海上变深电缆宽频宽方位地震采集现场作业难点及解决方案

Difficulties and Solutions to the Offshore Seismic Survey with Variable-depth Streamer and Wide-azimuth

随着海上已发现油气田陆续进入开发和生产阶段,对于地震资料品质的要求也越来越高,斜缆宽频和多船宽方位采集方法对于解决构造精确成像和后续的储层精细描述是一个有效的解决手段。但是在变深度电缆宽频宽方位地震资料采集的过程中,面临的主要作业难点有:海上平台障碍影响施工和近偏数据获取,斜缆抖动噪音偏大,以及缺乏相适应的现场宽方位面元信息质控手段。通过现场实验,分别提出了变观作业,优化扩展器、电缆前导段、尾部电缆布设,以及宽方位向量片面元质控等措施,有效解决了前述问题,为今后的生产提供了宝贵的经验。

With the offshore oil and gas fields entering the stage of development and production, the requirement to the quality of seismic data becomes higher and higher. The variable-depth streamer broadband and multi vessel wide-azimuth acquisition are the effective methods for acquiring the qualified data to meet the requirement of precise imaging and reservoir characterization. In the process of acquisition, some difficulties should be overcome by efforts, such as the lack of near information caused by offshore platform barriers, variable-depth streamer jitter noise, and the lack of WAZ seismic bin quality control method. In order to solve the problems mentioned above, the authors conducted a series of field experiments, including variable geometry acquisition, optimization of the deflectors, lead-in cables and tail cables layout, off-set vector tile quality control. The results demonstrate they are effective and can be taken as reference to future similar operations.