AFA Documentation
Breadcrumbs

General Reservoir & Production Engineering Workflows

Introduction:

According to T. A. Blasingame [2007, 2020, 2024], the following procedure (modified) is recommend for any RTA work.

Step

Name

Comment

1

Data Review

Look for consistency between rates and pressures. Identify abhorrent data

Common Issues with Production Data Include:

Refer to Rate-Pressure Correlation

2

Data Clean

Remove spurious data from analysis (in AFA, this is done effectively through advanced data science)



a. This may include averaging, smoothing algorithms, splines, wavelets, etc

b. Outlier detection

Data modification must always honour the true cumulative production

3

  1. Identify Flow Regimes

a. Time-Rate-Pressure Correlation using Diagnostic Plots:

  1. vs time or material balance time (tmb); See Pressure Normalized Decline Analysis

  2. or vs Sqrt[time] (I.e. Linear Analysis)

  3. Production Exploration, q or cumulative production

  4. Decline Analysis used to supplement the more rigorous model-based methods. Note there must be sufficient data for extrapolation.

    1. The strength of such methods are the simplicity that these models have to data fitting.

    2. The weakness is that they are not true solutions to fluid flow in porous media.


b. Analytical Model Using FMB and Rate Transient Analysis (RTA) or related Plots:

  1. Normalized Pressure Integral (NPI) Plots,

  2. Beta Plots,

  3. Blasingame Plots,

  4. Flowing Material Balance and FMB Productivity Index (PI) plots

    1. Very useful for establishing the presence of boundary-dominated flow and to estimate OHIP. Often useful even in the presence of significant or extreme data bias.

  5. and other plots (in AFA, this is an automated procedure).

4

History Match

Compare Physics (or Science) Model to the observed raw data

5

Refine Model Parameters

A 2nd or 3rd pass of review may be required,.

See Also:

References:

  • T. A. Blasingame, Production Data Analysis in Tight Gas Sands, 2007 Anadarko Tight Gas Workshop, 04 December 2007, Woodlands TX

  • Anderson, D. M., Stotts, G. W. J., Mattar, L., Ilk, D., and T. A. Blasingame. "Production Data Analysis—Challenges, Pitfalls, Diagnostics." Paper presented at the SPE Annual Technical Conference and Exhibition, San Antonio, Texas, USA, September 2006.

  • T. A. Blasingame, “Pressure Transient Analysis (PTA), Rate Transient Analysis (RTA), and Decline Curve Analysis (DCA) Methods for Wells in Unconventional Reservoirs”, SPE Denver Section - General Meeting, 15 December 2020.

  • D. Ilk, A. D. Perego, J. A. Rushing, & T. A. Blasingame “Integrating Multiple Production Analysis Techniques to Assess Tight Gas Sand Reserves“. SPE 114947. 2008