Production Data Analysis in Tight Gas Sands

Transcription

1 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 1/79

2 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands Before We Start Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 2/79

3 Before We Start: Prod. Analysis in Tight Gas Sands Model-Based Production Analysis: Use of an analytical or numerical model in the analysis. Use all components: Model, MB, History Match, Arps. Empirical Production Analysis: Arps or other "approximate" rate equations. Need better "diagnostics" for application. Gotchas: Can not estimate reserves without pss flow behavior. Be (very) careful with application of Arps equations Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 3/79

4 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands Orientation Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 4/79

5 Orientation: Tight Gas/Shale Gas (TG/SG) Systems Facts for TG/SG Resources: (North America) Reserves are in the 1000's of TCFs. Development is the fastest growing segment. Have production potential for BCFs/D. Fiction for TG/SG Resources: Can be developed on the cheap. Well completions/well stimulations will save the day. Reservoir Engineering (and Geology) does not matter Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 5/79

6 Orientation: TG/SG Geology/Petrophysics Geology/Petrophysics: Issues Reservoirs are below water zone(s). Reservoirs are typically over-pressured. Reservoirs have extreme vertical heterogeneity (layers). Reservoirs have significant lateral heterogeneity. Reservoir quality is controlled by deposition Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 6/79

7 Orientation: TG/SG Reservoir Engineering Reservoir Engineering: Issues Typically over-pressure/over-temperature (HP/HT). Water saturation can be very high (30-70 percent). Pressure transient testing is a waste of time. Production data analysis is too "simple." We tend to assume wells do not interfere. Multilayer effects can dominate performance Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 7/79

8 Orientation: Data Integration SPE and An Integrated Work-Flow Model to Characterize Unconventional Gas Resources: Part I Geological Assessment and Petrophysical Evaluation An Integrated Work-Flow Model to Characterize Unconventional Gas Resources: Part II Formation Evaluation and Reservoir Modeling K.E. Newsham, SPE, Anadarko Petroleum Corp. and J.A. Rushing, SPE, Anadarko Petroleum Corp. Q. Is there a comprehensive data integration model? A. The Petrophysical Integration Process Model (PIPM) papers SPE and are a good start Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Strengths of this approach: All pertinent data are used. The integration process confirms/disputes data correlations. Weaknesses of this approach: Data. Data. Data. Expertise/experience. Slide 8/79

9 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands History Evaluation of Reservoir Performance for Tight Gas Sands Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 9/79

10 Pressure Transient Analysis: Fractured Wells Q. Is a finite-conductivity vertical fracture model relevant? A. Yes (of course). SPE 6014 Transient Pressure Behavior for a Wen With a Finite-Conductivity Vertical Fracture H. Cinco-Ley, Instituto Mexicano del Petroleo F. Samaniego-V., Instituto Mexicano del Petroleo N. Dominguez, Instituto Mexicano del Petroleo Finite-Conductivity Fracture (SPE 6014) Most popular model for PTA. Virtually all fractured well analyses Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 10/79

11 Pressure Transient Analysis: Fractured Wells Q. Is a choked or damaged fracture the same as a finite-conductivity vertical fracture? A. No not even in a "practical sense." Fracture damage is difficult to assess and a "fracture face skin" model should be used to represent damage. SPE Transient Pressure Analysis: Finite Conductivity Fracture Case Versus Damaged Fracture Case Heber Cinco-Ley, PEMEX and UNAM Fernando Samaniego-V., PEMEX and UNAM 2007 Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 11/79

12 Pressure Transient Analysis: Fractured Wells Q. How do we characterize, model, validate the multiple fracture concept? A. Very complex models have been developed for multiple, arbitrary-oriented vertical fractures. SPE Constant-Rate Drawdown Solutions Derived for Multiple Arbitrarily-Oriented Uniform-Flux, Infinite-Conductivity, or Finite-Conductivity Fractures in an Infinite-Slab Reservoir D.P. Craig, Halliburton and T.A. Blasingame, Texas A&M U Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Tri-Fracture Solution (SPE ) Restimulation case. Pressure transient test is matched by tri-fracture solution. Must re-think well stimulation/ evaluation practices. Slide 12/79

