Shell Script to extract text from File

HI - I am looking for a Shell Script which can extract Text from the file. I have a logfile with name Server.log. It contains logs of a process. On any incident occurrence one KeyLine is being printed in log file as "Process Ends With ID# <16Digit Process ID>" I want to find all the such occurrence in the file and extract 2000 lines before this KeyLine and 1000 Lines after this KeyLine and Save in log with with name <16Digit Process ID>.log. The script should not be giving error for cases like if number of lines below KeyLine is less than 1000 then it should print all the lines below that <16Digit Process ID>rather giving exception of not having 1000 lines.