Dynamic Modeling of Gas Lift Designs and Operations

Transcription

1 40 th Gas-Lift Workshop Houston, Texas, USA Oct , 2017 Dynamic Modeling of Gas Lift Designs and Operations Jason Bigelow, Gas Lift Engineer Matthew Clark, Gas Lift Engineer Schlumberger 2017 Gas-Lift Workshop 1

2 Agenda Background Case Studies Analysis Conclusion 2017 Gas-Lift Workshop 2

3 Background Traditional gas lift method steady state designs Provide services for unique gas lift situations Dynamic modelling available to bridge the gap 2017 Gas-Lift Workshop 3

4 Case Studies Multi-point injection Unloading vs API standard Burst disc/long duration unloading 2017 Gas-Lift Workshop 4

5 Case Study 1 Multi-point Injection Client had issue with valve plugging Determine if placing a deeper redundant gas lift valve would eliminate the need for intervention Multi-point injection concerns 2017 Gas-Lift Workshop 5

6 Case Study 1 Multi-point Injection 2017 Gas-Lift Workshop 6

7 Case Study 1 Multi-point Injection 2017 Gas-Lift Workshop 7

8 Case Study 1 Multi-point Injection FLOW THROUGH TOP VALVE GAS INJECTION RATE 50% Plugged 25% Plugged 0% Plugged 75%75% Plugged Time, Hrs 2017 Gas-Lift Workshop 8

9 Case Study 2 Unloading vs API First unloading on project Well design vs changed parameters => unload Compare with API 1 bbl/min 2017 Gas-Lift Workshop 9

10 Case Study 2 Unloading vs API 2017 Gas-Lift Workshop 10

11 Case Study 2 Unloading vs API 1 bbl/min industry standard for unloading fluid through gas lift mandrel Risk of valve damage flow cutting at higher rates Currently using API standard for unloading to maintain low flow rate Determine injection rates profiles to ensure 1bbl/min is not exceeded Examine pressure build up in casing and tubing then compare with field data 2017 Gas-Lift Workshop 11

12 Case Study 2 Unloading vs API Initial OLGA modelling to achieve maximum of 1bbl/min during unloading Injection Rates Results 2017 Gas-Lift Workshop 12

13 Case Study 2 Unloading vs API Annular liquid volume ANNULAR VOLUME Time, Hrs 2017 Gas-Lift Workshop 13

14 Case Study 2 Unloading vs API Annular unloading animation 2017 Gas-Lift Workshop 14

15 Case Study 2 Unloading vs API Tubing unloading animation 2017 Gas-Lift Workshop 15

16 Case Study 2 Unloading vs API OLGA Predicted Rate INJECTION PRESSURE Gas injected through valve Time, Hrs Expected annulus pressure profile for successful unloading 2017 Gas-Lift Workshop 16

17 Case Study 2 Unloading vs API Unloading case optimization Maintaining 1bbl/min throughout entire unloading process Modelling shows a 50% reduction in unloading time over field data. Subject to availability of gas for unloading (natural gas versus nitrogen) 2017 Gas-Lift Workshop 17

18 Case Study 2 Unloading vs API API rates put into OGLA 2017 Gas-Lift Workshop 18

19 Case Study 2 Unloading vs API Initial OGLA model conservative to API and field data but adapting to 1 bbl/min through the valve had different slopes than API. OLGA model injection rates can be increased at the beginning of the process for higher rate through the valve closer to 1bbl/min to save time Unloading profiles match typical pressure profiles of a successfully unloaded well Further refinement of model completed to match field data to determine fluid rates through valve 2017 Gas-Lift Workshop 20

20 Case Study 3 Long Duration Unloading Deepwater subsea well Burst disc in the valve 1.5 bbl/min unloading through XLift* valve Unloading well over months 2017 Gas-Lift Workshop 21

21 Case Study 3 Long Duration Unloading Manifolded gas injection choke 2017 Gas-Lift Workshop 22

22 Case Study 3 Long Duration Unloading OLGA model 2017 Gas-Lift Workshop 23

23 Case Study 3 Long Duration Unloading Flow through the tubes 5 Tube Gas Lift Flow Rates Flow Rate (MMscf/d) Tube 1 Tubes 2 and 3 Tubes 4 and 5 Tubes 6 and Time (hr) 2017 Gas-Lift Workshop 24

24 Case Study 3 Long Duration Unloading Burst disc study Sudden fluid rate through orifice with ruptured disc 2017 Gas-Lift Workshop 25

25 Case Study 3 Long Duration Unloading CFD model Analyze hot spots 2017 Gas-Lift Workshop 26

26 Case Study 3 Long Duration Unloading Unloading in stages 2017 Gas-Lift Workshop 27

27 Conclusion Plugging top valve effects on 2 nd valve Nitrogen unloading Burst disc and long duration unloading 2017 Gas-Lift Workshop 28

28 Questions 2017 Gas-Lift Workshop 29

29 Copyright Rights to this presentation are owned by the company(ies) and/or author(s) listed on the title page. By submitting this presentation to the Gas-Lift Workshop, they grant to the Workshop, the Artificial Lift Research and Development Council (ALRDC), and the American Society of Mechanical Engineers (ASME), rights to: Display the presentation at the Workshop. Place it on the web site, with access to the site to be as directed by the Workshop Steering Committee. Place it on a CD for distribution and/or sale as directed by the Workshop Steering Committee. Other uses of this presentation are prohibited without the expressed written permission of the company(ies) and/or author(s) who own it and the Workshop Steering Committee Gas-Lift Workshop 30

30 Disclaimer The following disclaimer shall be included as the last page of a Technical Presentation or Continuing Education Course. A similar disclaimer is included on the front page of the Gas-Lift Workshop Web Site. The Artificial Lift Research and Development Council and its officers and trustees, and the Gas-Lift Workshop Steering Committee members, and their supporting organizations and companies (here-inafter referred to as the Sponsoring Organizations), and the author(s) of this Technical Presentation or Continuing Education Training Course and their company(ies), provide this presentation and/or training material at the Gas-Lift Workshop "as is" without any warranty of any kind, express or implied, as to the accuracy of the information or the products or services referred to by any presenter (in so far as such warranties may be excluded under any relevant law) and these members and their companies will not be liable for unlawful actions and any losses or damage that may result from use of any presentation as a consequence of any inaccuracies in, or any omission from, the information which therein may be contained. The views, opinions, and conclusions expressed in these presentations and/or training materials are those of the author and not necessarily those of the Sponsoring Organizations. The author is solely responsible for the content of the materials. The Sponsoring Organizations cannot and do not warrant the accuracy of these documents beyond the source documents, although we do make every attempt to work from authoritative sources. The Sponsoring Organizations provide these presentations and/or training materials as a service. The Sponsoring Organizations make no representations or warranties, express or implied, with respect to the presentations and/or training materials, or any part thereof, including any warrantees of title, noninfringement of copyright or patent rights of others, merchantability, or fitness or suitability for any purpose Gas-Lift Workshop 31