Summary
Resolution and location accuracy of imaging systems are related but distinct parameters and require different measurements to determine. Location accuracy involves the determination of the location of an impulse in X, Y, and Z space. Resolution involves the ability to distinguish and separate two independent impulses. If it is known that only one impulse is present in the data, the location of the impulse is the location of the peak in the system response. If there are 2 impulses spaced close together, one must be able to determine the peak system response of each impulse.
For this study the location accuracy and resolution parameters are evaluated using both real data and synthetics. The parameters that most impact location accuracy and resolution are aperture, Signal-to-Noise (S/N), and receiver density in the receiver grid used for recording. The aperture required for good quality resolution is on the order of 1.5 times the depth of the impulse. S/N is defined as the ratio of the peak waveform of the signal to the RMS of the background. S/N has been studied in detail using synthetics and the results will be shown in the oral presentation. The S/N required for good quality is on the order of 0.4 to 1.0 but depends on the aperture and on the length of the integration time in the depth imaging used for direct fracture imaging. The receiver density within the aperture impacts both the required aperture and the S/N.
