Statoil Petroleum As

Equinor Energy As

Baard Kaasa

Arne Olav Fredheim

Pål Viggo Hemmingsen

Knut Arild Maråk

Bernt Henning Rusten

Lars Henrik Gjertsen

Per Halvard Billington

Gunleiv Skofteland

Pal Viggo Hemmingsen

Knut Arild Marak

A method and system for dehydration of a gas phase and hydrate inhibition of a liquid hydrocarbon phase in a multiphase hydrocarbon fluid stream containing water. The method may include (i) separating the hydrocarbon fluid stream into a liquid phase and a first gas phase, (ii) adding hydrate inhibitor to the first gas phase, and (iii) separating off condensed liquids and a second gas phase. The first gas phase has a water dew point that is lower than the initial multiphase hydrocarbon fluid stream and the second gas phase has a lower water dew point than the first gas phase. The hydrate inhibitor has a water content that is low enough to enable it to dry the first gas phase, the hydrate inhibitor being separated off with the condensed liquids and mixed with a part or all of the liquid phase from the separation to inhibit the liquid phase.

Combined dehydration of gas and inhibition of liquid from a well stream

The present invention concerns a method for lowering the water dew point subsea in a produced multiphase hydrocarbon fluid stream containing water, the method comprising the steps of: separating () the hydrocarbon fluid stream () into a liquid phase () and a first gas phase (); cooling () the first gas phase in a controlled mariner to knock out water or condensing water and optionally other condensates while keeping the fluid above a hydrate formation temperature thereof; separating off condensed liquids () and a second gas phase; wherein the second gas phase () has a water dew point which is lower than that of the initial multiphase hydrocarbon fluid stream. The invention also concerns a system for lowering the water dew point subsea.

Method and system for lowering the water dew point of a hydrocarbon fluid stream subsea

A subsea heat exchanger for cooling or heating a hydrocarbon-containing fluid includes a convection section enclosed by a shell or enclosure comprising, one or more heat exchanging fluid inlet(s) and outlet(s), one or more hydrocarbon-containing fluid inlet(s) and outlet(s), and one or more fluid carrying convection tube(s) adapted for heat transfer between the hydrocarbon-containing fluid on the inside of the tube(s) and a surrounding heat exchanging fluid on the opposite side of the tube(s). The heat exchanger also includes one or more flow regulating device(s) for controlling the hydrocarbon-containing fluid outlet temperature. The heat exchanging fluid circulates in a closed circuit for heat transfer both with said hydrocarbon-containing fluid and with surrounding sea water on the outside of the enclosure.

Subsea heat exchanger and method for temperature control

The invention relates to a method and an apparatus for the removal of polyvalent cations, in particular divalent cations, from mono ethylene glycol. Mono Ethylene Glycol (MEG) is used to prevent hydrate formation in pipelines transporting gas, condensate and water. It may also contribute to pipeline corrosion control. The invention describes a method for the removal of polyvalent cations from mono ethylene glycol, comprising providing a feed of aqueous mono ethylene glycol comprising dissolved gas and salts of divalent cations (rich MEG), heating the aqueous mono ethylene glycol to a heated mixture, causing precipitation of at least part of the salts and release of at least part of the dissolved gas, in particular carbon dioxide, separation of released gas from the mono ethylene glycol, separation of at least part of the precipitated salts from the mono ethylene glycol, distillation of at least part of the water from the heated mixture, to yield hot dewatered mono ethylene glycol (lean MEG), wherein a first part of the hot dewatered mono ethylene glycol is lead back to the aqueous mono ethylene glycol feed to provide at least part of the heat for heating the aqueous mono ethylene glycol.

Method and apparatus for the removal of polyvalent cations from mono ethylene glycol

The present invention concerns a method for lowering the water dew point subsea in a produced multiphase hydrocarbon fluid stream containing water, the method comprising the steps of: separating () the hydrocarbon fluid stream () into a liquid phase () and a first gas phase (); cooling () the first gas phase in a controlled manner to knock out water or condensing water and optionally other condensates while keeping the fluid above a hydrate formation temperature thereof; separating off condensed liquids () and a second gas phase; wherein the second gas phase () has a water dew point which is lower than that of the initial multiphase hydrocarbon fluid stream. The invention also concerns a system for lowering the water dew point subsea.

The invention relates to a multi-phase distribution system, a sub sea heat exchanger provided with such a multi-phase distribution system, the use of such a multi-phase distribution system and a method of temperature control for hydrocarbons. The invention provides an improved control over multi-phase mixtures comprising hydrocarbons and improvements in the controlling of heat exchanging processes.

Multi-phase distribution system, sub sea heat exchanger and a method of temperature control for hydrocarbons

The invention provides a process for the production of a lean liquid hydrate inhibitor composition from a rich liquid hydrate inhibitor composition in which the liquid hydrate inhibitor has a boiling point above that of water, which process comprises: (a) feeding said rich liquid hydrate inhibitor composition to a first distillation vessel; (b) withdrawing a water and inhibitor containing vapor from said first distillation vessel and feeding it to a second distillation vessel; (c) withdrawing water vapor from said second distillation vessel; (d) withdrawing a lean hydrate inhibitor composition from said second distillation vessel in liquid form; (e) withdrawing a lean hydrate inhibitor composition from said first distillation vessel in liquid form; (f) withdrawing liquid from said first distillation vessel and removing solids therefrom; wherein the withdrawal of steps (e) and (f) may be of a single liquid stream and wherein at least a portion of the lean hydrate inhibitor composition withdrawn from said first distillation vessel is not recycled into said first distillation vessel.

Growing community of inventors

Ranheim, Norway

Baard Kaasa