自然伽马测井在水文地质孔填砾中的应用

填砾是水文地质勘探孔成井的一个关键工艺,该工艺的一个难点就是填砾过程的深度测量,因无法及时判断填砾面位置及填砾过程中出现的"悬空"现象,导致勘探孔无法止水分层或报废,特别是在细颗粒含水层区成井,因填砾失败导致井报废的实例很多。通过自然伽马测井利用裸孔和填砾前、后的曲线对比,可以测量填砾面位置,解决了填砾过程中砾面深度测量的困难;可以发现填砾成井过程中产生的不利现象,为成井采取补救措施提供信息帮助,有利于保证成井质量。

An application of natural Gamma-ray logging in graveling for hydrogeological hole

Filling gravel is a key process in well completion for hydrogeological hole,one of the difficulties of this process is the depth measurement of the gravel-filling process.Because of the inability to timely determine the position of the gravel layer and the "hanging" phenomenon during the gravel-filling process,the hydrogeological hole cannot be stratified or abandoned,especially for the well completion in the fine-grained aquifer area.There are many examples of wells that abandoned due to failing of gravelling.According to the comparison of the curves before and after graveling through natural gamma-ray logging,it is possible to measure the position of the gravel layer and solve the difficulty of measuring the depth of gravel layer in the process of graveling and find the unfavorable phenomenon during the process of graveling.This provides associated information for the remedial measures to well completion,as well as help to ensure the quality of the well.