海洋钻井天车升沉补偿系统不同摇摆装置性能分析

Performance analysis of different swing devices in crown-block heave compensation system for offshore drilling

关键词:  海洋钻井  天车升沉补偿  摇摆装置  窜绳  线性加权和法

Key words:  offshore drilling  crown-block heave compensation  swing device  wirerope movement  linear weighted sum method

摘要:

天车升沉补偿系统广泛应用于浮式海洋钻井平台,不同的摇摆装置设计方案对摇摆臂受力变化、钢丝绳运动规律及升沉补偿效果均有重要影响。针对3套典型的天车升沉补偿系统摇摆装置方案建立数学模型并进行数值计算,基于线性加权和法建立各影响因素的权重表和综合评价标准,并对3套方案进行评价。结果表明,钢丝绳内绕式方案Ⅰ和方案Ⅱ中摇摆臂须承受变化幅度较大的交变载荷,易疲劳受损;且钢丝绳直弯交变长度较大,窜绳现象明显,给系统控制精度带来较大影响;钢丝绳外绕式方案Ⅲ具有摇摆臂受力平稳、钢丝绳直弯交变长度小、无窜绳现象等特点;基于线性加权和法评定方案Ⅲ为优秀,方案Ⅱ为良好,方案Ⅰ为中等。

Abstract:

The crown-heave compensation device is widely applied in the floating offshore drilling platform, and its wirerope enwinding ways have very important influence on the swing arm 's force variation, wirerope 's motion rule and the heave compensation efficiency. Faced with three typical swing device schemes in the crown-block heave compensation system, the mathematical model was established and numerical calculations were done; and based on the linear weighted sum method, the weight table of each factor and comprehensive evaluation standard were established, and then the three schemes were evaluated. The results show that the swing arms need to bear an alternating load which has big varying amplitude in the inner enwinding wirerope scheme Ⅰ and scheme Ⅱ.The straight-curved alternating length of wirerope is large, and the wirerope moving phenomenon is obvious, which greatly affects the system control precision. But the outer enwinding wirerope scheme Ⅲ has some characteristics, including that, the swing arm 's stress is smooth, there is no wirerope moving phenomenon, and the wirerope 's straight-curved alternating length is smaller.Based on the linear weighted sum method, the scheme Ⅲ is rated as excellent, the scheme Ⅱ as well and the plan Ⅰ as medium.