Impact of Water Hammer in Deep Sea Water Injection Wells

Abstract

Water hammer is a known pressure pulse or surge that may occur by the instant shut-in of a valve in a flow line. Sudden momentum change may create a pressure cyclic pulse that could cause damage to valves, bending parts in tubing, and/or joints. Usually this effect has been well managed in surface facility design; however, it tends to be overlooked in subsurface well design. Additional possible impact by water hammer in subsurface wells could be on the sandface completions. The severe water hammer could cause failure of formation integrity, resulting in sand production. It may also damage the wellbore and downhole completions. Especially for deep sea water injection and/or production operations, water hammer effect needs to be thoroughly investigated and properly managed because it could be more severe due to longer flow line and higher flow rate. The purpose of this study is to have a comprehensive investigation on water hammer effect for an actual water injection well in Chevron's deep water project with different design parameters and operating parameters. The design parameters include a) height of vertical riser; b) tubing diameter; c) injectivity index (skin or completion type); d) sandface wellbore length; and e) well deviation. The operational parameters include a) injection rate; b) closing time; and c) injection water temperature. Multiphase transient fluid flow model OLGA is used for the water hammer simulation. Results of the water hammer parameter study for optimum well design and operating strategy are reported here. It is shown that the impact of water hammer can be significantly mitigated or eliminated at well design stage or by adjusting the operating parameter(s).

Simulation of Multiphase Fluid-Hammer Effects During Well StartUp and Shut-In

“…In the transient shut-in period, the flow rate could increase by as much as 10 times that of the production rate at a steadystate condition. Setting the closing valve at the topside platform would cause a higher peak pressure if compared with one set at the wellhead or bottomhole-this finding was in agreement with that derived from a specific case study without considering flowline and riser by Choi and Huang (2011). Another observation from the study was that the presence of a short flowline could help to reduce the pressure surge dramatically.…”

“…Wang et al (2008) studied the water hammer in water injectors with a field trial in which pressure pulses generated from rapid shut-ins at different well depths in a soft-formation case and a perforated water injector, respectively, were recorded. Tang and Ouyang (2010) and Choi and Huang (2011) studied the effect of water hammer on deepwater-injectionwell design. However, a general guide to relieve fluid-hammer effects upon well startup or shut-in is still incomplete.…”

Dynamic Modeling of Channel Formation During Fluid Injection Into Unconsolidated Formations

“…The main assumptions in these works involve the presence of sharp fractures as defined in linear-elastic-fracture mechanics; however, these assumptions are far from reality for unconsolidated formations. Therefore, some alternative concepts such as viscous fingering, fluidization, and channelization had been proposed for consolidated and unconsolidated formations to explain some of these concerns (Damme et al 1993;Johnsen et al 2006;Huang et al 2011;Mahadevan et al 2012). In these works, a combination of experimental observations, descriptive mathematical models, and discrete-element models has been used to investigate this problem.…”

Emergency Pump-Rate Regulation to Mitigate Water-Hammer Effect—An Integrated Data-Driven Strategy and Case Studies

“…The emergency shut-in of injection wells may induce large pressure pulses that can cause wellbore integrity problems, such as sand-face failure and sand production [27,28]. This issue has drawn more concerns in offshore wells, where a higher safety criterion is required for platforms and facilities above sea [29,30]. Recent studies have extended research to the tubing string vibration in high-pressure and high-production gas wells.…”