Pressure-transient behavior of heterogeneous naturally fractured reservoirs

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6900093

Jalali-Yazdi, Y

An analytical parameter estimation method for the analysis of pressure transient data in heterogeneous naturally fractured reservoirs is presented here. Two types of models are considered, double porosity and triple porosity. A general double porosity model is formulated that allows a mode of interporosity flow ranging from pseudo-steady state to unsteady state. The method of parameter estimation consists of pattern recognition, type curve matching, and auxiliary correlations. Pattern recognition verifies the amenability of data to analysis as well as the applicability of the model to observed behavior. A type curve is developed that determines the condition of interporosity flow and yields the reservoir parameters accordingly. Auxiliary correlations estimate the reservoir parameters from the characteristic coordinates of the transition curve. These correlations complement type curve analysis and provide criteria for well test design. Triple porosity models are developed to analyze pressure transient data that exhibit anomalous behavior during the transition period. The models allow two matrix layers with distinct properties to be present in varying proportions. Anomalies are acute when the matrix layers have response-time coefficients that differ by at least two orders of magnitude. This coefficient is defined as a layer's fractional storativity to its weighted interporosity flow coefficient. When anomalies are acute, parameter estimation yields the fractional fracture storativity (Omega/sub f/), the weighted arithmetic mean of the interporosity flow coefficients (lambda/sub m/), and the response-time coefficient of each layer (tau).

• Research Organization: University of Southern California, Los Angeles (USA)
• OSTI ID: 6900093
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
04 OIL SHALES AND TAR SANDS
040300 -- Oil Shales & Tar Sands-- Drilling
Fracturing & Mining
FLOW RATE
FRACTURED RESERVOIRS
POROSITY
PRESSURE EFFECTS
STRUCTURAL MODELS