An Analytical Approach for Strain Analysis of Buried Steel Pipeline in Mining Subsidence Areas

2017 ◽  
Author(s):  
Mengying Xia ◽  
Hong Zhang
Keyword(s):  
Oil And Gas ◽  
Axial Strain ◽  
Compressive Strain ◽  
Reduction Factor ◽  
Mining Subsidence ◽  
Operating Pressure ◽  
Long Distance ◽  
Complex Load ◽  
Steel Pipeline ◽  
Subsidence Area

Mining subsidence is one of the typical geological hazard threats for long distance oil and gas pipeline. Pipelines in subsidence areas will encounter complex load conditions, which probably will lead to rupture or local buckling failure. An analytical strain calculation model for steel pipeline in mining subsidence areas was proposed. Accuracy of the model was validated by comparing with the finite element results. Based on the proposed model, parametric study was conducted to investigate the influences of main effect factors on the pipe strain. Results show that, the maximum compressive strain occurs in the middle of the subsidence area, and the maximum tensile strain occurs on the edge of the subsidence area. Axial strain of the pipeline in the subsidence area increases with the increase of overlying strata stiffness, strike length and mining depth. But the mining thickness has a negligible effect on the axial strain. The increase of operating pressure, buried depth and pipe-soil interaction reduction factor will increase the axial strain, while a larger pipe wall thickness will induce a smaller axial strain.

Effectiveness of Ultraviolet Light For Mitigating Risk of Microbiologically Influenced Corrosion in Steel Pipeline

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
M. K. F. M. Ali ◽  
N. Md. Noor ◽  
N. Yahaya ◽  
A. A. Bakar ◽  
M. Ismail
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Microbiologically Influenced Corrosion ◽  
Metal Loss ◽  
Desulfovibrio Vulgaris ◽  
Pipeline System ◽  
Long Distance ◽  
Gas Industry ◽  
Internal Corrosion ◽  
Steel Pipeline

Pipelines play an extremely important role in the transportation of gases and liquids over long distance throughout the world. Internal corrosion due to microbiologically influenced corrosion (MIC) is one of the major integrity problems in oil and gas industry and is responsible for most of the internal corrosion in transportation pipelines. The presence of microorganisms such as sulfate reducing bacteria (SRB) in pipeline system has raised deep concern within the oil and gas industry. Biocide treatment and cathodic protection are commonly used to control MIC. However, the solution is too expensive and may create environmental problems by being too corrosive. Recently, Ultraviolet (UV) as one of the benign techniques to enhance mitigation of MIC risk in pipeline system has gained interest among researchers. An amount of 100 ml of modified Baar’s medium and 5 ml of Desulfovibrio vulgaris (strain 7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API 5L-X70 coupons at the optimum temperature of 37°C and pH 9.5 for fifteen days. This was then followed by exposing the medium to UV for one hour. Results from present study showed that UV radiation has the ability to disinfect bacteria, hence minimizing the risk of metal loss due to corrosion in steel pipeline. 

Study on the Assets Integrity Management System of Long Distance Oil and Gas Pipeline

2006 ◽  
Author(s):  
Weibin Wang ◽  
Wenqiang Tong ◽  
Zupei Yang ◽  
Muyang Ai ◽  
Hongsheng Cui ◽  
...  
Keyword(s):  
Management System ◽  
Oil And Gas ◽  
Gas Pipeline ◽  
Research Development ◽  
Practical Application ◽  
Long Distance ◽  
Steel Pipeline ◽  
System Risk ◽  
Integrity Management ◽  
And Function

The integrity management system of steel pipeline is an international popular pattern of assets management at present. It has important meaning and effect that establishing and consummating a set of assets integrity management (AIM) system with practical application value in all the integrity management system. By using the AIM system, risk can be identified and ranged timely; more detect and assess data may be gained; the maintenance and remedy cost can be saved and the monitoring become more convenient and quick. Thereby, the AIM system can contribute to dynamic and circular integrity management. According to the latest research development of integrity management in the international, this paper illustrate the assets integrity management in detail from the aspect of the application of assets integrity management, design way, workflow, and function introducing, which is based on the design module of assets integrity management.

ECA of Pipeline With Girth Weld Strength Mis-Matching Subjected to Large Strain

2009 ◽  
Author(s):  
Zhengmao Yang ◽  
Shashi Kumar ◽  
Jens P. Tronskar
Keyword(s):  
Base Metal ◽  
Structural Integrity ◽  
Oil And Gas ◽  
Large Strain ◽  
Axial Strain ◽  
Weld Strength ◽  
Assessment Procedure ◽  
Long Distance ◽  
Acceptance Criteria ◽  
Gas Field

