基于智能传感器技术钻井液密度检测的研究

Study of Drilling Fluid Density Detection Based on Intelligent Sensor

钻井液密度在线测量是录井过程中较难解决的问题,因为钻井液是在不停地循环流动,钻井液池中的钻井液还要不停地搅拌,其温度变化范围较大,钻井现场的环境也较恶劣,这给准确测量密度带来了一定的困难,针对这些问题,本文介绍一种基于智能传感器技术的钻井液密度检测新方法.其核心是硅谐振传感器技术,由单晶硅谐振式传感器上的两个H型振动梁分别将差压信号转换为频率信号,再将两频率之差直接传送到CPU进行数据处理,经D/A转换器转换为与钻井液密度相对应的4～20mA输出信号.克服传统钻井液密度测量大多采用压敏电容式传感器,存在准确度低、易损坏、易漂移等缺点,具有高精度、高稳定性、高可靠性的特点.

The online detection of drilling fluid density is still a problem that can not be easily solved in the process of gas logging. Because the drilling fluid is circulating all the time, the drilling fluid in the pool is always churning, in which there is a large changing range of the temperature, and the spot environments of gas logging are also severe, all these brought certain difficulties in detecting the density. Based on these problems, this paper introduced a new method to detect drilling fluid density based on intelligent sensor, the core of which is silicon resonant sensor technology. Two H model resonant beams located at single crystal silicon resonant sensor convert differential pressure to frequency signals respectively, then difference of two frequency signals are transmitted to CPU, and transformed into 4 ~ 20mA output signal corresponding drilling fluid density by D/A converter. This method got over the shortcomings of typical drilling fluid density detection used piezocapacitive sensor, such as low accuracy, shattered easily, easy drift …etc., has high precision, stability and reliability characters.