Study on Error Correction Method for Measurement of Rheological Properties of Mud under the Influence of Pulsating Flow

The performance of drilling fluid plays an extremely important role in oil drilling, in the drilling, the main functions of the drilling fluid including bottom hole cleaning, carrying cuttings, control and balance the formation pressure, etc., in the completion, the function of the drilling fluid protect the reservoir. The rheological property of drilling fluid is an important indicator parameter of drilling fluid properties, Conventional measurement method based on the well site to use paradigm six-speed viscometer to manual measurement, measurement time is too long, manual operation error, human cost and other issues, led to the drilling safety risk, In this paper, a real-time rheological measurement method of drilling fluid is proposed, which adopts two series of variable diameter measuring tubes. When the flow rate through the measuring tube, the shear rate and shear stress of the drilling fluid can be obtained by measuring the pressure difference between the two ends of the measuring tube, and the mathematical model can be used to improve the accuracy of viscosity detection, greatly shorten the measuring period, and realize the automatic measurement of drilling fluid rheology. However, because the pulse of diaphragm pump has influence on the pressure measurement of the pulsating flow rate of different pipe diameters, and the device uses the pipe pressure difference data to calculate the viscosity, so the error correction and analysis of the downward influence data of the pulsating flow rate are carried out, thus improving the accuracy of the device to measure the rheological property of drilling fluid.