Structural Integrity and Mechanical Design of a Probe of High Pressure and High Temperature for Oil Wells Applying Finite Elements Tools

Author(s):  
Erik Rosado Tamariz ◽  
Rito Mijarez Castro ◽  
Agustín Javier Antúnez Estrada ◽  
Alfonso Campos Amezcua ◽  
David Pascacio Maldonado ◽  
...  

Measurement of high pressure and high temperature (HPHT) tools is regularly carried out in the hydrocarbons sector to determine not only the characteristics and performance of fluids inside the well, but also to evaluate the mechanical condition of the pipes and the automation of production. The mechanical features of these tools are significantly influenced by the mechanical design of the structure, which eventually affects their performance and integrity. This paper describes the design process and the analysis of the structural integrity of a HPHT measuring tool for oil wells in its sensors section. The classical theories of mechanical design and specifications of the ASME boilers and pressure vessels code were used. The study is performed for several operation variables in a numerical model using a commercial code of finite element method to determinate the maximum principal stresses, total displacements and safety factor in the mechanical elements that form the device. The numerical results were compared with the experimental data source from the laboratory tests.

Author(s):  
Rafael F. Solano ◽  
Bruno R. Antunes ◽  
Alexandre S. Hansen ◽  
T. Sriskandarajah ◽  
Carlos R. Charnaux ◽  
...  

Global buckling is a behavior observed on subsea pipelines operating under high pressure and high temperature conditions which can jeopardize its structural integrity if not properly controlled. The thermo-mechanical design of such pipelines shall be robust in order to manage some uncertainties, such as: out-of-straightness and pipe-soil interaction. Pipeline walking is another phenomenon observed in those pipelines which can lead to accumulated displacement and overstress on jumpers and spools. In addition, global buckling and pipeline walking can have strong interaction along the route of a pipeline on uneven and sloped seabed, increasing the challenges of thermo-mechanical design. The P-55 oil export pipeline has approximately 42km length and was designed to work under severe high pressure and high temperature conditions, on a very uneven seabed, including different soil types and wall thicknesses along the length and a significant number of crossings. Additionally, the pipeline is expected to have a high amount of partial and full shutdowns during operation, resulting in an increase in design complexity. During design, many challenges arose in order to “control” the lateral buckling behavior and excessive walking displacements, and finite element analysis was used to understand and assess the pipeline behavior in detail. This paper aims to provide an overview of the lateral buckling and walking design of the P-55 oil export pipeline and to present the solutions related to technical challenges faced during design due to high number of operational cycles. Long pipelines are usually characterized as having a low tendency to walking; however in this case, due to the seabed slope and the buckle sites interaction, a strong walking tendency has been identified. Thus, the main items of the design are discussed in this paper, as follows: lateral buckling triggering and “control” approach, walking in long pipelines and mitigate anchoring system, span correction and its impact on thermo-mechanical behavior.


2020 ◽  
pp. 114808
Author(s):  
Paulo C.F. da Câmara ◽  
Liszt Y.C. Madruga ◽  
Nívia do N. Marques ◽  
Rosangela C. Balaban

Author(s):  
Olivier Ancelet ◽  
Ste´phane Chapuliot

Modified 9Cr-1Mo steel (T91) is a candidate material for pressure vessels and for some internal structures of GCR (Gas Cooled Reactors). In order to validate this choice, it is necessary, to check if it is covered by the existing design codes, concerning its procurement, fabrication, welding, examination methods and mechanical design rules. A large R&D program on mod 9Cr-1Mo steel has been undertaken at CEA in order to characterize the behavior of this material and of its welded junctions. In this program, the role of the Laboratory for structural Integrity and Standards (LISN) is to develop high temperature defect assessment procedures under fatigue, creep and creep-fatigue loadings, to validate the existing methods (developed on austenitic stainless steels as 316L(N) for the fast reactors) and to get new experimental data on Mod 9Cr-1Mo steel. This paper presents the experimental program undertaken to develop defect assessment under creep loading and describes the main results obtained. Then a creep propagation law is proposed for the Mod 9Cr-1Mo steel at 550°C. To validate the experimental interpretation, a numerical analysis with a 3D finite element model is proposed and allows to model the propagation of the crack. Finally, a comparison of the experimental and the numerical data and in particular of the C* value is investigated.


