南黄海盆地的地震方法试验

THE EXPERIMENT OF SEISMIC PROSPECTING METHOD ON THE SOUTHERN YELLOW SEA BASIN

本文简要地叙述了我们在南黄海盆地进行地震采集方法试验的情况,分析了各种采集参数情况下的资料质量,并讨论了各种采集参数对地震剖面质量之影响。由此作者认为,在一定地震电缆接受排列长度的情况下,加大气枪阵容积(即增加震源能量)和适当选择地震接受电缆的沉放深度,可以改善地震剖面的质量,增加对深层的勘探能力。在我们的240道电缆排列长度情况下,电缆沉放12m深度是合适的。如果要进一步改善地震剖面之质量,则必须增加地震震源之容积,即增加震源的能量。

We experienced the seismic prospecting method on the Southern Yellow Sea Basin in the August 14th～15th, 2000. We use our "Tanbaohao" ship, which was bought from the Western Geophysical Cooperation in 1994 to carry out the experiment. We used 240 channel seismic streamer (made by I/O company) of receiving and recording systems, and four air gun sub-array with a total volume of 3000 in^3 for the source system. We test the volume of the air gun array and the down depth under the sea level of the streamer. We found that bigger volume of the air gun array and suitable down depth (closing the one fourth wave length) under the sea level of streamer are good exploration for the deeper layers. On this leg we prospected good reflection of 5.2～6.5 seconds (two-way travel time), and interpreted it as the bottom of the Paleozoic sediments. Therefore, we believe that in the Southern Yellow Sea Basin the water depth is too shallow (less 80m), so using 240 channel streamer system and 12m down depth under the sea level, four air gun array(total volume are 3000 in^3) and 10m down depth under the sea level, are good collecting system for exploration of the deeper layers.