13 Pressure Transient Analysis: New Diagnostics Q. Better flow regime identification for pressure transient data? A. -Derivative Function (power law formulation). SPE The Pressure Derivative Revisited Improved Formulations and Applications N. Hosseinpour-Zonoozi, D. Ilk, and T.A. Blasingame, SPE, Texas A&M University -derivative general schematic plot (No WBS). -derivative fractured well (inf-cond) (No WBS). -derivative Infinite-acting radial flow, with WBS. -derivative horizontal well (inf-cond) (No WBS). -derivative radial flow, dual-porosity (no WBS) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) -derivative Match for Well 12 (SPE 9975). Slide 13/79

14 Production Analysis: Fractured Wells Q. Do fracture flow regimes really matter? A. Depends on your perspective transient flow helps to quantify reservoir/fracture properties, BUT fracture extension determines reserves in low permeability reservoirs. SPE/DOE 9839 Use of Constant Pressure, Finite Capacity Type Curves for Performance Prediction of Fractured Wells in Low-Permeability Reservoirs J.K. Thompson, ARCO Oil and Gas Company 2007 Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 14/79

15 Production Analysis: Fractured Wells Q. Fracture orientation, elliptical flow geometry, and reservoir properties inter-relations, significance, practical issues? A. Virtually all fractured wells in very low permeability reservoirs are presumed to have an elliptical drainage area for contacted fluids in-place. SPE/DOE 9851 Fracture Optimization in a Tight Gas Play: Muddy "J" Formation, Wattenbarg Field, Colorado C.N. Roberts, Amoco Production Co Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 15/79

16 Production Analysis: Fractured Wells Q. Elliptical flow for analysis of production data? A. Probably the "best" answer particularly for "transition flow from transient to boundarydominated flow. SPE Evaluation of the Elliptical Flow Period for Hydraulically-Fractured Wells in Tight Gas Sands Theoretical Aspects and Practical Considerations S. Amini, D. Ilk, and T. A. Blasingame, SPE, Texas A&M University 2007 Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 16/79

17 Production Analysis: Diagnostics Q. Better flow regime identification for production data analysis? A. -Derivative Function (power law formulation). SPE Application of the -Integral Derivative Function to Production Analysis D. Ilk, N. Hosseinpour-Zonoozi, S. Amini, and T.A. Blasingame, SPE, Texas A&M University dp D /dln(t D ) vs. t D [Semilog] dln(p D )/dln(t D ) vs. t D [ -deriv.] p D -functions (Radial Flow). q D -functions (Radial Flow). dq D /dln(t D ) vs. t D [Semilog] dln(d D )/dln(t D ) vs. t D [ -deriv.] q D -functions (Elliptical Flow F E =1000) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) q D -functions (Elliptical Flow F E =1). Slide 17/79

18 Production Analysis: Pitfalls Q. What are the pitfalls in production data analysis? A. What is not a pitfall? Poor data, poor records, etc. SPE Production Data Analysis Challenges, Pitfalls, Diagnostics D. M. Anderson, G.W.J. Stotts, L. Mattar, Fekete Associates Inc., D. Ilk, and T. A. Blasingame, Texas A&M U. log(q g ) and p wf vs. t good synchronization of data. p wf vs. q g "crude" correlation plot. Rate functions vs. G p /q g diagnostic plot. Deconvolved pressures vs. t (ultimate test of data) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 18/79

19 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands Recent Work by Blasingame et al. Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 19/79

20 Excerpts from: SPE Evaluation of the Elliptical Flow Period for Hydraulically-Fractured Wells in Tight Gas Sands Theoretical Aspects and Practical Considerations S. Amini, D. Ilk, and T.A. Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (979) SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 20/79

21 Executive Summary: Elliptical Flow System Description: This work provides a new set of decline type-curves for a fractured well in an elliptical flow system: Finite-conductivity hydraulic fracture of half-length, x f. Closed elliptical-shaped boundary. Canonical distance is equal to the fracture length. Schematic of the elliptical reservoir model SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 21/79

