Bibliography processing of seismic reflection data using. This recorded wavelet is minimum phase of some frequency bandwidth, and during data processing it is converted we hope into a zerophase wavelet, making interpretation easier and more accurate. Oreilly members experience live online training, plus books, videos, and digital content from. Wavelet phase mismatches frequently occur between final processed seismic data and synthetics created from well logs.
Those individuals may be processing geophysicists, seismic. Borehole seismic data processing and interpretation. How do we convert the seismic trace wavelet to zero phase which is. Note the frequency notch, identified by the cursor at 125 hz. Seismic unx package a free open seismic processing, research, and educational software package. Seismic data are usually processed to be zerophase, and we.
The application of variablefrequency directional seismic wave technology under. It is the shortest possible wavelet for any given spectrum. Providing this broad band, zero phase wavelet is the processing goal of deconvolution. Early in our careers as geophysicists, most of us took at least one course on seismic signal analysis where we were taught that standard wiener deconvolution converts the minimumphase source. Source designature sgf is the process of collapsing the farfield signature into a desired output wavelet generally a zerophase wavelet.
A typical marine farfield source signature in a wavelet calculator. Pgc product spw parallel geoscience corporation was started in 1988 with the purpose of writting easy to use seismic processing software. The seismic processing procedure designed to convert the field wavelet to the desired broad band zero phase wavelet is deconvolution. The shape of the source wavelet generated by a vibroseis is a zerophase wavelet. Seismic processing and imaging gain deeper insight with the industrys most accurate subsurface imaging tools. The farfield signature estimation can be improved by making use of. And by this step we designed a filter that we multiply it with the source. This type of process can be performed with the geoquest software.
Nonzerophase wavelets are converted to zerophase wavelets to achieve the best. This course is an introductory course designed for individuals who work with seismic data. Only minimal processing would be required if we had a perfect acquisition system. Vista seismic data processing software is a windowsbased application that can be used during the early stages of acquisition qc to complete processing of 2d and 3d seismic data. The purpose of acquiring and processing seismic data is to learn something about the earths interior. As we know the mixed phase data would not give the real twtt through the medium. How do we convert the seismic trace wavelet to zero phase. There are many opensource seismic reflection data processing software programs. On the other hand, the accepted wisdom is that vibroseis is a zerophase source. An operator is then constructed which converts the minimum phase wavelet to the zerophase wavelet and this operator is then applied to the seismic data. Seismic data interpretation 16 in an extremely simplified way seismic pulses displayed on seismic sections can be grouped into two main types, minimum phase and zero phase. Reflections on the deconvolution of land seismic data. The processing of other seismic data and many nonseismic data often follows similar principles.
The solutions to these problems are to convert the mixedphase wavelet to zero phase in seismic processing or to extract the mixedphase wavelet, know its effects, and use it when modeling. When interpreting seismic data it is important to realize that the. This is a list of free and opensource software for geophysical data processing and interpretation. Seismic reflection is one of the most popular methods in geophysical prospecting. Phase and polarity assessment of seismic data seg wiki. Software using seismic processing using vista software. It is well suited for indepth hruhr marine seismic processing, realtime marine 2d3d seismic qc, onboard fast track. Reflections on the deconvolution of land seismic data cseg. Data conditioning encompasses a wide range of technologies designed to address numerous challenges in the processing sequencefrom data calibration and regularization. During the seismic processing workflow a deconvolution and phase correction step is normally applied and the phase of the data will be set as either zero phase or mixed phase. The desired output processing wavelet is derived from a zero phase equivalent of the modeled instrument response which is tapered to match the natural decay of the farfields amplitude spectrum.
Although causal and acausal zerophase frequency filtering are procedures routinely used in seismic signal processing, many users of respective software tools are not fully aware of at first glance subtle. In summary, the scientists have proven that the second way. A zerophase wavelet is symmetric with respect to zero time and peaks at zero time. Zerophase data tend to provide sharper definition and less distortion between stratigraphic features in the subsurface, such as sand and shale layers. The signature looks pretty close to a minimum phase wavelet, as you might expect. Vista desktop seismic data processing software provides data processing from earlystage acquisition qc to final processing and interpretation of 2d and 3d seismic data acquired on land or offshore or as. This attitude to the phase spectra of seismic signals can be explained by. Kh10030mf seismic processing software globe claritas uses an interactive graphical application to coordinate 2d or 3d seismic. No more than 50% of seismic data achieves zero phase.
Another goal of deconvolution is to produce a wavelet with a simple phase character, ideally a zero. Comparison of land seismic data with and without wavelet processing. It contains 16 standalone applications handling the full range of seismic. Deghosting and designature removing the seismic ghost. Deconvolution during seismic processing can convert data of mixed phase to zerophase data, but is not always successful. How can i determine the phase of processed 2d seismic data. In fact, the wavelet was synthesized using the zerophase sinusoids of equal peak amplitude. Use the latest seismic processing software to prepare the data for interpretation. Providing precise velocity information, as well as true seismic wavelet welltie with phase, frequency, and timedepth, a zerooffset vsp is the only. The ix1 software is typically executed on two primary computers in the system. Conocophillips open cps software flatirons tomographic refraction statics. To collapse seismic wavelet and suppress short period multiple reflections. Seismic reflection is one of the most popular methods in geophysical.
Zerophase wavelets are symmetrical in shape about zero time whereas nonzerophase wavelets are asymmetrical. My preferred way of doing this ive been working in seismic data. Several methods of zerophase conversion are commonly applied. The purpose of seismic processing is to manipulate the acquired data into an image that can be used to infer the subsurface structure. Another example for employing phase in seismic processing is shown by mitrofanov and priimenko. The popular and innovative seismic processing and imaging solutions from the. This is the simplest method of zerophase conversion, often improves resolution and well ties and is a good benchmark test. The two common methods of deconvolution are deterministic deconvolution and statistical deconvolution. The overall objective of this course is to introduce entry level andor junior geophysicists and geoscientists. This seismic data contains the desired zero phase wavelet figure 5b. Pertaining to seismic data whose wavelet is symmetrical about zero time. The researchers have given a comparison between amplitude and phase spectra in detecting pinchouts of the oil and gas spectrum and thin layers in their paper. Several windows can be extracted and results compared to synthetic seismograms for accuracy. Zero phase is the objective of almost all seismic data processing today and its interpretive benefits are well known, however it is difficult to achieve.
In exploration for seismic stratigraphic interpretation the interpreter really needs to know is whether the data are processed to zero phase and whether the. Software to download usgs earthquake hazard program. Inputoutput discgath reads anysort segy file and outputs. Thus, information about the phase spectrum of the observed signal is lost or substantially distorted. Deconvolution attempts to compress the wavelet, thereby increasing the resolution of the seismic data. Radexpro is a seismic processing software on windows. Seismic data is often converted to zerophase to improve resolution and aid interpretation. Prism is opensource software used for automatically processing strongmotion records, and is intended to be used by individuals or strongmotion networks. Deconvolution during seismic processing can convert data of mixed phase to zerophase. Applicationspecific seismic data conditioning and processing for confident imaging from the field to the final volume, seismic data goes through many processes and workflows. During processing, deterministic zerophase wavelet shaping corrections are. Unlock your geophysics data potential with the industrys most advanced geophysical processing software solution. The source designature process consists of two components.