Study on the general layout of semi-submersible offshore drilling platforms based on process flow

Abstract

The general layout of 6^th generation semi-submersible drilling platforms is the main factor impacting the efficiency of their drilling operations. This paper provides a compound/integrated algorithm based on process flow that is aimed at improving efficiency, while giving attention to stability and safety at the same time. The paper describes the process flow of dual drilling centers and a hierarchical division of rigs based on the different modes of transportation of various drilling support systems. The general layout-centripetal overall arrangement spatially was determined based on drilling efficiency. We derived our modules according to drilling functionality; the modules became our basic layout units. We applied different layout algorithm to mark out the upper and lower decks. That is, the upper deck was designed based on the lowest transportation cost while the lower deck’s calculations were based on the best-fit scope. Storage configurations in columns and pontoons were also considered for the layout design. Finally the center of gravity was taken into consideration and the general layout was adjusted accordingly, to result in an optimal center of gravity. The methodology of the general layout can provide a reference for implementation of domestic designs of semi-submersible rigs.

摘 要

第六代半潜式钻井平台装备复杂, 尤其双钻井中心应用对平台布局带来新变化, 总体布局设计是平台钻井作业效率的重要影响因素。 本文系统研究总体布局设计, 提出工程使用布局设计方案。 首先建立双钻井中心钻井作业流程图, 确定布局原则, 以钻井效率为基本出发点, 对平台各支持/服务系统输送方式进行规划设计, 按各种输送方式对平台层次进行划分, 确定以双钻井中心为中心的空间向心布局方案, 按作业功能对平台设备设施进行模块划分, 以模块作为基本布局单元, 对上、 下甲板采用不同布局算法进行布局规划, 上层平台以输送成本最低利于输送算法布置, 下层平台采用最适合面积算法, 优先布置大尺寸模块, 并对立柱、 下浮体存储进行规划。 最后研究布局对平台重心影响, 进行重心计算并依据重心变化进行布局调整。 本文针对半潜平台复杂大系统, 采用层次划分和模块分解方法进行布局规划方案对我国半潜式 钻井平台设计有一定借鉴意义。