Advanced Analysis Identifies Greater Efficiency for Testing BOPs in Deep Water

摘要

Pressure testing Blowout Preventers (BOPs) withSynthetic-Based Mud (SBM) requires lengthy testing times asa result of pressure/volume/temperature (PVT) influencesassociated with SBM. PVT influences are especiallypronounced in deepwater and high-pressure test environments.This project was motivated by an effort to betterunderstand the mechanics that transpire during BOP testing.The primary objective was to demonstrate that the pressuredecline is quantified by the fluid PVT behavior, mechanicalinfluences, and thermodynamics of pressurization andsubsequent cool down. The second objective was todemonstrate that the pressure decline caused by a leak can bedetected reliably and efficiently with high resolutionpressure data.It was theorized that the phenomena primarily result fromheat added to the system during pressurization. To pursue thisinvestigation, real-time PVT data was gathered at thecementing unit (CU) suction and discharge while testing theBOP. In addition, pressure-temperature (P-T) gauges wereplaced in the drillstring: one at the drill floor, one at themidpoint between the drill floor and the BOP, and one abovethe BOP stack. The gauges confirmed significant heat up asthe system was pressured up for each test. The pressuredecreased as the system cooled back towards the ambient.Modeling techniques were developed to understand the systemresponse. This paper presents salient aspects of dataacquisition, data interpretation, and modeling techniques.Results demonstrate the potential to significantly impactthe industry with respect to safety, time, and costs forBOP testing.