Seismic interpretation and depth conversion of the. Use of full azimuth seismic and microseismic for unconventional plays fams. Pdf reprocessing wideazimuth towed streamer seismic data for. Synthetic and field data applications suggest that this new method can effectively separate and image diffractions.
Seismic interpretation an overview sciencedirect topics. Well data are gotten from rock samples and measurements at depth from a wellbore. Subsalt seismic illumination study university of houston. The primary goal of seismic interpretation is to make maps that provide geologic information reservoir depth structure, thickness, porosity, saturation, etc. Schlumberger announces completion of multiclient wide. Improved imaging for prospect definition working with wide and full azimuth seismic data koc perspective adel elemam, kuwait oil company 09. The maximum offset and azimuth distribution achievable is a function of the spread length and width. Gray and head, 2000, hall et al, 2000, gray et al, 2002. The results also demonstrate the efficiency of the new method in clarifying subsurface smallscale objects, which can provide finer information about these structures for seismic interpretation. Wide azimuth acquisitions provide a full azimuthal illumination of the structures. Evolution of marine acquisition technology after wide azimuth. Using the resunet model, we develop a fault versus azimuth analysis based on offset vector tile ovt data, which, as common azimuth seismic data, provides more detailed and useful information for. Us7391673b2 method of wide azimuth seismic acquisition.
Obstacles in the analysis of azimuth information from prestack seismic data. Land seismic data was acquired over a permian carbonate field with a wide azimuth acquisition template, such that the recorded 3d seismic data is inherently sourcetodetector azimuth rich. Summary ani it is becoming popular to extract fracture information from wide azimuth pp reflection seismic data. Well data required for interpretation are wireline logs gamma ray logs, resistivity logs, porosity log, sonic logs, density logs and neutron logs or equivalent rock property model, check shot data. Interpretation of depositional facies using seismic attributes. The next challenge is to further improve subsalt images in areas with existing waz coverage. This, in turn, leads to better geological interpretation. Orientation of all conductive fractu res from fmi log interpretation. Before interpreting and exploring the deep areas of interest, shallow complexity. The successful application in the bohai bay demonstrated its feasibility.
Us20070159921a1 method of wide azimuth seismic aquisition. Azimuthal anisotropy analysis of wide azimuth pwave seismic data for fracture orientation and. A progression in survey effort from one vessel towing sources and streamers sailing a survey area in two or more directions to several vessels sailing a survey area in two or more directions, some of them possibly only towing sources, represents the operational contrasts between multi azimuth maz, wide azimuth waz, and full azimuth faz 3d seismic. Fracture detection using 3d seismic azimuthal avo cseg recorder. Additionally, analysing azimuthal variations of the seismic response may offer. Wide azimuth deepwater seismic society of exploration. In partnership with the dagang oilfield, we used the channel sand body seismic physical model to study the characteristics of widenarrow azimuth acquisition footprints and analyzed and compared the two types of footprints and their effects on target imaging. Wide azimuth seismic surveying is firmly established as a key element in subsalt exploration and production in the gulf.
Widenarrow azimuth acquisition footprints and their effects. The ovtdomain wideazimuth prestack seismic interpretation technology is composed of five key pre stack analysis and interpretation. Horizon attributes were first used in the mid1980s for interpreting fault traces on reservoir horizons. In conclusion, poorly vintage seismic data has been shown to possess a high value despite its irregular geometry and low resolution. In the staggered acquisition that has been deployed in the gulf of mexico since june 2012, significant reductions in line change azimuth distribution. In addition, plentiful azimuth information is retained in the spiral gather data obtained after highdensity wide azimuth seismic acquisition and ovt domain pstm processing. Benefits of integrated approaches for solving imaging. Schlumberger executes contract with statoil for multiclient. Manual picking is difficult due to the workload and possible. Multiphysics integration of wideazimuth seismic and.
A variety of short to long offset source positions are used for a wide range of sourcereceiver azimuths. By leveraging the modern signalprocessing innovations, the final results produced a better overall reflection image focused on the angle azimuth stacks suitable for fault interpretation, avo and avaz analysis. Pdf on aug 17, 2017, antonello simonetti and others published reprocessing wideazimuth towed streamer seismic data for nearsurface. The topic of anastasia pooles electure is wide azimuth acquisition with radial domain interpolation for fluvial morphology interpretation. Chasing the faults within a permian carbonate using wide. Enhancing subsurface imaging and reservoir characterization in the marcellus shale play, northeast pennsylvania, through advanced reprocessing of wide azimuth 3d seismic.
