ORACLE CLOB problem

Pleas can you help me?
I Have problem with ORACLE CLOB field. I try copy data
from clob field into richedit, but this not working.

procedure TForm1.SpeedButton1Click(Sender: TObject);
var
  TempStream : TMemoryStream;
  Stream1    : TBlobStream;
begin
  TempStream := TMemoryStream.Create;
  try
    Query1TXT_CLOB.SaveToFile('1.TXT');
    Stream1 := TBlobStream.Create(Query1TXT_CLOB, bmRead);
    TempStream.CopyFrom(Stream1, Stream1.Size);
    TempStream.Position := 0;
    RichEdit1.Lines.LoadFromStream(TempStream);
  finally
    TempStream.Free;
    Stream1.Free;
  end;
end;