基于电导法的原油含水率测量改进方法

Method for Optimizing Moisture Content of Crude Oil Based on Electric Conductivity Method

基于电导法开展原油含水率测量具有硬件结构简单,系统稳定可靠及测量准确等特点。根据Maxwell模型原理,电导法测量原油含水率需要获知纯水相电导率。然而,开展井下实时含水率测量时,纯水相电导率无法直接测得,直接使用预设的纯水相电导率无法真实得出井下原油的实时含水率。鉴于此,本文根据原油的馏分性质,通过测量不同温度下两组油水混合相的电导率值并进一步推导得出原油含水率表达式,规避纯水相电导率测试问题及预设纯水相电导率不精确问题,实现对现有原油含水率测量方法的改进。基于ARM Cortex-M4处理器及多种传感器测量技术开展了实验研究。实验结果表明,当测量含水率大于90%的油水两相流时,误差可在2%以内,当测量纯水相矿化度在7 g/L以内的油水两相流时,含水率误差基本不受矿化度影响。实验结果验证了优化方法理论的有效性,具有实际应用的可行性。

Based on the conductance method,the measurement of crude oil moisture content has the characteristics of simple hardware structure,stable and reliable system and accurate measurement.According to the Maxwell model principle,the conductance method for measuring the moisture content of crude oil requires knowledge of the pure water phase conductivity.However,when the real-time water content measurement in the underground is carried out,the conductivity of the pure water phase cannot be directly measured,and the real-time moisture content of the crude oil can not be obtained by directly using the preset pure water phase conductivity.In view of this,according to the crude oil’s fraction properties,by measuring the conductivity values of the two oil-water mixed phases at different temperatures and further deriving the crude oil moisture expression,avoiding the pure water phase conductivity test problem and the preset pure water phase conductance rate is not accurate,and the improvement of the existing crude oil moisture measurement method is realized.Experimental research was carried out based on ARM Cortex-M4 processor and various sensor measurement technologies.The experimental results show that when measuring the oil-water two-phase flow with water content greater than 90%,the error can be within 2%.When measuring the oil-water two-phase flow with the pure water phase salinity within 7 g/L,the water content error is basically not Affected by the degree of mineralization.The experimental results verify the validity of the optimization method theory and have practical application feasibility.