Analysis of Production Data Module for: Analysis of Reservoir Performance Analysis of Production Data T.A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX 77843-3116 (979) 845-2292 — t-blasingame@tamu.edu PETE 324 (03A) — Analysis of Production Data

Analysis of Production Data Production data — "low frequency" (taken at large (or even random) intervals) and "low resolution" (data quality (i.e., accuracy) is minimal). Simple Analysis: Rate-time decline curve analysis. EUR analysis (usually rate-cumulative or variation). New stuff — advanced analysis based on a simple, yet robust model (e.g., Knowles qg-Gp analysis) Decline type curve analysis: Systematic, model-based analysis approach. Model identification — transient data analysis. Volume estimates — pseudosteady-state behavior is dictated by material balance (very consistent). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Example Case Rate and pressure profile for a mid-continent (U.S.) gas well, note the daily and seasonal fluctuations in the data. PETE 324 (03A) — Analysis of Production Data

Production Analysis — EUR Analysis Estimated ultimate recovery (EUR) profile for a mid-continent (U.S.) gas well — there is considerable variation in the data. PETE 324 (03A) — Analysis of Production Data

Production Analysis — WPA (Data Edit Plot) Note the transient "spikes" are edited out of the data used for type curve matching. This dataset is more or less typical. PETE 324 (03A) — Analysis of Production Data

Production Analysis — WPA Approach Note that the WPA approach provides a unique analysis/ interpretation of the well performance history. PETE 324 (03A) — Analysis of Production Data

Production Analysis — the hard way... "Van Everdingen-Meyer Method: "Analysis by simulation" (use analytical solution to define x-axis plotting function). Considers all of the data, needs a complete model to generate an appropriate analysis/interpretation. Theoretically simple, practical. Pro: Theoretically simple and practical (can use field data). Con: Limited by solution model as well as data quality. From: SPE 15482 — Whitson and Sognesand (1988). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Original Type Curve Approach "Analytical" rate decline curves: Data from van Everdingen and Hurst (1949), replotted as a rate decline plot (Fetkovich, 1973). This looks promising — but this is going to be one really big "type curve." What can we do? Try to col-lapse all of the trends to a single trend during boun-dary-domination flow (Fet-kovich, 1973). From: SPE 04629 — Fetkovich (1973). From: SPE 04629 — Fetkovich (1973). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Fetkovich Type Curves Composite Transient Type Curve: Collapses the transient flow trends into "stems" related to reservoir size and skin factor (Fetkovich, 1973). Composite Total Type Curve: Addition of the "Arps" empirical trends for "boundary-dominated flow behavior (Fetkovich, 1973)." Assumptions: Constant bottomhole pressure. "Liquid" flow (not gas). From: SPE 04629 — Fetkovich (1973). From: SPE 04629 — Fetkovich (1973). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Fetkovich Type Curves (1) Fetkovich "Analytical" Type Curve. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Fetkovich Type Curves (2) Fetkovich "Composite" Type Curve (analytical/empirical). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves Fetkovich Derivative Type Curve: Good concept, but just try to take the derivative of produc-tion data... Fetkovich-McCray Type Curve: Concept is to generate "inte-gral" functions for data analy-sis, much better performance than simply using rate. Still Need: Variable pressure/rate methods. Other models — fractured wells, horizontal wells, etc... From: SPE 28688 — Doublet, et al (1994). From: SPE 25909 — Palacio, et al (1993). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves UNFRACTURED Well Case: Variable Rate/Pressure Approach: Use "material balance time" (x-axis) and "pressure drop nor-malized rate" (y-axis) functions. Good news: New concept provides unique behavior during boundary- dominated flow regime. Not-So-Good-News: Wellbore pressure data are critical. From: SPE 25909 — Palacio, et al (1993). From: SPE 28688 — Doublet, et al (1994). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (1) "Fetkovich-McCray" Type Curve for an Unfractured Well — Production Time Format. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (2) "Fetkovich-McCray" Type Curve for an Unfractured Well — Material Balance Time Format. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves FRACTURED Well Cases Infinite-conductivity vertical fracture case Finite-conductivity vertical fracture case(s). From: SPE 35205 — Doublet, et al (1996). From: Current Work — Pratikno (2002). From: Current Work — Pratikno (2002). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (3) "Fetkovich-McCray" Type Curve for a Fractured Well (Infinite Conductivity) — Material Balance Time Format. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (4) "Fetkovich-McCray" Type Curve for a Fractured Well (FcD=0.5) — Material Balance Time Format. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (5) "Fetkovich-McCray" Type Curve for a Fractured Well (FcD=10) — Material Balance Time Format. PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves Horizontal Well Cases — "Infinite-conductivity" horizontal well case(s). From: SPE 29572 — Shih, et al (1995). From: SPE 29572 — Shih, et al (1995). From: SPE 29572 — Shih, et al (1995). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves Decline Type Curve Analysis: "Break-glass-in-case-of-fire" cases From: SPE 30774 — Doublet, et al (1995). From: Unpublished — Marhaendrajana (2002) (multiwell analysis — do not use). From: SPE 30774 — Doublet, et al (1995). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves (6) "Fetkovich" Type Curve for an Unfractured Well — Water Influx model ("ramp rate" case). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Decline Type Curves Agarwal, et al Methodology: Basically the same as Blasingame, et al work. More like pressure transient test analy-sis/interpretation. From: SPE 57916 — Agarwal, et al (1998). From: SPE 57916 — Agarwal, et al (1998). From: SPE 57916 — Agarwal, et al (1998). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Multiwell Analysis Multiwell case can be "recast" into single well case using cumulative production for entire field. Homogeneous reservoir example shows that all cases (9 wells) align — same behavior observed for heterogeneous reservoir cases. From: SPE 71517 — Marhaendrajana (2001). From: SPE 71517 — Marhaendrajana (2001). From: SPE 71517 — Marhaendrajana (2001). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Reality Check Production data analyses and pressure transient analyses "see" the reservoir as a volume-averaged set of properties. New solutions/models will also have this view of the reservoir, but quantifying heterogeneity may be possible by the analysis of data at the "local" level. Scaling will remain a major issue — regardless of the mechanism used to analyze reservoir performance. From: Simulator Parameter Assignment and the Problem of Scaling in Reservoir Engineering — Halderson (1986). PETE 324 (03A) — Analysis of Production Data

Production Analysis — Future Future of Production Data Analysis: Evolutionary changes: Better data acquisition (major issue). Multiwell analysis (major issue). Better software (major issue). More reservoir/well solutions (minor issue). Revolutionary changes: Direct dataflow into integrated packages for analysis/simulation (5-10 years). Real-time rate-pressure optimization, simul-taneous monitoring and control (5-10 years). PETE 324 (03A) — Analysis of Production Data

Analysis of Production Data End of Presentation Module for: Analysis of Reservoir Performance Analysis of Production Data End of Presentation T.A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX 77843-3116 (979) 845-2292 — t-blasingame@tamu.edu PETE 324 (03A) — Analysis of Production Data