楚雄盆地红层地震采集效果影响因素

Factors Affecting Seismic Acquisition Effects on Red Bed in Chuxiong Basin

楚雄盆地红层地震资料信噪比低,噪声干扰较强,提高信噪比是该区地震勘探的重要研究内容之一。通过对该区地震地质条件和以往资料的研究,重点分析了影响其地震采集效果的各种因素,认为:(1)地表和地下地质结构的双重复杂性是造成地震资料品质较差的根本原因;(2)激发岩性、激发点位置、岩层含水性和干扰波发育,以及检波器组合、观测系统设计的局限性是影响其采集效果的主要因素。针对这些影响因素,为提高资料信噪比和改善剖面叠加成像效果,提出楚雄盆地地震勘探采取多道数、小道距、长排列、高覆盖次数的观测技术是行之有效的。同时指出该盆地下一步的地震采集方法攻关方向应当采用宽线采集技术,以满足页岩气勘探需要。

Seismic data of red bed in Chuxiong Basin show low signal-to-noise ratio and strong noise interference. Improvement of signal-tonoise ratio is one of the important areas in study of seismic exploration in this region. Based on the study of seismic geological conditions in this region as well as the data acquired in the past, this paper analyzes various factors affecting seismic acquisition effects in this region and draws the following conclusions. First of all, the dual complexity of surface and underground geological structure is the fundamental cause for poor quality of seismic data. Secondly, the main factors affecting seismic acquisition effects include shooting lithology, shot point location, watery stratum and development of interference wave, and limitation of geophone array and geometry design. Focusing on those factors and improvement of signal-to-noise ratio and stack section imaging effect, this paper comes up with a series of effective technologies seismic exploration of Chuxiong Basin, such as multiple channels, small group interval, long array and high folds. Meanwhile, it also points out that wide line acquisition technology is the study area of seismic acquisition method at the next stage in this basin to meet the demand for shale gas exploration.