1 / 16

New Decline Curve Tool for GOM 3 /GOMsmart & “Forgotten Oil & Gas Study”

New Decline Curve Tool for GOM 3 /GOMsmart & “Forgotten Oil & Gas Study”. 2012 GOM 3 User Conference at Anadarko John D. Grace, Ph.D. Earth Science Associates. New Tool Objectives.

tanith
Download Presentation

New Decline Curve Tool for GOM 3 /GOMsmart & “Forgotten Oil & Gas Study”

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. New Decline Curve Tool for GOM3/GOMsmart & “Forgotten Oil & Gas Study” 2012 GOM3 User Conference at Anadarko John D. Grace, Ph.D. Earth Science Associates

  2. New Tool Objectives • Provide a robust tool for forecasting production & estimating remaining resources by completion/completion interval • Introduce optional new method for refining decline curve analysis accounting for “breaks in regime” • Internally, use tool in batch mode to identify opportunities for further production

  3. Decline Curves • Use regression analysis to forecast a production series beyond the last observation • With forecast “integrate under the curve” for remaining resources ≥ abandonment level • Use confidence intervals on regression to estimate confidence intervals on remaining • Use analysis of breaks in time series to improve on “naïve” regression models

  4. Stereotypical Decline Curve Oil Production 400 300 Barrels per day 200 100 1 3 2 4 Years on Production

  5. Fitting a Decline Curve • Classical functional forms of decline curves • Exponential (rate vs. time) • Hyperbolic (rate vs. time) • Linear (rate vs. cumulative production) • P/Z vs. cumulative production (gas only) • Where does the estimable decline start? • Global maximum production rate? • At the last significant structural break in regime?

  6. Exponential Decline Model

  7. Hyperbolic Decline Model

  8. Linear Decline Model

  9. (P/Z) Linear Model

  10. Improving & Choosing Model • Statistical measures of “goodness of fit” • R2 and “predicted R2” • Statistics on estimated parameter of decline • Still under research (e.g., retrospective forecast) • Actuarial approach (cum. prob. den. function) • Optimal choice of structural break • Last break – problem of shutting down well • Compare candidate breaks (& forms) against cdfs • Allow user to chose break point

  11. Actuarial Approach to EUR Oil Gas 1 1 0.8 0.8 0.6 0.6 Cumulative Prob. 0.4 0.4 0.2 0.2 0 0 30 20 0 10 40 50 0 2 4 6 BCF Million bbls Conditioning Variables: Drilling date, perf thickness, geologic age, reservoir volume, reservoir permeability, GOR, oil viscosity, gas specific gravity, reservoir drive mechanism, operator (?)

  12. Exploiting Structural Break in Regime Terminal Regime Break Global Max Default: We find break Option: You set break

  13. Adding Water to Analysis

  14. Tool Interface (in GOMsmart) Tool looks the same in GOM3 & the GOMsmart Map but is called from the Hot Link Tool

  15. Tool Output Charts Reports Excel Download

  16. “Forgotten Oil & Gas Study” • Motivated by running Decline Curve Tool in batch mode • ~60,000 completions/ completion intervals • Sensitivities to abandonment rate

More Related