it into the annular area between the outer pipe 30 and the riser pipe 7 this is accomplished by a seawater intake 46 a circulation pump 48 an electric heater 50 and an attachment interface 52 prior to the opening of valve 5 and throttling gas into the riser pipe 7 the rov 32 and belly skid 34 heats seawater to 150 u00b0 f and circulates it into the annular area 42 this fills the annular area 42 with 150 u00b0 f seawater rather than the 34 u00b0 f seawater which would have been in it otherwise when the valve 5 is opened a hydrate is not formed as it enters an area as hot as you want it to prevent gas and water vapor mixture from going down to a temperature low enough to form hydrates other methods are available for providing a heat source to prevent the formation of hydrates such as providing electric heaters within the annular area 42 prior to the opening of the valve 5 electricity could simply be sent to the electric heaters from the surface or from the rov to heat the seawater 40 in the annular area 42 the present method of preheating a volume of seawater to prevent the formation of hydrates is shown in these drawings as a part of a vertical riser pipe 7 going to the surface the method could be equally well used along a horizontal flowline associated with a subsea installation or the subsea installation itself in the case of some subsea installations there is enough piping to allow formation of the hydrates directly on the subsea system hydrates are formed and are remediated at a combination of temperatures and pressures rather than having a single simple temperature.