Optimization of insulation on subsea oil and gas equipment

Ramechecandane Somassoundirame,Eswari Nithiyananthan

doi:10.1007/s13202-020-01065-2

Ramechecandane Somassoundirame, Eswari Nithiyananthan

Open Access

https://doi.org/10.1007/s13202-020-01065-2

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Abstract

Optimization of insulation on subsea oil and gas equipment can lead to significant cost and weight reduction. A judicious combination of commercially available Finite Element Analysis (FEA) software with evolutionary optimization algorithms can efficiently serve this purpose. In the present study, the optimization of insulation on a gate valve has been presented with due emphasis on the methodology adapted. A parameterized model of the gate valve with several dimensions of interest has been chosen for the numerical experiment. Of the various Design of Experiment (DOE) techniques, the Optimal Space Filling (OSF) method has been considered for generating the samples owing to its robustness and the associated computational cost. The insulation in subsea systems is usually supposed to satisfy two contradicting constraints, it must be ensured that the temperature of the production fluid remains above the Hydrate Formation Temperature (HFT) and at the same time the production fluid temperature cannot be too high, as to create structural damage of the seals in High Pressure High Temperature (HPHT) applications. The sample cases are run simultaneously in a cluster and a response surface is created using genetic aggregation using the various samples those are generated by OSF. The resulting response surface is finally subjected to optimization using the calculus based/gradient based methods. In the present investigation, the optimization is performed using the NonLinear Programming with Quadratic Lagrangian (NLPQL) and Adaptive Single Objective (ASO) Methods. The results obtained show that almost two thirds of the insulation can be effectively removed without compromising on the thermal efficiency of the system. Similar savings have been witnessed in several other cases/subsea geometries that the authors are aware of. The presented case is truly representative of a wide class of subsea applications and the proposed methodology can be suitably adjusted to customer specific requirements to provide suitable results.

Highlights

The world is still reeling under the pressure of the pandemic and the organizations are increasingly focused on cost-cutting measures and retaining market share in a dramatically shrinking economy
The portion of the insulation closer to the actuator can be safely removed without compromising on the thermal performance of the system
The optimization of insulation on a subsea gate valve has been numerically analyzed using a judicious combination of Design of Experiments (DOE) and Optimization algorithms

Summary

Introduction

The world is still reeling under the pressure of the pandemic and the organizations are increasingly focused on cost-cutting measures and retaining market share in a dramatically shrinking economy. ANSYS® DesignXplorer is used for the optimization of insulation on subsea production systems and their components. The search methods are more time consuming and their accuracy depends on the nature of the objective functions and varies with the number of iterations. The commercial code ANSYS® DesignXplorer has a set of gradient based algorithms which are highly efficient in solving single objective functions with multiple constraints (both equality and inequality constraints). The optimization of insulation on a subsea gate valve has been carried out using NonLinear Programming with Quadratic Lagrangian (NLPQL) and Adaptive Single Objective (ASO) algorithms. An efficient blend of Design of Experiments (DOE) and optimization methods applied to subsea systems has not been adequately explored in existing literature

Literature survey

Results

Results and discussion

Conclusion

Compliance with ethical standards