Leakage Monitoring of Subsea Blowout Preventer Control System

Abstract

Abstract Presented in this paper is a model-based approach for leakage detection and identification in subsea blowout preventer (BOP) hydraulic control system. A physics-based model is implemented to quantify the overall leak rate of BOP control fluid from surface hydraulic power unit (HPU) to subsea BOP operator. The model input is the measured pressure at the surface main accumulator stack, and the model parameters are accumulator stack characteristics including precharge pressure and total fluid volume. To isolate the leak path in the BOP control system, a model-based leak indicator is derived for each of the control pod main rail pressure regulators. The performance and robustness of the proposed approach is investigated by conducting a what-if analysis using a virtual BOP model built in a simulation environment. The fluid leak monitoring algorithm is applied to field data collected from several deepwater drilling rigs. The results show that the proposed methodology is able to detect and monitor control fluid leak within the BOP control system.