Petrochemistry and Chemical Engineering

Biography

Biography: Awojoyogbe Bamidele

Abstract

It is noted with keen interest that the advancements in instrumentation and software over recent years have led to increased research activities in the application of magnetic susceptibility methods in the hydrocarbon industry. Such interests are basically centred on magnetic susceptibility measurement and their integration with magnetometer and other surface geophysical surveys and with soil magnetic studies accomplished in the laboratory. In spite of the wide utilization of magnetic methods and magnetic susceptibility techniques in geophysical exploration, very limited research data are available on the magnetic susceptibility of natural reservoir fluids (crude oils, formation waters and other reservoir related fluids such as injection and drilling fluids). Also, magnetic susceptibility has not been able to provide sufficient contrast between sand, gravel, clays and other sedimentary rocks. In fact, it has been noted that one of the major challenges in the application of magnetic methods is the isolation of weak magnetic anomalies as a result of low concentrations of the magnetic minerals in sediments. This shows that we need additional contrast sources to confirm the measured magnetic susceptibility of reservoir fluids and the surrounding rock matrix. Fortunately, magnetic resonance offers us an opportunity of relating the magnetic susceptibility to the T1 and T2 relaxation times which are unique to different materials. Therefore, we present a method by which magnetic susceptibility of reservoir rocks and fluids can be related to the observed physical and chemical features via NMR relaxation based on the fundamental Bloch NMR equations. From our single and simple analytical results, we can determine the fluid flow velocity, viscosity for wetting phases, viscosity for non-wetting phases, the interfacial tension between two fluids, the contact angle measured from the side of the wetting phase, permeability, the component of gravity in x direction between fluid displacement and the density difference between displaced and displacing fluids. These parameters will enable us to express the relative magnitude of viscosity or gravity over capillary forces as well as the ratio in viscosities. In addition to the geometrical description of the medium, these parameters fully characterize the displacement in terms of the distributions of the various quantities (such as pore size or permeability) at the various scales and correlation lengths.