The Application of X-ray Micro Computed Tomography (Micro-CT) of Core Sample for Estimation of Physicochemical Treatment Efficiency

Abstract

Abstract Today, the oil industry faces a number of problems encountered in exploration and exploitation of oil and gas fields. At the same time, thanks to the joint efforts of experts in various fields of science and technology, there are new kinds of specialized research, which in combination with other methods of laboratory and field testing can improve the efficiency of existing technologies through an integrated approach to data acquisition and analysis. At present, increasing attention of researchers is drawn to a variety of nondestructive testing methods (research) associated with the use of various types of computer tomography (X-ray, magnetic resonance and others.). Application of research of this type in combination with other methods is wide enough and is only limited by the scientific training and applied knowledge as well as the scientists’ ability to invent. Particular attention is paid by the authors of this work to the following core areas of laboratory research: the study of the structure of the pore space of rock samples in order to evaluate the reservoir properties of the productive formation, complex filtration and tomographic studies to assess the extent of damage to the reservoir (as a result of the acid treatment, alkali treatment, hydraulic fracturing, killing operations on production and injection wells, evaluation of the depth of penetration of drilling mud filtrate into the formation, precipitation of resins, asphaltenes and paraffin in the bottomhole formation zone). Simulation of this process in a specially equipped laboratory allows for the assessment of the depth of penetration of the gelling agent into the formation or will help to establish the effectiveness of other ways to reduce water production, change the injectivity profile of injection wells, etc. This article presents the results of several types of special studies and a series of data to draw conclusions about the high significance of the research. The paper describes the standard type of study to assess the porosity of productive stratum rock (for example, collectors with hard to recover reserves of the Bazhenov Formation of Western Siberia), the method of evaluation of formation damage resulting from asphaltene deposits in the operation of wells with bottomhole pressure below the gas saturation pressure, and the results of the application of computer tomography in the evaluation of the results of classic acid treatment of bottom-hole zone of wells in carbonate hydrocarbon (oil and gas) bearing reservoirs. Studies have shown that the application of computer tomography in some cases, allows to obtain data on the processes of reduction or increase in permeability taking place in a core due to the introduction of any of compositions in the bottomhole formation zone. Construction of three-dimensional models can improve the degree of comprehensibility and effectively visualize data of models built (for example, models of porous space and the rock matrix). Ultimately, the results of X-ray computer tomography are very easy to understand, highly visual and can be presented in a variety of projects, from high-quality preparation of geological and technical measures in wells to inclusion of field development projects.