Exploring the Concept Selection Process in subsea field development projects

Author(s):  
Oyvind Jia-Chen Aslie ◽  
Kristin Falk
2015 ◽  
Vol 55 (2) ◽  
pp. 454
Author(s):  
Greg Saunders ◽  
Matthew Poole

This extended abstract describes the field development concept selection process for Karoon Gas Australia, as part of the appraisal and commercialisation of an oil resource in offshore Brazil. From an engineering design perspective, the concept selection phase offers the greatest opportunity to create project value. Options must be carefully considered before rigorous investigation to provide a firm foundation for key decisions. The concept selection study and option consideration began with a two-day framing and option identification workshop. Nine key decisions were identified as having significant impact on the feasibility and cost of the development. These included the wellhead type, hydrate management strategy, floating production storage and offloading vessel (FPSO) capacity, FPSO location, mooring type, subsea architecture, product export and expansion provisions. Assessment criteria were agreed on for each of the key technical decisions; these were applied in the evaluation of options defined. This workshop facilitated definition and agreement for the technical study scope. The subsequent investigation and selection process focused on the key development decisions that needed to be made immediately, compared to those that could be made at a later stage of the development. These decisions encompassed technical viability, dry trees versus wet trees, flow assurance, mooring type and processing capacity. A geologically complex reservoir drove many elements of the development selection process. This extended abstract highlights that the final solution balances risk management with maximising project value. The recommended base development concept is analogous to many developments already implemented in Brazil and is flexible enough to accommodate a realistic range of outcomes from future appraisal wells.


2021 ◽  
Vol 143 (10) ◽  
Author(s):  
Rohan Prabhu ◽  
Rainmar L. Leguarda ◽  
Scarlett R. Miller ◽  
Timothy W. Simpson ◽  
Nicholas A. Meisel

Abstract The capabilities of additive manufacturing (AM) open up designers’ solution space and enable them to build designs previously impossible through traditional manufacturing (TM). To leverage this design freedom, designers must emphasize opportunistic design for AM (DfAM), i.e., design techniques that leverage AM capabilities. Additionally, designers must also emphasize restrictive DfAM, i.e., design considerations that account for AM limitations, to ensure that their designs can be successfully built. Therefore, designers must adopt a “dual” design mindset—emphasizing both, opportunistic and restrictive DfAM—when designing for AM. However, to leverage AM capabilities, designers must not only generate creative ideas for AM but also select these creative ideas during the concept selection stage. Design educators must specifically emphasize selecting creative ideas in DfAM, as ideas perceived as infeasible through the traditional design for manufacturing lens may now be feasible with AM. This emphasis could prevent creative but feasible ideas from being discarded due to their perceived infeasibility. While several studies have discussed the role of DfAM in encouraging creative idea generation, there is a need to investigate concept selection in DfAM. In this paper, we investigated the effects of four variations in DfAM education: (1) restrictive, (2) opportunistic, (3) restrictive followed by opportunistic (R-O), and (4) opportunistic followed by restrictive (O-R), on students’ concept selection process. We compared the creativity of the concepts generated by students to the creativity of the concepts they selected. The creativity of designs was measured on four dimensions: (1) uniqueness, (2) usefulness, (3) technical goodness, and (4) overall creativity. We also performed qualitative analyses to gain insight into the rationale provided by students when making their design decisions. From the results, we see that only teams from the restrictive and dual O-R groups selected ideas of higher uniqueness and overall creativity. In contrast, teams from the dual R-O DfAM group selected ideas of lower uniqueness compared with the mean uniqueness of ideas generated. Finally, we see that students trained in opportunistic DfAM emphasized minimizing build material the most, whereas those trained only in restrictive DfAM emphasized minimizing build time. These results highlight the need for DfAM education to encourage AM designers to not just generate creative ideas but also have the courage to select them for the next stage of design.


1976 ◽  
Vol 16 (1) ◽  
pp. 107
Author(s):  
M. A. Delbaere

Oilfield operators have always looked for ways of reducing the costs of oil and gas development projects and especially when investment costs were critical to project economics. Tubingless completions have evolved over the last 30 years in North America to fill the need for reduced investment costs particularly in the case of fields with either limited reserves or limited profitability.Tubingless completions basically utilise small diameter tubulars to function as both production casing and flowstring. The tubulars are cemented in the borehole, not to be removed or recovered until the field is depleted and/or the well abandoned. The technique is limited in application to those fields with no corrosion or wax or hydrate problems and with a limited requirement for reservoir stimulation and workovers. The greater the number of operations performed within the tubingless well bore the greater the risk of losing the well.The main benefits of tubingless completions are as follows:Reduction in development well completion costs.Marginally productive hydrocarbon zones can be completed and tested.Completion of individual gas zones of multi-pay wells within their own permanently segregated flowstrings at much lower capital and operating costs.The experience this far with Kincora gas field development wells indicates the tubingless completion method to be completely feasible for gas wells drilled in the Surat Basin and possibly in other areas of Australia.


Author(s):  
Rohan Prabhu ◽  
Rainmar L. Leguarda ◽  
Scarlett R. Miller ◽  
Timothy W. Simpson ◽  
Nicholas A. Meisel

Abstract The capabilities of additive manufacturing (AM) open up designers’ solution space and enable them to build designs previously impossible through traditional manufacturing. To leverage AM, designers must not only generate creative ideas, but also propagate these ideas without discarding them in the early design stages. This emphasis on selecting creative ideas is particularly important in design for AM (DfAM), as ideas perceived as infeasible through the traditional design for manufacturing lens could now be feasible with AM. Several studies have discussed the role of DfAM in encouraging creative idea generation; however, there is a need to understand concept selection in DfAM. In this paper, we investigated the effect of two variations in DfAM education: 1) restrictive DfAM and 2) dual DfAM (opportunistic and restrictive) on students’ concept selection process. Specifically, we compared the creativity of the concepts generated by the students to the creativity of the concepts selected by them. Further, we performed qualitative analyses to explore the rationale provided by the students in making these design decisions. From the results, we see that teams from both educational groups select ideas of greater usefulness; however, only teams from the restrictive DfAM group select ideas of higher uniqueness and overall creativity. Further, we see that introducing students to opportunistic DfAM increases their emphasis on the complexity of designs when evaluating and selecting them. These results highlight the need for DfAM education to encourage AM designers to not just generate but also select creative ideas.


Author(s):  
Hanqing Zhang ◽  
Derek Smith

Dry tree top-tensioned risers (TTRs) are widely used on floating production systems such as TLPs and Spars for drilling, completion, workover and production. The interference between neighboring TTRs is an important consideration which has a direct impact on the total TTR payload budget and the wellbay size for floater sizing and cost. Since the realistic sizing of a floater is essential towards the concept selection process for a field development, TTR interference should be addressed at the early stages of an offshore oilfield development. If the floater is a tension leg platform (TLP) and the field has strong current with associated extreme waves, riser interference may be very challenging and can have direct impact on riser design and the sizing and layout of the TLP. The waves and the oscillating motions of the TLP will have effects on riser interference. The oscillating motion of the TLP can excite the vibrational motion of the risers, and the wave-induced velocity of water particles and the motions of the risers with the movement of the TLP increases the relative flow acting on each riser. The combined effects will increase the deflection of the risers and thus the likelihood of riser interference. The industry has not seen an acceptable interference analysis approach yet which can account for the combined effects of current, waves, and TLP motions. This paper proposes two engineering approaches for the interference analysis of top tensioned risers for tension leg platforms with the combined effects of current, surface waves, and associated floater motions being addressed.


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