scholarly journals Modelling of Time-Dependent Wellbore Collapse in Hard Brittle Shale Formation under Underbalanced Drilling Condition

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-21
Author(s):  
Shanpo Jia ◽  
Zhiqiang Xiao ◽  
Bisheng Wu ◽  
Caoxuan Wen ◽  
Lufeng Jia
Keyword(s):  
Immersion Time ◽  
Progressive Failure ◽  
Drilling Fluid ◽  
Progressive Collapse ◽  
Failure Process ◽  
Chemical Properties ◽  
Whole Process ◽  
Drilling Condition ◽  
Shale Formation ◽  
Physical And Chemical

In recent years, the lithologic traps in a mid-depth formation are the focus of oil or gas exploration and development for eastern oilfields in China. The Shahejie Formation develops thick hard brittle shale, and the wellbore instability problem is prominent due to obvious hydration effect for long immersion time during drilling. Through the analysis of laboratory tests and field test results of physical and chemical properties and microstructure and mechanical properties of hard brittle shale, the instability mechanism is discussed for the wellbore in the shale formation. To simulate the whole process of progressive collapse of a wellbore in a hard brittle shale formation, a coupled hydraulic-mechanical-chemical (HMC) model is developed and this model is compiled with ABAQUS software as the solver. Then the coupled HMC model is applied to simulate the progressive evolution process of wellbore collapse in a hard brittle shale formation, and the influence of different parameters on the progressive failure of the wellbore is analysed. The results show that the wellbore enlargement rate increases with the drilling fluid immersion time and the influence of different parameters on the wellbore enlargement rate is different. The water absorption diffusion coefficient and the activity of the drilling fluid have the most obvious influence on the expansion of the wellbore, and the sensitivity is strong. The permeability of shale has little effect on the wellbore enlargement rate. The calculated progressive failure process of the wellbore is basically consistent with that of the actual drilling.

scholarly journals A Strategy to Synthesize Multilayer Graphene in Arc-Discharge Plasma in a Semi-Opened Environment

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2279 ◽  
Author(s):  
Hai Tan ◽  
Deguo Wang ◽  
Yanbao Guo
Keyword(s):  
Discharge Plasma ◽  
Arc Discharge ◽  
Chemical Reduction ◽  
Chemical Properties ◽  
Chemical Vapor ◽  
Chemical Components ◽  
Multilayer Graphene ◽  
Whole Process ◽  
Hazardous Chemical ◽  
Physical And Chemical

Graphene, as the earliest discovered two-dimensional (2D) material, possesses excellently physical and chemical properties. Vast synthetic strategies, including chemical vapor deposition, mechanical exfoliation, and chemical reduction, are proposed. In this paper, a method to synthesize multilayer graphene in a semi-opened environment is presented by introducing arc-discharge plasma technology. Compared with previous technologies, the toxic gases and hazardous chemical components are not generated in the whole process. The synthesized carbon materials were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Raman spectra technologies. The paper offers an idea to synthesize multilayer graphene in a semi-opened environment, which is a development to produce graphene with arc-discharge plasma.

Basic Performance Research of Polymer Intercalation Clay

2012 ◽  
Vol 578 ◽  
pp. 183-186
Author(s):  
Xiao Chun Cao ◽  
Yi Qin ◽  
Yan Na Zhao ◽  
Kun Ke
Keyword(s):  
Drilling Fluid ◽  
Chemical Properties ◽  
Drilling Fluids ◽  
Technical Problems ◽  
Clay Particles ◽  
Polymer Properties ◽  
Physical And Chemical ◽  
Performance Research ◽  
And Chemical Properties

Using the preliminary research of the polymer properties, the different between the physical and chemical properties of new polymer-clays nanometer composites and clay have been studied. Different polymers are used to evaluate experiment. Based on a large number of lab experiments, the changes of rheological property and API filtration property of polymer-clay drilling fluids nanometer composites are studied. The results show that clay particles could become smaller and the composites drilling fluid have the role of controlling loss and enhancing cake quality. The prepared composites could be used to solve the technical problems in drilling fluid.

