Production system analysis for Woollybutt mature oil field using dynamic simulation
Ryosuke Yokote A , Vanni Donagemma A and Juan Carlos Mantecon AA Eni Australia
B SPT Group
The APPEA Journal 51(1) 135-146 https://doi.org/10.1071/AJ10009
Published: 2011
Abstract
This paper describes how multi-phase flow dynamic simulation techniques were applied to support and optimise the day to day production operations for the Woollybutt oil field on the North West Shelf, Australia. Eni Australia is the operator of the: Woollybutt oil project, which consists of two separate fields; Woollybutt North, which has three production wells; and Woollybutt South, which has one production well– Woollybutt–4H (WBT–4H). WBT–4H is located about 7 km from the floating production storage and offloading (FPSO) facilities and shares the production flowline with two other production wells from the Woollybutt North field. Production from WBT-4H accounts for more than 60% of the total production. For this reason, achieving steady production from this well is the highest priority for the operations.
To understand the hydrodynamic behaviour and to maximise production from WBT–4H, the production system for the Woollybutt South field was modelled from WBT–4H reservoir inflow points to the FPSO using a commercial dynamic simulation software package. The model successfully matched the pressures measured at the permanent down hole gauge (PDHG) and upstream production subsea choke dynamically, using the arrival pressure at the FPSO and the measured gas lift rate at the FPSO as input data. The model was used to identify the reason for slugging , to locate where the slugging conditions were originating, as well as to investigate optimum gas lift rate and the impact of bringing other wells on production from the Woollybutt South field. Furthermore, the model was used to identify the cause of sudden severe slugging, which forced to reduce the subsea production choke opening. The simulation work concluded that an unstable gas injection at the gas lift orifice valve (GLOV) induced severe slugging. This conclusion was validated operationally in the field soon after.
Results of the multi-phase flow dynamic simulation provided good understanding of the hydrodynamic behaviour in the production system and are used to make informed decisions to support and optimise the day to day production operations.
Ryosuke Yokote (Rio) graduated from Tohoku University in 1995 with a master of science in resource engineering. In 1995, he joined INPEX as a petroleum engineer working in Australia, Indonesia and Japan. He worked for well tests for the Ichthys field in Australia and the Abadi field in the Timor Sea, Indonesia. While he was an interface engineer for Ichthys project, he extended his expertise to flow assurance engineering with a focus on well modelling. In 2009, he was employed by Eni Australia in Perth, where he is currently working as a senior petroleum engineer in the operations and reservoir department, supporting daily production and drilling/completions operations. Member: SPE. rio.yokote@eniaustralia.com.au |
Vanni Donagemma graduated from Parma University in 1988. He started working in geotechnical studies, participating in the feasibility of several projects with SPEA European Engineering Group. In 1990, he started his career in the oil and gas industry as a mud logger and in 1992 was employed by the Eni group as reservoir geologist. In 1997, he was posted to Aberdeen for the development of the T-Block fields and in 2000 was back to Ravenna (Italy) to monitor and follow up production from offshore gas fields. In 2002, he was appointed as a reservoir characterisation coordinator in Milan and then was assigned to the Kashagan project in The Hague in 2003 where he was responsible for the reservoir geological studies. In 2006, he was posted to Perth with Eni Australia where is now working as reservoir manager in the operations and reservoir department. vanni.donagemma@eniaustralia.com.au |
Juan Carlos Mantecon has broad-field experience of more than 30 years operating, developing, and managing projects with a focus on design and production optimisation, flow assurance and reservoir engineering for both offshore and onshore fields in Argentina, Venezuela, Canada, USA, Romania, Indonesia, Scotland, Malaysia, Brunei and Australia. He worked in several operating and services companies. In 2003, he joined the SPT GROUP and he is now a global wells and integrated systems advisor based in Perth. He has a Bachelor of Science in mechanical engineering, Master of Science in petroleum engineering–both from The University of Buenos Aires–and earned postgraduate studies from The University of Alberta, Canada, and The University of Texas. He lectured at The University of NSW, The University of WA and Curtin University of Technology. He authored and co-authored numerous papers. He is also chair of the API work group working on the recommended practice for the use of dynamic simulation. Member: SPE and chartered professional engineer of the Institution of Engineers, Australia. juan.mantecon@sptgroup.com |
