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Shear-wave Previous HitAnisotropyNext Hit in Very Porous Oil-bearing Sands: Applications in Perforation Strategy and Production Optimization


 Theodore Klimentos1, Taher El-ZefZaf2, Mohamed AbdelFatah2, Maher Omara2

(1) Schlumberger, Cairo, Egypt (2) General Petroleum Company (GPC), Cairo, Egypt

 In this case-study, shear-wave Previous HitanisotropyNext Hit data was acquired by dipole shear sonic logging over several porous sandstone formations, intersected while drilling a well in the Gulf of Suez. The cross-dipole shear-wave data from the dipole shear sonic imager tool was processed to obtain oriented fast and slow shear waves. Previous HitAnisotropyNext Hit was then used to determine the orientation and magnitude of the principal horizontal stresses. Several highly porous sandstone zones exhibited significant shear-wave Previous HitanisotropyNext Hit. This observation indicates that the shear-wave Previous HitanisotropyNext Hit, which occurs in sands of about 30% porosity is more likely attributed to a significant stress imbalance. So far, the general perception has been that shear-wave Previous HitanisotropyNext Hit occurs more often in tighter rocks, e.g., carbonates or low porosity sands. The observed shear-wave Previous HitanisotropyNext Hit azimuth has a NW-SE orientation, which is consistent with the known tectonic regime of the Gulf of Suez stress trend, i.e., the Clysmic-fault trend. Due to Previous HitanisotropyNext Hit, there is a significant difference between the magnitudes of the minimum and maximum horizontal stress. The Previous HitanisotropyNext Hit information proved to be very valuable in optimizing the perforation and production strategy due to the fact that sanding was suspected to occur. Sanding analysis was thus performed prior to the test and maximum critical drawdowns were calculated taking into consideration the shear-wave Previous HitanisotropyNext Hit. The main technology value obtained from this study is that it clearly demonstrates the presence of significant shear-wave Previous HitanisotropyNext Hit in shallow deposited, oil-bearing and highly porous sands, which to the authors' knowledge has very seldom been reported in the literature, if ever. Therefore, this observation may assist in promoting and enhancing the usage and benefits of the shear-wave Previous HitanisotropyTop technology in highly porous-sands.