电容式含水率仪在高含水条件下的测量模型

The measurement model of capacitive watercutmeter in highwater-cut environment

随着油田开发的不断进展，油井的含水率随之升高，目前广泛使用的电容式含水率仪器已不能适应油田开发的需要，针对这一问题，文章从理论和实验中证明在低频条件下油井水是一种导体，提出了高含水条件下电容式含水率仪的测量模型，计算表明：电容与含水率之间是非线性关系，电极绝缘层厚度是影响探头的关键，厚度增大线性变好，但灵敏度下降，反之，绝缘层越薄，测量灵敏度越高，线性变差，为了提高仪器对高含水的测量灵敏度应采用线性测量电路。

With the continual advancement of oil field development, water cut in oil well is increasing. At present, the capacitive watercutmeter widely used can be not suited to the needs of oil field development. In accordance to this question, water in oil well is a conductor in low frequency is IJroved from theory and experiment is this paper. The measurement model of capacitive watercutmeter in high - water - cut environrnent is proposed- the calcu1ation shows that between capacitor and water cut there is a nonlinear relation, The thickness of electrode insulating barrier is the key to affect a probe. The more thickness increases, the better linearity will become, but the sensitivity will be dropped. On the contrary, the thinner insulatinft barrier is, the higher measurement sensitivity is and the worse linearity becomes. In order to enhance neasurement sensitivity to high - water - cut, the linear measurement circuit should be employed.