sed or operator in set of regex

sed or operator in set of regex

The bash script I wrote is supposed to modify my text files. The problem
is the speed of operation. There are 4 lines of each file I want to
modify.
This is my bash script to modify all .txt files in a given folder:
srcdir="$1" //source directory
cpr=$2 //given string argument
find $srcdir -name "*.txt" | while read i; do
echo "#############################"
echo "$i"
echo "Custom string: $cpr"
echo "#############################"
# remove document name and title
sed -i 's_document=.*\/[0-9]\{10\}\(, User=team\)\?__g' $i
# remove document date
sed -i 's|document date , [0-9]\{2\}\/[0-9]\{2\}\/[0-9]\{4\}
[0-9]\{2\}:[0-9]\{2\}:[0-9]\{2\} MDT||g' $i
# remove document id
sed -i 's|document id = 878h67||g' $i
# replace new producer
sed_arg="-i 's|Reproduced by $cpr|john smith|g' $i"
eval sed "$sed_arg"
done
I dont know how to concatinate all my sed commands in one command or two,
so the job would be done faster ( I think! )
I have tried the OR operator for regex | but no success.