scholarly journals Comparison of Detection Capability by the Controlled Source Electromagnetic Method for Hydrocarbon Exploration

Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1839 ◽  
Author(s):  
Zhenwei Guo ◽  
Jianxin Liu ◽  
Jianping Liao ◽  
Jianping Xiao
Keyword(s):  
Water Environment ◽  
Horizontal Resolution ◽  
Low Noise ◽  
Hydrocarbon Exploration ◽  
High Resistivity ◽  
Detection Capability ◽  
Controlled Source ◽  
Transverse Resistance ◽  
Sea Bed ◽  
Occam’S Inversion

Marine controlled-source electromagnetic (CSEM) is an efficient offshore hydrocarbon exploration method that has been developed during the last 18 years. Sea Bed Logging (SBL) and towed streamer electromagnetic (TSEM) are two different data acquisition systems. We compared these two methods by using 1D sensitivity modeling and 2D Occam’s inversion. Based on this research, we tested the effect of frequency, offset range, water depth, reservoir size, and reservoir depth on the detection capability of the two acquisition methods in terms of sensitivity. In order to test the methodology clearly and simply, the geological model was extremely simplified for the inversion. The effect of these parameters on resolution was checked as another purpose. To easily evaluate our inversion results, a simple quantity was employed that we called the anomaly transverse resistance ratio. In the shallow water environment, both the SBL and the TSEM systems had a good sensitivity to the high resistivity targets. However, in the deep water environment, the SBL system had a low noise floor. Then, it could provide better detectability to the deep target. The TSEM had the advantage in terms of the horizontal resolution because of the dense in-line sampling of the electric field.

scholarly journals Increasing the sensitivity of controlled-source electromagnetics with synthetic aperture

Geophysics ◽  
2012 ◽  
Vol 77 (2) ◽  
pp. E135-E145 ◽  
Author(s):  
Y. Fan ◽  
R. Snieder ◽  
E. Slob ◽  
J. Hunziker ◽  
J. Singer ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Low Frequency ◽  
Building Blocks ◽  
Radar Imaging ◽  
Hydrocarbon Exploration ◽  
Synthetic Aperture ◽  
Detection Capability ◽  
Sea Floor ◽  
Controlled Source ◽  
Controlled Source Electromagnetics

Controlled-source electromagnetics (CSEM) has been used as a derisking tool in the hydrocarbon exploration industry. We apply the concept of synthetic aperture to the low-frequency electromagnetic field in CSEM. Synthetic aperture sources have been used in radar imaging for many years. Using the synthetic aperture concept, big synthetic sources can be constructed by adding the response to small sources (building blocks) in different ways, and consequently, big sources with different radiation patterns can be created. We show that the detectability of hydrocarbons is significantly enhanced by applying synthetic aperture to CSEM data. More challenging targets such as deep reservoirs (4 km below sea floor) can be detected. The synthetic aperture technique also increases the sensitivity of the field to subsurface targets in the towing streamer acquisition. We also show that a pseudovertical source (orthogonally distributed dipole pairs) can be constructed synthetically, and that the detection capability of this pseudovertical source is increased by applying field steering. The synthetic aperture concept opens a new line of research in CSEM, with the freedom to design suitable synthetic aperture sources for a given purpose.

scholarly journals Source modification for efficiency enhancement of marine controlled-source electromagnetic method

2021 ◽  
Vol 18 (2) ◽  
Author(s):  
Amir Rostami ◽  
Noorhana Yahaya ◽  
Hassan Soleimani ◽  
Muhammad Rauf ◽  
Tadiwa E Nyamasvisva ◽  
...  
Keyword(s):  
Electromagnetic Wave ◽  
Shallow Water ◽  
Method Of Moments ◽  
Experimental Setup ◽  
Efficiency Enhancement ◽  
Shooting Methods ◽  
Detection Capability ◽  
Controlled Source ◽  
Element Simulation ◽  
Electromagnetic Source

Abstract Controlled-source electromagnetics is a strongly efficient technique to explore deep-water marine hydrocarbon reservoirs. However, the shallow-water unsolved limitations of electromagnetic shooting methods still exist. In this regard, this work aims to alter the existing conventional electromagnetic source such that it can converge the down-going electromagnetic wave while simultaneously dispersing the up-going electromagnetic energy to minimise the airwave in shallow water. This work presents computed electric current distribution inside a modified transmitter, using a method of moments. Simulation and an experiment-based methodology are applied to this work. Finite element simulation of the response of the modified transmitter displayed the capability of the new transmitter in dispersing the airwave, by 15%. The experimental setup confirmed a better performance of the new transmitter, showing hydrocarbon delineation of up to 48%, compared to the existing conventional transmitter, with 25% oil delineation at the same depths in the same environment. Modification of the electromagnetic source to unbalance the up-down signals may have the potential to enhance the delineation magnitude of the target signal and, as a result, significantly improve oil detection capability.

