Abstract
In anticipation of important technological advancements, during the 21st century, it is worthwhile discussing the frontiers of the current formation evaluation and petrophysics. Today, formation evaluation has limits, dictated by the available logging technologies, core-analysis expertise, petrophysical models and interpretation methods. Technological advancements in logging measurements, core-analysis or petrophysical interpretations can contribute to widening the horizon of formation evaluation and magnifying its value in the oil and gas business.
Logging technologies and services currently provided have various limitations. The resolution of the logging tools has not come below one foot. The depth-of-investigation of almost all the logging tools has not exceeded a couple of feet into the formation. Data acquisition in most of the logging tools has limited speed. Logging technologies have not yet enabled direct and continous measurements of formation permeability and electrical properties.
Similarly, there are some limitations in the petrophysical models and interpretation methods available. Deterministic petrophysics has limited capability in characterizing minerals in the formation. Non-deterministic, or probabilistic petrophysics, has prediction capability to some minerals, yet its prediction of formation minerals is non-unique. Insufficient mineralogical-description of formation lithology can introduce inaccuracy in the calculation of formation-porosity. Inadequate characterization of rocks and their types can have negative effects on estimating water-saturation and permeability in the formation. Technology and expertise enabling factual representation of formation parameters are essential for obtaining state-of-the-art formation evaluation.
Core data is considered the ground truth and can have a corner-stone role in formation evaluation. Different core-analysis laboratories could give different measurements of the same attributes from the same core. Standardization of procedures among core-analysis laboratories is highly needed for better formation evaluation and petrophysics.
