Effect of Shale Distribution on Hydrocarbon Sands Integrated with Anisotropic Rock Physics for AVA Modelling: A Case Study

Abstract

Shales can be distributed in sand through four different ways; laminated, structural, dispersed and any combination of these aforementioned styles. A careful analysis of well log data is required for the determination of shale distribution in sand affecting its reservoir quality. The objective of this study is to characterize the effect of shale distribution on reservoir quality of sands using well log data. The correlation of well data in terms of lithology has revealed four sand and three shale layers in Lower Goru Formation acting as a major reservoir in the study area. Our results indicate that the laminated type of shale distribution prevails at the Basal sand level, which does not affect its reservoir quality greatly. The remaining layers of variable vertical extent show a variety of shale distribution models affecting their reservoir quality adversely. We also present anisotropic rock physics modelling for AVA analysis at Basal sand level.

Caracterización petrofísica 1D de los yacimientos de la cuenca Canning, Australia

“…Posterior a la determinación del modelo de porosidad total, y con el fin de aplicar el modelo correcto para la porosidad efectiva de la roca (ϕ e ), se hizo fundamental la determinación del tipo de distribución de lutitas contenidas en la roca. Dado que estas pueden ser de cuatro tipos: laminares, estructurales, dispersas o combinaciones (Asquith, 1998;Ali et al, 2016). Por lo cual, a través de la gráfica de distribución de lutitas de Thomas y Stieber (1975) fue posible visualizar el tipo de lutita contenida en los yacimientos de interés.…”

Diagnosing of clay distribution in argillaceous sandstone by a rock physics template

“…The clay distribution has significant influence on the elastic properties of argillaceous sandstone (Minear, 1982;Sams and Andrea, 2001;Tyagi et al, 2009;Knackstedt et al, 2010;Andrea et al, 2003;Cosenza et al, 2014;Ali et al, 2016). The previous studies show that the distribution of clay in argillaceous sandstone could be divided into three types (Thomas and Stieber, 1975;Minear, 1982;Han et al, 1986;Chu, 1987;Sams and Andrea, 2001;Ali et al, 2016;Zhao et al, 2020): dispersed clay, cemented clay and matrix clay. The matrix here is rock physical rather than the geological definition, which indicates the solid component of the rock.…”