A priori, pwave velocity in wide azimuth presents more variations dependingon the direction of propagation. Seismic attribute analysis provides information related to structure, stratigraphy, and reservoir properties. In 20092010, shells use of wideazimuth seismic surveys led to. The license also includes collaboration with westerngeco in the seismic processing phase. We are used to the convenience of acquiring overlapping shot gathers in straight lines, as we can sort the data into common. The system enables full azimuth, angledependent seismic imaging using reflection data recorded through seismic acquisition surveys, especially wide azimuth and long offset data. Seismic attributes and their applications in seismic.
During this presentation she will demonstrate how an. Widenarrow azimuth acquisition footprints and their. Houston, march 27, 2020schlumberger in cooperation with breckenridge geophysical, llc announce the completion of the acquisition and processing of the mckenzie draw 3d wide azimuth waz multiclient survey covering 412 mi 2 in martin, andrews, dawson and gaines counties, texas. A goal of the instant invention is, of course, to assemble a wide azimuth seismic. Pdf multiazimuth and wideazimuth lessons for better seismic. This is followed by a discussion of how avaz can be used in structural interpretation. Heloise lynn specializes in the expression and use of anisotropy in multidimensional datasets multi azimuth, multicomponent, and time lapse, 3d azimuthal seismic acquisition design, azimuthal seismic processing, and azimuthal seismic interpretation. This geometry allows the data to be subdivided into azimuth sectors, so that stacks of different illumination directions can be generated.
At present, the study on acquisition footprints has become a hot spot. An ultra high density, full wide azimuth seismic survey for the future jeanjacques postel cggveritas 2nd finding petroleum event on onshore seismic. Azimuth and offset in design of successful 3d survey, by. A seismic interpretation study should access the following data sets 2d or 3d seismic data cube. As a geophysicist in the oil and gas industry since 1975, she is knowledgeable about seismic reflection data acquisition. As impressive as these results often are, the techniques. Pdf widegeometry 3d land seismic acquisition in limited.
The third and final stage of the hierarchy of seismic interpretation is seismic attribute analysis taner and sheriff, 1977. For the first survey acquired using this technique. An example from the bb2 block, changyuan lmd oil field, songliao basin, china shunguo cheng, yan jiang, jie li, cao li, yanhui wang, and liheng xu. Separating and imaging diffractions of seismic waves in the. Overall, the pwave seismic data are of excellent quality with a high signaltonoise ratio with broad spectral content approaching 100 hz figure 1. Obstacles in the analysis of azimuth information from. The higher costs of acquiring wide angle seismic data and the computing power. Shotbased preprocessing solutions for wide azimuth towed. Common azimuth seismic data fault analysis using residual u. Wideazimuth obc seismic data optimization for avo and avaz. We appreciate your continued support and understanding. A seismic shift cggveritas wideazimuth technology represents seismic shift in gulf of mexico. Wide azimuth seismic surveying is firmly established as a key element in subsalt exploration and production in the gulf of mexico.
Seismic exploration in the deepwater gulf of mexico was based for many years on the 3d acquisition method and, as a result, significant oil discoveries were made and most of the plays were found below salt or in intrasaltbody basins. Wide azimuth or waz is a term describing a seismic data acquisition technique where separate source vessels are used to record seismic reflections from areas out to the side of the recording spread. Also, the wide azimuth illumination study would include the vertical transverse isotropic velocity field, as a second part of the analysis. The ovtdomain wide azimuth prestack seismic interpretation technology is composed of five key prestack analysis and interpretation techniques focused on ovt gathers. The seismic properties of salt poses an additional problem for marine seismic surveys, it attenuates seismic waves and its structure contains overhangs that are difficult to image. Separating and imaging diffractions of seismic waves in. Reservoir prediction in a development area with a highdensity well pattern using seismic sedimentology. Pdf marine seismic data analysis involves data acquisition, data. In an industry where the pace for new acquisition technology is often slow, the rapid acceptance of marine wideazimuth towed streamer acquisition methods as the new standard in deep water gulf of. Acquiring more azimuths for improved offshore seismic. Geophysics resolution, high quality 3d seismic images kom. This led to another variation on the nats survey type, the wide azimuth towed streamer or waz or wats and was first tested on the mad dog field in 2004.
