基于模拟油井的井下测试仪温度修正校准方法

针对石油井下射孔压力测试中,在射孔完井过程中会释放大量的热量,压阻式压力传感器的温度效应成为影响测试精度的主要因素。为准确测取井下压力,用现有模拟油井试验装置模拟井内高温高压环境建立了校准系统。在多个温度环境下进行校准试验,通过与溯源性校准的标准测试系统的对比计算,利用最小二乘法得出压阻传感器在不同温度条件下的灵敏度,根据测试仪采集的实时温度数据值修正了压力数据,计算表明压力曲线峰值比修正前小1.4 MPa,为压力峰值的2.08%,表明该压阻传感器温度效应产生的影响不可忽略,基于模拟油井的温度修正校准方法能有效减小温度效应的影响,提高了测试精度。

Temperature Correction Calibration Method for Downhole Tester Based on Simulative Oil Well

In the oil well perforation pressure testing, a lot of heat will be released during the process of perforation. The temperature effect of piezoresistive pressure sensor is a main factor influencing the testing precision. To accurately measure the downhole pressure, we had set up calibration system with existing wells simulation test device. The simulation test device is used to simulate downhole high temperature and high pressure environment. Several calibration tests were done under multiple temperature environments. The test results were contrasted with the standard test system. The standard test system was trace calibrated. The piezoresistive sensor sensitivity under different temperature conditions was draw out by the least square method. At last, the pressure data was modified according to the real-time temperature data which is collected by tester. Calculation shows that the peak pressure curve is 1.4 MPa smaller after modification. This account for 2.08% of the peak pressure. And it shows that the impact of piezoresistive sensor temperature effect should not be neglected. The temperature correction calibration method for downhole tester based on simulative oil well can effectively eliminate the effect of temperature, improve the test accuracy.