A method of supplying injection fluid to a subsea facility

Abstract

A method of supplying injection fluid to a subsea facility, the method includes the step of arranging a storage container at a first subsea location, supplying the storage container with injection fluid from a surface facility, moving the storage container to a second subsea location and supplying the injection fluid from the storage container at said second subsea location to the subsea facility, wherein the second subsea location is closer to the seabed than the first subsea location. Preferably the storage container at the second subsea location is supported by the seabed.

What is claimed is: 
     
         1 . A method of supplying injection fluid to a subsea facility, the method comprising the steps of:
 arranging a storage container at a first subsea location,   supplying the storage container with injection fluid from a surface facility,   moving the storage container to a second subsea location and   supplying the injection fluid from the storage container at said second subsea location to the subsea facility,   
       wherein the second subsea location is closer to the seabed than the first subsea location. 
     
     
         2 . The method of  claim 1 , wherein the first subsea location is a subsea location below the splash zone, such as at least about 2.5 m below the splash zone. 
     
     
         3 . The method of  claim 1 , wherein the first subsea location is a subsea location from about 10 m to about 100 m below the water surface. 
     
     
         4 . The method of  claim 1 , wherein the second subsea location is at least about 100 m below the first subsea location. 
     
     
         5 . The method of  claim 1 , wherein the storage container is a rigid container, a flexible container or a combination thereof. 
     
     
         6 . The method of  claim 5 , wherein the container comprises a flexible container and where the storage container in the second subsea location is at least partly enclosed in a mechanical protection structure. 
     
     
         7 . The method of  claim 6 , wherein the method comprises moving the flexible storage container from the first location to the second location, comprising encasing said flexible storage container in said mechanical protection structure at said second subsea location. 
     
     
         8 . The method of  claim 5 , wherein the mechanical protection structure is a rigid mechanical protection structure. 
     
     
         9 . The method of  claim 7 , wherein the storage container encased in the mechanical protection structure in the second position is arranged directly at the seabed. 
     
     
         10 . The method of  claim 9 , wherein the storage container optionally encased in the mechanical protection structure in the second position is arranged at a foundation structure. 
     
     
         11 . The method of  claim 1 , wherein the storage container has a storage capacity of at least about 500 m 3 . 
     
     
         12 . The method of  claim 1 , wherein the storage container is maintained substantially at the first location during the supplying of the storage container with injection fluid from the surface facility. 
     
     
         13 . The method of  claim 1 , wherein the subsea facility comprises a subsea facility comprising at least one of a drilling facility or a production facility. 
     
     
         14 . The method of  claim 1 , wherein the surface facility comprises a floating unit. 
     
     
         15 . The method of  claim 1 , wherein the method comprises launching the storage container from the surface facility prior to arranging the storage container at the first subsea location. 
     
     
         16 . The method of  claim 1 , wherein the method comprises lifting the storage container from its second location prior to arranging the storage container at the first subsea location. 
     
     
         17 . The method of  claim 16 , wherein the method comprises decoupling an injection pipe from the storage container prior to lifting the storage container from the second location. 
     
     
         18 . The method of  claim 1 , wherein the method comprises coupling an injection pipe to the storage container for supplying the injection fluid from the storage container to the subsea facility after having located the storage container at the second location. 
     
     
         19 . The method of  claim 1 , wherein the method comprises coupling a supply pipe to the storage container for supplying the storage container with injection fluid from the surface facility and decoupling the supply pipe from the storage container prior to moving the storage container from the first location to the second location, wherein the coupling of the supply pipe to the storage container is performed at the first location. 
     
     
         20 . The method of  claim 1 , wherein the injection fluid is selected from inhibitors, dispensing agents, descalers, biocides, demulsifiers, buoyant and non-buoyant chemicals, MEG, methanol or any combinations comprising one or more of these.