Study Of Flammable Hydrocarbon Gas Deflagration Process On Offshore Drilling Platform

Because of gas and oil resources in onshore and shallow waters area becoming depleted,and plenty amount of oil and gas reserved in the deep sea leads to increasing exploration and production oil and gas in the deepwater area.However,deepwater offshore oil and gas exploration and production are characterized by complex engineering system,difficult weather conditions and far from onshore,which makes high probability to occurs deflagration explosion risk in offshore drilling platforms,if accidents occurred will cause huge consequences on causality loss,economic losses,and environmental disaster.Offshore drilling platforms are characterized by multiple decks,which have a different kind of equipment's,those equipment's during deflagration explosions accident act like as obstacles,and intensity the explosion consequence.In this thesis presented the experimental and numerical study of flammable hydrocarbon gas deflagration process on the offshore drilling platform.The main thesis contents includes:(1)Through semi open square pipeline experimental system investigate the interaction between flame and equipment 's on offshore drilling platform during deflagration process.From the experiment results,observed with the increasing number of obstacles from without up to 3,the maximum overpressure increase by 507.4%(obstacle 1),and 737.8%(obstacle 2)and 786.8%(obstacle 3).Furthermore,with the increasing obstacles separation distance from ignition source the maximum overpressure down by 3.02%(400 mm),15.5%(500 mm),and 56.4%(600 mm).In addition,while increasing separation distance between obstacles,in the beginning the maximum overpressure rise and at 100-150 mm separation distance the highest maximum overpressure were observed,eventually it start decreasing.Moreover,with the increasing obstacle angle,the maximum overpressure increases and obstacle at an angle 135°highest maximum overpressure occurred from amongst obstacles angle,and eventually the maximum overpressure starts decreasing.(2)To study numerical deflagration process in offshore drilling platform FLACS software used.On the simulation results observed for all the combustion product of flammable gas cloud at the beginning was slow,gradually the combustion process becomes strong and violent chemical reaction occurred which causes rise maximum pressure of deflagration process.On above main deck offshore drilling platform without obstacle the maximum overpressure is 0.75kpa.Meanwhile,with the presence of obstacles,the maximum overpressure was 0.86kpa,and in the intermediate deck the maximum overpressure was 16.37kpa.Based on the overpressure criteria deflagration simulation in intermediate deck the maximum overpressure may cause serious damage for lower limit of serious structural.Besides,on dispersion simulation has been done at different wide direction and wind speed,at the same wind speed flammable gas cloud dispersion process observed,wind direction at 1600 longer time took to exit from the drilling platform compared flammable gas dispersion process wind direction at 2400,which is because of obstacle's restrict the flow of flammable gas to exit from the drilling platform.