Using Difference of Fast- and Slow Shear Wave for Fractured Oil-water Discrimination
C. Luo, X.Y. Li and F. Zhang
Event name: 79th EAGE Conference and Exhibition 2017
Session: Seismic Anisotropy in Fractured Reservoirs - The Anisotropic Signatures
Publication date: 12 June 2017
Info: Extended abstract, PDF ( 1.59Mb )
Price: € 20
Oil-water discrimination is of great significance to design and adjust development project for oilfields. For fractured reservoir, based on anisotropic S-wave splitting information, it be-comes possible to effectively solve such problem that the traditional longitudinal wave explo-ration is difficult to deal well with due to the similar bulk modulus and density of these two fluids. In this abstract, by analyzing the anisotropic character of HTI medium, reflection coef-ficient differences between fast and slow S-wave caused by fluid substitution were verified. Then through wave field response analysis of the three-layer fractured model, we found that water saturation causes lower amplitude difference between fast and slow S-wave, while the oil case is corresponding to higher amplitude difference. Therefore, a new class attribute was proposed, that is, the amplitude energy of the fast and slow shear wave, used for oil-water distinction. This new attribute was applied to the 3D3C seismic data of carbonate fractured reservoirs in the Luojia area of Shengli Oilfield in China. It shows that the prediction result of energy attribute has a good consistency with well information, and hence demonstrates the great advantages and potential of this new attribute in oil-water recognition.