Petroleum Engineering 324 Well Performance Daily Summary Sheet Spring 2009 Blasingame/Ilk. Date: Materials Covered in Class Today: Comment(s):

Transcription

1 Petroleum Engineering 324 Well Performance Daily Summary Sheet Spring 2009 Blasingame/Ilk Date: Materials Covered in Class Today: Comment(s):

2 Pressure Transient Analysis Pressure Buildup Test Analysis Lee Text Example 2.2 Thomas A. Blasingame, Ph.D., P.E. Department of Petroleum Engineering Texas A&M University College Station, TX (USA)

3 Notes:

4 Pressure Buildup Test Analysis: Lee Ex. 2.2 Given: These attached data were taken from a pressure buildup test performed on an oil reservoir the reservoir is assumed to be homogeneous. Reservoir properties: φ0.039 p i 4600 psia r w ft h69 ft c t 20x10-6 psia -1 A150 acres (square reservoir) Oil properties: B1.136 RB/STB μ0.80 cp Production parameters: q250 STB/D t p 13,630 hr

5 Log-Log Plot: Flow Regime Identification dp Δp' Δt ws and for radial flow only, ( Δp' ) rf dδt 1 ln(10) m sl

6 Log-Log Plot: Flow Regime Identification dp Δp' Δt ws and for radial flow only, ( Δp' ) rf dδt 1 ln(10) m sl

7 Log-Log Plot: Flow Regime Identification Wellbore Storage Coefficient, C s : C s qb 24m wbs (250 STB/D) (1.136 RB/STB) 24 (970 psi/hr) RB/psi Permeability, k: k qbμ 1 (250 STB/D) (1.136 RB/STB) (0.8 cp) h [ Δ ' ] (69 ft) (30 psi) p rf 7.65 md Δp' rf 30 psi (from the plot) m sl ln( 10) x Δp' rf 70 psi/cycle

8 Wellbore Storage: Cartesian Plot pws pwf (Δt 0) + mwbs Δt

9 Wellbore Storage: Cartesian Plot pws pwf (Δt 0) + mwbs Δt

10 Wellbore Storage: Cartesian Plot Wellbore Storage Coefficient, C s : C s qb 24m wbs (250 STB/D) (1.136 RB/STB) 24 (970 psi/hr) RB/psi Pressure at the instant of shut-in, p wf (Δt0): p wf ( Δt 0) 702 psia p ws p ( Δt 0) wf + m wbs Δt

11 Infinite-Acting Radial Flow (IARF): Semilog Plot

12 Infinite-Acting Radial Flow (IARF): Semilog Plot

13 Infinite-Acting Radial Flow (IARF): Semilog Plot Permeability, k: k qbμ (250 STB/D) (1.136 RB/STB) (0.8 cp) m h (70 psi/cycle) (69 ft) Skin Factor, s: pws,1hr pwf s m sl sl ( Δt (1451 psia) (702 psia) s (70 psi/cycle) s ) k log φμct rw 7.65 (7.65 md) log (0.039) (0.8 cp) (20x10 psi ) (0.198 md NOTE: m sl IS FORCED FROM THE LOG-LOG PLOT ft)

14 Infinite-Acting Radial Flow (IARF): Horner Plot qbμ t pδt qbμ k pws pwf ( Δt 0) log log s kh t p + Δt kh φμct r 2 w

15 Infinite-Acting Radial Flow (IARF): Horner Plot qbμ t pδt qbμ k pws pwf ( Δt 0) log log s kh t p + Δt kh φμct r 2 w

16 Infinite-Acting Radial Flow (IARF): Horner Plot Permeability, k: k qbμ (250 STB/D) (1.136 RB/STB) (0.8 cp) m h (70 psi/cycle) (69 ft) Skin Factor, s: s sl pws,1hr pwf msl ( Δt (1451psia) (702 psia) s (70 psi/cycle) 0) t p k log log t p + φμc r t w (13630 hr) log (13630 hr) + 1 (7.65 md) log (0.039)(0.8 cp) (20x10 psi ) (0.198 s ft) 7.65 md NOTE: m sl IS FORCED FROM THE LOG-LOG PLOT.

