Myrontsov M. Instrumental-methodological complex for electric and induction logging for complex geological structure investigation

The thesis is devoted to the theoretical development of an instrumental-methodological complex for electric and induction logging and the reasoning of its use efficiency including the use in tough conditions. The method of increasing the efficiency of the inverse problem solution for multiprobe logging, which is connected with the error calculation in geoelectrical characterization of a bed depending on a measurement error, was developed. The efficient factorization method for inverse problems of induction logging was proposed, in which a stable method based on solving of the first kind Fredholm equation of convolution type is used for solving an one-dimensional problem along the axis of bed. It was shown that this method can also be applied to inverse problems of the pulse induction logging. Two principles of creating facilities with multiprobe "focusing" characteristics was proposed, namely: the principle based on non-crossing of current lines in a conducting medium and the other based on the pulse power supply. It was shown that for equipment built on these principles the inverse two-dimensional problem can be factorized with high degree accuracy. On the base of mathematical modeling, it was demonstrated that proposed instrumental-methodological complexes permit to study conductivity characteristics of topical models used in geophysical investigation of wells including: intricately built thin-layer and anisotropic collectors, anomalously low resistivity collectors, collectors of residual oil-saturation, "false" collectors and objects in horizontally inclined and horizontal wells. Keywords: geophysical investigation of wells, electric logging, induction logging, inverse problem, instrumental-methodological complex, characteristics of spatial resolution, horizontal well, horizontally inclined well.