22 Executive Summary: Elliptical Flow System Deliverables: Series of decline type-curves for a well with finite conductivity vertical fracture centered in a bounded, elliptical reservoir. Field case applications of the new set of type curves on the analysis of production data from tight gas reservoirs. E. Tx tight gas (0.006 md) N. Tx very tight gas ( md) N. Tx tight gas (0.003 md) Mexico very tight gas (0.001 md) Very powerful diagnostic tool for evaluating fractured wells in low to ultra-low permeability gas reservoirs SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 22/79

23 Development of the Solution: Type Curves Type curve for a fractured well centered in a closed (homogeneous) elliptical reservoir F E =1, various ξ 0 -values; q D functions versus t DA format. Type curve for a fractured well centered in a closed (homogeneous) elliptical reservoir F E =10, various ξ 0 -values; q D functions versus t DA format. Discussion: The equivalent constant rate format type curves for this work are shown in q D versus t DA format (this simplified the transient regime). Various elliptical fracture conductivities: F E = 1,10,100, and SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 23/79

24 Development of the Solution: Type Curves Type curve for a fractured well centered in a closed (homogeneous) elliptical reservoir F E =100, various ξ 0 -values; q D functions versus t DA format. Type curve for a fractured well centered in a closed (homogeneous) elliptical reservoir F E =1000, various ξ 0 -values; q D functions versus t DA format. Discussion: Objective: To demonstrate the elliptical boundary model as a diagnostic to establish the elliptical flow regime using production data. We utilize type curve solutions in terms of the equivalent constant rate case presented in "decline" form (q D and t DA ) SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 24/79

25 Validation and Application: East TX Tight Gas Discussion: Daily rate and pressure data show good correlation. "Better-than-average" data acquisition practices yield high-quality production data for the analysis/interpretation for this case (SPE 84287) SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 25/79

26 Validation and Application: East TX Tight Gas Discussion: Diagnostic plot confirms the very good correlation of data for this case. Strong indication of fractured well regimes tending to boundary flow SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 26/79

27 Validation and Application: East TX Tight Gas Discussion: Excellent data match confirms the validity of the "elliptical" model. Model parameters: F E = 1, ξ 0 = "Average" analysis results: k md, x f 300 ft, G p 1.6 BSCF SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 27/79

28 Validation and Application: Mexico Very Tight Gas Discussion: Good data acquisition (monthly data > 40 years) rate data is consistent, and constant p tf p wf is reasonable considering production/location. The reservoir permeability < md (all analyses). This is the only well in the field (no possibility of well interference) SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 28/79

29 Validation and Application: Mexico Very Tight Gas Discussion: Diagnostic plot indicates extraordinary character in data (1/2 slope trend high fracture conductivity), very good diagnostic trends. Very low permeability estimate is expected SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 29/79

30 Validation and Application: Mexico Very Tight Gas Discussion: Outstanding data match confirmation of the elliptical boundary model. Model parameters: F E = 100, ξ 0 = "Average" analysis results: k md, x f 825 ft, G p 23.0 BSCF SPE Hydraulic 2007 Fracturing Anadarko Technology Tight Gas Conference Workshop College Station, Texas January 2007 SPE Evaluation 05 of December the Elliptical 2007 Flow The Period Woodlands, for Hydraulically-Fractured TX Wells in Tight Gas Sands Production Data Theoretical Analysis in Aspects Tight Gas and Sands Practical Considerations (Amini/Ilk//Blasingame) T.A. Blasingame Texas A&M U. (05 December T. Blasingame 2007) Texas A&M U. (29 January 2007) Slide 30/79

31 Excerpts from: SPE Application of the -Integral Derivative Function to Production Analysis D. Ilk, N. Hosseinpour-Zonoozi, S. Amini, and T.A. Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (979) Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 31/79

32 Rationale For This Work The primary purpose of this work is to introduce and demonstrate the application of the -integral-derivative function for production analysis (PA). Our mechanism to promote this work is to provide an inventory of "type-curve" solutions for various bounded reservoir models to increase the resolution for the diagnostics of production data. The -derivative function for PA is defined in terms of the rate and pressure integral and integral-derivative functions for smoothness and clarity Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 32/79

