高邮凹陷南断阶带低信噪比地区地震勘探技术

Seismic acquisition in the low signal-to-noise ratio area of the south step-fault zone in Gaoyou sag.

高邮凹陷南断阶带地区是江苏油田的主要产油区。本区地下构造经历了多期改造,三、四级断层非常发育,地层破碎;地表村镇密集,乡镇工业发达,并有大面积的养殖区。这些不利条件导致资料信噪比较低。为此,在地震勘探上着重采取了5项技术措施:①面向目标的观测系统设计优化;②激发参数的优选;③优化接收参数,压制环境噪音;④应用卫星遥感图分束精细设计;⑤资料精细处理。通过上述技术措施,使所获三维资料信噪比较老资料有了质的提高,为江苏油田新发现了一批油气构造圈闭。

The south step-fault zone in Gaoyou sag is the major oil producing area in Jiangsu oilfield. The subsurface structure has undergone several alterations in geologic history, leading to development of faults of grade three and four, and fracturing of strata. The zone densely dots towns and villages as well as large acreages of aquaculture and poultry, with developed rural industry. These factors hamper to acquire seismic data of desired signal-to-noise ratio. Five techniques have been demonstrated effectiveness in seismic data acquisition. They are target-oriented layout design, optimization of shooting parameters, optimization of receiving parameters to suppress ambient noises, bin refinery by remote sensing image, and fine data processing. Compared to legacy data, the new data are substantially improved in S/N. A batch of hydrocarbon-bearing structural traps has been delineated.