Steel catenary risers (SCR) are an enabling technology for deepwater environments. Tools to analyse and design SCRs are available which show that the point where the riser first touches the soil, termed the touchdown point (TDP), exhibits complex behaviour that has been the subject of a number of recent research programmes. The soil parameters used in SCR analysis can have a significant effect on riser response, especially the predicted fatigue life.If soil parameters and analytical models are chosen too conservatively they can make the predicted fatigue life unrealistically low, conversely using non-conservative soil parameters and soft soil models results in fatigue lives that may be unrealistically high.This paper describes state of the art vertical pipe/soil interaction models developed for use in SCR analysis. These model pipe movement vertically downwards (soil stiffness) and vertically upwards (soil suction). The models are based upon test data from the STRIDE and CARISIMA JIP's and information from existing papers. The models are currently being used in many Gulf of Mexico deepwater projects that involve SCRs.
This paper summarizes enabling technologies that operators can utilize when planning their field lifecycles, from development and construction through to decommissioning. By approaching field development in a holistic manner, it is possible to minimize total expenditure (TOTEX; the sum of both capital and operational expenditures), whilst also maximizing return on investment and hydrocarbon recovery.
With long-term regulatory compliance and production enhancement in mind, early introduction of flexibility into a subsea field infrastructure can enable simplified well or equipment access for common life of field activities, such as erosion sensor replacement. The resulting systems also permit execution of appropriate interventions by utilizing modest and therefore lower cost multi-service vessels (MSV) in place of larger multi-functional rigs at a premium.
In the following sections, eight different examples of various subsea production problems are presented, with an overview of how they were successfully resolved. These examples serve to demonstrate that the technologies required to deliver advanced production enhancement solutions are sufficiently mature. The paper concludes by demonstrating how more robust planning and provision for flexibility within subsea production system (SPS) design can lead to more rapid resolution and improved financial returns. Supporting these examples, discussion is provided on how digital analysis and hydraulic treatments can be used to help provide early identification and resolution of issues, thereby themselves acting as means of ultimately achieving production enhancement.
By adopting the approaches outlined within this paper, a step-change in production performance is within reach. Subsea systems designed for life of field may include digital technologies to perform on-going advisory services, live fluid sampling capability to assess production performance, and flexible architectures with access points. The optimization of on-going production and necessary intervention can drive informed operational decisions and continual optimization of the field.
The results include a reduction in operational risk exposure, maximized ultimate oil recovery, and the ability to effectively manage unplanned changes in performance. This forward-looking approach to field development, combined with a high degree of flexibility, is crucial for supporting prudent investment within today's challenging environment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.