Well-log constrained inversion for lithology characterization: a case study at the JZ25-1 oil field, China

Zhang, Q., Chen, Y., Guan, H. and Wen, J., 2016. Well-log constrained inversion for lithology characterization: a case study at the JZ25-1 oil field, China. Journal of Seismic Exploration, 25: 121- 129. With an estimated total reserve of over 800 million barrels of oil equivalent (BBOE), JZ25-1 field is the largest light oil field in the Bohai Bay Basin, Eastern China. The reservoir rocks are mainly sandstones in the Paleocene Shahejie Formation (Es). Thus, a deep understanding of sand distribution is crucial to the efficient development of the field. In this paper, we performed lithology characterization using the well-log constrained inversion. Through seismic-well tie, initial modeling and simulated annealing, we obtained an acceptable inversion result. Using the wave impedance model as a constraint, we created sand thickness map with Kriging interpolation. The result indicates that sand bodies in the lower Es3 were thicker than those in the upper formation, and the thickness of sandstones varies laterally in the study area.
- Aki, K. and Richards, P., 2002. Quantitative Seismology (2nd ed.). University Science Books,
- Herndon, VA.
- Chen, Y. and Fomel, S., 2015. Random noise attenuation using local signal-and-noise
- orthogonalization. Geophysics, 80: WD1-WD9.
- Chen, Y. and Ma, J., 2014. Random noise attenuation by f-x empirical mode decomposition
- predictive filtering. Geophysics, 79: V81-V91.
- Gan, S., Chen, Y., Zu, S., Qu, S. and Zhong, W., 2015. Structure-oriented singular value
- decomposition for signal enhancement of seismic data. J. Geophys. Engineer., 12: 262-272.
- Roy, W., 1997. The accuracy of well ties: Practical procedures and examples. Expanded Abstr.,
- 67th Ann. Internat. SEG Mtg., Dallas: 816-819.
- Srivastava, R.P. and Sen, M.K., 2010. Stochastic inversion of prestack seismic data using
- fractal-based initial models. Geophysics, R47-R59.
- Xu, C., Zhou, X., Deng, J., Wei, G. and Lai, W., 2010. Geological significance in discovering
- large Jinzhou 25-1 light oilfield in Liaoxi sag. China Offsh. Oil Gas, 23: U7-U11.