wily old bird;old slicker

This paper analyzes current situation of Petro China and points out that 70% of PetroChina's oil production still comes from old fields where considerable residual recoverable reserves still exist.

通过对中国石油所面临的形势进行分析,指出目前中国石油产量的70%仍然来自老油田,其剩余可采储量仍相当可观。

Quick discrimination of ageing frying oil and hogwash oil from good edible vegetable oil with thin layer chromatography;

薄层色谱法快速鉴别潲水油和煎炸老油的研究

The practice and recognition of exploration management about old petroliferous districts in Subei Basin.;

苏北老油区勘探管理工作的实践与认识