Fracture simulation model for API X80 Charpy test in Ductile-Brittle transition temperatures

2020 ◽  
Vol 182 ◽  
pp. 105771 ◽  
Author(s):  
Ji-Su Kim ◽  
Yun-Jae Kim ◽  
Myeong-Woo Lee ◽  
Ki-Seok Kim ◽  
Kazuki Shibanuma
Keyword(s):  
Simulation Model ◽  
Transition Temperatures ◽  
Charpy Test ◽  
Brittle Transition ◽  
Fracture Simulation

Influence of Specimen Geometry and Strain Rate on Ductile-Brittle Transition Characterisation of Reactor Pressure Vessel Steels Using the Small Punch Technique

2015 ◽  
Author(s):  
Jack Adams ◽  
Roger C. Hurst ◽  
J. Bryan Borradaile ◽  
Martin R. Bache
Keyword(s):  
Strain Rate ◽  
Health And Safety ◽  
Charpy Impact ◽  
Charpy Impact Test ◽  
Transition Curve ◽  
Charpy Test ◽  
Small Punch ◽  
Code Of Practice ◽  
Brittle Transition ◽  
Post Test

The small punch (SP) tensile test, originally developed for assessing the integrity of nuclear containments, has seen a renaissance in recent years with the introduction of a Code of Practice and a standardisation proposal. For nuclear applications, the extremely low volumes of material that are required allows specimens to be manufactured from quasi-destructive scoop samples, surveillance specimens or even previously tested Charpy specimens. The low volume of material also alleviates the health and safety requirements and the cost associated with testing active materials. By assessing the energy absorbed before fracture, it is possible to build an entire SP ductile-brittle transition curve using less material than is required for a single Charpy test. Small punch testing has been performed on SA 508-3 NESC-1 spinning cylinder material to establish ductile-brittle transition data, for comparison to that obtained by conventional Charpy impact test techniques. Multiple SP ductile-brittle transition curves have been constructed, building upon the framework of the existing Code of Practice. Novel geometries and associated machining techniques employed to incorporate notches into the surface of the SP specimen, and also the application of relatively high strain rates have been investigated. Post-test fractography illustrates the influence of both stress raising features and strain rate on small punch fracture behaviour.

Design and assessment of a penile fracture simulation model

2021 ◽  
Author(s):  
A.A. Kozan ◽  
M. Logan ◽  
A. Parnham ◽  
M. Liew ◽  
B. Barrass ◽  
...  
Keyword(s):  
Simulation Model ◽  
Penile Fracture ◽  
Fracture Simulation

scholarly journals Empirical estimation of uncertainties of Charpy impact testing transition temperatures for an RPV steel

2020 ◽  
Vol 6 ◽  
pp. 57
Author(s):  
Bernard Marini
Keyword(s):  
Charpy Impact ◽  
Simple Expression ◽  
Impact Testing ◽  
Data Sets ◽  
Transition Temperatures ◽  
Empirical Estimation ◽  
Charpy Test ◽  
Rpv Steel ◽  
Charpy Impact Testing ◽  
Estimation Of Uncertainties

The aim of the present work is to derive empirically a simple expression of the uncertainties on Charpy transition temperatures (TT), which depends only on the test temperatures and the number of tests at each of these temperatures. Calculations of the TT uncertainties of a RPV steel are performed based on an empirical representation of Charpy test results and a Monte Carlo procedure to generate large numbers of data sets for different test matrices. Applying usual procedures to determine the TT to the generated data sets gives access to the distributions of these quantities from which the uncertainties are calculated.An analytical expression for these uncertainties is proposed.

Developing a Tool for 3D Reservoir Simulation of Hydraulically Fractured Wells

2007 ◽  
Vol 10 (01) ◽  
pp. 50-59 ◽  
Author(s):  
Josef R. Shaoul ◽  
Aron Behr ◽  
George Mtchedlishvili
Keyword(s):  
Simulation Model ◽  
Reservoir Simulation ◽  
Hydraulic Fracture ◽  
Fracture Plane ◽  
Tight Gas ◽  
Fracture Conductivity ◽  
Fracture Width ◽  
Fracture Simulation ◽  
Reservoir Simulator ◽  
Actual Fracture

Summary This paper describes the development and capabilities of a novel and unique tool that interfaces a hydraulic fracture model and a reservoir simulator. This new tool is another step in improving both the efficiency and consistency of connecting hydraulic fracture engineering and reservoir engineering. The typical way to model hydraulically fractured wells in 3D reservoir simulators is to approximate the fracture behavior with a modified skin or productivity index (PI). Neither method captures all the important physics of flow into and through the fracture. This becomes even more critical in cases of multiphase flow and multilayered reservoirs. Modeling the cleanup phase following hydraulic fracture treatments can be very important in tight gas reservoirs, and this also requires a more detailed simulation of the fracture. Realistic modeling of horizontal wells with multiple hydraulic fractures is another capability that is needed in the industry. This capability requires more than an approximate description of the fracture(s) in the reservoir-simulation model. To achieve all the capabilities mentioned above, a new tool was developed within a commercial lumped 3D fracture-simulation model. This new tool enables significantly more accurate prediction of post-fracture performance with a commercial reservoir simulator. The automatically generated reservoir simulator input files represent the geometry and hydraulic properties of the reservoir, the fracture, the damaged zone around the fracture, and the initial pressure and filtrate fluid distribution in the reservoir. Consistency with the fracture-simulation inputs and outputs is assured because the software automatically transfers the information. High-permeability gridblocks that capture the 2D variation of the fracture conductivity within the reservoir simulator input files represent the fracture. If the fracture width used in the reservoir model is larger than the actual fracture width, the permeability and porosity of the fracture blocks are reduced to maintain the transmissibility and porous volume of the actual fracture. Both proppant and acid fracturing are handled with this approach. To capture the changes in fracture conductivity over time as the bottomhole flowing pressure (BHFP) changes, the pressure-dependent behavior of the fracture is passed to the reservoir simulator. Local grid refinement (LGR) is used in the region of the wellbore and the fracture tip, as well as in the blocks adjacent to the fracture plane. Using small gridblocks adjacent to the fracture plane is needed for an adequate representation of the filtrate-invaded zone using the leakoff depth distribution provided by the fracture simulator. The reservoir simulator input can be created for multiphase fluid systems with multiple layers and different permeabilities. In addition, different capillary pressure and relative permeability saturation functions for each layer are allowed. Introduction Historically, there have been three basic approaches commonly used for predicting the production from hydraulically fractured wells. First, analytic solutions were most commonly used, based on an infinite-conductivity or, later, a finite-conductivity fracture with a given half-length. This approach also was extended to cover horizontal multiple fractured wells (Basquet et al. 1999). With the development of reservoir simulators, two other approaches were developed. For complicated multiwell, multilayer, multiphase simulations (i.e., full-field models), the fracture stimulation was usually approximated as a negative skin. This is the same as increasing the effective wellbore radius in the simulation model. An alternate approach, developed initially for tight gas applications, was to develop a special-purpose numeric reservoir simulator that could explicitly model the flow in the fracture and take into account the special properties of the proppant, such as the stress-dependent permeability or the possibility of non-Darcy flow. Such models typically were limited to a single-layer, single-phase (oil or gas) situation.

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