Failure Mode and Effects Analysis of Choke and Gate Valves In A Back Pressure Manifold

Abstract

Choke and gate valves are critical components of a back pressure manifold (BPM), supporting pressure regulation, flow control, and isolation during drilling operations. Their failure may compromise well-control reliability and operational safety. This study identifies and prioritizes failure modes of choke and gate valves using a workshop-based Failure Mode and Effects Analysis (FMEA). Data were obtained from workshop observations, hydrostatic testing, maintenance documentation, and consensus assessments by three maintenance personnel. Four choke-valve and five gate-valve failure modes were evaluated based on severity, occurrence, and detection ratings, from which Risk Priority Numbers (RPNs) were calculated. The results showed that choke-valve seat erosion or wear had the highest RPN of 324, followed by leakage, erosion, or wear at the gate/seat-ring interface with an RPN of 225, and sticking or unresponsive operation of the choke-valve stem and actuator with an RPN of 210. The choke valve exhibited a higher average RPN than the gate valve because its throttling function exposes internal components to substantial pressure drops, accelerated flow, turbulence, and possible particle-induced erosion. The findings demonstrate that sealing-surface integrity and valve-operating reliability are the main maintenance priorities. Maintenance strategies should combine RPN ranking with severity assessment and incorporate internal visual inspection, hydrostatic and functional testing, dimensional examination, cleaning, lubrication verification, and targeted nondestructive testing. Although the identified degradation mechanisms require further verification, this study provides a structured basis for prioritizing BPM valve inspection and maintenance.