海底管线平管起吊的参数灵敏度

参考平管起吊相关研究,结合相关工程项目,确定舷吊位置、浮筒位置和浮筒间距为主要设计参数。利用大型水动力软件OrcaFlex建立海底管线平管起吊模型,分析管线的运动响应及吊绳张力的时间历程变化,研究管道的有效张力和曲率及舷吊张力对不同总体布置参数的敏感性和变化规律。     

采用ANSYS 5.7的海底管线起吊过程非线性有限元静力分析

海底管线安装过程中经常采用对接起吊法,在这一过程中管线应力状态较复杂,管线的变形属于大位移几何非线性变形,同时还要考虑管线的双层结构.本文采用有限元分析软件ANSYS5.7模拟管线的起吊过程,采用ANSYS5.7提供的点点接触单元(Contact 52),浸没管单元(Pipe59),直管单元(Pipe16)对管线起吊过程进行接触非线性和几何非线性有限元分析,得到了较为满意和直观的结果.计算结果可以给出指定起吊高度情况下的管线内管、外管的应力分布以及管线和海底泥面接触点的位置,进而可以校核起吊过程中管线内、外管的强度和稳定性是否满足要求.为海底管线起吊对接计算提供了一种新的思路和方法.     

交叉海底管道探测方法研究

随着海洋石油工业的迅速发展,铺设于海底的管道及电缆数量迅速增加,海底管缆交叉现象日益频繁。海底管缆交叉现象给安全生产和环保带来极大的隐患。及时了解交叉海底管缆的位置、状态等信息,为交叉海底管缆的维护提供科学是交叉海底管线探测工作的首要任务。本文根据大量工程经验,对交叉海底管道探测技术及实施方法进行了归纳总结,结合实例数据,对各探测方法适用性进行了总结。本文工作对提高交叉海底管线探测效率具有重要意义。     

计算机技术在海底管道施工中的应用

在海洋工程领域中,计算机技术在众多方面所表现出来的优越性对于海底管道的施工颇具指导意义.本文从滩浅海油田开发的现状入手,从提高和完善海底管道施工技术的角度,提出了采用计算机技术辅助海底管道施工及防护的新思路,详细阐述了计算机技术在海底管道稳定性分析、海底管道凸起及悬跨应力分析、海底管道涡激振动分析、海底管道立管结构预制及起吊分析等方面所开发的软件的工作原理和对海底管道施工及防护的辅助作用,并进一步说明了这些软件的运行过程和应用效果.     

海底管道腐蚀后的剩余强度评价

海底管道通常会因腐蚀而形成各种不同类型的缺陷,影响管道的承载能力和使用寿命。本研究在准确掌握管道缺陷发展情况的基础上,分别根据行业规范和采用有限元方法对海上油田含有腐蚀缺陷的原油管线进行剩余强度评价,判定海底管道修复的必要性和修复的紧迫程度,以确定最终的管线修复方案,可供类似海底管道修复工程参考。     

海底管道高强法兰与厚壁管焊接技术

(一)前言 在JZ9-3沉箱工程海底管线设计施工中,输油管线立管要穿过沉箱舱壁与海底管线平管通过法兰连接。穿舱壁管与法兰连接处不仅受到原油中复杂介质的压力作用及腐蚀作用,而且还受到     

仿生防冲刷系统在埕岛油田中的应用

埕岛油田地处黄河口滩海交界地带,大面积区域冲刷造成海底管线出现悬空安全隐患.海底仿生防冲刷保护系统基于海洋仿生学原理,通过仿生海草的粘滞阻尼作用,降低海流流速,促进泥沙淤积,其应用于埕岛油田海底管线悬空治理具有显著的促淤埋管效果.介绍了该系统的特点、防冲刷作用机理以及应用效果,为河流及海底管线的防护提供参考.     

埕岛油田海底管道修复施工技术探讨

考虑到胜利油田埕岛海域海底管线的修复及维护施工难度大,分析埕岛油田浅海区域内海底管道漏点、外管变形及断裂的修复方法,同时对修复的施工工艺进行探讨。     

典型深水顶部张紧立管的设计方法

顶部张紧立管(TTR)是用于连接运动的浮式生产设施和海床上的海底系统的管道,顶部张紧立管可用于钻井、完井及生产.本文将简单介绍TTR在前期初步设计阶段的设计考虑因素,并以典型深水平台概念设计研究课题中确定的TTR立管设计参数和结构型式为例,简要介绍TTR的强度分析方法,供海底管道设计者参考.     

