Kansas Geological Survey Open-file Report 2003-31

Production data

Field production recorded by lease
Wharton Lease - 3 wells
Becker Lease - 2 wells
Waugh Lease - 6 wells

Barrel test (Oil & Water) data available from 1989 to date - 1 test per year

Field developed between 1977 to 1985
Majority of wells drilled in 1983

Initial oil production history missing in each well

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How to reconstruct oil production history?

Advanced Decline Curve Analyses

Match available production (rate/time) data with a model.

Production data normally includes both transient and depletion declines

• Transient - decline caused by fluid expansion with continually increasing drainage area
• Depletion - decline after drainage radius reaches outer boundaries

Decline curves analyse production data from depletion period only.

Used to estimate missing production data or to predict future production provided production practices remain unchanged.

This method estimates reserve volumes that are in pressure communication - ultimately recoverable by the wells.

Type curves, theoretical solutions to flow equations, are often used for decline analyses.

Fetkovich decline type curves were used here.

Model assumptions

Well producing under constant BHP
Well is centered in a circular drainage area
No-flow occurs at drainage boundaries

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