Research On Seepage Mechanism Of Water Flooding Based On X-ray CT Scanning

X-CT technology has been widely applied in petroleum geology and oil and gas fields exploitation.In this paper,characteristic of X-CT technology and advantages of its application in the field of experiments in petroleum exploitation are discussed.The way X-ray produces and various effects produced by interaction between X-ray and materials are also involved.Based on X-CT scanning instruments,which is self-developed,application of X-CT technology in water flooding seepage mechanism has been studied and results followed are obtained:(1)Features and basic theory of X-CT technologyWith its unique advantages,X-ray is applied so widely.In this paper,characteristics of X-ray,such as penetration,fluorescence,ionization and attenuation are discussed;advantages of X-ray in oilfield exploitation and development are also discussed.X-ray generation process and X-ray interaction with objects when X-ray penetrate objects,producing serious effects including photoelectric effect,electron pair effect,Compton scattering,Rayleigh scattering,are introduced.The probability of four effects in water flooding and its impact on test results are discussed.(2)Research of X-CT instrumentBased on summary of previous results from existing X-CT instrument and principles,a set of X-CT scanning instrument was designed and developed independently,the composition,principle,characteristics of the equipment and the methods of calculating the fluid saturation in rock are introduced.(3)Application research of X-CT technique for water displacementWith the X-CT instrument designed,water displacement experiments are carried out,after which porosity and fluid saturation distribution are analyzed.Compared saturations of oil and water measured by X-CT with those calculated by JBN and studied water flooding seepage mechanism,it is proposed that correctness of the seepage curve obtained by JBN method can be detected by water saturation curve calculated through the two methods.