Author(s):  
Guohua Chen ◽  
Bonuan Chen

Based on the typical in-service high pressure vessels made of PCrNi3MoVA for producing synthetic crystal, a systematic technology of material fracture toughness estimation, structural integrity assessment, and life extension is carried out for the in-service equipment with the following aspects: macroscopically and microscopically analyzing, the tests including KIC, AKV, FATT (50%), the predicting method of fracture, system safety assessment, and the life extension technology. Some practical conclusions can be obtained from the test and analysis as follows: The main failure factors for this kind of high pressure vessels include heat treatment processes, temper brittleness, and stress corrosion; It is found that the value of FATT (50%) increased very significantly; The comparison between the test results and the predicted results of the value of KIC is also performed, and it is shown that the value of KIC of in-service equipment can be estimated by the formula presented by Barsom-Rolfe or in API 579 with the value of AKV, The test temperature is recommended at least to reach 25 C (or room temperature) for the repaired vessels; The life extension technologies are put forward for this kind of in-service super-high pressure vessels.


2020 ◽  
Vol 10 (17) ◽  
pp. 5890
Author(s):  
Jiyoung Yoon ◽  
Junkyu Park ◽  
Jinhyoung Park

When designing a hand caliber with a high-temperature, high-pressure internal fluid transport pipe, reliability, safe use, and performance must be considered. Reliability refers to the stress caused by thermo-mechanical load; safe use refers to the low-temperature burns that might occur upon contact, and high-temperature burns caused by gas leakage occurring in the cylinder gap; and performance refers to projectile velocity. In this study, numerical simulation methods for heat transfer, structure analysis, and gas leakage are proposed so that solutions can be designed to account for the above three criteria. Furthermore, a hand-caliber design guide is presented. For heat transfer and structural analysis, mesh size, the transient convective heat transfer coefficient, and boundary conditions are described. Regarding gas leakage, methods reflecting projectile motion and determination of the molecular weight of the propellant are described. As a result, a designed hand caliber will have a high reliability, because the thermo-mechanical stress is lower than the yield stress. There will be little risk of low-temperature burns, but there will be a high temperature-burn risk, owing to gas leakage in the cylinder gap. The larger the cylinder-gap size, the greater the gas leakage and the smaller projectile velocity. The presented numerical simulation method can be applied to evaluate various aspects of other structures that require high-temperature, high-pressure fluid-transport pipes.


2021 ◽  
Author(s):  
Xuming Chen ◽  
Ray Zonoz ◽  
Hamid A. Salem

Abstract It is critically important for elastomer sealing components in blowout preventers (BOP) and wellheads to meet the pressure and temperature rating requirements under the newly released American Petroleum Institute (API) standards, API 16A (fourth edition) and API 6A (twenty-first edition) respectively. Extrusion resistance under high pressure and high temperature is one of the most critical challenge for the elastomer sealing components to meet the above API standards. This challenge is related to the basic properties of elastomer materials and mechanical design of the sealing components. This paper outlines how a simple and low-cost approach was developed to evaluate extrusion resistance of elastomer sealing components, and the correlation between critical tear pressure and extrusion gap of the two elastomers seals was evaluated using a power law equation. This correlation revealed that the above challenges of elastomer sealing components for BOPs and wellheads/Christmas trees is related to the weak strength of elastomers under high temperature and large clearances (extrusion gap) in current designs. New materials and/or new mechanical design to overcome such a challenge were also provided and discussed in this paper. The paper will help practicing engineers understand the challenge of material selection, mechanical design, and API testing as well as better understand the capability and limitation of sealing components for blowout preventors and wellhead applications under high pressure and/or high temperature (HPHT).


2015 ◽  
Vol 789-790 ◽  
pp. 80-84
Author(s):  
Muhammad Aslam Md Yusof ◽  
Norazwan Wahid ◽  
Nor Hazimastura Hanafi

Synthetic based mud has been widely used in the drilling operation because of its good properties. However, prolonged exposure of the mud in high temperature causes degradation of the good mud properties because of chemical instability. Because of that concern, this study intends to improve the performance of SBM with nanosilica at different concentration in high temperature high pressure (HTHP) applications. nanosilica with size of 10-20 nm has been selected for this study. The involving parameters in this study include the manipulation of nanoparticles concentration by total mud weight between 0 to 1.78 wt. %, and performance at temperature up to 350°F. The enhanced formulation has given significant benefits by reducing the filtration up to 41.67% and act as the rheology modifier in HTHP condition. Moreover, the optimum amount of nanosilica is 0.71% of total mud weight to avoid further rheological and filtration degradation.


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