中石化下扬子地区油气地震勘探攻关进展及方向

中石化下扬子地区油气地震勘探面临着极其复杂的地表条件和复杂的地下构造,地震资料信噪比低、成像效果差,因而该区的油气勘探工作未能取得显著突破。为此,中国石化开展了多轮地震攻关并取得了一些进展,包括基于地震模拟的观测系统优化技术、城镇工业发达区高效地震激发技术、弱反射信号保护与提取技术、深度域速度建模与成像等技术,这些技术的应用提高了资料的信噪比,增强了中、古生界地层的地震反射能量,剖面成像效果明显改善,地震解释发现了一批有利区带及圈闭。钻探结果表明地震资料可靠、准确。下一步地震勘探的主要攻关方向建议开展以满足叠前成像的基于模型正演的观测系统设计研究,继续开展提高地震激发效率研究以及低信噪比复杂构造成像和各向异性处理方法研究等,进一步探索提高下扬子地区地震勘探效果的技术方法。

During seismic exploration,extremely complex surface and underground geologic conditions can be observed in the Lower Yangtze area.Low signal-to-noise ratio (SNR) seismic data and poor imaging restricts oil and gas exploration in this area.As a result,SINOPEC conducted several rounds of seismic exploration research that included seismic observation system optimization based on seismic simulation,effective seismic excitation in urbanized industrial developed areas,and extraction of weak reflection signals.Velocity modeling and imaging technology for depth domains as well as other technologies were employed in this research.After these methods were applied,the SNR and imaging were improved,the seismic reflection energy of the Middle and Paleozoic strata were enhanced,and several favorable zones and traps were discovered through seismic interpretation.The accuracy of the seismic data was verified through drilling results.The next phase of this research should be to design an observation system to improve pre-stack imaging,and improve seismic excitation efficiency.In addition,the imaging of complex structures with low SNR and anisotropic processing research should be conducted,and seismic exploration in the Lower Yangtze area should advance.