Fracture Mechanics Analysis of GI All-Ceramic Crowns

2013 ◽  
Vol 750-752 ◽  
pp. 529-532
Author(s):  
Cheng Fan
Keyword(s):  
Clinical Application ◽  
Process Analysis ◽  
Failure Process ◽  
Chemical Properties ◽  
Ceramic Materials ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Analysis System ◽  
Physical And Chemical ◽  
Ceramic Crown

Dental ceramic materials have approximate color and translucency with natural tooth, which is unmatched by other restorative materials. Because of its beautiful appearance, good physical and chemical properties, all-ceramic crown restorations are more widely used., However, due to the brittleness of ceramics and the stress mismatch between different materials, dropping or fracture phenomenon of porcelain veneer is often occurred in clinical application during the service period of all-ceramic crowns. The porcelain veneer failure mechanism is still not very clear, in this paper, the force performance of all-ceramic crowns is analyzed using the RFPA (realistic failure process analysis) system. The crack initiation, propagation and failure process of all-ceramic crown can be clearly observed and the research results provide guidance for clinical application

Numerical Simulation of Failure Process of VITA All-Ceramic Crowns

2012 ◽  
Vol 602-604 ◽  
pp. 544-547
Author(s):  
Cheng Fan ◽  
Geng Chen ◽  
Shan Shan Wang
Keyword(s):  
Process Analysis ◽  
Failure Process ◽  
Chemical Properties ◽  
Ceramic Materials ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Analysis System ◽  
Materials Failure ◽  
Physical And Chemical ◽  
Ceramic Crown

Ceramic materials has approximate color and translucency with natural tooth, which is unmatched by other restorative materials. Because of its beautiful appearance, good physical and chemical properties, all-ceramic crown restorations are more widely used. However, due to the brittleness of ceramics and the stress mismatch between different materials, failure phenomenon is often observed during the service period of all-ceramic crowns. The failure process and mechanism are not clear, in this paper, the force performance of all-ceramic crowns is analyzed using the RFPA (realistic failure process analysis) system. The crack initiation, propagation and failure process of all-ceramic crown can be clearly observed and the research results provide guidance for clinical application.

scholarly journals Wiper Trips Effect on Wellbore Instability Using Net Rising Velocity Methods

2018 ◽  
Vol 11 (1) ◽  
pp. 14-28
Author(s):  
Ali K. Darwesh ◽  
Thorkild M. Rasmussen ◽  
Nadhir Al-Ansari
Keyword(s):  
Drilling Fluid ◽  
Chemical Properties ◽  
Field Work ◽  
Physical And Chemical Properties ◽  
Shale Formations ◽  
Wellbore Instability ◽  
Fluid Properties ◽  
Physical And Chemical ◽  
Drawing Program ◽  
And Chemical Properties

Background:This paper discusses the wiper trip effects on well instability in shale formations.Objectives:Problematic shale interval sections have been studied for the time spent on the wiper trip operations. Lifting efficiency and well wall instability change with the time analyzed. Detailed drilling operation, formation heterogeneity, rheological and filtration characteristics of polymer water-based mud are discussed. Physical and chemical properties of the drilled formation and drilling fluid are also studied.Materials and Methods:Wiper trips are analyzed using a typical drawing program to find the relations between the most controllable parameters. For that, two calculation models have been implemented to find the net rising cutting particles velocity in the annular. The relation between the net rising velocity and wiper trips is analyzed. Laboratory works have been done to support the findings of field work.Results:Strong relations have been found between the wiper trip impacts and lithology types of the penetrated shale.Conclusion:A modified drilling program is proposed in relation to changes in casing setting depth and drilling fluid properties that make the operations more efficient in cost and time.

scholarly journals Applications of Biodiesel in Drilling Fluids

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ashraf Ahmed ◽  
Salaheldin Elkatatny ◽  
Saad Al-Afnan
Keyword(s):  
Chemical Reactivity ◽  
Drilling Fluid ◽  
Chemical Properties ◽  
Temperature Stability ◽  
Lessons Learned ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Long Chain Fatty Acid ◽  
Drilling Muds ◽  
Physical And Chemical

