关键词: Walkaway-VSP, 速度, Tar因子, Q因子, 各向异性, 深度偏移, 纵横波, 波阻抗反演

Abstract: 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.

Key words: Walkaway-VSP, velocity, Tar, Q, anisotropy, depth migration, P-wave and S-wave, wave impedance inversion