Geomage

United States
United States
SEARCH FILTERS
Time filter
Source Type

Rauch-Davies M.,Geomage | Berkovitch A.,Geomage | Deev K.,Geomage
SEG Technical Program Expanded Abstracts | Year: 2014

Unconventional reservoirs are becoming more and more conventional but successful drilling within these reservoirs has a unique set of problems. Most wells are drilled horizontally through the reservoir rock and fracking technology is applied to generate permeabilty and produce hydrocarbons. The pre-drill knowledge of natural fracture swarms and small offset faults is very important as these geological elements can interfere with the drilling and fracking process and influence the production rate. Seismic resolution from conventional reflection imaging is generally not sufficient to resolve these small scale rock properties. Diffracted waves are events that are produced by the scattering of a wave after it meets a discontinuity such as fracture swarms, small amplitude faults and karsts that cause local sharp changes in the geometrical or lithological characteristics. A method for diffraction imaging that is based on coherent summation of diffracted waves was applied to a 3D data set over an unconventional oil reservoir. An integrated study that includes well information, diffraction energy and seismic attributes showcases the usefulness of diffraction events to predict fracture swarms within the Bazhenov formation, which is a black shale in West Siberia. © 2014 SEG.


Rauch-Davies M.,Geomage | Berkovitch A.,Geomage | Deev K.,Geomage | Landa E.,OPERA
SEG Technical Program Expanded Abstracts | Year: 2013

MultiFocusing technology allows obtaining better images in cases of low fold data, poor signal- to- noise ratio or sparse 3D acquisition. Local parameters of the observed wavefield in pre-stack seismic records that are estimated during the MultiFocusing process are of great interest for many seismic applications such as signal enhancement, velocity model building and such. In the presence of nonhyperbolic arrival times, a local common offset MultiFocusing approximation for the traveltime stacking surface description is used to accurately approximate the traveltimes of seismic events. We present this signal enhancement scheme and demonstrate its efficiency. © 2013 SEG.


Rauch-Davies M.,Geomage | Deev K.,Geomage | Kachkachev-Shuifer M.,Geomage | Berkovitch A.,Geomage
SEG Technical Program Expanded Abstracts | Year: 2014

Diffraction imaging has become an attribute that's being used to map naturally occurring fractures in unconventional reservoirs. However, diffractions are generated whenever the wave encounters an irregularity that's of detectable size. As such, the diffractivity attribute should not be restricted to fracture detection but should be used to map caves (karst), base and shape of salt features, fault detection and possibly separating leaking faults from un-breached reservoir spaces. The extraction of the diffractive part of the wave-field is challenging due to the small magnitude of the event and the noise in the seismic data. We will present the theory and application of a method for diffraction imaging that uses the MultiFocusing principal, which is based on a coherent summation of the diffracted waves and suppression of the reflective part. We implemented azimuthal diffraction imaging, which extracts the diffractivity along chosen azimuths. These results contain not only information regarding small scale discontinuity but also the direction of these features. © 2014 SEG.


Rauch-Davies M.,Geomage | Berkovitch A.,Geomage | Deev K.,Geomage
SEG Technical Program Expanded Abstracts | Year: 2013

Unconventional reservoirs are being explored using conventional exploration methods but successful drilling within these reservoirs has a unique set of problems. Most wells are drilled horizontally through the reservoir rock and fracking is applied to generate permeability and produce hydrocarbons. The pre-drill knowledge of natural fracture swarms and small offset faults is very important as these geological elements can either help increasing the flow rate or can interfere with the drilling and fracking process and negatively influence the production rate. Seismic resolution from conventional reflection imaging is generally not sufficient to resolve these small scale rock properties. Diffracted waves are events that are produced by the scattering of a wave after it meets a discontinuity such as fracture swarms, small amplitude faults and karsts that cause local sharp changes in the geometrical or lithological characteristics. We are presenting the method for diffraction imaging, using MultiFocusing that is based on coherent summation of diffracted waves on three case examples. © 2013 SEG.


Goussev S.,Exploration Consultant | Rauch-Davies M.,Geomage | Smith P.A.,Addax Petroleum | Weber J.,CGG GravMag Solutions
Leading Edge | Year: 2014

We present a concept and methodology for the prediction of deep stratigraphic targets of the incised-valley trap type from the prospect-scale integrated interpretation of the gravity, magnetic, seismic, and well data. The key components in this concept are the "reference" stratigraphie target, identified and delineated on 2D seismic sections, and the "tuning" filter designed from the target's spatial dimensions. The tuning-filter-derived residual gravity anomalies are evaluated and sorted out to keep those that have the highest probability of being associated with sand accumulations of the incised-valley type. The concept and methodology of its application are illustrated with an example of the case study in the East Texas/North Louisiana sedimentary basin.