33 Orientation: Pressure/Rate Integral Functions Dimensionless pressure/rate integral decline functions: p q Ddi Ddi 1 t ( tdd) tdd 0 1 t ( tdd ) tdd 0 Dd Dd q p Dd Dd ( ) d ( ) d Dimensionless pressure/rate integral derivative decline functions (analog to well testing derivative function): p q Ddid Ddid d ( tdd) tdd pddi ( tdd) dt Dd d ( tdd ) tdd qddi ( tdd dt Dd ) 2007 Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 33/79

34 Orientation: -Integral-Derivative (Derivation) d dtdd qddi ( tdd ) 1 tdd 1 q ( ) 2 Dd d ( tdd ) 0 tdd 1 tdd [ qddi( tdd )] qdd ( tdd ) qddi ( tdd ) d ln[ qddi( tdd )] d ln[ tdd ] 1 tdd qddi( tdd ) Derivative of data w.r.t. time d dtdd qddi( tdd ) qdd ( tdd ) "Well testing derivative" Steps: 1. Derivative of rate integral function with respect to time function. 2. Use the power-law formulation for the derivative. 3. Obtain the -derivative using rate and rate integral functions. 4. Or obtain the - derivative using rate integral and rate integral derivative (well test analog) functions. -integral derivative representation [ qddi( tdd )] 1 qdd ( tdd ) qddi( tdd ) or [ qddi( tdd )] qddid ( tdd ) qddi( tdd ) 2007 Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 34/79

35 Orientation: "Type Curve" Representations Dimensionless Rate Integral Derivative Function, q Ddid "Power Law " Dimensionless Rate Integral Derivative Function, [q Ddi ] ( ) ( ) Transient Flow Region 1 Schematic of Dimensionless Rate Integral Derivative Functions Various Reservoir Models and Well Configurations (as noted) DIAGNOSTIC plot for Production Data (q Ddid and [q Ddi ] ) Fractured Well in a Bounded Circular Reservoir (Finite Conductivity Vertical Fracture) 2 [q Ddi ] = 0.5 (linear flow) ( ) ( ) ( ) ( ) Legend: (q Ddid ) ( [q Ddi ] ) Unfractured Well (Radial Flow) Fractured Well (Finite Fracture Conductivity) Fractured Well (Elliptical Reservoir) Unfractured Well in a Bounded Circular Reservoir Fractured Well in a Bounded Elliptical Reservoir (Finite Conductivity Vertical Fracture) Dimensionless Material Balance Decline Time, t Dd,bar =N pdd /q Dd NO Wellbore Storage or Skin Effects [q Ddi ] ~ 1.0 (boundary dominated flow) Boundary- Dominated Flow Region Rate -Integral-Derivative "Diagnostic Plot": Unfractured and fractured well configurations note the distinction of "transition" flow regimes that the [q Ddi (t Dd )] function provides. Analog of decline type curve analysis. 1 1 Plotting Functions: [(q Ddi (t Dd )] versus N p /q o : (Rate -Integral-Derivative) [(q Ddi (t Dd )] = (?) IARF k+s (1/4) Fin. Con. F cd (1/2) Inf. Con. x f (?) Horizontal? (1) BDF N The primary utility of the -integral-derivative is the resolution that this function provides for cases where the pressure drop/rate can be represented by a power-law function Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 35/79

36 Field Examples: East Tx Gas Well (SPE 84287) SPE "History Plot": Daily production rate and pressure data used for production and well test analysis. Excellent quality data. Note the effect of shut-ins and daily fluctuations Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 36/79

37 Field Examples: East Tx Gas Well (SPE 84287) Discussion (Diagnostic Plot): Excellent performance of [q Dd (t Dd )] data function (fractured well model). Very-low k, very long transition to boundary-dominated flow. "Average" analysis results: k md, x f 290 ft, G p BSCF Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 37/79

38 Field Examples: East Tx Gas Well (SPE 84287) Discussion (Analysis by Modeling): Very good overall history match of the generated responses and raw data. Analysis results are very close to original results [Pratikno, et al 2003] Anadarko Tight Gas Workshop (16 April 2007) 05 December 2007 The Woodlands, Rocky TX Mountain Oil & Gas Technology Symposium Production Data Application Analysis in Tight of thegas -Integral SandsDerivative Function to Production Analysis T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Hosseinpour-Zoonozi/Amini/Blasingame Slide 38/79

