Research On Volumetric Compression Properties Of Gelled Crude Oil

When the gelled crude oil pipeline restarted,the crude oil was subjected to compression force,which made the crude oil present complicated volumetric compression properties.In order to fully research the volumetric compression properties of gelled crude oil and serve the studies of the gelled crude oil pipeline restarting,this paper explored the volumetric compression properties of gelled crude oil including the volumetric compression deformation and apparent compression coefficient of gelled crude oil based on the gelled crude oil compression experimental device.The gelled crude oil compression experimental device was designed and developed with new sealing structure,new measuring structure and new measuring instrument.Compared with the same existing compression experimental device,this device had better improvements and can measure without contact.The program used to process pictures in batches was written based on the image processing software,which guarantee the accuracy of data and the efficiency of processing.In view of the particularity of the sealing structure,the volumetric compression experiments of intermediate liquid were needed to carry out based on this device to accurately measure the volumetric compression coefficient of intermediate liquid.What's more,the compression deformation laws and the compression coefficient were obtained.The volumetric compression deformations of the selected intermediate liquid don't exit time effects and the deformation has a good response to the pressure.The volumetric compression coefficient of intermediate liquid is small and it's not easy to be compressed,so it's reasonable to select this liquid and the sealing structure for this paper.The volumetric compression deformation properties of the gelled crude oil under constant pressure were studied based on the compression experiment.The compression creep model was introduced and the relevant laws of the volumetric compression deformation properties were obtained.The gelled crude oil has compression creep property and its deformation has time effect under constant pressure.According to that,the scientific pressurization method called constant pressure single-load pressurization was determined.The creep deformation of gelled crude oil belongs to fast steady state and its deformation rate decreases with the increase of the pressure in the low pressure,while the creep deformation is slow steady state and its deformation rate increases with the increase of the pressure in the middle and high pressure.The laws of compression coefficient of gelled crude oil were studied and the concept of apparent compression coefficient of gelled crude oil was introduced.The apparent compression coefficient of gelled crude oil is different in different pressure ranges,which shows a piecewise linear relationship.The apparent compression coefficient of gelled crude oil in low pressure is larger than that in middle and high pressure.And the apparent compression coefficient of gelled crude oil in low pressure decreases with the increase of temperature affected by the compression property of gas void,while the apparent compression coefficient in middle and high pressure increases with the increase of temperature indicating the compression property of crude oil itself.In addition,the compression coefficient of liquid crude oil and the apparent compression coefficient in middle and high pressure comply with the same law.