SharePoint - Value does not fall within the expected range in SPQuery

 SPList oList = oWebsiteRoot.Lists["List_Name"];

    SPQuery oQuery = new SPQuery();
    oQuery.ViewFields = "<FieldRef Name='Field1'/>" + 
        "<FieldRef Name='Field2'/>";
    oQuery.Query = "<Where><Geq><FieldRef Name='Field2'/>" +
        "<Value Type='Number'>1000</Value></Geq></Where>";
    SPListItemCollection collListItems = oList.GetItems(oQuery);

    foreach (SPListItem oListItem in collListItems)
    {
        .......
    }