Study on Reservoir Internal Stress Variation and Mud Shale Horizontal Section Slippage Induced by Interregional Pore Pressure Based on Stick-Slip Theory

2021 ◽  
Author(s):  
Chaoyang Hu ◽  
Fengjiao Wang ◽  
Qingjun Deng ◽  
Jianjun Xu ◽  
Chi Ai
Keyword(s):  
Internal Stress ◽  
Pore Pressure ◽  
Horizontal Section ◽  
Stick Slip ◽  
Stress Variation

scholarly journals Application of the Mathar Method to Identify Internal Stress Variation in Steel as a Welding Process Result

2017 ◽  
Vol 25 (2) ◽  
pp. 125-136
Author(s):  
Dariusz Kowalski
Keyword(s):  
Internal Stress ◽  
Welding Process ◽  
Internal Stresses ◽  
Induced Voltage ◽  
Stress Variation ◽  
Steel Members ◽  
Electric Arc Welding ◽  
Destructive Measurement ◽  
Non Destructive ◽  
Excessive Stress

Abstract The paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage, including Barkhausen noise The analysis of the latter allows to assess internal stresses in a surface layer of the material. The second method, essential in the paper, is a semi-trepanation Mathar method of tensometric strain variation measurement in the course of a controlled void-making in the material. Variation of internal stress distribution in the material led to the choice of welding technology to join. The assembly process altered the actual stresses and made up new stresses, triggering post-welding stresses as a response for the excessive stress variation.

Research on the Gas Migration Regularity of Municipal Solid Waste Landfill in the Solid-Liquid-Gas-Heat Interaction

2011 ◽  
Vol 243-249 ◽  
pp. 2216-2219
Author(s):  
Xiao Li Liu ◽  
Wen Jing Si ◽  
Chun Ying Zhu
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Pore Pressure ◽  
Gas Flow ◽  
Flow Direction ◽  
Volumetric Strain ◽  
Horizontal Section ◽  
Municipal Solid Waste Landfill ◽  
Waste Landfill ◽  
Solid Liquid

With the establishment of large municipal solid waste landfills, the interaction of geological environment in landfill (seepage field, stress field and temperature field, etc.) has not to be ignored. The multi-field coupling problem of the municipal solid waste landfill is getting attention. But at present the study mainly concentrated on the solid-liquid-gas-heat coupling problem, the study of the waste gas of the municipal solid waste landfill is less. Gas diffusions, gas emissions, and gas collection are related to the secondary pollution problems of the municipal solid waste landfill. This paper established mathematical model which based on the solid-liquid-gas-heat interaction and researched the gas migration rule of the municipal solid waste landfills. The mainly work are as follows: (1) the definite conditions of dynamic model, (2) the solution of dynamic model, (3) results and analysis. The main conclusions are as follows: (1) Pore pressure along the gas flow direction is nonlinear distribution and shows decline trend. As time increases, the pore pressure of each horizontal section decreases. (2)The volumetric strain of the municipal solid waste landfill is nonlinear distribution along the gas flow direction and shows an increasing tendency. As time increases, volumetric strain of each horizontal section increases.(3)As the change of time, the pore pressure first increases, then decreases.(4) In the initial stage, as the change of time, gas output increases rapidly. When it achieves the maximum size, the production quantity of gas reduces and gradually tends to be a quantitative value.

Fatigue Testing and Analysis of a Deep Water Steel Tube Umbilical

2008 ◽  
Author(s):  
Alan Dobson ◽  
Dave Fogg
Keyword(s):  
Mathematical Model ◽  
Fatigue Testing ◽  
Steel Tube ◽  
Steel Tubes ◽  
Stick Slip ◽  
Stress Variation ◽  
Slip Mechanism ◽  
Deep Waters ◽  
Bending Loads ◽  
The Mathematical Model

Rapid analysis of dynamic umbilical structures during the design phase requires a robust mathematical model of the component stresses due to static and alternating loads. The following discusses the validation of a model, through full scale testing, used to assess the stresses and strains present within steel tubes, in umbilical structures typically used in dynamic service in deep waters, such as found in the Gulf of Mexico and offshore West Coast of Africa. The validation focuses upon the complexity of the mathematical model and the influence of tension magnitude the stick-slip mechanism and the stress variation around the circumference of the tubes when under the influence of bending loads.

Dynamic Modelling of Horizontal Shafts With Annular Surface Contact and Friction: Application to Oilwell Drilling

2014 ◽  
Author(s):  
Md. Mejbahul Sarker ◽  
D. Geoff Rideout ◽  
Stephen D. Butt
Keyword(s):  
Three Dimensional ◽  
Dynamic Modelling ◽  
Lateral Vibration ◽  
Horizontal Section ◽  
Stick Slip ◽  
Rock Interaction ◽  
Bottom Hole ◽  
Proposed Model ◽  
Bottom Hole Assembly ◽  
Friction Dynamics