Mineral exploration with 3-D controlled-source electromagnetic method: a synthetic study of Sukhoi Log gold deposit

2019 ◽  
Vol 219 (3) ◽  
pp. 1698-1716 ◽  
Author(s):  
M Malovichko ◽  
A V Tarasov ◽  
N Yavich ◽  
M S Zhdanov
Keyword(s):  
Finite Difference ◽  
Gold Deposit ◽  
Large Scale ◽  
Mineral Exploration ◽  
Mineral Deposit ◽  
Hydrocarbon Exploration ◽  
Contraction Operator ◽  
Inversion Algorithm ◽  
Controlled Source ◽  
Regularized Inversion

SUMMARY This paper presents a feasibility study of using the controlled-source frequency-domain electromagnetic (CSEM) method in mineral exploration. The method has been widely applied for offshore hydrocarbon exploration; however, nowadays this method is rarely used on land. In order to conduct this study, we have developed a fully parallelized forward modelling finite-difference (FD) code based on the iterative solver with contraction-operator preconditioner. The regularized inversion algorithm uses the Gauss–Newton method to minimize the Tikhonov parametric functional with the Laplacian-type stabilizer. A 3-D parallel inversion code, based on the iterative finite-difference solver with the contraction-operator preconditioner, has been evaluated for the solution of the large-scale inverse problems. Using the computer simulation for a synthetic model of Sukhoi Log gold deposit, we have compared the CSEM method with the conventional direct current sounding and the CSEM survey with a single remote transmitter. Our results suggest that, a properly designed electromagnetic survey together with modern 3-D inversion could provide detailed information about the geoelectrical structure of the mineral deposit.

Sea Bed Logging (SBL), a remote resistivity sensing technique for in hydrocarbon exploration

2003 ◽  
Author(s):  
S. Ellingsrud ◽  
J. Hesthammer ◽  
H.E.F. Amundsen ◽  
T. Røsten ◽  
S. Johansen ◽  
...  
Keyword(s):  
Hydrocarbon Exploration ◽  
Sea Bed

scholarly journals Multitransient electromagnetic demonstration survey in France

Geophysics ◽  
2007 ◽  
Vol 72 (4) ◽  
pp. F197-F209 ◽  
Author(s):  
Anton Ziolkowski ◽  
Bruce A. Hobbs ◽  
David Wright
Keyword(s):  
Current Source ◽  
Hydrocarbon Exploration ◽  
Input Current ◽  
Impulse Responses ◽  
Full Waveform ◽  
Transverse Resistance ◽  
Survey Line ◽  
Exploration And Production ◽  
Hydrocarbon Exploration And Production ◽  
Step Responses

We describe the acquisition, processing, and inversion of a multitransient electromagnetic (MTEM) single-line survey, conducted in December 2004 over an underground gas storage reservoir in southwestern France. The objective was to find a resistor corresponding to known gas about [Formula: see text] below the survey line. In data acquisition, we deployed a [Formula: see text] inline bipole current source and twenty [Formula: see text] inline potential receivers in various configurations along the [Formula: see text] survey line; we measured the input current step and received voltages simultaneously. Then we deconvolved the received voltages for the measured input current to determine the earth impulse responses. We show how both amplitude and traveltime information contained in the recovered earth impulse responses reveal the lateral location and approximate depth of the resistive reservoir. Integrating the impulse responses yields step responses, from which the asymptotic DC values were estimated and used in rapid 2D dipole-dipole DC resistivity inversion to find the top of the reservoir. A series of collated 1D full-waveform inversions performed on individual common midpoint gathers of the step responses position the top and bottom of a resistor corresponding to known gas in the reservoir and also obtain the transverse resistance. The results imply that the MTEM method can be used as a tool for hydrocarbon exploration and production.

