Events

Dr. Zoya Heidari, Assistant Professor at Texas A&M University, will give a talk entitled "Hydrocarbon Reserve Evaluation in Anisotropic Formations with Complex Pore Geometry and Composition using Electrical Measurements"

Abstract:

Complex pore geometry and rock composition as well as heterogeneous and anisotropic nature of organic-rich mudrocks and carbonates significantly affect their physical properties such as electrical resistivity and dielectric permittivity. These electrical properties are used to estimate in situ hydrocarbon saturation. Conventional methods for well-log-based assessment of hydrocarbon saturation include interpretation of (a) electrical resistivity logs through resistivity-porosity-saturation models (e.g., Archie’s equation and the dual-water model) and (b) dielectric permittivity logs using volumetric techniques such as the Complex Refractive Index Model (CRIM). In the application of these approaches to formations with complex pore structure and composition such as organic-rich mudrocks, the impact of rock fabric, complex pore-structure (e.g., organic and inter-granular pores), pyrite, and kerogen networks have not been taken into account. The aforementioned limitations cause significant uncertainty in estimates of hydrocarbon reserves. In addition to the complex rock physics, integration of the rock properties and models obtained from fine scale (e.g., core- and pore-scale) to coarse scale (e.g., well-log- and reservoir- scale) has always been a challenge in heterogeneous and anisotropic formations.In this presentation, the effects of complex pore structure, rock fabric, and directional connectivity of kerogen, pyrite, and pore networks on electrical properties of organic-rich mudrock and carbonate examples will be discussed. Furthermore, a new analytical model will be introduced for assessment of water-filled porosity and hydrocarbon saturation that takes into account rock fabric. The results of numerical simulations show that (a) the directional connectivity of mature kerogen network has measurable impact on directional electrical resistivity of the rock and the corresponding estimates of fluid saturations and (b) pyrite’s presence, even in low concentrations, and its directional connectivity affect electrical resistivity and dielectric permittivity of the rock. Neglecting the presence of kerogen and pyrite can result in up to 18% and 23% underestimate of hydrocarbon saturation, respectively. Laboratory experiments of electrical properties complement numerical simulations by estimating model input parameters and validating the assumptions. The results also confirm the importance of taking into account rock fabric and directional connectivity of conductive rock components in upscaling of electrical properties in anisotropic rocks.Biography:Zoya Heidari is an Assistant Professor in the Harold Vance Department of Petroleum Engineering at Texas A&M University in College Station, and the Chevron Corporation Faculty Fellow in Petroleum Engineering. She received a Ph.D. (2011) in petroleum engineering from The University of Texas at Austin. Zoya is the founder and the director of the Texas A&M Joint Industry Research Program on “Multi-Scale Formation Evaluation of Unconventional and Carbonate Reservoirs.” Zoya was one of the recipients of the 2014 TEES Select Young Faculty Fellows award from the College of Engineering at Texas A&M University. She was selected as one of the distinguished speakers of the Society of Petrophysicists and Well Log Analysts (SPWLA) in 2014. She was also one of the recipients of 2012 SPE Petroleum Engineering Junior Faculty Research Initiation Award to develop her research program on formation evaluation of unconventional reservoirs. Her research interests include petrophysics, borehole geophysics, inverse problems, rock physics, reservoir characterization of unconventional and carbonate formations, and completion petrophysics.

Biography:

Zoya Heidari is an Assistant Professor in the Harold Vance Department of Petroleum Engineering at Texas A&M University in College Station, and the Chevron Corporation Faculty Fellow in Petroleum Engineering. She received a Ph.D. (2011) in petroleum engineering from The University of Texas at Austin. Zoya is the founder and the director of the Texas A&M Joint Industry Research Program on “Multi-Scale Formation Evaluation of Unconventional and Carbonate Reservoirs.” Zoya was one of the recipients of the 2014 TEES Select Young Faculty Fellows award from the College of Engineering at Texas A&M University. She was selected as one of the distinguished speakers of the Society of Petrophysicists and Well Log Analysts (SPWLA) in 2014. She was also one of the recipients of 2012 SPE Petroleum Engineering Junior Faculty Research Initiation Award to develop her research program on formation evaluation of unconventional reservoirs. Her research interests include petrophysics, borehole geophysics, inverse problems, rock physics, reservoir characterization of unconventional and carbonate formations, and completion petrophysics.