Lateral whirl vibrations in long sections of horizontal oilwell drillstrings, which are essentially enclosed shafts lying on the low side of the wellbore, are potentially destructive to the bit, pipes and downhole tools. Forward or backward whirl can lead to impact with the borehole, and stick slip and bit bounce can cause tool joint failure, twist-off, and bit damage. A complete deviated drillstring has been modelled by having decoupled axial and torsional segments for the vertical and curved portions, and nonlinear three-dimensional multibody segments with lateral vibration in the final horizontal section ending at the bit. The model can predict how axial and torsional bit-rock reactions are propagated to the surface, and the role that lateral vibration near the bit plays in exciting those vibrations and stressing components in the bottom-hole-assembly. The proposed model includes the mutual dependence of these vibrations, which arises due to bit-rock interaction and friction dynamics between the drillstring and wellbore wall.

scholarly journals Shear resistance and continuity of subglacial till: hydrology rules

2010 ◽  
Vol 56 (200) ◽  
pp. 1104-1114 ◽  
Author(s):  
Neal R. Iverson
Keyword(s):  
Pore Pressure ◽  
Shear Resistance ◽  
Effective Pressure ◽  
Stick Slip ◽  
Viscous Shear ◽  
Whillans Ice Stream ◽  
Recurrence Intervals ◽  
Excess Pore Pressures ◽  
Stick Slip Motion ◽  
Basal Till

AbstractThe field observations of G.S. Boulton stimulated widespread interest in deformable beds. Shear resistance of till in its critical state is insensitive to strain rate and increases linearly with effective pressure. During unsteady deformation, pseudo-viscous shear resistance can be caused by dilation of consolidated tills and resultant pore-pressure decline. This effect is probably uncommon, however, because susceptible tills of low hydraulic diffusivity are also those least likely to consolidate significantly during effective-pressure transients. Stick-slip motion at Whillans Ice Stream, Antarctica, indicates that its basal till must weaken during rapid slip and strengthen during longer periods of slower slip. Recurrence intervals for rapid-slip episodes there (6-18hours) indicate that till-strength variations, if driven by changes in pore pressure either related or unrelated to basal freezing, are focused in the uppermost several centimeters of the bed. Ploughing of grains at the bed surface and associated excess pore pressures in adjacent till can account for rate-weakening during rapid slip, with pore-pressure decay causing strengthening between slip episodes. By promoting shallow, sluggish subglacial water flow and low effective pressure, soft beds may help sustain themselves by slowing their own transport. Soft-bed shear resistance, kinematics and continuity are problems rooted in subglacial hydrology.

Effect of modifying substances on internal stress variation in gelatin films

1979 ◽  
Vol 21 (5) ◽  
pp. 1298-1305 ◽  
Author(s):  
G.I. Burdygina ◽  
I.V. Falina ◽  
P.V. Kozlov
Keyword(s):  
Internal Stress ◽  
Stress Variation ◽  
Gelatin Films

scholarly journals Three-dimensional flows of pore pressure-activated Bingham fluids

2019 ◽  
Vol 29 (11) ◽  
pp. 2089-2125 ◽  
Author(s):  
Anna Abbatiello ◽  
Tomáš Los ◽  
Josef Málek ◽  
Ondřej Souček
Keyword(s):  
Pore Pressure ◽  
Three Dimensional ◽  
Large Data ◽  
Three Dimensions ◽  
Cauchy Stress ◽  
Internal Flows ◽  
Stick Slip ◽  
Slip Boundary ◽  
Advection Diffusion Equation ◽  
Long Time

We are concerned with a system of partial differential equations (PDEs) describing internal flows of homogeneous incompressible fluids of Bingham type in which the value of activation (the so-called yield) stress depends on the internal pore pressure governed by an advection–diffusion equation. After providing the physical background of the considered model, paying attention to the assumptions involved in its derivation, we focus on the PDE analysis of the initial and boundary value problems. We give several equivalent descriptions for the considered class of fluids of Bingham type. In particular, we exploit the possibility to write such a response as an implicit tensorial constitutive equation, involving the pore pressure, the deviatoric part of the Cauchy stress and the velocity gradient. Interestingly, this tensorial response can be characterized by two scalar constraints. We employ a similar approach to treat stick-slip boundary conditions. Within such a setting we prove long-time and large-data existence of weak solutions to the evolutionary problem in three dimensions.

Study on the Stress Variation Mechanism for the Rails under the Wheels Repeated Rolling Effects

2014 ◽  
Vol 597 ◽  
pp. 551-556
Author(s):  
Hua Song ◽  
Lin Bang Song ◽  
Jin Kai Yao ◽  
Fa Bo Lian ◽  
Wei Li
Keyword(s):  
Boundary Conditions ◽  
Internal Stress ◽  
Stress Variation ◽  
The Real ◽  
Real Geometry ◽  
Variation Mechanism ◽  
Relationship Of ◽  
The Relationship ◽  
Heavy Rail

Abstract：Based on the real geometry and boundary conditions of the wheels and rails, the models of 60kg/m U75V heavy rail and the wear regions of LM are built using ANSYS/LS-DYNA software. The internal stress value and variation of the heavy rails that were repeatedly crushed by the rolling wheels are analyzed using the ANSYS/LS-DYNA3D software. The relationship of the internal stress and variation of heavy rails with the repeated rolling of the wheels are obtained. It provides an important theoretical proof and reference significance to prevent the different failure behaviors of the rails.

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