Computing prestack kirchhoff time migration on general. Topography correction and topographic kirchhoff migration. This paper aims at getting better resolution by applying two migration algorithms. He has completed many depth imaging projects including marine and land datasets. Using a 2d synthetic seismic data, obtained from the modeled velocity integrated into well data, the depth migration techniques kirchhoff and rtm reverse time migration were applied. Multicomponent kirchhoff migration geophysics seg library. For conve nience, most production kirchhoff migration programs use single. However this image analysis depends on having sufficient spatial resolution in the backscattered signal.
Multimode 3d kirchhoff migration of receiver functions at. Multimode 3d kirchhoff migration of receiver functions at continental scale f. Especially in the case of converted waves, true ccp stacking is not always achievable in such areas. It is particularly attractive due to its speed and targetoriented capability, which enable efficient velocity model building and updating. Feb 04, 2016 migration is the process of correcting these dip and positioning errors as an automatic digital procedure. A simplified conceptual basis is 1 the superposition principle, 2 pythagoras theorem, and 3 a subtle and amazing analogy called the exploding reflector concept. Our implementation images arrivals that propagate at 90 and higher angles as turning waves. Kirchhoff prestack depth migration is a technique that was developed in exploration geophysics and that maps scattered phases observed on seismograms located at the surface back at depth to scattering points see, e. True amplitude kirchhoff prestack time migration, yu zhangs weighting function 2000 is used to handle the true amplitude weight. Here are the guidelines for geophysical software and algorithms papers. Pdf wave equation calculation of most energetic traveltimes. Currently the synthetic aperture focusing technique saft, which is closely related to kirchhoff migration, is used in most cases for imaging. A wavefield extrapolation based summation for prestack depth. Migration of seismic data not only moves the dipping events to the correct spatial.
The earliest form, kirchhoff summation migration, intuitively follows the situation depicted in figure 1. How are seismic signals from a particular period of time transformed in depth. Ultrasonic echo testing is a more and more frequently used technique in civil engineering to investigate concrete building elements, to measure thickness as well as to locate and characterise builtin components or inhomogeneities. Only the seismic velocity must be known which, unfortunately, is no small feat in many. Parallelization of 3d kirchhoff depth migration is challenging due to its high demand of compute time, memory, storage and io along with the need of their effective management. The resulting migration procedure, known as kirchhoff migration, compares favor ably with other methods.
Volve is a decommissioned field in the central part of the north sea and was discovered in 1993, the plan for development and operation pdo was approved in 2005 and was on stream in 2008. We used an anisotropic kirchhoff prestack depth migration approach in order to account for the strong anisotropy in the seve nappe complex that was detected by laboratory measurements on cosc1 core samples wenning et al. Our simulations demonstrated up to 22 x performance improvement on the proposed rc platform comparing with the pure software solution running on a p4 2. Seismic migration is the process by which seismic events are geometrically relocated in either space or time to the location the event occurred in the subsurface rather than the location that it was recorded at the surface, thereby creating a more accurate image of the subsurface. In essence, recorded amplitudes on cmp traces are summed along the diffraction trajectories dictated by the assumed subsurface velocity distribution, and the sums are placed at the apexes of the curves, one curve for each sample point in. Therefore, prestack migration is a preferred alternative. An overview of depth imaging in exploration geophysics cgg. Migration of seismic data university of california, davis.
Prestack kirchhoff time migration pktm is an efficient imaging method for processing seismic data due to its io flexibility and targetorientation and recently has become a common routine step in the seismic data processing flow bevc, 1997. Illustration of a kirchhoff migration where diffraction energy in the input section of a is summed and relocated at the scatter point location in b the migrated section. Kirchhoff prestack depth and time migration schlumberger. Nevertheless, the real bottleneck in 3d prestack processes is the sheer amount of input and output data. Threedimensional prestack kirchhoff migration of deep seismic. All methods of seismic migration involve the backpropagation or continuation of the seismic wavefield from the region where it was measured earths surface or along a borehole into the region to be imaged. Parallel processing of prestack kirchhoff time migration on a. Imaging complex geologic structure with singlearrival kirchhoff. A method of seismic migration that uses the integral form kirchhoff equation of the wave equation. Migration is the process of correcting these dip and positioning errors as an automatic digital procedure. Ground penetrating radar gpr based land mine detection has a main challenge of having an accurate image analysis method that is capable of reducing false alarms. This paper presents a method for elastic and viscoelastic imaging of multicomponent seismic data. The kirchhoff migration method is popular in seismic explo ration imaging because.
