WATER SATURATION MODELLING AND ESTIMATION OF ELASTIC PROPERTIES OF POROUS ROCKS MODEL

• Main Author: Raka Fauzan, Muhammad
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68531
• Institution: Institut Teknologi Bandung

Elastic properties of rocks in hydrocarbon reservoirs have different characteristics due to the difference in the presence of fluid in the rocks' porous. Although it has been well studied before, the influence of fluid saturation on elastic properties is not widely understood when considering the effect of the spatial distribution of fluids. Therefore, in this study, the effect of fluid spatial distribution is analyzed on the elastic properties of rocks. A numerical approach using the digital rock physics (DRP) method was chosen to understand the elastic properties of rock which are difficult to explain analytically. The calculation of elastic properties was carried out on 3D Berea and Fontainebleau rock sample images with six-dimensional variations. The simple water filling model (SWF) and patchy water filling model were implemented to the digital rock image, then the elastic properties were calculated using the finite element method (FEM). From the results, there is a consensus between the calculation results and the reference as indicated by the increase in the value of the bulk modulus and P wave velocity. Meanwhile, it is shown that the shear modulus and the S wave velocity are independent of the saturation value. The difference in the two saturation models shows the influence of the spatial distribution of fluid on the velocity of the elastic waves. The patchy saturation model shows suitability with the drainage process which is described by a slow increase in the value of the P wave velocity. On the other hand, the SWF saturation model gives similar results by using the imbibition process. The SWF model is not yet accurate in describing the physical processes that occur inside the rock. This could be due to the inhomogeneous shape of the sample structure, pore connectivity, and the physical phenomenon of water film (WF).