川西新场宽方位三维三分量地震资料采集及效果分析

Wide Azimuth 3D3C Seismic Data Acquisition and Effect Analysis in Xinchang Area West of Sichuan

川西新场地区以致密砂岩裂缝性气藏为主,新851井在深层获得了良好的天然气显示,但以往资料在描述深层气藏时存在一些缺陷,如难以很好解决断裂展布、储层非均质性和裂缝预测等问题;为此开展了宽方位三维三分量地震勘探研究。首先,分析了野外资料采集方法,主要包括宽方位观测系统、地震仪器系统、提高分辨率和信噪比的方法、采集方法试验等。然后,对野外采集资料的纵横波覆盖次数、单炮品质、频率扫描、各向异性特征、剖面质量等方面进行了分析。结果表明,宽方位三维三分量地震采集为新场地区裂缝性气藏勘探提供了可供研究的基础资料,可满足裂缝预测、各向异性研究和AVO油气检测研究。最后,提出了下一步需要解决的定向问题、噪声问题、耦合问题,分辨率问题、转换波静校正问题和各向异性问题。

There are mainly tight sandstone fracture gas reservoirs in Xingchang area west of Sichuan.Although a vast gas reservoir is exploited in the deep-seated strata of 851-well location,original seismic data have many disadvantages in describing deep-seated gas reservoirs.For example,it is difficult to solve problems of fault distribution,reservoir heterogeneity,and fracture prediction based on the data.Therefore,research on wide azimuth 3D3C seismic exploration is conducted.Firstly,a field acquisition method is analyzed including wide 3D3C observation system,seismograph,method of improving resolution and signal-to-noise,and test on acquisition method.Secondly,seismic data acquired from the field including their folds of P and converted wave,shot quality,frequency scan,anisotropic feature,and profile quality are discussed,which indicates that the acquisition data offer basic data for research on fracture reservoirs and meet the requirements of research on fracture prediction,anisotropy,and AVO hydrocarbon examination. Lastly,some problems to be solved are raised in near future,such as orientation problem,noise problem,coupling problem,resolution,static correction of converted wave,and anisotropic problem.