39 Excerpts from: CIPC Production Data Analysis Future Practices for Analysis and Interpretation D. Ilk, Texas A&M U. L. Mattar, Fekete Associates, Inc. and T.A. Blasingame,* Texas A&M U. *Department of Petroleum Engineering Texas A&M University College Station, TX Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 39/79

40 Meet the Family (CIPC ) ILK, Dilhan MATTAR, Louis BLASINGAME, Tom (aka: "The Kid") (aka: "The Wizard") (aka: "El Guerrero") "The straight line leads to the downfall of humanity." F. Hundertwasser "Happiness... it lies in the joy of achievement, in the thrill of creative effort." Vincent van Gogh "Only the wisest and stupidest of men never change." Confucius 2007 Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 40/79

41 Rationale For This Work Current methods are SUFFICIENT for: Diagnostics (identification of reservoir model) Analysis (variety of models, well conditions, etc.) Modeling (very good to outstanding options) Tools we will need shortly (or even NOW). Data handling (very large data sets, poor data) Better diagnostics (more information from data) Analysis (self-checking/correlation of q and p wf ) Modeling (merger of analytical/numerical models) "Tell us what you want, and we will paint it the way we see it" Anonymous 2007 Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 41/79

42 Modern PA: Generic PA Analysis Procedure Procedure: Step 1: Data Review Review "Production History Plot" for data quality/correlation. Step 2: Data Review Data correlation check (p wf (or p tf ) vs. rate plot). Crude comparison, only for general trends. Step 3: Clean/Edit Data for Clarity Remove spurious data from log-log data plots used for diagnosis. Step 4: Identify Flow Regimes (Diagnostics) Identify characteristic flow regimes using normalized PI/Blasingame plots. Step 5: Compare Data to Reservoir Model Use "Type Curves" to compare/match the data with a reservoir model. Step 6: Refine Model Parameters Improve match of model parameters (k, s, x f, F cd,...) using individual type curves, simulation models, and/or regression methods. Step 7: Summary History Match Final "history match" of model and raw well performance data (p wf and q) Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 42/79

43 Field Examples: Mid-Continent Gas Well Step 1 Step 2 Step 3 Diagnostic Data Analysis Plots: Good quality data, unusual in that the production is limited (Step 1). p wf and q g data appear to be only correlated at early times (Step 2). The (q g / p p ) trend is corrupted due to the cyclical series of production/ shut-in sequences (these data must be edited for diagnostic purposes) (Step 3) Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 43/79

44 Field Examples: Mid-Continent (US) Gas Well Step 4a Step 5a Log-Log Analysis: (fractured well) Two possible scenarios for the reservoir model (radial flow or damaged fractured well) (Step 4a). Type curve match using high conductivity elliptical flow solution (poor early time match) (Step 5a). -integral-derivative does not match at early times, depletion flow is confirmed (Step 6a). Step 6a 2007 Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 44/79

45 Field Examples: Mid-Continent (US) Gas Well Step 4b Step 5b Log-Log Analysis: (unfractured well) Two possible scenarios for the reservoir model (radial flow or damaged fractured well) (Step 4b). Very good match with the unfractured well model (well behaves as if it were not stimulated) (Step 5b). -integral-derivative confirms that formation damage/poor stimulation is likely (Step 6b). Step 6b 2007 Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 45/79

46 Field Examples: Mid-Continent (US) Gas Well Step 7b Summary History Match: (unfractured well) An extraordinary "history match" of the rate and pressure is obtained using the unfractured well in bounded circular reservoir (Step 7). Rate and pressure measurements are considered precise Anadarko Tight Gas Workshop (12 June 2007) 05 December 2007 The Woodlands, TX Canadian International Petroleum Conference Production Data Production Analysis Data in Tight Analysis Gas Sands Future Practices for Analysis and Interpretation T.A. Blasingame Texas A&M U. (05 December 2007) Ilk/Mattar/Blasingame Slide 46/79

47 Excerpts from: SPE Evaluating the Impact of Waterfrac Technologies on Gas Recovery Efficiency: Case Studies Using Elliptical Flow Production Data Analysis D. Ilk,* Texas A&M U. J.A. Rushing, Anadarko Petroleum Corp. R.B. Sullivan, Anadarko Petroleum Corp. and T.A. Blasingame, Texas A&M U. *Department of Petroleum Engineering Texas A&M University College Station, TX SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 47/79

