Well testing for solution gas drive reservoirs

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6371869

Serra, K V

This work presents new procedures for analyzing well-test pressure data obtained at a well producing a solution-gas-drive reservoir. The main results obtained in this work is that effective permeabilities as a function of oil saturation can be computed directly from drawdown and buildup pressure data. The physical system consists of the radial flow of oil and gas in the presence of immobile connate water through a cylindrical reservoir with a fully penetrating well at the center. Porosity is assumed to be constant. Capillary and gravity effects are neglected and the flow is considered to be isothermal. It is assumed that the fluid can be described by the Black-oil model (..beta..-Model). Results are generated from a computer simulator that uses a sequential method as the numerical procedure of solution. Pressure-squared analysis procedures are introduced to analyze both drawdown and buildup data. Computational procedures to determine initial oil mobility, initial oil effective permeability, skin factor, and average pressure from pressure-squared analysis are presented. Boundary dominated flow is also considered. A time dependent factor deviation factor that indicates the difference between the material balance equation for solution-gas-drive reservoirs and the liquid material balance equation is introduced. It is shown that the pseudo-steady state flow equation for the liquid case can be modified to include the multi-phase flow case for oil-gas, provided the correct material balance equation is incorporated. It is then shown that the liquid MBH function can be used to estimate average a pressure in solution-gas-drive reservoirs.

• Research Organization: Tulsa Univ., OK (USA)
• OSTI ID: 6371869
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
ASSOCIATED GAS
BOUNDARY CONDITIONS
CALCULATION METHODS
COMPUTERIZED SIMULATION
DATA ANALYSIS
DIFFERENTIAL EQUATIONS
DRAWDOWN
EQUATIONS
FLOW RATE
FLUID FLOW
FLUIDS
GAS FLOW
GASES
MATERIAL BALANCE
MATHEMATICAL MODELS
MULTIPHASE FLOW
OIL SATURATION
OIL WELLS
PERMEABILITY
POROSITY
PRESSURE MEASUREMENT
PRESSURIZING
RESERVOIR ROCK
SATURATION
SIMULATION
STEADY FLOW
STEADY-STATE CONDITIONS
TESTING
TIME DEPENDENCE
WELLS