Biodiesel, referred to as the monoalkyl ester of long-chain fatty acid ester that is synthesized by the complete transesterification of triglycerides, has captured the attention of drilling researchers attributing to its magnificent characteristics such as the high flash point, excellent lubricity, nontoxicity, high biodegradability, and abundant feedstock resources, which make it ecofriendly and technically and economically feasible for a sustainable drilling operation. There are several studies that reported and documented the usage of biodiesel in drilling fluids on laboratory and field scales. In this paper, the production and the key physical and chemical properties of biodiesel are thoroughly reviewed. Moreover, the applications of biodiesel in drilling muds either as base fluids or additives were comprehensively surveyed. The literature review revealed that the challenges of biodiesel applications in drilling mud systems are related to its chemical reactivity and adverse interactions with some additives, along with its performance deficiency at temperature above 120°C. Therefore, further investigation on temperature stability and additive compatibility is recommended. In addition, as a new approach, it is recommended to study the potentiality of using crude waste oils in drilling mud formulations. The lessons learned and recommendations stated in this paper will assist in enhancing the proved use of biodiesel and drilling fluid optimization.

Acoustic Transceiver Optimization Analysis for Downhole Sensor Data Telemetry via Drillstring

2013 ◽  
Vol 302 ◽  
pp. 389-394
Author(s):  
Ai Min Ning ◽  
Cheng Li ◽  
Zhao Liu
Keyword(s):  
Acoustic Waves ◽  
Channel Model ◽  
Signal To Noise Ratio ◽  
Drilling Fluid ◽  
Chemical Properties ◽  
Sensor Data ◽  
Noise Sources ◽  
High Data ◽  
Quarter Wavelength ◽  
Physical And Chemical

Downhole sensor data telemetry using acoustic waves along the drillstring helps to know the physical and chemical properties of the formation and drilling fluid in Logging While Drilling. However, complex drillstring channel characteristics and normal downhole drilling operations will often adversely affect the quality of acoustic telemetry. Based on a theoretical channel model, we analyze the effects of transceiver optimal placements on acoustic transmission through a periodic drillstring. Considering the downhole noisy conditions including the surface noise sources, the downhole noise sources and multiple reflection echoes, dual acoustic receivers and an acoustic isolator are analyzed to improve the Signal-to-Noise Ratio and the capacity of the uplink channel. By arranging two receivers spaced one-quarter wavelength apart at receiver ends, the suppression results of one-way downlink noises are evaluated with the aid of the channel transient simulation model. Then the isolating results of uplink noises from drilling bit are investigated, with regard to the isolator placed between the downhole transmitter and a noise source. These methods, in conjunction with the complex drillstring features, show that the uses of the available transceiver design and signal processing techniques can make the drillstring as a waveguide for transmitting downhole sensor information at high data rate.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Biophysical Measurement of Molecular Weight of Foot-and-Mouth Disease RNA Fragments

1974 ◽  
Vol 32 ◽  
pp. 262-263
Author(s):  
Sydney S. Breese ◽  
Howard L. Bachrach
Keyword(s):  
Chemical Properties ◽  
Foot And Mouth Disease ◽  
Mouth Disease ◽  
Distilled Water ◽  
Bovine Plasma ◽  
Mouth Disease Virus ◽  
Foot And Mouth ◽  
Carbon Coated ◽  
Rna Fragments ◽  
Physical And Chemical

Continuing studies on the physical and chemical properties of foot-and-mouth disease virus (FMDV) have included electron microscopy of RNA strands released when highly purified virus (1) was dialyzed against demlneralized distilled water. The RNA strands were dried on formvar-carbon coated electron microscope screens pretreated with 0.1% bovine plasma albumin in distilled water. At this low salt concentration the RNA strands were extended and were stained with 1% phosphotungstic acid. Random dispersions of strands were recorded on electron micrographs, enlarged to 30,000 or 40,000 X and the lengths measured with a map-measuring wheel. Figure 1 is a typical micrograph and Fig. 2 shows the distributions of strand lengths for the three major types of FMDV (A119 of 6/9/72; C3-Rezende of 1/5/73; and O1-Brugge of 8/24/73.

Tailoring microstructures of materials through biomimetics

1993 ◽  
Vol 51 ◽  
pp. 500-501
Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Chemical Properties ◽  
Design And Synthesis ◽  
Structure Sensitive ◽  
Macro Scale ◽  
Methods Of Synthesis ◽  
Successive Level ◽  
Engineering Materials ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Synthesis Of Materials

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.

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