OracleDataReader dr = cmd.ExecuteReader();

ORA-00911
invalid character

Cause: identifiers may not start with any ASCII character other than letters and numbers. 
$#_ are also allowed after the first character. Identifiers enclosed by doublequotes may contain 
any character other than a doublequote. Alternative quotes (q'#...#') cannot use spaces, 
tabs, or carriage returns as delimiters. For all other contexts, consult the SQL Language Reference Manual.

public OracleDateTime GetOracleDateTime(
	int i
)

 richTextBox1.Text = dr.GetString(0);

string oradb = "Data Source=BI_TEST;User Id=scott;Password=tiger;";
            OracleConnection conn = new OracleConnection(oradb);  // C#
            conn.Open();
            OracleCommand cmd = new OracleCommand();
            cmd.Connection = conn;
            cmd.CommandText = "select name from c_objects where id=9205";
            cmd.CommandType = CommandType.Text;
            OracleDataReader dr = cmd.ExecuteReader();
            dr.Read();
            richTextBox1.Text = dr.GetString(0);
            
            //public OracleDateTime GetOracleDateTime(1);
            //label1.Text = dr.GetOracleDate(0);

            OracleCommand cmd2 = new OracleCommand();
            cmd2.Connection = conn;
            cmd2.CommandText = "SELECT TO_CHAR(CURRENT_DATE, 'DD-MON-YYYY HH:MI') FROM DUAL";
            cmd2.CommandType = CommandType.Text;
            OracleDataReader dr2 = cmd.ExecuteReader();
            dr2.Read();
            //richTextBox1.Text = d2.GetString(0);
            label1.Text = dr2.GetString(0);

            conn.Dispose();