رسائل ماجيستير
English
2018
Transient Wellbore Pressurization Correlation & HIPPS Response Time in Multiphase Flow
Rahul N. Gajbhiye, Dhafer A. Al-Shehri, أحمد عبدالكريم عبدالله حمود
كلية هندسة البترول وعلوم الأرض-جامعة الملك فهد للبترول والمعادن · السعودية
HIPPS (High Integrity Pressure Protection System) is a widely used system in the petroleum industry to protect downstream flowlines that are rated below the full SIWHP (Shut-in Wellhead Pressure) from high-pressure events. The development of wells with high shut-in pressures makes it increasingly expensive to design the flowlines with a conventional mechanical form of protection. Therefore, selecting a thinner flowline wall and reduced pressure class flanges valves and other equipment could reduce material and overall CAPEX costs and favored as the economic option. In the absence of mechanical protection and relief systems in these underrated flowlines, HIPPS becomes the primary pressure protection method, if traditional Emergency Shut-Down (ESD) system protection should fail.According to the Minerals Management Service and Granherne Limited, there is a significant risk involved in high pressure and high rate wells. Therefore, HIPPS implementation requires a better understanding of the implications of timing, testing, and material selection in order to justify regulatory requirements. One of the key requirements is determining the “High-High” trip point, the minimum setting pressure required for activating the system. This calculation is crucial to the performance of the system since it is defined by the envelope of the wellbore pressure build-up time. Another key requirement to determine the High-High trip point is HIPPS Valve Response Time, which varies based on valves type and vendor providers.In this transient flow assurance study, the aim is to develop a generalized correlation to estimate the wellbore pressure build-up time for the selected fields taking into account different studied parameters. The study covers data from three oil fields with various Fluid Properties, GOR’s, Reservoir Pressures, Productivity Index, Depths and Shut-in Wellhead Pressures (SIWHPs). The study will investigate the effect of each parameter on the pressure build-up time and relate it to the system trip point. Then, the optimum “High-High” trip points for each field will be defined based on analysis of the pressure build-up effects to the downstream flowline at the worst-case.The worst-case is defined as a blockage that may occur to the downstream flowlines near the HIPPS system. It varies based on the specifics of the system being investigated. For instance, the downstream valve/blockage may be a valve or it may be a hydrate plug that has formed somewhere in the flowline. In this study, the blockage is defined as a sudden shutdown of the Pad Limit Valve (PLV).