Well test analysis for gas-condensate reservoirs

Thesis/Dissertation · Sat Dec 31 23:00:00 EST 1988

OSTI ID:5807338

Vo, D T

This dissertation provides a detailed description of the performance of gas condensate producing wells and proposes well test analysis procedures for such systems as well as far volatile oil and black-oil reservoirs. Synthetic well test data generated from a compositional simulator are used in the analysis of drawdown and buildup tests. For wells producing at constant rate during the transient flow period, the use of the pseudopressure approach is reviewed. Several existing analysis methods are compared. These include the single-phase gas pseudopressure, the steady-state analogue, the pressure-squared function, and the GOR method. A new method, based on pressure derivatives, for computing the appropriate pseudopressure function is introduced. For wells producing multiple phases at constant pressure during the transient flow period, a new method for approximating the pseudopressure is introduced. The advantage of this approach is that relative permeability data are not required. The method allows for approximate procedures to calculate sandface effective permeability and skin factor from either the semilog method or the use of constant pressure type curves. For multiphase flow during the boundary-dominated flow period, the procedure of plotting p/Z versus cumulative production is extended for a wide range of fluid systems. Appropriate pseudopressure and pseudotimes are introduced to correlate the responses of gas condensate producing wells to the constant rate liquid solution for the depletion period. Analysis of the isochronal testing for gas condensate producing wells is briefly examined. The effects of liquid condensation, rate sequence, rock and fluid properties, and near-well skin damage on the slope of the back-pressure curves and AOF estimate are investigated.

• Research Organization: Tulsa Univ., OK (USA)
• OSTI ID: 5807338
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ANALOG SYSTEMS
COMPARATIVE EVALUATIONS
DATA ANALYSIS
DRAINAGE
ENGINEERING
FLUID FLOW
FUNCTIONAL MODELS
GAS CONDENSATE WELLS
MULTIPHASE FLOW
OIL WELLS
PERMEABILITY
PRESSURE DEPENDENCE
PRESSURIZATION
PRODUCTION
RESERVOIR ENGINEERING
RESERVOIR PRESSURE
SIMULATORS
TESTING
TIME DEPENDENCE
WELLS