Simulated And Experimental Studies On Measuring The Grease Stain Thickness By Acute Angle Compton Scattering Method

Oil pipelines may be stopped by the oil crust formed in the oil tube. To avoid this, it is necessary to find an approach to measure oil crust thickness from outer side of the tube.Γray scattering method is an effective and convenient way for this. In this paper, based on the Compton scattering theory, a simulated experiments together with simulation by MCNP code system has been carried out to study measuring the grease stain thickness in oil pipeline by acute angle scattering method ofγray.First, based on the previous work, simulating oil tube using an iron plate, suppose that there is crust just at one inner side of the tube (that is to say the side which close to detector and ray source), an acute angle scattering experiment was carried out on to real oil crust using 60Coγsource. Then a MCNP simulation of the experiment was made in the same geometrical condition to observe the relationship between scattering photon numbers and grease stain thickness. The result shows that there certainly exists a linear relation between crust thickness and scattering photon number (fits with the result of wax simulating crust experiment), the experiment and simulation results fits very well. Especially for 45°incident angle the value of R2 is, on the whole, bigger than 0.99, means that 45°incident angle is a good choice for the linear relationship between scattering photon number and oil crust thickness .Acute angle scattering is feasible.In second step, closing the real situation, using iron tube from oil field and circular-shaped oil crust as measuring object, observations on to the relation between crust thickness and scattering photon number was made under the same condition as the previous experiment. Also have the result that experiment and MCNP simulation fits well, got that the linear correlation coefficient and measuring precision was so well compared to the parameters of other angles when the incidence angle equals to 15, 22.5, and 45 degrees while the scattering angle equals to 60 degree. This provided a parameter which may possibly make the error smaller for the future application of the method. As we see, acute angle scattering method, certainly, is a very applicable way to measure oil crust thickness.This paper is an initial research work of testing oil crust thickness by using"the reflectiveγ-ray instrument". All the results show that measuring oil crust thickness by acute angle scattering method is feasible in principle. All above the discussion contributes experimental basis and feasible program guidance to the development of "surfaceγmeter for oil crust measurement".