Decline Curve Analysis (DCA) in Minutes, Not Hours
Arps, Duong, and modified hyperbolic models with auto-fit regression. Built for petroleum engineers who need accurate forecasts fast.
See a fitted curve, EUR estimate, and decline parameters in about 30 seconds.
MCPRun this workflow from Claude or Cursor. Connect Petrolytx in one secure sign-in.Connect AI →Deterministic Curve Fit
Run a sample decline curve analysis (DCA) to see fitted decline parameters and EUR in ~30 seconds.
EUR
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MBO
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Built by reservoir engineers, for petroleum engineers
Worked example · Exponential decline
From daily oil rate to remaining production
Consider a hypothetical well producing 100 barrels of oil per day at the forecast start. An exponential decline of 5% nominal per month gives a month-12 rate of 54.9 bbl/day and 27,071 barrels produced during those 12 months.
This is a fixed teaching example with assumed inputs, separate from the interactive sample well above.
1. Set the time and rate units
- Initial rate, qi
- 100 bbl/day
- Nominal decline, D
- 0.05 per month (5%)
- Arps b-factor
- 0, exponential
- Time convention
- 30 days per tutorial month
- Selected stopping rate
- 10 bbl/day
Nominal and effective decline differ. Here the effective annual decline is 1 − exp(−0.05 × 12) = 45.1%. Keep that distinction when entering an annual decline estimate.
2. Calculate rate and cumulative volume
q(t) = 100 × exp(−0.05 × t) bbl/day
Np(t) = 30 × [100 − q(t)] / 0.05 bbl
t is elapsed months. The factor of 30 converts a daily rate integrated over months into barrels. These are continuous-curve volumes, with no downtime.
| Month | Rate (bbl/day) | Cumulative (bbl) |
|---|---|---|
| 0 | 100.0 | 0 |
| 6 | 74.1 | 15,551 |
| 12 | 54.9 | 27,071 |
| 24 | 30.1 | 41,928 |
3. State the recovery limit
The curve reaches 10 bbl/day at ln(100 / 10) / 0.05 = 46.1 months. Integrating to that cutoff gives 54,000 bbl of remaining modeled production. With an assumed 75,000 bbl already produced, total modeled recovery is 129,000 bbl.
The stopping rate is an assumption, not a calculated economic limit. Revenue, operating cost and ownership determine when continuing production stops making economic sense.
Before using a forecast
Check downtime, workovers and changes in operating conditions before fitting a decline. Review the fitted interval and the forecast tail; a high R² describes a historical fit and does not establish future accuracy. This synthetic curve is not a reserves classification.
Method reference: ResInsight’s Arps rate and cumulative equations. The inputs and calculations here are Petrolytx’s illustrative example.
Stop Wrestling With Spreadsheets
Hours of manual parameter tweaking
Auto-fit regression finds optimal parameters in seconds
Complex Excel formulas prone to errors
Validated Arps calculations you can trust
No visibility into model fit quality
Real-time R-squared and diagnostics
Difficult to compare decline models
Compare models side-by-side with R² fit statistics
Manual EUR calculations
Automatic EUR with economic limits
No way to aggregate multi-well forecasts
Group forecasting with type curve generation
Everything You Need for Decline Analysis
Professional-grade DCA tools without the enterprise price tag
Multiple Decline Models
Exponential, hyperbolic, harmonic, and Duong models. Modified hyperbolic with terminal decline switch for unconventional wells.
Auto-Fit Regression
Grid search optimization evaluates thousands of parameter combinations to find the best fit. R² statistics help you assess fit quality.
EUR Calculator
Estimated Ultimate Recovery with configurable economic limits. Calculate remaining reserves and well life instantly.
Rate-Time & Rate-Cumulative
Switch between linear and semi-log views. Rate-time and rate-cumulative plots for comprehensive analysis.
Flexible Import & Export
Import from ARIES, PHDWin, CSV, or Excel. Export forecasts to CSV for use in your existing workflows.
Multi-Well Analysis
Analyze individual wells or aggregate portfolios. Build type curves from analog wells with P10/P50/P90 statistics.
Frequently Asked Questions
What decline models are supported?
Exponential, hyperbolic, harmonic, and Duong models. Modified hyperbolic with automatic terminal decline switching is also available for unconventional wells.
How does the auto-fit work?
Grid search optimization evaluates thousands of parameter combinations and selects the best fit based on R-squared while avoiding physically unrealistic parameters.
Can I import my existing production data?
Yes. Import from CSV, Excel, or paste directly. ARIES and PHDWin export formats are also supported.
What's included in the 14-day trial?
Full access to all decline curve analysis features for 14 days, including auto-fit, multi-well analysis, and export. A payment method is required to start the trial.
How accurate are the forecasts?
Accuracy depends on data quality, the fitted interval, future operating conditions, and the forecast model. R-squared measures agreement with historical data; a high value does not guarantee future accuracy. Review the decline parameters, stopping rate, and forecast tail before saving.
Simple, Transparent Pricing
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- 250 wells, 10 projects
- Economics & sensitivity analysis
- Contextual analog discovery
- Type curves (P10/P50/P90)
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- Everything in Pro
- Capital Dossiers — cited decision memos
- Unlimited wells & projects
- Priority support
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Auto-fit Arps, Duong, and modified hyperbolic declines, then export forecasts your team can verify.
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