In recent years, the strain based design for pipeline has been widely accepted by the industry, but the definition of a rational flaw acceptance criteria for girth welds subjected to axial strain within the context of the existing codified fracture mechanics based assessment procedures is problematic since these are essentially stress based. To extend the FAD method to the large strain conditions, several challenges i.e. weld strength mismatching, fracture toughness, and welding residual stresses have to be understood. With appropriate modifications as per DNV-RP-F108 [1], the assessments procedure detailed in BS7910 document for stress based situations have been used successfully for several projects to develop acceptance criteria for pipeline installation involving plastic straining. But only weld metal strength over-match comparing with base metal is considered in DNV-RP-F108 [1]. High strength line pipes are required to reduce the transmission cost of natural gas in long distance and internal clad with corrosion resistant alloy (CRA) is used for transportation of sour gas. Steel manufactures have developed such line pipes to develop new oil and gas field. The inconel filler metal was selected as weld consumable for the production girth weld in the lay budge. From the all weld tensile tests, it was found that the yield strength of the weld is under-match comparing the base metal, and the pipeline maybe subjected to a strain level up to 1.0% due to the lateral buckling. In this research the effect of weld strength mismatching on the structural integrity of the pipeline subjected to large strain was studied. The Engineering Critical Assessment (ECA) was performed to derive the critical flaw acceptance criteria for the AUT system. The segment tests and numerical analysis were performed to validate the assessment procedure, and the finite element analyses of the pipeline girth weld with surface crack in the weld centre were carried out to investigate the effect of bi-axial loading on the ECA results.

Numerical Study on the Effect of Defect Length upon Burst Capacity of Composite Repaired Pipe

2021 ◽  
Vol 879 ◽  
pp. 179-188
Author(s):  
Kah Qi Lim ◽  
Chao Bao ◽  
Mohd Syahrul Hisyam Mohd Sani ◽  
Lim Kar Sing
Keyword(s):  
Oil And Gas ◽  
Numerical Study ◽  
Burst Pressure ◽  
Pipeline System ◽  
Repair System ◽  
Operating Pressure ◽  
Long Distance ◽  
Element Analysis ◽  
Frp Composites ◽  
The Difference

Pipeline system is one of the essential infrastructures in oil and gas industries as it is used to transport oil and gas over long distance. However, pipelines will undergo damages and deteriorations after being used for some years, especially when corrosion occurs. Corrosive pipes will experience reduction in wall thickness resulted a lower remaining strength of the pipe, and consequently lead to failure once the remaining strength unable to withstand the desired operating pressure of the pipe. Therefore, additional strength from repairing job needs to be provided, for instance, by using fibre-reinforced polymer (FRP) composites. Unlike the corroded pipeline assessment codes, the pipeline repair codes that are used to design composite repair system of corroded pipe do not include the defect geometries such as defect length. In this study, burst pressure of the composite repaired pipeline with different defect lengths and the effect of the defect length upon the burst capacity of composite repaired pipe are investigated. The study is carried out by finite element analysis on various defective pipes with different defect length sizes. The results show that the difference of the burst pressure subjected to various defect lengths is 15.59% and this had proved that there is effect of defect length upon the burst capacity of composite repaired pipe. This finding can be very useful for optimizing the existing repair design.

Strain Prediction for X80 Steel Pipeline Subjected to Strike-Slip Fault Under Compression Combined With Bending

2015 ◽  
Author(s):  
Xiaoben Liu ◽  
Hong Zhang ◽  
Yanfei Chen
Keyword(s):  
Compressive Strain ◽  
Strike Slip ◽  
Numerical Results ◽  
Strike Slip Fault ◽  
Fe Model ◽  
Long Distance ◽  
Steel Pipeline ◽  
Reliability Based Design ◽  
Applicable Range ◽  
X80 Steel

Strike-slip fault is one main kind of PGD faced by long distance gas pipelines. Based on non-linear finite element method, a numerical model for buried pipeline under strike-slip fault was proposed. The model was proven to be reasonable by comparing the numerical results with previous researcher’s experiment results. By using the FE model, peak compressive strain of X80 steel pipeline subjected to strike-slip fault under compression combined with bending was studied. The sensitivities of the diameter, wall thickness, soil rigidity, fault displacement and crossing angle on the peak compressive strain of the pipeline are examined in detail. Furthermore, based on numerous numerical results, a regression equation for predicting peak compressive strain of X80 steel pipeline is proposed. The applicable range of the formula is given. 15 true design cases in the Second West to East pipeline Project in China were investigated to demonstrate the accuracy and applicability of the proposed methodology by comparing the predicting peak compressive strain results with FEM results. The proposed method can be referred in the strain-based and reliability-based design for X80 steel pipelines subjected to strike-slip fault.