48 Rationale For This Work The primary objectives of this study are: To assess the stimulation effectiveness, and To compare recovery efficiencies of the various "waterfrac" technologies used in the Bossier tight gas sand play (East Texas Basin, US). Utilized a set of decline type curves developed for the analysis of production data acquired from the elliptical flow period commonly observed in hydraulically-fractured wells completed in tight gas sands. [SPE (2007)] SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 48/79

49 Rationale For This Work To find the proper balance between: Well spacing, Selection of stimulation treatment, and Gas recovery efficiency. We have evaluated the production performance for 12 wells where different types of stimulations were used. Our overall goal is to improve the correlation between the well spacing and the creation of optimal hydraulic fractures (fracture length and conductivity). SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 49/79

50 Case Studies: Small Waterfrac 20/40 Proppant Production history plot (daily flowrate and pressure measurements). Diagnostic log-log plot (dimensionless rate decline and rate decline integral functions). Discussion: Diagnosis of the Well Performance Data A consistent character in the rate and pressure functions is observed q g and p wf data correlation appears to be good to very good. q g / p p diagnostic functions appear to be relevant earliest third of data appear off-trend (weak q g and p wf correlation at early time?). Treatment 7745 bbls of slick water; 63,000 lbs 20/40 proppant. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 50/79

51 Case Studies: Small Waterfrac 20/40 Proppant Elliptical boundary decline type curve match (moderate conductivity, near-circular drainage geometry). Production history plot with model match (excellent flowrate match, good pressure match). Discussion: Analysis Results Discrepancy at early times is observed probably an early-time artifact (shape of integral-derivative), possibly some modest fracture damage. Excellent match of the model and the rate history, good match of the pressure history "balance" of analysis between the diagnostic functions and the production history. k= md, x f =129 ft, F E =10, o =2.0 (near-circular), G=1.28 BSCF. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 51/79

52 Case Studies: Large Waterfrac 40/70 Proppant Production history plot (daily flowrate and pressure measurements). Diagnostic log-log plot (dimensionless rate decline and rate decline integral functions). Discussion: Diagnosis of the Well Performance Data Very good rate and pressure correlation (perhaps excellent!), with little (apparent) mismatch is observed (all major features observed in the flowrates are observed in the pressures, and vice-versa). Very strong data trends transient signature suggests (very) low fracture conductivity (1/4 slope). Boundary-dominated flow is evident. Treatment 12,545 bbls of slick water; 254,600 lbs 40/70 proppant. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 52/79

53 Case Studies: Large Waterfrac 40/70 Proppant Elliptical boundary decline type curve match (very high conductivity, "fat" elliptical drainage geometry). Production history plot with model match (very good flowrate match, acceptable/poor pressure match). Discussion: Analysis Results Excellent match of the q g / p p functions with a vertical fracture of (very) low conductivity in an elliptically bounded reservoir system. (Very) poor pressure match at early times, under prediction of the flowrate during this time can attempt an improved match by a slight increase in fracture conductivity. Fair match of p wf data and model. k= md, x f =212 ft, F E =1, o =1.50 ("fat" ellipse), G=2.97 BSCF. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 53/79

54 Case Studies: Hybrid Waterfracs Production history plot (daily flowrate and pressure measurements). Diagnostic log-log plot (dimensionless rate decline and rate decline integral functions). Discussion: Diagnosis of the Well Performance Data Erratic nature of the flowrate profile is seen (liquid loading). Major features of the liquid loading observed for the flowrate data are reasonably well-correlated with the calculated bottomhole pressures. Very clear diagnostic trends are obtained after judicious editing of the q g / p p function (1/2 slope during transient flow, 1/1 slope for BDF). Treatment 2082 bbls of slick water bbls of cross-link gel; 510,140 lbs 20/40 proppant. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 54/79

