Petroleum Engineering 324 Well Performance Daily Summary Sheet Sring 2009 Blasingame/Ilk Date: Materials Covered in Class Today: Comment(s):
Pressure Transient Analysis Pressure Buildu Test Analysis Lee Text Examle 2.2 Thomas A. Blasingame, Ph.D., P.E. Deartment of Petroleum Engineering Texas A&M University College Station, TX 77843-3116 (USA) +1.979.845.2292 t-blasingame@tamu.edu
Notes:
Pressure Buildu Test Analysis: Lee Ex. 2.2 Given: These attached data were taken from a ressure buildu test erformed on an oil reservoir the reservoir is assumed to be homogeneous. Reservoir roerties: φ0.039 i 4600 sia r w 0.198 ft h69 ft c t 20x10-6 sia -1 A150 acres (square reservoir) Oil roerties: B1.136 RB/STB μ0.80 c Production arameters: q250 STB/D t 13,630 hr
Log-Log Plot: Flow Regime Identification d Δ' Δt ws and for radial flow only, ( Δ' ) rf dδt 1 ln(10) m sl
Log-Log Plot: Flow Regime Identification d Δ' Δt ws and for radial flow only, ( Δ' ) rf dδt 1 ln(10) m sl
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 si/hr) 0.0122 RB/si Permeability, k: k qbμ 1 (250 STB/D) (1.136 RB/STB) (0.8 c) 1 70.6 70.6 h [ Δ ' ] (69 ft) (30 si) rf 7.65 md Δ' rf 30 si (from the lot) m sl ln( 10) x Δ' rf 70 si/cycle
Wellbore Storage: Cartesian Plot ws wf (Δt 0) + mwbs Δt
Wellbore Storage: Cartesian Plot ws wf (Δt 0) + mwbs Δt
Wellbore Storage: Cartesian Plot Wellbore Storage Coefficient, C s : C s qb 24m wbs (250 STB/D) (1.136 RB/STB) 24 (970 si/hr) 0.0122 RB/si Pressure at the instant of shut-in, wf (Δt0): wf ( Δt 0) 702 sia ws ( Δt 0) wf + m wbs Δt
Infinite-Acting Radial Flow (IARF): Semilog Plot
Infinite-Acting Radial Flow (IARF): Semilog Plot
Infinite-Acting Radial Flow (IARF): Semilog Plot Permeability, k: k qbμ (250 STB/D) (1.136 RB/STB) (0.8 c) 162.6 162.6 m h (70 si/cycle) (69 ft) Skin Factor, s: ws,1hr wf s 1.1513 m sl sl ( Δt (1451 sia) (702 sia) s 1.1513 (70 si/cycle) s 6.25 0) k log + 3.2275 2 φμct rw 7.65 (7.65 md) log 6 1 2 (0.039) (0.8 c) (20x10 si ) (0.198 md NOTE: m sl IS FORCED FROM THE LOG-LOG PLOT. + 3.2275 2 ft)
Infinite-Acting Radial Flow (IARF): Horner Plot qbμ t Δt qbμ k ws wf ( Δt 0) 162.6 log + 162.6 log 3.2275 + 0. 8686s kh t + Δt kh φμct r 2 w
Infinite-Acting Radial Flow (IARF): Horner Plot qbμ t Δt qbμ k ws wf ( Δt 0) 162.6 log + 162.6 log 3.2275 + 0. 8686s kh t + Δt kh φμct r 2 w
Infinite-Acting Radial Flow (IARF): Horner Plot Permeability, k: k qbμ (250 STB/D) (1.136 RB/STB) (0.8 c) 162.6 162.6 m h (70 si/cycle) (69 ft) Skin Factor, s: s 1.1513 sl ws,1hr wf msl ( Δt (1451sia) (702 sia) s 1.1513 (70 si/cycle) 0) t k log log + 3.2275 1 2 t + φμc r t w (13630 hr) log (13630 hr) + 1 (7.65 md) log 6 1 2 (0.039)(0.8 c) (20x10 si ) (0.198 s 6.25 + 3.2275 2 ft) 7.65 md NOTE: m sl IS FORCED FROM THE LOG-LOG PLOT.
Average Reservoir Pressure: Cartesian Plot ws a ex[ bδt] and ws 1 b d dδt [ ws ]
Average Reservoir Pressure: Cartesian Plot ws a ex[ bδt] and ws 1 b d dδt [ ws ]
Conventional PTA Plots: Questions to Consider Q1. What are the "conventional" PTA lots? A1. Listing of lots: Log-log (diagnostic) lot (Δ w and Δ w ') (reservoir boundaries, WBS, k) Semilog lot ( w vs. log[t]) (k,s) Early-time Cartesian lot ( w vs. t) (WBS) Late-time Cartesian lot (Δ w vs. dδ w /dt) (average reservoir ressure) Q2. Strengths of "conventional" PTA lots? A2. Samling: Observation of straight-line or constant behavior. Simlified "flow regime" relations that can be used to estimate reservoir and/or well roerties. Q3. Weaknesses of "conventional" PTA lots? A3. Samling: Can observe "artifact" regimes (e.g., linear flow) that are not real. Observe only art of the overall behavior in time, can be limiting in a diagnostic sense.
Person on my left is: Person on my right is: Name: Section: Petroleum Engineering 324 Well Performance Quiz 18 Log-Log Analysis/Interretation for a Pressure Buildu Test [25 March 2009] Given: These data were extracted from an IDEAL ressure buildu test sequence run on a roducing oil well. The Log-log data lot is attached. Reservoir roerties: φ0.30 r w 0.28 ft c t 3.67x10-5 sia -1 h59 ft Oil roerties: B1.625 RB/STB μ 0.39 c Production arameters: t 1000 hours q1000 STB/D Governing Relations: (IARF Infinite-Acting Radial Flow): qbμ 1 k 70.6 h [ Δ' ] IARF qb Cs... (Log-log lot) 24 mwbs Required: You are to estimate the following: Log-log Analysis: (Use the Δ' data on the log-log lot) Wellbore storage coefficient, C s 0.12 RB/sia Formation ermeability, 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)