Geologia
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ISSN 0138-0974
e-ISSN: 2353-0782
Issue Date
2011
Volume
T. 37
Number
Nr 1
Description
Journal Volume
Geologia
T. 37 (2011)
Projects
Pages
Articles
Metody elektromagnetyczne w prospekcji naftowej
(Wydawnictwa AGH, 2011) Stefaniuk, Michał
Hydrocarbons saturating rocks give rise to anomalous changes in physical properties of geological medium and measured geophysical fields, thus allowing discovering and recognizing of oil and gas fields. Deposit complexes are characterized by resistivity increased by 1-4 orders of magnitude. Resistivity contrast appear at the lower boundary of deposit, between reservoir rock saturated with mineralized water and saturated with hydrocarbons, as well as at the upper boundary with low-resistivity sealing clayey rocks. Moreover, a contrast of environment's ability to electric polarization induced by electric current flow appears at the boundary between hydrocarbons and formation water. The indirect indicator of a hydrocarbon deposit is the near-surface zone of sulfide mineralization connected with the hydrocarbon diffusion, which modifies magnetic properties and electric polarization ability of the medium. Examples of investigations made in the zone of the Carpathian oil field »Grabownica« and gas field »Rudka« in the Carpathian Foredeep are presented.
Pola elektromagnetyczne źródeł dipolowych
(Wydawnictwa AGH, 2011) Miecznik, Juliusz
Equations satisfied by vectors of electric and magnetic field were derived based on Maxwell's equations. In the case of time-dependent harmonic fields these are so called wave equations. Potential functions, i.e. vector potential and scalar potential, that also satisfy the wave equation were used. Vector and scalar potentials are related with electric and magnetic field by means of a number of equations. To determine the electromagnetic field in a non-homogeneous medium one should define the boundary conditions for vectors of electric and magnetic field and vector potential. The paper presents analytical formulae for EM field components for electric dipole and magnetic dipole in a homogeneous space and half-space. Parameters of real measurement arrays that fulfill conditions of electric dipole and magnetic dipole are given. So called near zone and far zone for EM survey are defined. EM field of infinitely long cable and ungrounded loop is characterized.
Metoda polaryzacji wzbudzonej w prospekcji złóż węglowodorów
(Wydawnictwa AGH, 2011) Wojdyła, Marek; Stefaniuk, Michał; Sada, Marek; Sito, Łukasz
The paper presents the method of induced polarization (IP) and focuses on its application to direct prospecting for hydrocarbon deposits. Induced polarization parameters that are obtained from measurements in time domain and frequency domain are presented. Classification of minerals and rocks based on induced polarization parameter was analyzed. Five examples of application of induced polarization method to discovering and recognizing hydrocarbon deposits by foreign companies were given. Methodology of field works made in Carpathians and Carpathian Foredeep with the use of equatorial and dipole-dipole arrays was described. Maps of phase parameter evaluated from results of equatorial array measurements for Grabownica and Rudka deposits as well as the plot of phase parameter along profile cutting the area of Rylowa deposit were analyzed. Cross-sections of three induced polarization parameters were made and analyzed with CSAMT resistivity sections in the area of Rudka deposit.
Podstawy metody procesów przejściowych i możliwości jej zastosowania w wykrywaniu złóż węglowodorów
(Wydawnictwa AGH, 2011) Klityński, Wojciech; Targosz, Paweł
This paper describes the principles of the transient electromagnetic method (time- domain electromagnetic method, TDEM) as well as TDEM measurement systems, data processing and 1D data interpretation techniques. The paper discusses also some problems of resolution and penetration depth of the method. We calculated and discussed TDEM sounding curves for three-layer geoelectric models, which consisted of a high-resistivity middle layer and low-resistivity upper and lower layers. The calculated curves were analysed from a viewpoint of a possible mapping of high-resistivity structures that could be hydrocarbon-prospective areas. The application of TDEM sounding to oil and gas exploration was evaluated.
Interpretacja złożonych struktur geologicznych z wykorzystaniem prostych i inwersyjnych modelowań pola magnetotellurycznego
(Wydawnictwa AGH, 2011) Wojdyła, Marek; Stefaniuk, Michał
General assumptions of 1D and 2D modeling and inversion were presented in this paper. Methodology of magnetotelluric data interpretation was described including analysis of dimensionality of geoelectrical medium and its influence on choosing the proper interpretation model. Relations between initial model and final results of inversion were shown based on magnetotelluric (AMT and CSAMT) data from Grabownica oil and gas field. The second example was from the Lodyna oil field. A possibility of interpretation of thin vertical layers, which can approximate the Lodyna field by 1D and 2D MT inverse procedures was analyzed. Dependences between final geological models and MT curve type (TE mode or TE mode) taken to interpretation were shown. Finally, methodology of interpretation was proposed.