55 Case Studies: Hybrid Waterfracs Elliptical boundary decline type curve match (very high conductivity, "thin" elliptical drainage geometry). Production history plot with model match (very good flowrate match, acceptable pressure match). Discussion: Analysis Results Extraordinary "type curve match" is observed for this case the well is effectively stimulated and a low reservoir permeability is expected. Model flowrate response corresponds well with the observed flowrate data. The pressure match is not as poor as it might seem given the very erratic nature of the flowrate function. k= md, x f =200 ft, F E =1000, o =1.00 ("thin" ellipse), G=1.60 BSCF. SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 55/79

56 Case Studies: Discussion of Results Results correlation plot G versus k. Results correlation plot G versus x f. Discussion: Effect of the Contacted Gas-In-Place Expectation higher reservoir permeabilities, higher contacted gasin-place estimates. Most small waterfrac cases are off-trend (a single on-trend point with high permeability and high contacted gas-in-place estimate is noted). Excellent correlation of contacted gas-in-place with fracture halflength confirming that "the fracture defines the reserves." SPE Annual 2007 Anadarko Technical Tight Conference Gas Workshop and Exhibition Anaheim, CA November 2007 SPE Evaluating 05 December the Impact 2007 of Waterfrac The Woodlands, Technologies TX on Gas Recovery Efficiency: Case Studies Production Using Data Elliptical Analysis Flow in Production Tight Gas Sands Data Analysis (Ilk/Rushing/Sullivan/Blasingame) T.A. Blasingame Texas A&M U. (05 December 2007) D. Ilk Texas A&M U. (12 November 2007) Slide 56/79

57 Society of Petroleum Engineers Applied Technology Workshop Analysis of Reservoir Performance Future View February 2007 Pier House Resort Key West, Florida (USA) Excerpts from: Production Analysis What Will it Take to Become Common Practice? Thomas A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 57/79

58 Society of Petroleum Engineers Applied Technology Workshop Analysis of Reservoir Performance Future View February 2007 Pier House Resort Key West, Florida (USA) Engineering Assessment of Reserves Theoretical/Empirical Methods Thomas A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 58/79

59 Reserves Estimation: Arps Rate-Time Relations Q. What are the "Arps" rate-time/cumulative-time relations? A. Sequence of relations for production extrapolation (with time). SPE East TX Gas Well 1 (Low Permeability Gas) (oil: p>p b ) (gas: ) 1.E+05 1.E+04 1.E+03 1.E Gas Production Rate, MSCFD Gas Flowrate Exponential Rate Model Hyperbolic Rate Model Wellbore Pressure Flowing Tubing Pressure, psig Producing Time, days SPE East TX Gas Well 1 (Low Permeability Gas) Gas Production Rate, MSCFD Cumulative Gas Production Exponential Model Hyperbolic Model 0 100, , , , , , , , ,000 1,000,000 1,100,000 1,200,000 1,300,000 Cumulative Gas Production, MSCF 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 59/79

60 Reserves Estimation: Fetkovich-Carter TC Q. What is the "Carter" Decline Type Curve, and how is it used? A. A numerically-generated gas rate solution (p wf =con) used as a "type curve" (data overlay) to estimate reservoir properties. From: Fetkovich, M.J.: "Decline Curve Analysis Using Type Curves," JPT (June 1980) From: Carter, R.D.: "Type Curves for Finite Radial and linear Gas Flow Systems: Constant Terminal Pressure Case," SPEJ (October 1985) Variables for the Carter Decline Type Curve kt 1 tdd gictir 2 2 w 1 re re 1 1 ln 2 rw rwa 2 q( t) q s Dd rwa rwe kh ( pi pwf ) r. e gibgi ln rwa 2 Transient Stems: (left) Numerical flow model (p wf = con). q(t) is concave up. Depletion Stems: (right) q(t) is concave down. b=0: p wf = con. b=1: q o = con. (q o / p). b>1: transient flow or external drive energy. : numerical gas flow cases ( =f(p wf /(p i )). Reservoir Properties: k y-axis match. G x&y-axis matches. s r ed match Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 60/79

61 Reserves Estimation: Rate-Cumulative Relations Q. What are the rate-cumulative relations? A. Relations for reserves extrapolation Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 61/79

