Early Production Systems (EPS) in Ultra Deep Water, a Way to Improve Reservoir Management and Field Economics

2000 ◽  
Author(s):  
C.P. Valenchon ◽  
S.J. Anrès ◽  
B.F. Baudouin ◽  
F.M. Biolley
2011 ◽  
Vol 51 (2) ◽  
pp. 671
Author(s):  
Hayden Marcollo ◽  
Christopher Carra

Floating early production systems (FEPS) are becoming more important to the successful exploitation of Australia's deep water oil and gas. Importantly, FEPS help oil and gas operators reduce deep water full field development risk, as uncertainty in the reservoir characteristics are reduced by obtaining dynamic data (that is, partially producing some of the reservoir). This paper will present a review of existing FEPS that are now in use or have previously been in use worldwide and will discuss where they are headed in the future. The paper focuses on: The selection of the floating and subsea-vessel, mooring, riser, mechanical connection, etcetera; Technology presently available; and, Addressing the requirements in situations where new floating and subsea technology is needed. The qualification limits of existing technology will be discussed in the context of what systems are ready and off-the-shelf for operators to make use of now. The choice of appropriate FEPS will be discussed as a function of: proximity to pipeline infrastructure, potential production rate, capability to re-inject associated gas, prevailing variation in year-round environmental conditions, waterdepth, and, geotechnical description of sea bottom. A high level conceptual case study showing typical costs for the implementation of a deep water FEPS will be presented as a way of understanding the potential upside and downside exposure for an operator considering undertaking a deep water FEPS program.


2016 ◽  
Author(s):  
Bert-Rik de Zwart ◽  
Jose Varghese ◽  
Prasanta Nayak ◽  
Aloke Saha ◽  
Anna Numpang ◽  
...  

2021 ◽  
Author(s):  
Sidnei Guerreiro Da Silva ◽  
Andre Athayde Gonçalves ◽  
William Albuquerque Da Silva ◽  
Rafael Di Lorenzo Filho

Abstract The characteristics of Pre-Salt carbonate reservoirs demand downhole chemical injection to prevent scale, asphaltene, and wax deposits, besides the need of H2S scavenger, and MEG, normally injected at Xmas tree (WCT). The poor performance of injection systems installed in Santos Basin, together with production risks associated to the lack of chemical injection, led the project team to re-evaluate design requirements, such as chemical products characteristics, production systems equipments, umbilicals, and chemical injection valves. In addition, umbilical failures are being observed in other deep-water fields, related to subsea control systems functions. This paper focuses on Company operational experience and lessons learned related to umbilicals and downhole chemical injection.


Author(s):  
Aldo Roberto Cruces Girón ◽  
Fabrício Nogueira Corrêa ◽  
Breno Pinheiro Jacob

Analysis techniques and numerical formulations are available in a variety for mooring and riser designers. They are applied in the different stages of the design processes of floating production systems (FPS) by taking advantage of both the accuracy of results and the computational costs. In early design stages, the low computational cost is more valued with the aim of obtaining fast results and taking decisions. So in these stages it is common to use uncoupled analysis. On the other hand, in more advanced design stages, the accuracy of results is more valued, for which the use of coupled analysis is adequate. However, it can lead to excessive computing times. To overcome such high computational costs, new formulations have been proposed with the aim of obtaining results similar to a coupled analysis, but with low computational costs. One of these formulations is referred as the semi-coupled scheme (S-C). Its main characteristic is that it combines the advantages of uncoupled and coupled analysis techniques. In this way, analyses can be performed with very fast execution times and results are superior to those obtained by the classical uncoupled analysis. This work presents an evaluation of the S-C scheme. The evaluation is made by comparing their results with the results of coupled analyses. Both type of analysis were applied in a representative deep water platform. The results show that the S-C scheme have the potentially to provide results with appropriate precision with very low computational times. In this way, the S-C scheme represents an attractive procedure to be applied in early and intermediate stages of the design process of FPS.


Author(s):  
S. Chandrasekaran ◽  
Arvind Kumar Jain ◽  
Syed Azeem Uddin

Abstract Offshore complaint structures dominate the deepwater oil exploration and production due to their adaptive geometric form and well-established construction practices. Semi-submersible is one of the widely preferred, floating production systems due to its form-dominant ability, better stability characteristics, and best constructional features. It is usually position-restrained using a dynamic-positioning system (active-restraining) or mooring system (passive-restraining); being less-sensitive to freak ocean environment is an added advantage. The Semi-submersible, chosen for the present study is based on a similar configuration of a 6th generation deep-water Hai Yang Shi You (HYSY) – 981 platforms, commissioned by the China National Offshore Oil Corporation (CNOOC) in 2012. A sixteen-point, spread catenary-mooring without submerged buoy (case-1) in the form of chain-wire-chain type configuration is used for position-restraining. Response behavior of the semi-submersible with a conventional spread catenary-mooring system with a submerged buoy (case-2) is compared. API spectrum is used for computing wind loads, while the JONSWAP spectrum is used to represent irregular waves for various directions of wave heading. The effect of non-linearly varying current is considered up to 10% of water depth. Numerical analyses of the semi-submersible are carried out under 10-years, and 100-years return period events using Ansys Aqwa. Under wind, wave, and current loads, motion responses of the Semi-submersible at 1500 m and 2000 m water depths are investigated for both the cases in time-domain. Dynamic mooring tension variations arise from the environmental loads are further investigated for a fatigue failure using the S-N curve approach. It is found that the fatigue life of the mooring lines after the inclusion of the buoy is enhanced. It was also observed that, during failure of mooring lines there is an increase in tension of the mooring lines which are adjacent to the failed mooring lines and this is due to the transfer of mooring load and hence reducing their fatigue life.


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