One of the critical problems in interpretation marine controlled-source electromagnetic geophysical data is taking into account anisotropy rock formations. We evaluated a 3D anisotropic inversion method based on integral equation method. applied this to full towed-streamer (EM) data. The EM system makes it possible collect with high production rate and over very large survey areas. At same time, has become challenging problem because huge number transmitter positions moving system, and,...

Michael S. Zhdanov, Masashi Endo, Noel Black, Lee Spangler, Stacey Fairweather, Andrew Hibbs, George A. Eiskamp and Robert Will present a feasibility study of permanent electromagnetic (EM) monitoring CO2 sequestration in deep reservoir using novel borehole-to-surface EM (BSEM) method.

ABSTRACT A towed streamer electromagnetic system capable of simultaneous seismic and data acquisition has recently been developed tested in the North Sea. We introduce a 3D inversion methodology for that includes moving sensitivity domain. Our implementation is based on integral equation method computing responses Fréchet derivatives uses re‐weighted regularized conjugate gradient minimizing objective functional with focusing regularization. present two model studies relevant to hydrocarbon...

Recent developments in large-scale geophysical inversions made it possible to invert the results of entire airborne surveys over large areas into 3D models subsurface. This paper presents methods for and interpretation data acquired by a multiphysics survey Saudi Arabia. The project involved acquisition, processing, electromagnetic, gravity, magnetic an 8000 square kilometer area. All collected were carefully analyzed inverted corresponding physical properties subsurface, including density,...

This paper develops a novel method of 3D inversion induced polarization (IP) survey data, based on generalized effective-medium model the IP effect (GEMTIP). The electrical parameters effective-conductivity are determined by intrinsic petrophysical and geometrical characteristics composite media, such as mineralization and/or fluid content rocks matrix composition, porosity, anisotropy, polarizability formations. GEMTIP multiphase conductive media provides quantitative tool for evaluation...

The generalized effective medium theory for induced polarization (GEMTIP) enables one to model and invert the complex resistivity (CR) spectra rock fluid parameters such as matrix resistivity, grain size, fraction volumes, porosity, saturations, polarizability. Moreover, GEMTIP can explain anisotropic in terms of orientation. In this work, is used laboratory-based measurements aforementioned properties. We have applied analyze IP phenomena both mineralized rocks, hydrocarbon-bearing...

ABSTRACT This paper develops the generalised effective‐medium theory of induced polarisation for rock models with elliptical grains and applies this to studying complex resistivity typical mineral rocks. We first demonstrate that developed model can correctly represent phenomenon in multiphase artificial samples manufactured using pyrite magnetite particles. have also collected representative from Cu–Au deposit Mongolia subjected them mineralogical analysis Quantitative Evaluation Minerals...

Abstract. We have determined the MLT distribution and KP dependence of ion upflow downflow thermal bulk oxygen population based on a data analysis using EISCAT VHF radar CP-7 obtained at Tromsø during period between 1990 1996: (1) both events can be observed any local time (MLT), irrespective dayside nightside, under magnetic disturbance level, quiet disturbed levels; (2) these are more frequently in nightside than dayside; (3) except midnight level difference occurrence frequencies is...

We present a multigrid integral equation (IE) method for three-dimensional (3D) electromagnetic (EM) field computations in large-scale models with inhomogeneous background conductivity (IBC). This combines the advantages of iterative IBC IE and quasi-linear (MGQL) approximation. The new EM modelling solves corresponding systems linear equations within domains anomalous conductivity, Da, Db, separately on coarse grids. observed fields receivers are computed using grids fine discretization....

We develop a new formulation of the integral equation (IE) method for three-dimensional (3D) electromagnetic (EM) field computation in large-scale models with multiple inhomogeneous domains. This problem arises many practical appli- cations including modeling EM fields within complex geoelectrical structures geophysical exploration. In applications, it is difficult to describe an earth structure using horizontally layered background conductivity model, which required efficient implementation...

We have investigated induced polarization (IP) effects in hydrocarbon‐bearing artificial rocks at frequencies greater than 100 Hz. examined the instrumental and electrode phase responses of Zonge International's complex resistivity (CR) system, optimized performance system for IP measurements over 1 mHz to 10 kHz frequency range. The reliability high‐frequency were confirmed by independent measurement same samples using Novocontrol BDS 80 system. Our results confirm presence rocks, suggest...

