After oracle 10.2.0.1.0 patch set 10.2.0.4.0,It does not work

Hi,ALL 

After I set patch on oracle 10.2.0.1.0,update to 10.2.0.4.0,it does not wrk at all. Error as below

ERROR:
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist

When startup upgrade execute till to Redo Buffers   ,it stopped.

I want to konow why   startup upgrade  stop ?

How can connect   to orcale instance?     

SQL> conn sys/system as sysdba
SQL> startup upgrade
Total System Global Area  167772160 bytes
Fixed Size                  1295608 bytes
Variable Size              96471816 bytes
Database Buffers           62914560 bytes
Redo Buffers                7090176 bytes