Prestack kirchhoff migration provides the flexibility to output selected cmp gathers in their migrated positions. Dug has extensive experience with complex depth imaging, depth migration and time migration projects from all major oil and gas precincts. May 30, 2016 seismic data processing 15, kirchhof migration 1. Wave equation calculation of most energetic traveltimes and amplitudes for kirchhoff prestack migration article pdf available in geophysics 686 november 2003 with 57 reads how we measure. Anisotropic kirchhoff prestack depth migration at the cosc1. This is not possible with prestack stolt migration which generates a volume of prestack migrated data. Access to this data base implies either a memory intensive or io bounded solution to the storage problem. Kirchhoff prestack depth migration kpsdm, a widely used seismic imaging algorithm in petroleum industry, is a typical iobound application since a large amount of seismic data and travel timetable data needs to be read from the storage system iteratively during runtime. Kirchhoff migration schlumberger oilfield glossary. The kirchhoff depth migration that we use is accurate, fast, and userfriendly and has a graphical interface that is simple and straightforward. It has many advantages over the other methods such as easy to program. Seismic data processing lecture 15 kirchhoff migration prepared by dr. In this article, a new scalable 3d kirchhoff depth migration algorithm is presented on state of the art multicore cpu based cluster. Dictionary entry for kirchhoff migration migration q.
Migration is also used to estimate seismic velocity and to provide. Nov 20, 2018 how are seismic signals from a particular period of time transformed in depth. Kirchhoff and fk migration to focus ground penetrating radar. However, for converted wave, few papers address the true amplitude issue for prestack kirchhoff migration because of complications due to asymmetric scattering angles. Seismic processing and imaging gain deeper insight with the industrys most accurate subsurface imaging tools. The images generated by the practical prestack kirchhoff time migration programs for the same realworld seismic data inputs on cpu and gpu are demonstrated. Such an option is attractive if one wants to pick rms velocity functions from the selected output gathers to create a migration velocity field. Many competing algorithms have been proposed by various authors.
This repository includes a seismic migration routine for common offset gathers using a kirchhoff depth migration. It is particularly attractive due to its speed and targetoriented capability, which enable efficient velocity model building and. He has also developed a migration algorithm based on wavefield extrapolation and summation for prestack time and depth migration and a lot of parallel migration software all kirchhoff time migration as well as 2d and 3d wave equation depth migration. If the address matches an existing account you will receive an email with instructions to reset your password. The final gpgpu approach on nvidia gtx 260 is more than 17 times faster than its original cpu version on intels p4 3. Image quality is further improved by the ability to honor both vertical and tilted transverse isotropy vti and tti.
Kirchhoff migrations fast, accurate subsurface imaging and efficient velocity model building. Our depth migration application features quality controls that include fold maps, trace offset and azimuth histogram displays. This process is necessary to overcome the limitations of geophysical methods imposed by areas of complex geology. Depth imaging depth migration downunder geosolutions. A relatively recent advance is represented by reversetime migration, which is related to wavefront migration. Migration aperture in the kirchhoff summation was discussed already in kirchhoff migration in practice. Efficient traveltime compression for 3d prestack kirchhoff. Relationship between pointshaped scattering body and diffraction hyperbola, kirchhoff migration principle.
High performance kirchhoff prestack depth proceedings of. This routine was an assignment for a university class and of course is highly specific. Apr 15, 2016 ground penetrating radar gpr based land mine detection has a main challenge of having an accurate image analysis method that is capable of reducing false alarms. Recall that a small aperture causes destruction of steeply dipping events. The kirchhoff migration is the most commonly used migration for depth and time imaging. Migration of seismic data moves dipping events to their correct positions. Kirchhofftype migration methods are widely used in the current oil and gas industry for both depth imaging and iterative velocity analysis. However, it may of course be adapted to other uses, within the limits of the license.
Much like our time migration software, the depth migration will handle your stratigraphy with steep dips. Prestack kirchhoff time migration on high performance. All methods of seismic migration involve the backpropagation. This combined experience, along with our advanced toolkit, means that we are ready and able to tackle any project, large or small. Using a reference velocity model, the energy is propagated back in depth to all the points in 3. During the migration stage, the code keeps track of the illumination strength as a smooth function of space, offset and time. Writing kirchhoff migrationmodelling in a matrix form crewes. Kirchhoff migrations are available as 3d prestack depth migration addon modules for geodepth. The arbitrary geometry property of kirchhoff migration also allows 3d data that is acquired with a bin spacing of 25m by 50m to be migrated to a new bin spacing of 20m by 20m. Nevertheless, it is the traveltime computation that poses numerical accuracy and efficiency challenges when implementing the kirchhoff summation method for 3d prestack depth migration. Kirchhoff migration migration is the basic image making process in reflection seismology.