62 Reserves Estimation: "Hyperbolic Plot" Discussion: Hyperbolic Plots Concept? Application? (verify the "hyperbolic" nature of the production data) (interactive plots used in conjunction with other methods) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 62/79

63 Reserves Estimation: q(t)=q i 1/[(1+D i t)^(1/b)] Q. Can the "hyperbolic" rate-time relation be derived? A. Sort of Loss Ratio: (empirical Arps (1942)) After Integration: b d dt a d dt 1 D d dt q dq/ dt 2: Camacho and Raghavan: (p<p b ) (SPE 19009) q q (1 bd t) i i (1 / b) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 63/79

64 Society of Petroleum Engineers Applied Technology Workshop Analysis of Reservoir Performance Future View February 2007 Pier House Resort Key West, Florida (USA) Modern Production Data Analysis A Complete Example Thomas A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX t-blasingame@tamu.edu 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 64/79

65 PA Example: log(q g ) and p wf vs. Time 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 65/79

66 PA Example: log(q g ) vs. Time (with rate extrapolations) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 66/79

67 PA Example: q g vs. G p (with rate extrapolations) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 67/79

68 PA Example: Arps Hyperbolic Type Curves 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 68/79

69 PA Example: p wf vs. q g Crossplot (quality check) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 69/79

70 PA Example: Normalized Log-Log Plot (model match) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 70/79

71 PA Example: "Blasingame" Log-Log Plot (model match) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 71/79

72 PA Example: PTA (match/comparison) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 72/79

73 PA Example: Summary Plot 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 73/79

74 Society of Petroleum Engineers Applied Technology Workshop Analysis of Reservoir Performance Future View February 2007 Pier House Resort Key West, Florida (USA) Production Data Analysis What remains Thomas A. Blasingame, Texas A&M U. Department of Petroleum Engineering Texas A&M University College Station, TX Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 74/79

75 What Remains: Future Work in PTA/PA "Technology... is a queer thing. It brings you great gifts in one hand, and it stabs you in the back with the other." C.P. Snow ( ) Discussion: Future Work in PTA/PA Additional reservoir/well models. (elliptical flow, moving boundary,...) Full incorporation of PVT character. (volatile oil, gas condensate,...) Reservoir scaling for PTA/PA. (scaling of petrophysical data?) Handling poor quality rate/pressure data. (major issue present/future) Continuously measured p wf and q data. (high frequency rates?) Multiple well analysis (integration). (analytical (mat. bal.) or numerical) Coupling of analysis/interpretation (3D/3P models). (over-determined?) Evaluation of multilayer systems. (I thought we already did this?) PA is the tool for tight gas, but must have data. (management?) 2007 Anadarko Tight Gas Workshop Analysis of Reservoir Performance Future View 05 December 2007 Society The Woodlands, of Petroleum TX Engineers Applied Technology Workshop Production Data Production Analysis in Analysis Tight Gas Sands What Will it Take to Become Common Practice? T.A. Blasingame Texas A&M U. (05 December T.A. Blasingame 2007) Texas A&M U. (09 February 2007) Slide 75/79

76 2007 Anadarko Tight Gas Workshop Reservoir Description/Characterization 04 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands Take Away Tom Blasingame Department of Petroleum Engineering Texas A&M University College Station, TX (USA) Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 76/79

77 Take Away: Production Analysis Guidelines Guidelines: Performance-Based Reservoir Characterizations REVIEW production data for consistency (allocations, accuracy, etc.). REVIEW well history, particularly recompletions/stimulations. PERFORM simplified analysis of production data (Arps, EUR, etc.). REVIEW measured rate/pressures (quality check). PERFORM model-based analysis of production (and well test) data Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 77/79

78 Take Away: Production Analysis in Tight Gas Sands Model-Based Production Analysis: Contacted gas-in-place increases with time. Helps to tie reservoir properties with performance. Empirical Production Analysis: Reserves extrapolations wrong (except at late times). Suitable for a 1-2 year projection (not much more). Gotchas: Data quantity and quality (frequency and accuracy). Failure to reference analysis to a reservoir model Anadarko Tight Gas Workshop 05 December 2007 The Woodlands, TX Production Data Analysis in Tight Gas Sands T.A. Blasingame Texas A&M U. (05 December 2007) Slide 78/79