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Quality Sonic Logs for Seismic Applications - Coursework Example

Summary
This coursework "Quality Sonic Logs for Seismic Applications" focuses on the quality of the sonic that has an effect on the velocity of the seismic during geological processes. The application of the continuous sonic logs has found its application in ascertaining the velocity…
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Extract of sample "Quality Sonic Logs for Seismic Applications"

Name Institution Instructor Subject Date Abstract The quality of the sonic has effect on the velocity of the seismic during geological processes. The application of the continuous sonic logs has found its application in ascertaining the velocity at given runs that occur at the surface. Various studies indicate that it is inevitable to avert errors that occur due to logging runs that occur at the surface. The recorded digital forms may be enhanced by the sonic log data. In a scenario where there is a great interaction between the data and processor. In quality control, the waveforms would find themselves. The waveforms emanating from the sonic logs and the normal logs gives an indication that the manner in which the signal has been detected in a major factor that contributes to errors in sonic logging. This is a result of the noise that contains an equal frequency as that of the signal. Introduction In a logging tool, there might be the crosstalk due to propagation of noise in a spatial manner. Apparently, there are logs which deem to fluctuate when they are very deep at several feet. The nature of velocity may also cause the fluctuation in case of high or low velocities. In order to avert such scenarios, the digital waveforms are processed (Deutsch 26). In cases of the transit times, the sonic tools may deem to short and not penetrate properly to areas that have been interfered due to low velocity. From various studies, it is apparent that the interval between the check shot and the derived sonic velocity of the sonic log may take the form of hundred feet. This gives a variance in the manner in which the seismic signals may be expressed at different pulse delays. In most application of the seismic application indicated in scenarios such as the extraction of the wavelets seismograph (Looff 6). This tends to interfere with the quality of the sonic logs. In cases of sonic logs that are long and meet certain quality that is higher in relation to those that are obtained in a seismic that arises due to the velocity actions. This leads them to occur at an interval of hundred feet. This vertical seismic may be minimized by reducing the error that occurs as a result of the propagation of waves. This action tends to be consistent in relation to the level of the sonics logs (Russell 56). In order to obtain a quality data of sonic log, it is imperative to improve the digital processing of the sonic waves. In the geophysical explorations there are occurrences in which the data may merge. This gives a clear view in which the geology of the fields may be conducted. The presence of the sonic log gives a record which is continuous in case of varying velocities. There is a detailed study that has to be interpreted in case of a hydrocarbon which has been trapped (Zou 22). The measurements of the geophysical boreholes lead to the formation of seismic sections. In situations where the seismic waves are used in conjunction with the sonic logs, it is important to integrate the sonic logs so as they differ from the seismic waves. The study of sonic finds in application in geophysics, geomechanics and petro physics. Methods The seismic time define the time in which the vertical check shot may be rectified and the based on the reference datum of a given seismic. This approximately occurs at hundred feet. The sonic time gives the time which has been integrated. This is achieved by taking different seismic and sonic bandwidth. There is presence of poor data that is sonic is a result of errors that emanates from the signal detection. In the situation in which the sonic logs are utilised, the sonic logs have to be modified such that, the measurements of the seismic may be obtained. In order to obtain the sonic times, all the sonic logs are integrated. This would differ from those values that are obtained from the seismic pulse. The action of the cycle skipping tends to cause the effects of drifting that occurs due to the discrepancies that occurs in various geometrical approaches. Figure 1 indicates the bandwidth at various depths The various seismic and sonic bandwidths that may lead to noise that may lead to difficulties in the detection of the signal. The sonic waveform are recorded digitally may lead to the formation of a derived waveform of a sonic log. The main purpose of digital recording is to ensure that there is enough interaction between the data and the processor at an instant. The waveforms that emanate from the sonic logs give one of the perfect ways in which the quality could be controlled. This gives an indication that, the sonic logs that give the waveform have a better performance as compared to the normal logs. The average internal velocity may be obtained as A problem of calibration would occur on the sonic logs that occur at thousands of feet as they exhibit forms of high and thin velocities. In case of shorter distance, there is presence of crosstalk that enhances the propagation in the formation of the waves that presume a compression wave. That would take in a given logging tool. Discussions This has a basis on the spatial consistency that accompanies the algorithim in the arrival of the initial precursor. In order to avert such scenarios, the sonic logs have to be long so as they may penetrate the formation which has not been interfered with. The effect of reduced noise to signal ratio leads to the errors would be more difficult to be detected whenever there is an action between the long spaced and the short spaced convections. The error seems to be more pronounce in the commercial tools that are long spaced. The effect of hot comparison on the sonic checks The errors that occur in the sonic logs have to be greatly reduced so as the application that are associated with the seismic may function properly. The nature of the sonic may be used in determining the velocity that occurs at various intervals (Haldorsen 88). Evidently, the order of hundred possess the velocity which are vivid as a result of the small intervals exhibited between the normal check shots and the sonic logs which are blocked. The displacement of waveform vs. time During various analysis, problems may arise in the analysis of the of the check shots due to the effect of conversions and noise that may cause interference. The interrelation of time and depth gives a challenge in which the seismic may be analyzed. Conclusions Conclusively, it is evident that, the manner in which the digital processing is done plays a great role in the manner in which the quality of sonic data may be enhanced. This is most applicable to waveforms that have spacings which are long. Additionally, it is evident that, the quality of the sonic logs enables the aspects of q attenuation to be realized in cases where there might be effects of wave forms. In case the case focussed on depth that is of the order of hundred feet, the nature of quality of the sonic waves could give a dependable velocity that could be used rather than relying seismic data that are based on the surface towards the holes. References Deutsch, Cris., Geostatistical Reservoir Modeling, New York: Oxford University Press,2002, Haldorsen,.Bob. Borehole acoustic waves. Oilfield Review, 2006.Print Looff, Kurt. The Application of Geophysical Borehole Logging as it Pertains to the Geologic Characterization of Salt Storage, Reservoir Storage and Brine Disposal. 2001. Print Pistre, Vest., Pabon, John., Plona, and Schilling, Klen. Estimation of 3D borehole acoustic rock properties using a new modular sonic tool. Madrid: EAGE 67th Conference and Exhibition. Print. Russell, Bell., Hampson, Dick., "The Old and the New in Seismic Inversion", CSEG Recorder. 2006. Print Zou ,Bentley. Integration of reservoir simulation with lapse seismic modelling. CSEG National convection , 2004. Print Read More
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