RTD modelling using radiotracer technique in porous media for oil recovery study.

Fluid flow in most reservoirs is anisotropic. The reservoir structures are usually layered and frequently contain significant heterogeneities leading to directional variations in the extent of flow. Hence, the effective fluid movement can be difficult to predict. Hence, there is an immediate need to investigate and understand the behavior of reservoir during water-flooding specifically the fluid flow and transport behavior using radiotracer. Thus, a lab scale of sand pack has been set up to investigate the compatibility of radiotracer technique in assisting the behavior of sandstone reservoir in Malaysia. A full packed of sandstone with grain size of 800-900µm has been set up for this study. The sand pack is then connected to water reservoir to introduce water-flooding activity. The radiotracer used is Br-82 with activity of approximately 1mCi. The irradiation of NH4Br is carried out at Nuclear Malaysia research reactor using Pneumatic Transfer System (PTS) facility for 3 minutes. Five (5) NaI scintillation detectors are also located at various places outside the reservoir to look at the anisotropic effect, the property of being directionally dependent, which implies different properties in different directions of Br-82. The optimization of Residence Time Distribution (RTD) model from radiotracer experiments will present the characterization of the porous media. This is important knowledge in order to optimize the oil recovery. The present study shows that, the porous media represents perfect mixers in parallel model. The selection of this model is due to the minimum value of root mean square RMS which is 0.217e−8. The optimized parameters of the respective model are τ1 = 848, τ2 = 145, J1 = 3.14, J2 = 3.18 and Q1/Q2 = 0.952. The objective of this study is to leverage the potential of radio-tracing technique, a method that is scarcely utilized in water-flooding studies. It is able to analyze the reservoir behavior and the information obtained can be set and optimize a development plan for increasing the oil recovery efficiency for EOR application. [ABSTRACT FROM AUTHOR]