Kuznetsova O.,PetroTraceServices | Landa E.,Opera | Karaulov A.V.,Geomage
New Geotechnology for the Old Oil Provinces | Year: 2013

A great part of global oil reserves (up to 25-50%) is concentrated in vuggy-fractured reservoirs. Thus, planning of such reservoir development requires an accurate identification of the respective areas, i.e. fractured zones. Traditional seismic images in such conditions are generally not effective, since they show the energy from strong reflectors, while cracks and vugs do not create regular reflections - they cause the appearance of diffraction component. On the other hand, a diffraction component of the wave field is a direct indicator to the presence of small-scale components in the media, including fractured rocks. The paper reviews theoretical aspects of new technique, developed by Geomage - Diffraction Multifocusing, designed for identification and analysis of vuggy-fractured reservoirs. Examples from the Western Siberia fields demonstrate the results of the Diffraction Multifocusing application for searching the fracture / high-permeability zones in the Bazhenov Formation. We show that the increase in the "diffraction image" readings - fracturing parameter - facies variability is associated with fault zones. The paper points to the probability of higher flow rates in the wells, located in areas with high diffraction readings.


Berkovitch A.,Geomage | Deev K.,Geomage | Landa E.,OPERA
First Break | Year: 2011

MultiFocusing technology can dramatically improve the quality of seismic imaging especially in cases of low fold data, poor signal-to-noise ratio and sparse 3D acquisition. MF technology, based on multiparameter analysis of the wavefield and summation along predicted time surfaces, has been applied to enhance time imaging sections by dramatically increasing the fold of coherent summation of seismic signals. One of the main limitations of the zero-offset MF method is a quasi-hyperbolic approximation for actual travel-time surfaces. COMF traveltime formulas provide an adequate representation of arrival times for arbitrary offset and source-receiver configuration. The COMF correction formula is remarkably accurate even for strong curved reflectors. The correlation procedure is repeated for each imaging point, for each offset and for each time sample. It is important to note that the described procedure can be applied locally within a small vicinity of each seismic trace and does not require global full offset approximation.


Schoepp A.,Royal Dutch Shell | Landa E.,Geomage | Labonte S.,Royal Dutch Shell
Society of Petroleum Engineers - SPE/AAPG/SEG Unconventional Resources Technology Conference | Year: 2016

Unconventional reservoirs have a unique set of problems. Most production wells are drilled horizontally through the reservoir rock and hydraulic fracturing is applied to increase permeability in the reservoir. The pre-drilling knowledge of natural fracture corridors and small offset faults is very important in this case. Seismic resolution from conventional reflection imaging is generally not sufficient to resolve such small scale rock properties. Diffracted waves are events generated by small scale subsurface heterogeneities and discontinuities (including fractures). Detection and imaging the diffractive component of the total wavefield opens a new perspective to find and characterize fracture zones in carbonate environment. Copyright 2014, Unconventional Resources Technology Conference (URTeC).


Berkovitch A.,Geomage | Deev K.,Geomage | Landa E.,OPERA
Leading Edge | Year: 2012

It is widely considered that, in regions with significant geologic complexity, methods which work directly in the depth domain are superior to methods which operate on prestack time data. So, for example, velocity analysis using depth migration and residual moveout became standard in the industry. The most common depth-velocity analysis attempts to flatten common-image-migrated gathers for main reflectors by measuring depth errors as a function of the offset. At the same time, the fact that most depth-domain algorithms are valid only for correct or nearly correct velocity models should not be underestimated. If this assumption is violated, they can lose their convergence properties or produce wrong results. © 2012 Society of Exploration Geophysicists.


Rauch-Davies M.,Geomage | Pelman D.,Geomage | Deev K.,Geomage
Society of Petroleum Engineers - SPE/AAPG/SEG Unconventional Resources Technology Conference | Year: 2016

Predicting fracture swarms and corridors in unconventional reservoirs is part of the sweet spot mapping workflow. Naturally occurring fracturing can either enhance the hydrocarbon production or diminish the effects of fracking. In any case, it is essential to be able to map them before any drilling decision is made. Commonly, these features are determined through indirect methods such as picking of horizons and faults and inferring areas that are under stress. Post stack attributes such as coherence and curvature are routinely utilized and in general add value to this task. Diffraction imaging is the only direct measurement of small scale discontinuities like fracture swarms and corridors. They are generated whenever the wave encounters an irregularity that's of detectable size and are not restricted to events that exhibit displacement like is needed for coherence or curvature. Diffractions are much weaker than the reflections and are generally lost in the seismic processing. To separate diffractions from reflections is challenging but we like to present the MultiFocusing diffraction imaging technology that is based on a coherent summation of the diffracted waves and suppression of the reflective part. Azimuthal diffraction imaging, which extracts the diffractivity along chosen azimuths adds information of the dominant fracture direction and will be discussed. Copyright 2014, Unconventional Resources Technology Conference (URTeC).

Loading Geomage collaborators
Loading Geomage collaborators