17 Average Reservoir Pressure: Cartesian Plot p ws p a exp[ bδt] and p ws p 1 b d dδt [ p ws ]

18 Average Reservoir Pressure: Cartesian Plot p ws p a exp[ bδt] and p ws p 1 b d dδt [ p ws ]

19 Conventional PTA Plots: Questions to Consider Q1. What are the "conventional" PTA plots? A1. Listing of plots: Log-log (diagnostic) plot (Δp w and Δp w ') (reservoir boundaries, WBS, k) Semilog plot (p w vs. log[t]) (k,s) Early-time Cartesian plot (p w vs. t) (WBS) Late-time Cartesian plot (Δp w vs. dδp w /dt) (average reservoir pressure) Q2. Strengths of "conventional" PTA plots? A2. Sampling: Observation of straight-line or constant behavior. Simplified "flow regime" relations that can be used to estimate reservoir and/or well properties. Q3. Weaknesses of "conventional" PTA plots? A3. Sampling: Can observe "artifact" regimes (e.g., linear flow) that are not real. Observe only part of the overall behavior in time, can be limiting in a diagnostic sense.

20 Person on my left is: Person on my right is: Name: Section: Petroleum Engineering 324 Well Performance Quiz 17 Log-Log Analysis/Interpretation for a Pressure Buildup Test [23 March 2009] Given: These data were extracted from an IDEAL pressure buildup test sequence run on a producing oil well. The Log-log data plot is attached. Reservoir properties: φ0.30 r w 0.28 ft c t 3.67x10-5 psia -1 h59 ft Oil properties: B1.625 RB/STB μ 0.39 cp Production parameters: t p 1000 hours q1000 STB/D Governing Relations: (IARF Infinite-Acting Radial Flow): qbμ 1 k 70.6 h [ Δp' ] IARF qb Cs... (Log-log plot) 24 mwbs Required: You are to estimate the following: Log-log Analysis: (Use the Δp' data on the log-log plot) Wellbore storage coefficient, C s 0.12 RB/psia Formation permeability, k 4.85 md Aggie Code of Honor: An Aggie does not lie, cheat, or steal or tolerate those who do. Required Academic Integrity Statement: (Texas A&M University Policy on Academic Integrity) "On my honor, as an Aggie, I have neither given nor received unauthorized aid on this academic work." (your signature)

21 One staple here. Name: Section: Date: Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] Assignment Coversheet (This sheet must be included with your work submission) Required Academic Integrity Statement: (Texas A&M University Policy Statement) Academic Integrity Statement All syllabi shall contain a section that states the Aggie Honor Code and refers the student to the Honor Council Rules and Procedures on the web. Aggie Honor Code "An Aggie does not lie, cheat, or steal or tolerate those who do." Upon accepting admission to Texas A&M University, a student immediately assumes a commitment to uphold the Honor Code, to accept responsibility for learning and to follow the philosophy and rules of the Honor System. Students will be required to state their commitment on examinations, research papers, and other academic work. Ignorance of the rules does not exclude any member of the Texas A&M University community from the requirements or the processes of the Honor System. For additional information please visit: On all course work, assignments, and examinations at Texas A&M University, the following Honor Pledge shall be preprinted and signed by the student: "On my honor, as an Aggie, I have neither given nor received unauthorized aid on this academic work." (Page 1 of 6) Aggie Code of Honor: An Aggie does not lie, cheat, or steal or tolerate those who do. Required Academic Integrity Statement: "On my honor, as an Aggie, I have neither given nor received unauthorized aid on this academic work." (Print your name) (Your signature) Coursework Copyright Statement: (Texas A&M University Policy Statement) The handouts used in this course are copyrighted. By "handouts," this means all materials generated for this class, which include but are not limited to syllabi, quizzes, exams, lab problems, in-class materials, review sheets, and additional problem sets. Because these materials are copyrighted, you do not have the right to copy them, unless you are expressly granted permission. As commonly defined, plagiarism consists of passing off as one s own the ideas, words, writings, etc., that belong to another. In accordance with this definition, you are committing plagiarism if you copy the work of another person and turn it in as your own, even if you should have the permission of that person. Plagiarism is one of the worst academic sins, for the plagiarist destroys the trust among colleagues without which research cannot be safely communicated. If you have any questions about plagiarism and/or copying, please consult the latest issue of the Texas A&M University Student Rules, under the section "Scholastic Dishonesty." Zero Tolerance Policy: You MUST submit this assignment in class ONLY.

