gistfile1.cs

 private List GetCostAnalysisList()
        {
            var lists = Sharepoint.LoadQuery(
                Sharepoint.Web.Lists.Where(list => list.Title == "cost-analysis-worksheets"));

            Sharepoint.ExecuteQuery();

            return lists.FirstOrDefault();
        }


private void UploadWorksheetToSharepoint(string fileName, string userName, Stream stream)
        {
            var content = new byte[stream.Length];
            stream.Read(content, 0, content.Length);

            var list = GetCostAnalysisList();

            var upload = list.RootFolder.Files.Add(new FileCreationInformation
                                                       {
                                                           Overwrite = true,
                                                           Url = fileName,
                                                           Content = content,
                                                       });
            Sharepoint.Load(upload);
            Sharepoint.ExecuteQuery();
        }