Research and Application on Technology of Flood-Storage and Flood-Detention of Coal Mining Subsidence Area of Suzhou Coal Mine

2014 ◽  
Vol 641-642 ◽  
pp. 80-83
Author(s):  
Jia Zhong Zheng ◽  
Mei Zhu ◽  
Zheng Long Wang
Keyword(s):  
Coal Mining ◽  
Dynamic Change ◽  
Storage Conditions ◽  
Flood Routing ◽  
Mining Subsidence ◽  
Subsidence Area ◽  
The Status ◽  
Suzhou City ◽  
Change Trend ◽  
Coal Mining Subsidence

The artical is based on the investigation of the basis of the status quo of Zhuxianzhuang and Luling coal mining subsidence area in Anhui province Suzhou city(hereinafter referred to as the "Zhu Lu subsidence area"), a preliminary analysis of the dynamic change trend of detention space in Zhu Lu subsidence area, and based on the hysteresis storage conditions of subsidence area, use the flood routing model to simulate the hysteresis effect of storage at different subsidence scenarios of different frequency flood. Finally, using the experience type channel evolution model and peak delay routing model further revealed storage effect on flood process of Zhu Lu subsidence area.

Designing CO2 Transmission Pipelines Without Crack Arrestors

2010 ◽  
Author(s):  
Graeme G. King ◽  
Satish Kumar
Keyword(s):  
Wall Thickness ◽  
Carbon Capture ◽  
Power Plants ◽  
Oil And Gas ◽  
Cost Optimization ◽  
Operating Conditions ◽  
Operating Pressure ◽  
Design Work ◽  
Industrial Facilities ◽  
Pipeline Network

Masdar is developing several carbon capture projects from power plants, smelters, steel works, industrial facilities and oil and gas processing plants in Abu Dhabi in a phased series of projects. Captured CO2 will be transported in a new national CO2 pipeline network with a nominal capacity of 20×106 T/y to oil reservoirs where it will be injected for reservoir management and sequestration. Design of the pipeline network considered three primary factors in the selection of wall thickness and toughness, (a) steady and transient operating conditions, (b) prevention of longitudinal ductile fractures and (c) optimization of total project owning and operating costs. The paper explains how the three factors affect wall thickness and toughness. It sets out code requirements that must be satisfied when choosing wall thickness and gives details of how to calculate toughness to prevent propagation of long ductile fracture in CO2 pipelines. It then uses cost optimization to resolve contention between the different requirements and arrive at a safe and economical pipeline design. The design work selected a design pressure of 24.5 MPa, well above the critical point for CO2 and much higher than is normally seen in conventional oil and gas pipelines. Despite its high operating pressure, the proposed network will be one of the safest pipeline systems in the world today.

An Interlocking Ligamentous Spinal Disk Arthroplasty with Neural Network Infrastructure

2010 ◽  
Vol 7 ◽  
pp. 55-79 ◽  
Author(s):  
Philip Boughton ◽  
James Merhebi ◽  
C. Kim ◽  
G. Roger ◽  
Ashish D. Diwan ◽  
...  
Keyword(s):  
Neural Network ◽  
Finite Element ◽  
Axial Compression ◽  
Wire Array ◽  
Axial Strain ◽  
Compressive Strain ◽  
Niti Wire ◽  
Motion Segment ◽  
Flexion Extension

An elastomeric spinal disk prosthesis design (BioFI™) with vertebral interlocking anchors has been modified using an embedded TiNi wire array. Bioinert styrenic block copolymer (Kraton®) and polycarbonate urethane (Bionate®) thermoplastic elastomer (TPE) matrices were utilized. Fatigue resistant NiTi wire was pretreated to induce superelastic martensitic microstructure. Stent-like helical structures were produced for incorporation within homogenous TPE matrix. Composite prototypes were fabricated in a vacuum hot press using transfer moulding techniques. Implant prototypes were subject to axial compression using a BOSE ® ELF3400. The NiTi reinforced implants exhibited reduction in axial strain, compliance, and creep compared to TPE controls. The axial properties of the NiTi reinforced Bionate® BioFI™ implant best approximated those of a spinal disk followed by Kraton®-NiTi, Bionate® and Kraton® prototypes. An ovine lumbar segment biomechanical model was used to characterize the disk prosthesis prototypes. Specimens were subject to 7.5Nm pure moments in axial rotation, flexion-extension and lateral bending with a custom jig mounted on an Instron® 8874. The motion preserving ligamentous nature of this arthroplasty prototype was not inhibited by NiTi reinforcement. Joint stiffness for all prototypes was significantly less than the intact and discectomy controls. This was due to lack of vertebral anchor rigidity rather than BioFI™ motion segment matrix type or reinforcement. Implant stress profiles for axial compression and axial torsion conditions were obtained using finite element methods. The biomechanical testing and finite element modelling both support existing BioFI™ design specifications for higher modulus vertebral anchors, endplates and motion segment periphery with gradation to a low modulus core within the motion segment. This closer approximation of the native spinal disk form translates to improvements in prosthesis biomechanical fidelity and longevity. Axial compressive strain induced within a TiNi reinforced Kraton® BioFI™ was found to be linearly proportional to the NiTi helical coil electrical resistance. This neural network capability delivers opportunities to monitor and telemeterize in situ multiaxis joint structural performance and in vivo spine biomechanics.

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