An introduction to marine controlled-source electromagnetic methods for hydrocarbon exploration

Geophysics ◽  
2007 ◽  
Vol 72 (2) ◽  
pp. WA3-WA12 ◽  
Author(s):  
Steven Constable ◽  
Leonard J. Srnka
Keyword(s):  
Data Streams ◽  
Oceanic Lithosphere ◽  
Academic Community ◽  
Hydrocarbon Exploration ◽  
Reflection Seismology ◽  
Deep Drilling ◽  
Controlled Source ◽  
Electromagnetic Methods ◽  
Military Applications ◽  
Geophysical Technique

Early development of marine electromagnetic methods, dating back about 80 years, was driven largely by defense/military applications, and use for these purposes continues to this day. Deepwater, frequency-domain, electric dipole-dipole, controlled-source electromagnetic (CSEM) methods arose from academic studies of the oceanic lithosphere in the 1980s, and although the hydrocarbon exploration industry was aware of this work, the shallow-water environments being explored at that time were not ideally suited for its use. Low oil prices and increasingly successful results from 3D seismic methods further discouraged investment in costly alternative geophysical data streams. These circumstances changed in the late 1990s, when both Statoil and ExxonMobil began modeling studies and fieldtrials of CSEM surveying in deep water (around [Formula: see text] or deeper), specifically for characterizing the resistivity of previously identified drilling targets. Trials offshore Angola in 2000–2002 by both these companies showed that CSEM data can successfully be used to evaluate reservoir resistivity for targets as deep as several thousand meters. Both companies leveraged instrumentation and expertise from the academic community to make swift progress. The resulting rapid growth in the use of marine EM methods for exploration has created a demand for trained personnel that is difficult to meet; nevertheless, at this time, CSEM data represent a commercial commodity within the exploration business, and acquisition services are offered by three companies. The ability to determine the resistivity of deep drilling targets from the seafloor may well make marine CSEM the most important geophysical technique to emerge since 3D reflection seismology.

Seismic image-guided 3D inversion of marine controlled-source electromagnetic and magnetotelluric data

2020 ◽  
Vol 8 (4) ◽  
pp. SS1-SS13 ◽  
Author(s):  
Randall L. Mackie ◽  
Max A. Meju ◽  
Federico Miorelli ◽  
Roger V. Miller ◽  
Carsten Scholl ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Structural Similarity ◽  
Hydrocarbon Exploration ◽  
Magnetotelluric Data ◽  
Controlled Source ◽  
Seismic Image ◽  
New Frontier ◽  
Gradient Fields ◽  
Resistivity Model ◽  
Geologic Interpretation

Geologic interpretation of resistivity models from marine controlled-source electromagnetic (CSEM) and magnetotelluric (MT) data for hydrocarbon exploration and reservoir monitoring can be problematic due to structural complexity and low-resistivity contrasts in sedimentary units typically found in new frontier areas. It is desirable to reconstruct 3D resistivity structures that are consistent with seismic images and geologic expectations of the subsurface to reduce uncertainty in the evaluation of petroleum ventures. Structural similarity is achieved by promoting a cross-gradient constraint between external seismically derived gradient fields and the inversion resistivity model. The gradient fields come from coherency weighted structure tensors computed directly from the seismic volume. Consequently, structural similarity is obtained without the requirement for any horizon interpretation or picking, thus significantly reducing the complexity and effort. We have determined the effectiveness of this approach using CSEM, MT, and seismic data from a structurally complex fold-thrust belt in offshore northwest Borneo.

scholarly journals A Robust Noise Mitigation Method for the Mobile RFID Location in Built Environment

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2143 ◽  
Author(s):  
Changfeng Jing ◽  
Tiancheng Sun ◽  
Qiang Chen ◽  
Mingyi Du ◽  
Mingshu Wang ◽  
...  
Keyword(s):  
Computational Complexity ◽  
Built Environment ◽  
Smart Cities ◽  
Low Cost ◽  
Low Noise ◽  
Location Based Services ◽  
Noise Detection ◽  
Detection Capability ◽  
Noise Mitigation ◽  
Mobile Rfid

The exact location of objects, such as infrastructure, is crucial to the systematic understanding of the built environment. The emergence and development of the Internet of Things (IoT) have attracted growing attention to the low-cost location scheme, which can respond to a dramatic increasing amount of public infrastructure in smart cities. Various Radio Frequency IDentification (RFID)-based locating systems and noise mitigation methods have been developed. However, most of them are impractical for built environments in large areas due to their high cost, computational complexity, and low noise detection capability. In this paper, we proposed a novel noise mitigation solution integrating the low-cost localization scheme with one mobile RFID reader. We designed a filter algorithm to remove the influence of abnormal data. Inspired the sampling concept, a more carefully parameters calibration was carried out for noise data sampling to improve the accuracy and reduce the computational complexity. To achieve robust noise detection results, we employed the powerful noise detection capability of the random sample consensus (RANSAC) algorithm. Our experiments demonstrate the effectiveness and advantages of the proposed method for the localization and noise mitigation in a large area. The proposed scheme has potential applications for location-based services in smart cities.

Sign in / Sign up

Export Citation Format

Share Document