PETREL Seismic Interpretation

Fluid catalytic cracking-1 link :https://youtu.be/ZpPgw188LOc Petroleum Refining Technology-1 :https://youtu.be/1Wqnv_gH1fQ Drill bits-Roller cone bit https://youtu.be/78RCKSTXGrY Rotary drilling rig components-1 Reservoir simulation-https://youtu.be/JMeDZD5BibE Petroleum Refining Technology-2 https://youtu.be/3RsaQVKZ1GQ seismic interpretation is the science (and art) of inferring the geology at some depth from the processed seismic record. ... Structural seismic interpretation is directed toward the creation of structural maps of the subsurface from the observed three-dimensional configuration of arrival times. Seismic Interpretation is the extraction of subsurface geologic information from seismic data. ... Reflection seismic data comprise: Continuity of reflections indicating geologic structure. Variability of reflections indicating stratigraphy, fluids and reservoir fabric. In the interpretation of seismic reflection data, horizons are the reflectors (or seismic events) picked on individual profiles. ... These reflectors represent a change in rock properties across a boundary between two layers of rock, particularly seismic velocity and density. 3-D seismic data have become the key tool used in the petroleum industry to understand the subsurface. In addition to providing excellent structural images, the dense sampling of a 3-D survey makes it possible to map reservoir quality and the distribution of oil and gas. An informal term used to denote a surface in or of rock, or a distinctive layer of rock that might be represented by a reflection in seismic data. The term is often used incorrectly to describe a zone from which hydrocarbons are produced. Seismic surveys use reflected sound waves to produce a “CAT scan” of the Earth's subsurface. Seismic surveys can help locate ground water, are used to investigate locations for landfills, and characterize how an area will shake during an earthquake, but they are primarily used for oil and gas exploration. An interpreter should clearly understand what conclusions are required from the data. Because so much information is available on the seismic, it is important to focus maximum attention on extracting the data pertinent to completing the objective task. Does the objective require evaluating the entire dataset from first sample to last, one stratigraphic sequence, or just one specific amplitude anomaly? This dictates what combination of the three basic interpretation types should be used, when the interpretation should be completed, and what supporting databases are required. Perhaps the most common interpretational pitfall, and certainly one of the most dangerous, is the mapping of events, amplitude, or AVO changes without qualification as to what geological analog they represent. To prevent this mistake, it is critical that all types of available geological data be gathered and merged with the seismic data. Key to this merging are well-constructed synthetic seismograms, vertical seismic profiling (VSP) data, and/or seismic models (see Synthetic seismograms, Checkshots and vertical seismic profiles, and Forward modeling of seismic data). This verifies the seismic signature of the target, the location of the mapping horizon, and the adequacy of the time-depth functions. Varying the synthetic seismogram or model parameters allows for the prediction of seismic responses for various lithologics and fluid types. Step two: building and merging datasets After developing an interpretation plan, the next step is to begin assembling the complete dataset. An inventory of available seismic data of all vintages is made, including p wave seismic, shear wave seismic, well data, velocity surveys, and VSP. The data are scanned for quality and suitability. At this point, a determination can be made whether the available data can reasonably support the goals of the project. Available well, core, test, paleontology, and outcrop data are gathered and organized for integration with the seismic data. Where available, gravity and magnetics data should be tied to the seismic data to identify the location of basement, salt bodies, igneous intrusives, and shale masses. Another type of data that sheds light on the geological conditions of a specific reservoir is pressure and production history data. These data can provide information on the presence and proximity of faulting and the size of fault blocks. If digital data are available, a decision must be made whether to use a workstation or proceed with a “paper interpretation.” Generally, a workstation offers the interpreter a valuable edge achieving a “correct” interpretation where detail is important (see Two-dimensional geophysical workstation interpretation: generic problems and solutions). For much regional work, paper is often still the most used medium due to the display limitations of the workstation screen. Seismic interpretations on paper, however, can always be digitized later for computer mapping .