盐水泥浆侵入条件下咸淡水界面测井识别方法研究

Logging recognition method of salt-fresh water interface under the condition of salt-cement mud invasion

淡水泥浆侵入条件下咸淡水界面的测井识别方法,国内很多学者早有相关研究,但对盐水泥浆侵入方面的研究相对滞后。传统的测井识别方法采用视电阻率和自然电位测井曲线划分地层岩性及确定咸淡水界面,但在盐水泥浆侵入条件下,视电阻率曲线受泥浆减阻侵入影响严重,无法准确划分地层岩性。文章通过对泥浆侵入机理的研究,总结出盐水泥浆侵入条件下测井响应特征,探索出盐水泥浆侵入条件下咸淡水界面的测井识别方法。研究表明,自然伽玛测井曲线不受泥浆性质干扰,在地层划分方面与其他方法相比具有优势。因此,利用自然伽玛和自然电位综合测井方法进行咸淡水界面的判别适用于盐水泥浆侵入地层。

Many domestic scholars have studied the logging identification method of saltwater-freshwater interface under the condition of freshwater mud intrusion,but the research on saltwater mud intrusion is relatively lagging behind.Traditional logging identification methods use apparent resistivity and natural potential logging curves to divide formation lithology and determine saltwater-fresh water interface.However,under the condition of saltwater mud intrusion,apparent resistivity curve is seriously affected by mud drag reduction intrusion,and can not accurately divide formation lithology.By studying the mechanism of mud invasion,this paper summarizes the logging response characteristics under the condition of saline mud invasion,and explores the logging identification method of saltwater-freshwater interface under the condition of saltwater mud invasion.The results show that the natural gamma ray logging curve is not disturbed by mud properties and has advantages over other methods in stratigraphic division.Therefore,the identification of saltwaterfreshwater interface using natural gamma ray and natural potential integrated logging method is suitable for saltwater mud intrusion into formation.