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Petromium Tools / Formula set GAS-DELIV-001

Gas-Well Deliverability

Backpressure fit · isochronal sequences · pressure-squared screening · V2.0

Mode
Units
Stored only in this browser · U1 pseudopressure integration is explicitly excluded from this release

Rate versus flowing sandface pressure

Deliverability curve

Deliverability curve

Rate against flowing pressure, with the measured tests

ControlledGAS-DELIV-001 v1.0.0
Gas deliverability rate versus flowing pressureGas deliverability rate versus flowing pressure0 ratetheoretical AOFpR0 pwf
Figure data
Measured tests behind the deliverability curve
Test
1
2
3
4
stabilized curveBlue points: included testsOutlined points: excluded tests

Rawlins-Schellhardt log-log fit

Regression of the entered flow tests

ControlledGAS-DELIV-001 v1.0.0
Log-log Rawlins-Schellhardt regressionLog-log Rawlins-Schellhardt regressionlog10 pressure-squared drawdownlog10 q
Figure data
Regression coefficients behind the log-log fit
QuantityValue
Coefficient C (SI)0
Exponent n0.8
Test points used4

An exponent outside 0.5 to 1.0 is outside the range the Rawlins-Schellhardt form is normally fitted over.

Flow and shut-in timeline

Test sequence

Flow-test sequence

Entered test periods in order

Schematic · not to scaleControlledGAS-DELIV-001 v1.0.0
Gas test flow and shut-in timelineGas test flow and shut-in timelineFlowShut-in / recovery1stabilized2stabilized3stabilized4stabilized
Figure data
Entered flow-test periods behind the sequence
Test
1
2
3
4

Timeline widths are relative to the longest declared cycle. Excluded points remain visible at reduced opacity.

Method and case

Test method

Fit C and n directly from stabilized multipoint data. Points are never rejected silently.

Absolute pressures and target

Pressure basis

Pressure function: p² - pwf². Real-gas pseudopressure is not calculated in V2.0 / formula v1.0.0.

Calculation complete

Calculation audit

0 warnings

Rate at target

25.681 MMscf/d

Theoretical AOF

28.9912 MMscf/d

Exponent n

0.8

Log fit R²

1

Calculation observations

THEORETICAL_AOF_ENDPOINT

AOF is the mathematical zero-flowing-pressure endpoint of the fitted curve, not an authorized operating rate.

PRESSURE_SQUARED_METHOD_ONLY

Version 1 uses pressure-squared analysis; real-gas pseudopressure is explicitly excluded pending U1 integration and numerical benchmarks.

Operational boundary: Calculation support only. The theoretical AOF is not an authorized operating rate, production authorization, test approval, or substitute for stabilized pressure-quality review, real-gas pseudopressure analysis where applicable, and competent reservoir-engineering review.

Declared sequence and included-point audit

Test points

Test point 1

Stabilized · included

Test point 2

Stabilized · included

Test point 3

Stabilized · included

Test point 4

Stabilized · included

Named local cases

Browser snapshots

Save a snapshot to restore an entered deliverability case on this device.

Screening scope

Model boundary

Selected method

Flow-after-flow

Included points

4

Excluded points

0

Included: single-well pressure-squared Rawlins-Schellhardt screening with declared test sequence.

Excluded: pseudopressure, multiphase/condensate effects, multilayer allocation, fracture interpretation, and test authorization.

GAS-DELIV-001 v1.0.0 · Lee-Wattenbarger · SPE 23440 Declared timing stays in the audit Theoretical AOF · not an authorized operating rate Pressure-squared method only