摘要经济的飞速发展,加快了人们对海上资源的开发、利用,海上油气资源的开采活 动日益频繁。管道和立管是海上油气田开发生产系统中必不可少的一部分。在铺设管 道与立管的过程中,稍有不慎,就可能导致管道和立管破损,因此需要专用的大型设 备--铺管船进行铺设。影响铺管作业正常进行的因素颇多,确保铺设的安全性十分严 重。因此,国内外学者对于风险分析的研究工作早已展开。本文主要研究的是铺管船 在进行铺管作业时的风险分析。分析各种失效模式的影响程度,并提出相应措施减少 风险发生的概率,主要内容如下:80974
(1)将铺管船的铺管作业过程划分成五个阶段:吊装上船、管段焊接、管段下 放、后挖沟回填、清管试压。对五个阶段涉及的复杂系统以及关键设备可能导致的失 效模式一一列举,同时将火灾、爆炸、管段坠落等突发状况也考虑在内。
(2)将铺管作业过程制成 FMEA 工作表,阐明失效模式、失效原因以及最终影 响,并通过计算得到失效模式的风险顺序数 RPN,依据最低可接受准则 ALARP 确定 十分重要的两种失效模式:管段坠落、动力定位失效。
(3)建立管段坠落 FTA,确定管段坠落为顶事件,逐层分析,找出导致失效模 式的最基本事件是焊点失效、防脱钩装置性能不佳;将引起动力定位失效的原因以及 导致的后果绘制成表格。根据风险矩阵确定严重等级,指明铺管船在六种作业工况下 的高风险失效模式。
(4)依据两种失效模式的风险分析结果,总结得出:铺管船进行铺管作业的过 程中应十分关注管段坠落和动力定位失效两种事故的发生,在进行作业之前应当对动 力定位系统进行检查,确保无故障,同时对参与人员进行严格的培训,规避人为因素 的影响;采用高效、安全的焊接方式,焊接人员应操作熟练,掌握正确的焊接温度。 防止焊点氧化、变形、外露等现象引起的假焊、脱焊。此外,还应确保防脱钩装置的 有效性,保证管段不会意外坠落,造成人员伤亡。
毕业论文关键词:铺管作业流程;关键设备;失效模式与影响分析;故障树分析;风险控制
AbstractWith the rapid development of economy, the demand of offshore resources is increasing。 Pipelines and risers are a major component of the offshore oil and gas development engineering。 In the process of the pipe-laying and riser installation, pipes and riser are easily damaged。 Therefore, pipe-laying vessel must be needed。 There are some factors which effect the pipe-laying operation and the safety of pipe-laying operation is essential。 Thus, the study of risk analysis is already well underway。 The paper studies the risk analysis of the pipe-laying operation for pipe-laying vessel。 The measures proposed in this paper are as follows:
(1)The process of pipe-laying operation for pipe-laying vessel is pided into five phases: lifting operation, pipe welding, pipe decentralization, trenching backfill, pigging pressure test。 Complex systems and key equipment may result the failure modes and all of them should be enumerate while fire, explosion, pipe-falling and other unexpected situations must be take into account。
(2)Making the FMEA worksheet of the pipe-laying process and calculating the RPN sequence number according to ALARP。 Ultimately, there are two important failure modes: pipe-falling, dynamic positioning failure。
(3)By establishing the FTA of pipe-falling, the failure modes can be found。 As a result, joint failures, poor performance of anti-decoupling must be take into account。
(4)As a result, the process of the pipe-laying operation should concern the occurrence of the pipe-falling and dynamic positioning failure。 Before performing the job, check the Dynamic Positioning System in order to ensure safety, while participants must perform a rigorous training in case of the influence of human factors。 By using the efficient and safe welding methods。 The welding operation of skilled staff should master the correct soldering temperatures。 Preventing solder oxidation, deformation, exposed and other phenomena caused by false welding and sealing off。 Furthermore, We should ensure the effectiveness of the anti-decoupling device in case of accidentally fall, and cause casualties。