Patents by Inventor Sverre Anderssen

Sverre Anderssen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Use of manganese oxide in drilling mud and oil well cement slurries
    Patent number: 5007480
    Abstract: The present invention relates to the use of manganomanganic oxide particles containing at least 90% by weight of manganomanganic oxide, said particles having a density of 4.50 to 4.75 g/cm.sup.3 and a particle size of at least 98% below 10 .mu.m, as a weight material for drilling mud fluids and for cement slurries for cementing oil wells.The manganomanganic oxide particles which are used are preferably recovered from off-gases which evolves during refining of ferro-manganese melts.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: April 16, 1991
    Assignee: Elkem A/S
    Inventor: Sverre Anderssen