Walkaway-VSP技术及其实际应用

文章介绍了Walkaway-VSP采集、处理和解释技术研究及其在塔里木油田和青海油田实际应用情况。Walkaway-VSP技术是一种炮点沿着一条(或多条)过井的直线激发(井中布置检波器接收信号)的VSP勘探方法,这种方式具有较高的覆盖次数,可以获得高质量的反射波成像,同时,由于检波器靠近储层,可以获得地层速度、吸收衰减、各向异性等信息。在信息采集方面,主要研究的是针对目标体的观测系统优化方法和纵横波的采集技术;在资料处理方面,主要是进行了快速高精度初至拾取及速度统计方法、Tar和Q值多炮统计方法、VSP子波反褶积技术、矢量波场分离技术、各向异性参数提取方法、基于射线追踪的VSP-CDP成像等方面的研究和攻关;在解释方面,主要是进行了时间及深度域标定、纵横波联合储层反演等技术研究。两个应用实例显示了Walkaway-VSP技术在油田勘探开发中良好的应用前景。

Research and Application of Walkaway-VSP Technology

This paper introduces the technology of Walkway-VSP acquisition, processing and interpretation and application results in Tarim Oilfield and Qinghai Oilfield. Walkaway-VSP is a category of variable offset VSP acquisition for which shot points are on one or more lines across the well and geophone are arrayed at borehole. Walkaway-VSP has high fold, and both acquired P-wave and S-wave data have good image quality; geophones are close to the reservoir, so it obtains reliable information such as velocity, absorption, anisotropy parameters and so on. It is mainly aimed at the goal body’s observation system optimization method and P-wave and S-wave acquisition technology during acquisition. Some technologies are studied such as high precision first break picking and velocity statistical method, Tar and Q statistical method, VSP wavelet deconvolution, vector wavefield separation, anisotropic parameters evaluation and VSP-CDP image based on ray tracing when processing. The technologies such as calibration at time and depth domain and P-wave and S-wave reservoir inversion are studied in the process of interpretation. The two applied examples indicate a promising application of the Walkway-VSP technology in the field during exploratory development.