基于目标的三维观测系统设计——以百色盆地北部陡坡带实际应用为例

3-D seismic geometry design based on object-an example of northern steep slope in Baise basin.

1. 中国地质大学(北京), 北京100083;2. 中国石油化工股份有限公司南方勘探开发分公司, 云南昆明650200;3. 成都理工大学能源学院, 四川成都610059;4. 中国石化集团西南石油局第二物探大队, 四川德阳618000

China University of Geosciences, Beijing 100083, China

广西百色盆地地下构造十分复杂,其北部地层高陡,断裂异常发育。以往的勘探,一是受仪器设备和技术条件的制约,观测系统CDP网格过大,排列长度较短;二是没有针对盆地中油气最富集的目标区(北部陡坡带) 进行针对性的观测系统设计,致使地震剖面的波组特征不明显,断点不清晰,构造难以准确落实。为查明百色盆地3条主控断层的产状、性质和展布情况,落实北部陡坡带的盆地边界地层接触关系,针对该区地震地质条件, 进行了基于目标的三维观测系统设计。首先,对以往的三维地震勘探观测系统进行了分析,找出了问题的症结所在;然后,提出了设计思路,并利用弹性波波动方程正演方法对目标区北部陡坡带进行了正演模拟,分析了不同地震地质条件下资料的品质以及满足地质条件的采集参数;最后,针对该区的复杂构造进行了基于目标的三维观测系统设计。在北部陡坡带,利用基于目标的观测系统采集的资料,信噪比得到了较大改善,品质较好,可用于精细构造解释。

As an acquisition design and working designmethod, Object-oriented Seismic Geometry is designed for the complicated geologic situations.The underground geologic structure of Baise basin in Guangxi is complicated: the stratum of northern basin is high and steep with developed fracture.Limited by instrument equipment and technicalmethod, traditional Geometry has too large CDP bin and shot array.Simultaneity, the Seismic Geometry is not designed specially for the Object-northern steep slope(favorable district of petroleum accumulation), the structure is difficult to determine because of inconspicuous events set and fault point.After applying elastic wave equation forward focusing on complicated geologic structure, Object-oriented Seismic Geometry is proposed to find out the characteristics and relationship of the stratum in northern steep slope at the basin border.S/N ratio of the data acquired by this geometry has been greatly improved.The quality of acquired data is able tomeet the needs of fine structure interpretation.