P-wave velocity anisotropy in Hamra Quartzites reservoir, Hassi Messaoud oil field in Algeria

The P-wave velocity and physical parameters were measured for core samples taken from Hamra Quartzites reservoir in Hassi Messaoud oil field (Algeria). The Pundit Lab tool was used to measure the P-wave velocity and the optical scanning technology was utilized for thermal conductivity. The permeability and porosity are also executed for cylindrical samples; these measures are taken under room temperature and ambient pressure. The physical and petrophysical measurements were carried out in order to search relationships between P-wave velocity anisotropy, thermal conductivity, grain size, density, P-wave velocity, thermal conductivity anisotropy, and porosity for all samples after their classification in uncemented and cemented sets. The origin of P-wave velocity anisotropy basing on thin section of samples and using microscopy analysis is also investigated. The obtained results show good correlation coefficients (R) between P-wave velocity anisotropy, grain size, P-wave velocity, and thermal conductivity in cemented set. The highest correlation coefficient is found between P-wave velocity anisotropy and thermal conductivity in cemented set ( R =0.92). The P-wave velocity anisotropy ranges between 9.93 and 11.14% for anisotropic samples. The microscopy analysis of thin sections for studied samples shows that open and closed microcracks are the origin of P-wave velocity anisotropy in Hamra Quartzites reservoir. The P-wave velocity anisotropy of samples is proportional to the width of parallel microcracks.