辽西葫芦岛东部表层调查方法比对实验

地震勘探中,近地表的不均匀性给激发、接收和静校正等工作带来较大困难。辽西葫芦岛东部地表地质条件复杂,浅表层速度及厚度差异大,表层调查工作直接影响到地下介质成像效果。为使该地区首次进行的地震勘探能够获取准确的静校正量数据、给井深设计提供依据、研究适合该区域的表层调查方法,同时为满足国家深部探测项目对实验方法比对研究的需求,结合小折射、地面微测井和井中微测井三种表层调查方法的工作原理,在该工区分别应用三种方法做同点比对实验,分析了不同调查方法的适用性及精确度。结果表明,三种方法得到的结果与岩性录井结果一致,均能有效探测高速层埋深,指导井深设计,其中:小折射成本较低,适合地面较平坦区段,虽然不够精细,但能够准确找到高速层,可用于井深设计或作为微测井方法的补充;地面微测井适合山高无水或者造山破碎带造成钻井严重漏水的地区,需要井中检波器与大地良好耦合;井中微测井最为精确,探测层位更为精细,能分辨更多层位,与岩性录井结果最接近,在静校正量获取方面具有明显优势。通过三种表层调查的比对,分析了不同方法的适用范围,为该工区选择合适的表层调查方法及方法参数选取提供依据,同时为其他地表复杂区域进行表层调查提供参考。

Comparison Experimental Research of Surface Survey Methods in the Eastern Huludao of Western Liaoning Province

In seismic exploration,the nonuniformity of near-surface brings great difficulties to excitation,receiving and static correction.The surface survey work directly affects the underground imaging as the geological conditions here is complex,there is a large difference of velocity and thickness for the surface region.In order to obtain accurate static correction data and provide the basis for well depth design,a good surface survey of the region is needed in SinoProbe project.This paper discusses the principle and field construction method of small refraction,ground-microlog and well-microlog.Then we do a comparison test of the three methods at the same site,and analyze the adaptability of different survey methods.The interpretation results of each method are also compared.The results obtained by the three methods are consistent with that of lithology logging.All three methods can effectively detect the depth of high-speed layer,and guide the well depth design.Cost of the small refraction method is the lowest,so it is suitable to relatively flat surface area.Using the method,we can find the high-speed layer accurately,so it can be used as supplement for micro-logging in the design of well depth.Ground-microlog is suitable for high mountain without water or serious leaking drilling area caused by organic fracture zone.This method requires good coupling of geophone and the earth in the hole.Well-microlog is the most accurate one.It can distinguish more layers,and is closest to lithology logging result,so it has obvious advantage in the static correct obtained.In conclusion,this article analyzes the scope where different methods applied,and compares them in three surface survey.It provides evidence on how the appropriate surface investigation method for the work area was chosen,also provides a reference for other complex surface area's surface investigation.