Study Of Key Technologies On CT Scanning Device In Dynamic Core Flow Test At High Temperature And High Pressure

In the development oil and gas fields,the core visualization method is one most of the important methods to study the mechanism of oil displacement in core pores,which is the key technology of enhancing oil recovery by the study of chemical mechanism.With the visible CT scanning technology,it can scan the core pores and different flooding processes,dynamically observing the distribution characteristics of seepage in the porous medium under different pressures,which obtains the distribution information characteristics of oil and water in the core.By using the security inspection machine and industrial CT,we completed the selection,design,installation and commissioning of key components,which included X-ray machines,rare earth fluorescent paper,ray input window materials,micro-light cameras,tracers,etc.,and performed an oil-water flooding CT scan experiment,which obtained a good dynamic oil-water distribution experiment result.It realized the key technology of the transmission of core by X rays,fluorescent paper imaging,tracers to enhance the contrast of oil and water under high temperature and pressure conditions.The main research contents and results are as follows:According to the experimental requirements of high temperature and high pressure,a device is designed.The X-ray is injected into the high-pressure vessel from the ray window at the bottom of the container,passing through the core to reach the X-ray detector,converted into visible light,then outputting to the low-light camera through the high-pressure glass window on the top cover of the vessel for image acquisition.The X-ray transmission technology to the core of the device realizes the dynamic flooding CT scan experiments under high temperature and high pressure conditions.The effect of the container shell on X-ray scattering and attenuation was analyzed.By the way of X-rays illuminating the core through aluminum windows and confining pressure gas,imaged on fluorescent paper,the image detection technology significantly improves image clarity,because the emission and reception of X-rays will not pass through the pressure vessel shell.A variety of ray window materials and confining gas were tested.The 2mm aluminum window and helium show the lowest effect on X-ray attenuation and scattering.According to the theory of ray absorption,the main active elements in the periodic table were analyzed.Iodobutane + lead isooctanoate and sodium iodide are respectively used for oil and water tracers.