VSP三分量微测井技术在表层调查中的应用

Application of 3C VSP uphole survey technique in near-surface survey.

微测井技术是表层调查的主要手段之一,但因其高昂的成本限制了微测井布设的数量。本文提出VSP三分量微测井技术,即采用地表激发、井中检波器接收的微测井观测方式,井筒直接借用地震勘探中的炮井。此法不仅降低了微测井的成本,而且增加了微测井分布密度。对于打穿低速层的微测井,可以直接利用高速层顶界的(?)时间作为解释表层结构的控制点。对于没有打穿低速层的微测井,可利用VSP技术中的上行波信息,提取完井深度以下的地层深度和速度信息。

Uphole survey technique is one of major tools of near-surface survey,but the number of layout of uphole survey is constrained by the higher cost. The paper presented 3C VSP uphole survey technique,i, e. uphole survey pattern adopting shooting in surface and receiving by geophone in hole, the shot-hole in seismic exploration is used as well for uphole surveying. The method not only reduced the cost of uphole survey,but also increased the density of distribution of uphole survey. The T0 times in top interface of high velocity can be used as control points of interpreted near-surface structure if the low-velocity layer of well for the uphole surveying is penetrated through, otherwise, the up-going wave information of VSP can be used to detect the depth and velocity data of beds below the depth of well.