临近海底天然气管线水域疏浚工艺探讨

针对海底油气管线保护性水域范围内的高精度疏浚施工问题,依托深圳港西部港区出海航道项目部西气东输天然气管道的疏浚开挖,建立一套海底管线保护性施工工艺与管理办法,以保证施工质量与管线安全,为类似工程提供参考借鉴。     

水下管道连接器设计研究及应用

随着全球海洋石油天然气开发从浅水走向深水,由于潜水员下潜深度有限,海底油气管道的连接必须通过水下机器人代替潜水员完成此项工作。因此各种管道连接技术也越来越多地应用于海洋石油开发中。水下管道连接器作为一种重要的自动安装连接装置,涉及到机械、液压、材料、防腐、密封等各个方面,具有免潜水员操作、安装便捷、可靠性高等特点,可广泛应用于水下油气管道连接。本文对已成功应用于南海某气田中水下采气树跨接管连接的水平机械式管道连接器和水下管汇发球器连接的垂直液压式管道连接器,从密封结构、导向结构、锁紧结构的设计进行了深入的阐述,并在连接器样机型式试验、产品防腐、水下安装等方面也进行了详细的说明。     

Experimental study of a suspended subsea module at different positions in the splash zone

During the lifting of submerged marine modules, the highest dynamic loads occur in the splash zone. These forces are highly dynamic and cannot easily be estimated with sufficient accuracy using simple calculations or high-fidelity computational fluid dynamics because of their irregular and complex geometries. We conducted an experimental study in a wave tank to investigate the dynamics of a large subsea module in the splash zone subject to irregular waves. The experiments were conducted using a 1:8 scale model of a subsea module, similar to that designed by Offshore Oil Engineering Co., Ltd., for the subsea pipeline from the Wenchang gas fields to the Yacheng pipeline. The model was examined at five different positions relative to the free surface, from completely above the surface to fully submerged. The resulting data are analyzed in the time and frequency domains. Spectral analysis and a dynamic effect parameter are used to analyze the dynamic loads on the subsea module. Several time-domain numerical analyses are performed with different peak periods, and the tension of the sub-slings is obtained. The experimental results for the relative forces and motions of the subsea module are presented, providing a reference for the design of other similar modules and their installation and validation data for computational modeling.     

水下灌浆定形式海底管道立管固定装置研究

针对海底管道立管管卡发生损坏或者脱落,影响海底管道安全运行的情况,研制新型水下灌浆定型式海底管道立管固定装置。讨论水下管卡的结构形式,材料的选择及管卡灌浆的工艺流程。实验证明,该新型管卡能够代替原有管卡很好地对立管起到保护作用,能确保海底管道的安全运行。     

国外海底管道局部屈曲研究综述

海底管道是海洋油气集输系统中最重要的组成部分之一,从铺设到服役都将承受多种载荷的作用,并可能发生局部屈曲且沿管道传播开来,由此造成严重的后果。海底管道的局部屈曲在管道安全性方面具有重要意义,已成为海底管道设计与评估中重要的内容。详细阐述了国外关于海底管道受外压、弯矩和轴力作用下的局部屈曲研究成果,论述了在单个载荷和多个载荷联合作用下的局部屈曲破坏机理,并提出了未来研究的建议。     

Laboratory tests and thermal buckling analysis for pipes buried in Bohai soft clay

Upheaval buckling of submarine pipelines occurs due to relative movement of pipeline and surrounding soil and is often triggered by high operational temperature of the pipeline, initial imperfection of the pipeline, or a combination of both. Since buckling can jeopardize the structural integrity of a pipeline, it is a failure mode that should to be taken into account for the design and in-service assessment of trenched and buried offshore pipelines. In this study, a series of vertical (uplift) and axial pullout tests were carried out on model pipe segments buried in soft clay deposit similar to that present in Bohai Gulf, China. Pipe segments with three different diameters (= 30 mm, 50 mm and 80 mm) were buried in different depth-to-diameter ratios ranging from 1 to 8. Based on the results of laboratory tests, nonlinear force–displacement relations are proposed to model soil resistance mobilized during pipeline movement. The proposed nonlinear soil resistance models are employed in finite element analysis of buried pipelines with different amplitudes of initial geometric imperfections. Thermal upheaval buckling behavior of pipelines operating at different temperatures is studied. Results show that the capacity of pipeline against thermal buckling increases with the burial depth and decreases with the amplitude of initial imperfection.     

