Lecture 7 Deliverability Testing of Gas Wells

Transcription

1 Petroleum Engineering 613 Natural Gas Engineering Deliverability Testing of Gas Wells Lecture 7 Deliverability Testing of Gas Wells At the end of this module, you will: Be able to describe the absolute open-flow (AOF) potential. Be able to describe the gas backpressure curve. Be able to describe how to conduct a "flow-after-flow" test. Be able to describe a "single point" test. Be able to describe the isochronal and modified isochronal test approaches. Be able to describe the Houpeurt theoretical gas-flow equations. Be able to describe the Rawlins and Schellhardt empirical gas flow equations. Be familiar with Houpeurt's comments regarding Eqs and Be familiar with "stabilization time" as it relates to deliverability testing. Be able to sketch a schematic plot (rate & pressure) for a "flow-after-flow" test. Be familiar with the major limitations of a "single point" test. Be able to sketch a schematic plot (rate & pressure) for an "isochronal" test. Be able to sketch a schematic plot (rate & pressure) for a "modified isochronal" test. From: Lee, W.J. and Wattenbarger, R.A.: Gas Reservoir Engineering, SPE (1996). Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 1

2 Petroleum Engineering 613 Natural Gas Engineering Rawlins and Schellhardt Relation (1936) Lecture 7 Deliverability Testing of Gas Wells q sc 2 C( p 2 p ) wf q sc = Flowrate at standard conditions, MSCFD (14.65 psia, 60 F) (ERCB prefers MMSCFD) p = Average reservoir pressure obtained by shutin of the well to complete stabilization, psia p wf = Flowing sandface pressure, psia C = A coefficient which describes the position of the stabilized deliverability line. n = An exponent which describes the inverse of the slope of the stabilized deliverability line. n Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 2

3 Deliverability Test Plot Simplified Flow Analysis Tom BLASINGAME Texas A&M U. Slide 3

4 Petroleum Engineering 613 Natural Gas Engineering Forchheimer (Houpeurt) (1959) ( wf bq ) 2 sc aq sc aq sc Lecture 7 Deliverability Testing of Gas Wells bq Original Pseudopressure New Pseudopressure p p wf aq sc 2 bq sc = Pseudopressure corresponding to. = Pseudopressure corresponding to p wf. 2 sc = Pseudopressure drop due to laminar flow and well conditions. = Pseudopressure drop due to inertial-turbulent flow effects. p z p 2 dp pp dp pbase z p p base z p ref p i p Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 4

5 Deliverability Test Plot LIT Flow Analysis Tom BLASINGAME Texas A&M U. Slide 5

6 Conventional Test Flow Rate and Pressure Diagrams Schematic Diagrams for Traditional 4-Point Tests Tom BLASINGAME Texas A&M U. Slide 6

7 Conventional Test Flow Rate and Pressure Diagrams Deliverability Plots for Traditional 4-Point Tests Tom BLASINGAME Texas A&M U. Slide 7

8 Isochronal Test Flow Rate And Pressure Diagrams Schematic Diagrams for an Isochronal Test Tom BLASINGAME Texas A&M U. Slide 8

9 Isochronal Test Flow Rate And Pressure Diagrams Deliverability Plots for Isochronal Tests Tom BLASINGAME Texas A&M U. Slide 9

10 Modified Isochronal Test Flow Rate and Pressure Diagrams Schematic Diagrams for a Modified Isochronal Test Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 10

11 Modified Isochronal Test Flow Rate and Pressure Diagrams Deliverability Plots for a Modified Isochronal Test Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 11

12 Wellhead Deliverability Plots Wellhead Deliverability Plot Wellhead IPR Plot Tom BLASINGAME Texas A&M U. Slide 12

13 Cullender Isochronal Flow Analysis From: Cullender, M. H. (1955). The Isochronal Performance Method of Determining the Flow Characteristics of Gas Wells. Society of Petroleum Engineers. Tom BLASINGAME Texas A&M U. Slide 13

14 Cullender Isochronal Flow Analysis From: Cullender, M. H. (1955). The Isochronal Performance Method of Determining the Flow Characteristics of Gas Wells. Society of Petroleum Engineers. Tom BLASINGAME Texas A&M U. Slide 14

15 Cullender Isochronal Flow Analysis From: Cullender, M. H. (1955). The Isochronal Performance Method of Determining the Flow Characteristics of Gas Wells. Society of Petroleum Engineers. Tom BLASINGAME Texas A&M U. Slide 15

16 Cullender Isochronal Flow Analysis From: Cullender, M. H. (1955). The Isochronal Performance Method of Determining the Flow Characteristics of Gas Wells. Society of Petroleum Engineers. Tom BLASINGAME Texas A&M U. Slide 16

17 Petroleum Engineering 613 Natural Gas Engineering Lecture 7 Deliverability Testing of Gas Wells Example 7.1 Lee and Wattenbarger 4-point Test Data From: Lee, W.J. and Wattenbarger, R.A.: Gas Reservoir Engineering, SPE (1996). Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 17

18 Petroleum Engineering 613 Natural Gas Engineering Lecture 7 Deliverability Testing of Gas Wells Example 7.1 Lee and Wattenbarger 4-point Test Data Rawlins and Schellhardt (p 2 ) From: Lee, W.J. and Wattenbarger, R.A.: Gas Reservoir Engineering, SPE (1996). Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 18

19 Petroleum Engineering 613 Natural Gas Engineering Lecture 7 Deliverability Testing of Gas Wells Example 7.1 Lee and Wattenbarger 4-point Test Data Rawlins and Schellhardt (p p ) From: Lee, W.J. and Wattenbarger, R.A.: Gas Reservoir Engineering, SPE (1996). Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 19

20 Petroleum Engineering 613 Natural Gas Engineering Lecture 7 Deliverability Testing of Gas Wells Example 7.1 Lee and Wattenbarger 4-point Test Data Houpeurt (p p /q g ) From: Lee, W.J. and Wattenbarger, R.A.: Gas Reservoir Engineering, SPE (1996). Tom BLASINGAME t-blasingame@tamu.edu Texas A&M U. Slide 20