Crosswell P Wave And S Wave Imaging And Application

With the further development of oil and gas exploration, we need to exactly image geologic targets. Because crosswell seismic has the feature of high resolution, high precision and high confidence, it has been widespread used. Since crosswell seismic data acquisition technology has been matured, however, data processing and interpretation are still barriers for the application of crosswell seismic technology; especially crosswell seismic imaging is the most important. For the three component data of crosswell seismic, we study the wave field characteristics; use scalar elastic wave reverse time migration technique to image P wave wavefield and S wave wavefield. Firstly we extract P wave field and S wave field from elastic wave data, and then use acoustic equation to image P wave field and S wave field separately, and then we obtain high resolution imaging section of P wave and S wave, provide the basis for detailed crosswell interpretation.In this paper, according to the unique crosswell acquisition system and P wave and S wave polarization relation on different components, we develop a method to separate P wave and S wave inτ? p domain based on the high-resolution Radon transform. We test it on modeling and real data, and successfully get P wave field and S wave field, which prepared for the next step of P wave and S wave imaging.We introduce reverse time migration applied in surface seismic imaging to crosswell seismic imaging. Using finite difference technique, we derive an arbitary-order accurate space, second-order accurate time, two-dimesional acoustic finite-difference scheme based on the rectangular grid. Comparison of several commonly used artificial boundary conditions, summarize their advantages and disadvantages, and ultimately select the mixed boundary conditions for calculating. In the finite-difference reverse time migration of acoustic wave, we adopt cross-correlation imaging condition. During the imaging process, we consider the imaging noise, take appropriate measure to eliminate it, and ultimately get satisfying imaging results. Apply this imaging algorithm for P wave and S wave field respectively, and achieve P wave and S wave imaging.Imaging for P wave and S wave on the model and actual crosswell seismic data, we obtained high precision P wave and S wave imaging section, which shows the advantages of mutli-wave exploration.