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An electrochemical method, which is the mass transfer analog of the hot film anemometer, has been developed to study flow fluctuations in the immediate vicinity of a wall. Electrodes mounted flush with the wall are the cathode of an electrolysis cell. At high enough voltages, the electric current is controlled by the rate of mass transfer to the cathode and the concentration of the reacting species at the surface is zero. These techniques allow the measurement of two components of the fluctuating velocity gradient at the wall. Results have been obtained on the structure of turbulence close to a wall and on the influence of drag reducing polymers on this structure.

Finding the best drilling locations in an extensive shale play holding is key to achieving production profile expectations and good economic metrics. Shale plays have been described as statistical plays. However, it becomes increasingly unacceptable to drill disappointing, underperforming wells as the operator and partners move from the exploration lifecycle stage into the appraisal and field development stages.The physical and chemical properties of shales dictate the economic success of development drilling programs. It is recognized that at least seven parameters must fall within empirically-determined ranges for a play to have economic production rates and estimated ultimate recovery (EUR) exceeding threshold internal rate of return (IRR) requirements.A geostatistical shale property workflow that high-grades 160-acre sections in a regional shale play, using a limited number of wellbores with standard logging suites is demonstrated. This paper extends the workflow from high-grading drilling targets to quantitative risk assessment. An application of the workflow to a multi-square mile U.S. shale play illustrates the analysis and its interpretation. The example shows that down-spacing well density in high-graded sections (high potential reward) is a quantitatively lower risk investment program than would normally be expected. Typically high reward opportunities, in the investment world, are expected to represent higher risk as well. Geostatistical analysis in the example play shows just the opposite behavior because the statistical nature of the local shale quality can be mapped and profitably drilled.Exploiting this geostatistical, high-grading workflow can accelerate an operator's development program with higher rewards, lower risk, and better rates of return than pursuing a uniform development program over a large regional play.