海洋内孤立波预警监测识别技术及其在流花16-2油田群开发中的应用

我国南海内孤立波发生频繁,由于其振幅大、流速强、能量集中等特点,已成为深海油气开发海上安装工程必须考虑的重大风险之一。依托现场守护船,提出一种内波流结构单体式监测、识别技术,采用KdV方程实现内波流预警,并成功应用于流花16-2油田群开发项目海管管线终端(PLET)安装、浮式生产储卸油装置(FPSO)锚系及水下管缆回接、空气潜水等高风险作业的内波流预警安全保障中,同时基于此次内波流预警监测结果对该海域的内波生成源和生成机制进行了探讨。应用期间采用该技术共监测、识别并发布内波预警450次。应用结果表明,约93%的内波预警时刻误差在10 min以内,平均误差为±3.90 min。统计分析结果表明,该海域的内孤立波主要来源于巴士海峡而非局地的潮地相互作用,大致可以分为两类:一类是直接产生于巴士海峡,西传至该海域;另一类是局地产生,主要是由巴士海峡产生的内波西传至陆坡浅化分裂生成或是由巴士海峡产生的内潮西传至陆坡由于非线性变陡机制产生。该内波流监测技术在流花16-2油田群开发项目的成功应用,可为南海其他类似项目提供直接的借鉴。

Observing, identification and early warning technology of internal solitary wave and its application in Liuhua 16-2 oilfield group development project

Internal solitary waves (ISWs) are active in the South China Sea. With characteristics of large amplitude, strong current and concentrated energy, ISW is one of the major risks that must be considered in offshore installation engineering of deep-sea oil and gas development. This paper introduces an observing and identification technology of ISW relying on the guard ship, which has been successfully applied to the ISW early warning of high-risk operations of Liuhua 16-2 oilfield group development project, such as subsea pipeline PLET installation, FPSO anchoring and underwater pipe cable tie-in, air diving and so on. Based on the results of the application, the ISW generation source and generation mechanism in Liuhua area are discussed. During the application period, 388 ISWs there are observed and identified by this technology. The mean time error of warning is 3.90 min. The error within 10 minutes accounts for about 93%. The results of statistical analysis show that the ISWs in Liuhua area mainly originate from the Bashi channel rather than from interaction between tide and local topography. The ISWs in this sea area can be roughly divided into two types: one is directly generated from the Bashi channel and propagates westward to this sea area; the other is locally generated, and mainly generated by the fission of ISWs from the Bashi channel, or the nonlinear steepening mechanism of internal tide from the Bashi channel. The successful application of this technology in LH16-2 oilfield group development project can provide direct reference for other similar projects in South China Sea.