海底管道巡检船研发设计

简要介绍自主研发设计的"海底管道巡检船"船型的主要技术性能和技术特点。该船定位为国内首艘海底管道巡检船,搭载专业声学探测装置,抗风浪性能良好,能够持久巡线并应急响应,其各项功能均针对渤海海域海底管道运维需求进行设计,能够保障海底管道安全运营,排除隐患以避免或最大限度降低管道泄漏造成的损失。     

Reliability-based design of subsea light weight pipeline against lateral stability

The application of non-metallic light weight pipeline (LWP) in subsea oil/gas transmission system is subject to subsea pipeline on-bottom stability problem because of their light weight. Additional weight required for the stabilization of subsea LWP is a critical item to consider when decreasing the cost of the pipeline system. This paper presents an effective approach to determine the additional weight by utilizing a reliability-based assessment of subsea LWP against on-bottom stability. In the approach, a dynamic non-linear finite element model (FEM), including a model of fluids-pipe-soil interaction for the subsea pipeline, is used to study the pipeline displacement response. In-place analysis of a flexible pipe is presented as an example of the authors' methodology. Results show that displacements are largely affected with and without considering the lift force. Additionally, the uncertainties of all parameters used in the model are considered. With 145 cases of FEM calculations being the samples, a response surface model (RSM) is developed to predict the pipeline lateral displacement using the software Design-Expert. Combing with the RSM equation, the Monte Carlo simulation method is employed to estimate the probability of exceeding pipeline stability. To calculate the reliability of LWP for different submerged weights, the method introduces a calibrated factor into the serviceability limit state (SLS) function. The proposed approach can be used to determine the additional weight required for the on-bottom stability of subsea pipelines while considering the uncertainties of all relevant parameters.     

The dynamics of deep water subsea lifting operations in super-harmonic resonance via the harmonic balance method

The dynamics of deep water subsea lifting operations experiencing super-harmonic resonance is analysed in this study. The harmonic balance method is used to solve the non-dimensional equation of motion of the system and the results are compared with time domain integration and with an equivalent energy dissipation model for typical subsea lifting scenarios. It is demonstrated that 1:3 and 1:5 super-harmonic resonances represent significant features of the response of the system and can lead to large dynamic forces in the cable, which may violate the structural limits of the system in real operations. The harmonic balance method presents results almost as accurate as the time domain integration but up to 25 to 35 times faster, while the equivalent energy dissipation model is not able to represent the super-harmonic resonances. Consequently, taking into account the dynamics introduced by super-harmonic resonances is necessary in the analysis of subsea lifting operations, as it can be the limiting design criterion in certain scenarios, and the harmonic balance method can be used as a fast and accurate method to solve this problem.     

用于预报离岸管线膨胀的简化技术（英文）

In this study, we propose a method for estimating the amount of expansion that occurs in subsea pipelines, which could be applied in the design of robust structures that transport oil and gas from offshore wells. We begin with a literature review and general discussion of existing estimation methods and terminologies with respect to subsea pipelines. Due to the effects of high pressure and high temperature, the production of fluid from offshore wells is typically caused by physical deformation of subsea structures, e.g., expansion and contraction during the transportation process. In severe cases, vertical and lateral buckling occurs,which causes a significant negative impact on structural safety, and which is related to on-bottom stability, free-span, structural collapse, and many other factors. In addition, these factors may affect the production rate with respect to flow assurance, wax, and hydration, to name a few. In this study, we developed a simple and efficient method for generating a reliable pipe expansion design in the early stage, which can lead to savings in both cost and computation time. As such, in this paper, we propose an applicable diagram, which we call the standard dimensionless ratio(SDR) versus virtual anchor length(LA) diagram, that utilizes an efficient procedure for estimating subsea pipeline expansion based on applied reliable scenarios. With this user guideline,offshore pipeline structural designers can reliably determine the amount of subsea pipeline expansion and the obtained results will also be useful for the installation, design, and maintenance of the subsea pipeline.