Identification of Earth's Permeability Zones and Evaluation of Their Parameters Using MTS and MVP Data

摘要

5-component magnetotelluric soundings (MT) allow for the realization of two independent electroprospecting methods. The first method - magnetotelluric soundings (MT) - is based on the measurement of 4 horizontal components (Ex, Ey, Hx, Hy). The second method - magnetovariational profiling (MVP) - is based on the measurement of 3 orthogonal magnetic components (Hx, Hy, Hz). The MT method has great capabilities for separating sub-horizontal geoelectric layers. At the same time, the MVP method is extremely sensitive to the presence of vertical or tilted borders and anomalous objects. The combination of these two methods thus allows for sufficiently detailed mapping of geoelectric cross-sections. At the same time, the position of anomalous (with respect to the containing layered area) zones plays a significant role in forecasting potential oil and gas deposits. Noteworthy, the MVP method response function allows, during the initial analysis of the field data, to already not only determine the position of these areas, but to also estimate the angle of incidence, the nature of depth proliferation, and the relative conductivity. This paper proposes a robust method of determining the parameters of anomalous objects. Such zones were identified in the course of a 3-D MT survey in the foothills of Uzbekistan. It has been established that these zones reach deep into the Palaeozoic foundation and their position correlates well with the position of productive wells.