深水钻井井身结构设计参数的选取

深水钻井具有自然灾害多、安全作业窗口窄、完井井眼大的特点。在实际工程设计中面临着套管下入层次多、可选尺寸少等问题,增加了深水井身结构设计的难度;因此在实际工程中特别需要更科学的井身结构设计方法。鉴于目前海洋钻井手册井身结构设计采用的设计参数是陆地钻井的经验值,缺乏对深水作业特点的考虑,因此十分有必要研究这些参数对于深水的适用性,以避免因设计不合理而造成的井下事故。在充分考虑深水钻井特点的基础上,给出了深水油气井井身结构设计参数的选取办法及推荐值;与传统的井身结构设计方法相比,深水井身结构设计还要考虑深水作业过程中隔水管解脱的工况,以及当量循环密度、井涌余量等参数的影响。研究对陆地及浅海钻井井身结构设计也具有一定的借鉴作用。

Choice of well structure design parameters under deepwater drilling condition

Environmental issues, narrow drilling window and large hole size, which lead to more casing points and less casing size, present difficult challenges in well structure design, so it is imperative to develop a better well structure design method in engineer practice. Since well structure design parameters used in offshore drilling manual are empirical values of onshore drilling and take scarce consideration of deepwater drilling characters, it is of great importance to choose competent design parameters which can be used in deepwater drilling to avoid down-hole accidents and problems. Based on the full consideration of deepwater drilling characters, this paper gives parameter selection measures and recommendations. Compare to common well structure design method, deepwater well structure design must take account of the influence of riser margin, equivalent circulating density, kick margin, etc. This research achievement has also provided references to the design and application of the onshore and shallow water well well structure design in the future.