An Efficient Modeling and Optimization Approach for Pressure Testing During Reentry Operation of Deepwater Drilling Riser System

Weiming Shao,Guoming Chen,Kang Liu

doi:10.1109/access.2020.2988290

Weiming Shao, Guoming Chen + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.2988290

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Abstract

Pressure testing should be conducted on auxiliary lines during riser reentry to ensure the seal security of connection positions. The proper setting of the number and positions of pressure testing is essential because it can significantly reduce the high costs of offshore drilling. However, the analysis and optimization models for pressure testing during riser reentry were not resolved satisfactorily in engineering practice. This study proposes an efficient optimization procedure for pressure testing during riser reentry. A time-efficiency evaluation model and a risk assessment model are established based on the pressure testing process and entropy theory. The modified artificial bee colony (ABC) algorithm is used to optimize the pressure testing process by incorporating the above proposed models. The optimization procedure is illustrated by a case study. The optimal results from the proposed procedure are compared with those from the recommended practices. The resulting variabilities due to seal reliability, water depth, and pressure testing time are also discussed. The study shows that the optimization procedure can improve the operation efficiency of the riser reentry process by 20% and 38% compared to two recommended practices. The proposed procedure is verified to be an efficient alternative for decision making in pressure testing to improve the economic efficiency and ensure safety during riser reentry.

Highlights

Offshore petroleum exploration and development is an industry with high investments and outputs, as well as risks
To balance the exploration and exploitation abilities and enhance the convergence rate of the artificial bee colony (ABC) algorithm for discrete optimization, four search strategies for pressure testing optimization are proposed in this paper
(ak t4s + bk t4B + ck t2 + t5) 1 − pck pck Because the reentry process of a riser system is divided into several pressure testing units, which are independent of each other, the time-efficiency evaluation model for pressure testing during riser reentry can be written as n n

Summary

INTRODUCTION

Offshore petroleum exploration and development is an industry with high investments and outputs, as well as risks. An efficient optimization procedure is developed for pressure testing during riser reentry based on the ABC algorithm with an improved search strategy that considers the unique problem characteristics. 3) The seal reliability is the probability of two riser joints successfully connecting without leakage of auxiliary lines at one time It can be calculated based on site statistics and updated dynamically according to the practices of deepwater drilling riser systems during reentry. The optimization objectives for pressure testing during riser reentry are to minimize the time costs and operation risk This problem is a typical multi-objective optimization problem, which can be solved by searching the entire Pareto front [30].

Results and analysis

TIME-EFFICIENCY EVALUATION MODEL

RISK ASSESSMENT MODEL

STANDARD CASE

CONCLUSION