Acid and Scale Inhibitor Squeeze Treatments on Two Subsea Gas Condensate Wells: Design of Subsea Connection, Treatment, Wells Start-Up and Results of the Operation.
- Stephan Hatscher (Wintershall Norge AS) | Maxim Kiselnikov (Wintershall Norge AS)
- Document ID
- Society of Petroleum Engineers
- SPE International Conference on Oilfield Chemistry, 8-9 April, Galveston, Texas, USA
- Publication Date
- Document Type
- Conference Paper
- 2019. Society of Petroleum Engineers
- H2S mitigation, subsea connection, stimulation, subea well, scale squeeze
- 3 in the last 30 days
- 140 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 9.50|
|SPE Non-Member Price:||USD 28.00|
On the Vega gas condensate and oil field in the Norwegian North Sea, two high temperature, high pressure (HTHP) gas condensate wells on one subsea template in 370 m water depth were acid and scale inhibitor treated in order to improve productivity by acid scale removal and prevent future scaling. Significant amount of work was undertaken on design and qualification of the treatment fluids. In order to reduce operation time and increase efficiency, a novel one-time connection concept was utilized. During the operations, wells were kicked off after energizing with gas bullheaded from the neighbouring well. The treatment fluids were designed to reduce consequences for the host facility due to H2S generated during the operation - this required optimization after understanding of the H2S source as witnessed in prior treatments.
The new concept with one-time connection was successfully employed and allowed for three subsequent well treatments in a row, thus saving at least two days vessel operations time. The gas injection from the neighbouring well - the one not treated at the moment - allowed for an efficient start-up of the treated well without need for larger nitrogen injection which would have led to contamination and potentially to flaring due to off-spec gas. The introduction of a batch with pH neutralizer and H2S scavenger batch into the treatment design to be placed into the production pipeline reduced H2S liberation and production to the host facilities, thus limiting the operational stress on the platform. Productivity of well A1 showed an immediately significant increase after the operations, whereas productivity of well A2 required a longer clean-up than originally anticipated.
|File Size||1 MB||Number of Pages||14|
Clemmit, A.F.,Balance, D.C.,Hunton, A.G. 1985. The Dissolution of scales in Oilfield Systems. Offshore Europe, Aberdeen, UK, 10-13 September 1985. SPE 19263. http://dx.doi.org/10.2118/19263-MS.
Nasr-El-Din, H.A.,Zabihi, M.,Kelkar, S.K.. 2007. Development and Field Application of a New Hydrogen Sulfide Scavanger for Acidizing Sour-Water Injectors. SPE International Symposium on Oilfield Chemistry, Houston, Texas, USA, 28 February to 2 March 2007. SPE 106442. http://dx.doi.org/10.2118/106442-MS.
Smith, P.S.,Clement, C.C.,Rojas, A.M. 2000. Combined Scale Removal and Scale Inhibition Treatments. Second International Symposium on Oilfield Scale, Aberdeen, UK, 26/27 January 2000. SPE 60222. http://dx.doi.org/10.2118/60222-MS.
Strong, A.J.,Wright, R.J.,Skelly, G.J. 1997. Well Stimulation: A Mature Asset Case Study. SPE Annual Technical Conference, San Santonio, Texas, 5-8 October 1997. SPE 38769. http://dx.doi.org/10.2118/38769-MS.
Wat, R.,Wennberg, K.,Holden, R.. 2008. The Challenges Associated With Performing and Combining Scale Dissolver and Squeeze Treatments in Kristin – A Subsea HP/HT Gas Condensate Field. SPE International Oilfield Scale Conference, Aberdeen, UK; 28/29 May 2008. SPE 114079. http://dx.doi.org/10.2118/114079-MS.