin

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.


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