川西新场—什邡地区三维连片河道砂岩处理技术

川西中浅层河道砂体厚度薄、宽度窄,地震识别难度大,保持地震反射振幅与波形的相对变化关系是地震技术识别砂体展布的前提。新场—什邡地区10块三维区块资料由于采集年代跨度大、采集仪器不同、观测系统不一样,导致单块数据之间存在系统时差以及振幅、频率和波形等不一致问题。在分析原始数据基础上,明确了三维连片河道砂岩目标处理面临的问题及难点,建立了一套解决该问题的方案与思路。资料处理以提高中浅层成像效果和突出河道砂岩地震响应特征为目的,主要对时差校正、去噪、静校正、振幅恢复与补偿、反褶积、地表一致性处理、剩余静校正、数据规则化、速度分析、偏移成像和道集优化等技术进行了研究、试验和分析,并完成实际数据处理。处理成果具有高信噪比、高分辨率和较高保真度的特点,区块之间波组连续稳定一致性好,可为后续构造解释、砂体刻画、储层预测和含气性识别等研究提供高质量的基础资料。

The Techniques of 3D Joint Channel Sandstone Processing in Xinchang-Shifang Area Western Sichuan

The medium shallow layer channel sandstone in Western Sichuan is thin in thickness and narrow in width, so it is very difficult to identify by seismic data. It is the premise for seismic technology to identify sand body distribution to keep the relative change relationship between seismic reflection amplitude and waveform. Because of the large time span of acquisition, different acquisition instruments and different geometry, there are some inconsistencies among the data in Xinchang-Shifang Area, such as system time difference, amplitude, frequency and waveform. Based on the analysis of the original data, the problems and difficulties in the target processing of the 3D joint channel sandstone are clarified, and a set of solutions and ideas are established. The purpose of data processing is to improve the imaging effect of middle and shallow layers and to highlight the seismic response characteristics of channel sandstone. It mainly studies, tests and analyzes the technologies of time difference correction, denoising, static correction, amplitude recovery and compensation, deconvolution, surface consistency processing, residual static correction, data regularization, velocity analysis, migration imaging and gather optimization, and completes the actual data processing. The processing results have the characteristics of high signal-to-noise ratio, high resolution and high fidelity. The wave groups between blocks have good continuity, stability and consistency, which can provide high-quality basic data for subsequent structural interpretation, sand body characterization, reservoir prediction and gas bearing identification.