22 Introduction: Name: Section: Date: Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] This problem consists of a pressure buildup test performed on an oil well. Be sure to perform all analyses and label each event. Given: These attached data were taken from a pressure buildup test performed on an oil reservoir the reservoir is assumed to be homogeneous. Reservoir properties: φ0.30 r w 0.28 ft c t 3.67x10-5 psia -1 h59 ft Oil properties: B1.625 RB/STB μ 0.39 cp Production parameters: q o 1000 STB/D t p 1000 hours Required: Pressure Buildup Analysis you are to estimate the following parameters: Part a Early Time Analysis Preliminary Log-log Analysis: (Use the Δp' data on the log-log plot) Wellbore storage coefficient, C s RB/psia Formation permeability, k md Cartesian Analysis: (Early Time Data) Pressure at the instant of shut-in, p wf (Δt0) psia Wellbore storage coefficient, C s RB/psia Part b Middle Time Analysis (Permeability and Skin Factor) Semilog (Δt) Analysis: (IARF Infinite-Acting Radial Flow) Formation permeability, k md Skin factor, s dimensionless Semilog (Horner) Analysis: (IARF Infinite-Acting Radial Flow) Formation permeability, k md Skin factor, s dimensionless (Page 2 of 6) Zero Tolerance Policy: You MUST submit this assignment in class ONLY.

23 Name: Section: Date: Part a Early Time Analysis Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] Preliminary Log-log Analysis: (Use the Δp' data on the log-log plot) Wellbore storage coefficient, C s RB/psia Formation permeability, k md (You MUST show all work and clearly identify/label ALL features) (Page 3 of 6) Work Space: Zero Tolerance Policy: You MUST submit this assignment in class ONLY.

24 Name: Section: Date: Part a Early Time Analysis Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] Cartesian Analysis: (Early Time Data) Pressure at the instant of shut-in, p wf (Δt0) psia Wellbore storage coefficient, C s psia (You MUST show all work and clearly identify/label ALL features) (Page 4 of 6) Work Space: Zero Tolerance Policy: You MUST submit this assignment in class ONLY.

25 Name: Section: Date: Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] Part b Middle Time Analysis (Permeability and Skin Factor) Semilog (Δt) Analysis: (IARF Infinite-Acting Radial Flow) Formation permeability, k md Skin factor, s dimensionless (You MUST show all work and clearly identify/label ALL features) (Page 5 of 6) Work Space: Zero Tolerance Policy: You MUST submit this assignment in class ONLY.

26 Name: Section: Date: Petroleum Engineering 324 Well Performance Exercise Problem 11 Analysis/Interpretation for a Pressure Buildup Test Assigned: 23 March 2009 Due: 25 March 2009 [to be submitted in class] Part b Middle Time Analysis (Permeability and Skin Factor) Semilog (Horner) Analysis: (IARF Infinite-Acting Radial Flow) Formation permeability, k md Skin factor, s dimensionless (You MUST show all work and clearly identify/label ALL features) (Page 6 of 6) Work Space: Zero Tolerance Policy: You MUST submit this assignment in class ONLY.