制约震源药柱地震响应的激发因素与试验

Shooting Factors Controlling Seismic Responses and Testing

油田探区的地震勘探工作从二维到三维,乃至多次重复勘探,总是习惯性地沿用同一品种的震源进行激发,也缺乏系统的激发因素试验与研究,取得地震资料一直面临相同的困惑,那就是低信噪比,低分辨率,地震剖面缺口深度大且频度高。为了寻找适合特定地表条件的震源药柱和激发条件,以勘探理论为依据,试验中选择了八种类型炸药,分别结合激发井深、药量、不同围岩及其含水性等开展了系列工作,以定量和定性手段相结合方式,确定了适应泌阳凹陷的激发因素,实际资料证明1kg的高爆速和中层震源弹激发可获得比以往8 kg中密度激发更好的资料品质。

Shooting has been conducted with the same kind of seismic source during 2D to 3D seismic exploration in oil fields, short of systematic experiment and study on the factors controlling the shooting, resulting in great challenges and problems in seismic ac- quisition, including low signal-to-noise ratio, low seismic resolution, and frequent deep gaps in seismic profiles. To find the suitable dynamite and explosive parameters for the specific surface conditions, 8 types of dynamite were selected based on seismic explora- tion theory to conduct the on site test. A series of quantitative and qualitative analyses have been finished at different downhole depth and different quantity of dynamite, different surrounding rocks and natural water. Finally the suitable shooting parameters have been selected for Biyang depression.It has been proved by the practical data that the seismic data quality is better, with 1 kg, high explo- sive speed and medium source play at present than 8 kg, middle-density dynamite in the past.