南方黔中碳酸盐岩裸露区地震采集方法探讨

Seismic data acquisition method for carbonate outcropped area in central Guizhou province of southern China

（中国石油化工股份有限公司西南分公司第二物探大队，四川德阳618000）

Second Geophysical Service Company, Southwest Bureau of Petroleum, SINOPEC, Deyang 618000, China

南方黔中地区地表出露不同地质年代的碳酸盐岩地层，地表起伏剧烈，地层倾角大，表层破碎，岩性复杂，表层结构纵、横向变化大，激发和接收条件差；溶洞、裂隙发育，散射严重；面波、折射波发育，次生线性干扰强；目的层埋藏深度变化大,断层发育，地腹构造复杂，构造部位的成像效果差；地震波吸收衰减严重，反射能量弱，信噪比低。针对这些问题，探讨了适合于黔中碳酸盐岩裸露区的地震资料采集方法。对采集因素——道间距、最大炮检距、覆盖次数、激发井深、激发岩性、激发药量、检波器组合方式等进行了细致分析，确定了小道距、长排列、高覆盖次数、深井饱和药量激发、多串检波器组合接收的采集方法。实际应用表明，采用该采集方法提高了资料的信噪比，提高了断层和地腹构造的成像效果，可以满足碳酸盐岩裸露区的勘探要求。

Outcrop of carbonate formation of different geological periods can be widely seen in central Guizhou province. There are some difficulties during data acquisition because of 1) the fluctuating surface, the steep dip angle of formations, and the complex lithology with big changes in horizon and vertical, resulting in bad shooting and receiving conditions, 2) the well-developed karst caves and fractures scattered in all directions, 3) the existing surface wave and refraction wave causing a strong secondary linear interference, 4) the big change in buried depth of target formation and the well developed faults, resulting in bad imaging effect, and 5) the strong absorption and attenuation making the S/N low. Aiming at these problems, the acquisition method suitable for this area was probed and the acquisition factors analyzed, including group interval, maximum offset, fold, shooting-well depth, shooting lithology, shooting explosive amount, and seismometer pattern layout. The acquisition method was ultimately determined as small group interval, long array, high fold, deep shooting depth, saturated shooting charges, and more strings of geophone array etc. The actual application shows that the acquisition method can enhance the S/N of seismic data, improve the imaging effect, and satisfy the exploration requirements in carbonate outcropped area.