State-of-the-Art Review of Nondestructive Testing With Computer-Assisted Tomography

Abstract

Abstract Computer assisted tomography (CAT) has been a revolutionary technique in medical radiology. Recently, CAT scanners started to be used as non-destructive testing facilities in different industrial applications. Most of the applications of the new technology are in the areas of petroleum engineering. Majority of this CAT scanner technology has been developed in the U.S.A. However, several Canadian companies have acquired CAT scanners and are using for novel commercial as well as research applications. This paper presents a comprehensive review of advances made in the areas of CAT scan technology as applied to the petroleum industry. petroleum industry. Recent efforts in developing CAT scan technology has been in the areas of core analysis methods. The ultimate objective is the quantitative monitoring of dynamic two- and three-phase experiments in porous media. Even though advances have been made in using CAT scan for quantitative evaluation of fluid flow, more research has to be done before gaining confidence in such a technique. This paper presents a critical review of recent research publications. Also, discussed is the possibility of using CAT scan as a unique reservoir possibility of using CAT scan as a unique reservoir characterization tool. Reservoir properties, such as direction and frequency of fractures, the presence of vuggs, stratification in the bedding presence of vuggs, stratification in the bedding plane, etc. may he identified only through plane, etc. may he identified only through non-destructive testing of reservoir cores. Various applications of CAT scanning to oil industry are discussed in detail. PRINCIPLES OF CAT PRINCIPLES OF CAT Recently, Kantzas has outlined in detail the principle of computer assisted tomography. principle of computer assisted tomography. Consequently, we will describe the principle only briefly. The original theory for reconstructing a complete image of an object from numerous views around the object was first described by Radon in 1917. The principle of CAT is based on emitting x-ray from a source which revolves around the object in consideration while one-dimensional projections of attenuated x-rays are collected by a projections of attenuated x-rays are collected by a detector on the other side of the source. These projections are collected as the sample travels projections are collected as the sample travels through the scanner longitudinally and are used to reconstruct a three-dimensional image of the object. Intensity values of attenuated x-rays are collected from small volumetric elements, called pixels. pixels. P. 523