Microseismic velocity model inversion based on moveouts of first arrivals
Tan Yuyang1, He Chuan1, Zhang Hongliang2
1. Institute of Oil & Gas, School of Earth and Space Sciences, Peking University, Beijing 100871, China;
2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Abstract：In order to accurately locate microseism sources, velocity models between treatment wells and monitoring wells are needed. For conventional approaches, such velocity model building needs exact perforation origin times, so that travel times of P-wave and S-wave first arrivals can be estimated to calibrate velocities. However perforation origin times are very difficult to be precisely measured in the practice. So in this paper, we develop a new method to invert the velocity model without knowing the perforation origin time. Instead of the travel times, our method adopts first arrival moveouts to invert velocity models based on Levenberg-Marquardt inversion algorithm. So it can overcome the limitation of conventional approaches when perforation origin times are unavailable or inaccurately measured. Both model and field dataset tests indicate that velocity models inverted by our method can locate the perforation shots back to their expected positions, although velocity models have some discrepancies, which could be caused by many factors such as monitoring deployment positions and first arrival picking errors. So the inverted velocity models can be used to locate microseism sources.
谭玉阳, 何川, 张洪亮. 基于初至旅行时差的微地震速度模型反演[J]. 石油地球物理勘探, 2015, 50(1): 54-60.
Tan Yuyang, He Chuan, Zhang Hongliang. Microseismic velocity model inversion based on moveouts of first arrivals. OGP, 2015, 50(1): 54-60.
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