Tracer- and pressure-test analysis for characterization of areally heterogeneous reservoirs

Journal Article · Fri Mar 01 04:00:00 EST 1991 · SPE Formation Evaluation (Society of Petroleum Engineers); (United States)

DOI:https://doi.org/10.2118/17365-PA· OSTI ID:5681785

Mishra, S ^[1]; Brigham, W E; Orr, Jr, F M ^[2]

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1. Intera Inc. (US)
2. Stanford Univ., CA (United States)

This paper compares simulated well-to-well tracer and transient pressure tests in a quadrant of a repeated five-spot with spatial variations in permeability. Single-layer heterogeneous media with an autocorrelated and log-normal permeability distribution are generated with a stochastic moving-average method. finite-difference simulation of pressure behavior in these systems indicates that the geometric means of effective permeabilities around injection and production wells is a good approximation for the steady-state interwell permeability. A dimensionless permeability difference, defined in terms of these quantities, correlates with a heterogeneity index, defined as the product of permeability variance and a dimensionless correlation length scale. Tracer flow is simulated with a particle-tracking procedure. Simulations show that when the heterogeneity index is small, tracer response can be matched with solutions of the convection-dispersion equation with a constant dispersivity that is proportional to the heterogeneity index. For large values of this index, preferential flow paths are created that cause tracer-breakthrough curves to behave as though they result from flow in a layered system. A method is proposed to estimate the heterogeneity index from pressure-test data and thus to predict the nature of the tracer response qualitatively.

• OSTI ID: 5681785
• Journal Information: SPE Formation Evaluation (Society of Petroleum Engineers); (United States), Journal Name: SPE Formation Evaluation (Society of Petroleum Engineers); (United States) Vol. 6:1; ISSN 0885-923X; ISSN SFEVE
• Country of Publication: United States
• Language: English

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CONVECTION
DISPERSIONS
DRILLING
ENERGY TRANSFER
FINITE DIFFERENCE METHOD
FLUID MECHANICS
FUNCTIONS
HEAT TRANSFER
HETEROGENEOUS EFFECTS
INJECTION WELLS
ITERATIVE METHODS
MASS TRANSFER
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NUMERICAL SOLUTION
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PERFORMANCE TESTING
PERMEABILITY
PLANNING
PRESSURE GRADIENTS
PRODUCTIVITY
RESERVOIR ROCK
RESPONSE FUNCTIONS
STOCHASTIC PROCESSES
TESTING
WELL DRILLING
WELLS