Basic Research Needs for Geosciences - Energetics Meetings and ...

PRIORITY RESEARCH DIRECTION:DYNAMIC IMAGING OF FLOW AND TRANSPORTTo overcome current limitations, two major future scientific challenges must be met. One is toimprove the far-field visibility of reservoir attributes that drive flow and transport systems fromthe pore scale to the basin scale, and a second challenge is to develop the ability to describe flow,transport, and chemical reactions from observations of subsurface materials and fluids from alimited number of wells.Meeting these challenges requires the development of a more thorough understanding of thenatural variability of geologic media, as well as the refinement of existing geophysical methodsand the development of new technology and methods of data analysis. The goal is to obtaindetailed information concerning the chemical reactions that occurred in the medium or arepresently occurring. The properties and geologic structure that control flow and transportphenomena need to be observed on a variety of scales, and scales appropriate to a particularproblem need to be identified. Ideally, flow, fluid mixing based on tracer tests, and activechemical reactions need to be sensed and visualized directly.In summary, the following research needs appear most critical:• Understanding the hierarchy of linear and nonlinear principles that govern the propagation ofphysical fields through geologic media• Advanced technologies for measuring physical, chemical and biological attributes that affectpropagation of physical fields from the core scale to the molecular level• Methods to quantify flow and reaction regimes from physical and chemical observations offluid and solid phases• Advanced measurement techniques based on improved theoretical, mathematical, andcomputational models for wave propagationSpatially and temporally continuous measurement of state variablesIt is currently possible to measure pressure and temperature adjacent to screened or openintervals within a well or at points in space (Figure 39). Recently, it has also become possible tomeasure temperature on the surface or shallow subsurface along continuous transects using fiberoptics. The latter technique has provided a leap forward in measuring spatially complexphenomenon because it greatly reduces the need to integrate or interpolate point data on criticalstate variables, thereby providing vastly enhanced ability to detect critical phenomena and toconstrain models. An important scientific challenge is to measure pressure, temperature, andpossibly other variables, such as fluid electrical conductivity and phase saturation, continuouslyalong transects emplaced via vertical or horizontal drilling in the subsurface.Smart tracersThe level of instrumentation of hydrocarbon reservoirs is steadily increasing, and the phrase,instrumented oilfield, is used regularly (Tura 2005). With current developments in micro- andnanotechnology, and the advent of smart dust (e.g., Kahn et al. 2000) new opportunities exist formassive instrumentation of the subsurface. New tracers could be miniature measurement anddata-relay devices, a combination of passive and active chemical tracers (Oates 2007), chemicaltracers that respond to physical fields (such as organo-metallic tracers), or a combination ofthese. All of these are considered tracers as smart tracers.Basic Research Needs for Geosciences: Facilitating 21 st Century Energy Systems 125