Towed streamer electromagnetic (EM) data acquired at the Mariner heavy oilfield in UK sector of North Sea have been inverted using a fast and efficient 3D anisotropic inversion code. The towed EM system was from single vessel. consisted horizontal bipole source electrode sensors housed cable. This enabled densely sampled grid over subsurface volume interest. purpose to estimate resistivity structure including Maureen Heimdal reservoir structures complex. algorithm is based on contraction...

One of the major problems in mineral exploration is inability to reliably distinguish between economic deposits and uneconomic mineralization. While mining industry uses many geophysical methods locate deposits, until recently, there was no reliable technology for identification characterization resources. The main goal this paper an application generalized effective-medium theory induced polarization (GEMTIP) studying complex resistivity typical rocks. We collected representative rock...

Summary There is a growing interest in developing innovative geophysical methods for monitoring hydrocarbon reservoirs. One emerging technique based on using the borehole electric current transmitter and grid of surface field receivers detailed mapping subsurface resistivity oil- gas-producing fields. This method often called Borehole to Surface Electromagnetic (BSEM) surveying. We introduce rigorous 3D inversion BSEM data integral equation approach adaptive regularization. have applied our...

Michael S. Zhdanov, Chris Anderson, Masashi Endo, Leif H. Cox, Martin Čuma, Glenn A. Wilson, Noel Black and Alexander V. Gribenko provide an early study of the challenges involved in validating offshore electromagnetic (EM) data acquired using a towed streamer receiver (currently under development) compare results with existing seabed-based marine controlled source (CSEM) technology.

Summary An ability to understand and control reservoir behavior over the course of production is necessary for optimization performance strategies. This goal can be achieved by geophysical monitoring propagation fluids within reservoir. Electromagnetic (EM) methods represent an important technique reservoirs, because they distinguish between hydrocarbons saline water based on their differing resistivities. The induced polarization (IP) effect represents another electrical characteristic...

During 2010, PGS conducted one of the first field trials their towed streamer electromagnetic (EM) system at Troll in Norwegian North Sea. Obviating need for ocean bottom receivers, towed-streamer EM enables CSEM data to be acquired simultaneously with seismic over very large areas frontier and mature basins higher production rates relatively lower cost than conventional CSEM. The are currently processed delivered as a spectrum frequency-domain responses. In this paper, we review large-scale...

Summary The moving sensitivity domain method has been very successful in 3D inversion of the data from large airborne EM surveys. modeling was based on integral equation (IE) method. However, survey areas with rough topography and high contrast, modelling finite element (FE) advantages. We use combined advantages IE FE methods a hybrid scheme to create stable efficient To increase computational efficiency, we have reformulated so that multiple transmitters are contained each domain. This...

Summary This paper demonstrates that the generalized effective-medium theory of induced polarization (GEMTIP) can properly represent (IP) phenomenon in rock samples collected from submarine hydrothermal deposit. The QEMSCAN mineralogical analysis is deployed order to clarify contents minerals samples. results complex resistivity (CR) measurements show produce strong IP effect, as expected results. CR data are inverted for GEMTIP model parameters taking into account analysis. inversion...

One of the major challenges in interpretation geophysical data remains ability to jointly invert multiple datasets for self-consistent 3D earth models different physical properties. To date, various attempts at joint inversion have been based on either correlations between properties, or by introducing structural similarities. In addition, there could be both property and models, these complexities cannot captured any existing techniques. Note that, practical applications, empirical...

We present an integral equation (IE) method for threedimensional (3D) electromagnetic (EM) field computations in large‐scale models with multiple inhomogeneous domains. This can take into account the EM coupling between different domains by making iterative calculations. The was tested modeling marine CSEM complex geoelectrical structures domains, such as bathymetry, salt domes, and reservoirs. Because this is based on IE approach, it calculate response of each domain separately. have also...

Summary Towed streamer electromagnetic (EM) data over the Mariner oilfield in UK sector of North has been inverted using a fast and efficient 3D anisotropic inversion code. The electric field were acquired with single vessel horizontal bipole source sensors housed towed densely sampled grid subsurface volume interest. algorithm is based on contraction integral equation method utilizing re-weighted regularized conjugate gradient technique to minimize an objective functional. This proven be...

We present a multigrid integral equation (IE) method for three‐dimensional (3D) electromagnetic (EM) field computations in large‐scale models with inhomogeneous background conductivity (IBC). This combines the advantages of iterative IBC IE and quasi‐linear (MGQL) approximation. The new EM modeling solves corresponding systems linear equations within domains anomalous conductivity, Da Db; separately on coarse grids. observed fields receivers are computed using grids fine discretization....