Rock physicists step out of the well location, meet geophysicists and geologists to add value in exploration analysis

Abstract

A primary task for a petroleum rock physicist is to link geological and geophysical interpretation practices and culture in such a way that they can be understood and applied in exploration and production of oil and gas. Specifically, this task asks for relations between key properties of the fluid-saturated rocks located in situ and quantities extracted from seismic and electromagnetic data. In spite of the hard work needed to establish a proper characterization of such relations, they are of limited if not insignificant value in exploration (out of the well location) if not adapted to key elements of geological processes and obtainable seismic and electromagnetic properties.

Combining burial history and rock-physics modeling to constrain AVO analysis during exploration

“…Per Avseth 1, 2 and Ivan Lehocki 3 Helset et al (2004) were the first to combine kinetic modeling of quartz cementation and associated porosity evolution, introduced by Walderhaug (1996), with rock-physics modeling using contact cement theory by Dvorkin and Nur (1996). Brevik et al (2011), Draege et al (2014), and Avseth et al (2014) further showed how burial history can be combined with rock physics to improve the understanding of seismic signatures in areas with complex tectonics or in frontier areas with limited well control. In this study, we utilize this integrated approach to predict sandstone texture and associated seismic properties as a function of geologic time for a North Sea case and a Barents Sea case.…”

Geophysical basin modeling: Methodology and application in deepwater Gulf of Mexico

“…The rock-physics model follows mechanical and chemical compaction laws when modeling the porosity and anisotropic or isotropic stiffness components from which properties such as P-and S-wave velocities, anisotropy, and density are calculated. The rock model is universally calibrated to various depositional and geohistory sets from hundreds of wells worldwide (Brevik et al, 2011), and the only parameterization needed is for lithology type and depositional attributes. Access to well-log data (also for better lithology and depositional attribute definition) helps to build confidence in the produced velocity and density fields.…”

“…The estimated models are, however, nonunique because several "earth models" may fit the measured data (Bakulin et al, 2010). Recently, rock-physics modeling has been proposed as an additional source of information in the derivation of the anisotropic subsurface response (Bachrach et al, 2010(Bachrach et al, , 2011Brevik et al, 2011). Li et al (2011) and Helgesen et al (2013) show further how rock-physics constraints could be used in combination with seismic data to better address the nonuniqueness problem.…”

“…The concept of linking geologic information through rock-physics transformation to obtain elastic model properties for application in integrated exploration analysis has been described by Brevik et al (2011Brevik et al ( , 2014 and is named geophysical basin modeling (GBM). In this paper, we further describe a multidisciplinary methodology and we show the application of GBM to seismic imaging in the deepwater Gulf of Mexico.…”

Geophysical Basin Modeling - Effective Stress, Temperature and Pore Pressure Uncertainty

“…Initial velocity and anisotropy models for anisotropic imaging are then constructed by guided interpolation/extrapolation of the estimated parameters at well locations throughout the full volume (Bakulin et al, 2009). It was shown that the incorporation of geo-history can be used to predict seismic velocities using rock physics modelling (Brevik et al, 2011). We call the use of basin modelling simulations with rock physics to predict elastic attributes which can be used for anisotropic velocity model building or AVO as Geophysical Basin Modelling (GBM).…”