Geometrical attributes, such as dip azimuth and continuity of the local reflecting surfaces, can be automatically extracted directly from the. The survey was designed to address the subsurface challenges of the permian basin such as shallow karsting. Physical modelling studies of 3d pwave seismic for fracture detection. Thoseparameters are similar to another seismic acquisition survey developed in the studied area.
Heretofore, as is well known in the seismic processing and seismic interpretation arts, there has been a need for a method of identifying and interpreting thin bed reflections. For each experiment, about 20 km2 of wideazimuth 3d data were acquired with a pwave source. The azimuth information derived from prestack seismic data at target layers is very sensitive to many aspects of the analysis process, making reliability a serious issue. Preferably, the source vessels will be positioned along side of the towed streamer configuration and most preferably.
Fracture detection using 3d seismic azimuthal avo cseg. The challenge now facing the industry is to further improve subsalt images in areas with existing wide azimuth coverage. This is concerned with study of wave shape, polarity, continuity, dip, frequency, phase, and amplitude. This is a seismic volume that contains the dip and azimuth at each seismic. Principles of 3d seismic interpretation and applications. The role of waz data in subsalt exploration and production in the gom is now firmly established. Since then there has been an explosion in the number of attributes that can be generated and displayed in 3d interpretation systems. Azimuthal anisotropy analysis of wide azimuth pwave seismic data for fracture orientation and density characterization in a tight gas reservoir wanxue xie, guangming he, le li, degang jin, dan chen, hua zhang, and yao zhao. Wideazimuth obc seismic data optimization for avo and. Multiphysics integration of wide azimuth seismic and potential field data for subsalt challenges. Attributes are measurements based on seismic data such as polarity, phase, frequency, or velocity.
According to a preferred aspect of the instant invention, there is provided a system and method for acquiring seismic data in a marine environment, wherein at least two source vessels are used in conjunction with a recording vessel which tows a plurality of hydrophone cables. Innovative petrotech solutions, inc principles of 3d seismic interpretation and applications instructor. Wide azimuth recording images rock and salt layers from patterns up to 360 of azimuth for superior resolution and interpretation of the seismic data, often providing information on rock layers that was previously invisible. Intermediateadvanced course description this course delivers techniques related to practical analysis and interpretation of 3d seismic. On including nearsurface zone anisotropy for static. Wide azimuth acquisition is one of the primary techniques being used in gulf of mexico surveys. Wideazimuth land processing the leading edge geoscienceworld. Seismic data interpretation 7 basic concepts in seismic interpretation 8.
Sep 19, 2017 a progression in survey effort from one vessel towing sources and streamers sailing a survey area in two or more directions to several vessels sailing a survey area in two or more directions, some of them possibly only towing sources, represents the operational contrasts between multi azimuth maz, wide azimuth waz, and full azimuth faz 3d seismic. Fault identification based on wideazimuth seismic data. The petrel ssd plugin enables users to plan, edit, execute, and analyze marine, land, obc, and vsp surveys. The petrel seismic survey design ssd plugin is a powerful survey design tool fully integrated into the petrel environment. Seafloor seismic acquisition using autonomous underwater. Wide azimuth acquisition waz wide azimuth acquisition can be useful when acquiring data for subsalt plays. Seismic interpretation of the top and base dinantian. Pdf demystifying marine seismic analysis researchgate. Numerous acquisition geometries are supported, including 2d and 3d narrow, wide, and multi and full azimuth. Through joint interpretation of wide azimuth seismic data, the fracture system in block a was delineated with more credibility. Wide azimuth or waz is a term describing a seismic data acquisition technique where separate. Multiazimuth and wideazimuth lessons for better seismic imaging. It addresses the imaging issues common to this area by recording a wider range of azimuths and offsets than conventional narrow azimuth acquisition techniques. The wide azimuth seismic survey underour study was acquired after hydraulic fracturing, such that our focus is on mapping the orientation and intensity of induced fractures and natural fractures, with the objec.
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