$cont = file_get_contents($file);
preg_match_all("/-{14}[\n\r](.*?)-{14}/",$cont,$array);
print_r($array);
<?php
$str = <<<EOF
--------------
blablabla
1235546
dgffdggff
--------------
Нужен текст
blablabla
1235546
dgffdggff
EOF;
$parts = array_map('trim', preg_split('/^-+$/m', $str, -1, PREG_SPLIT_NO_EMPTY));
var_dump($parts);array(2) {
[0]=>
string(27) "blablabla
1235546
dgffdggff"
[1]=>
string(50) "Нужен текст
blablabla
1235546
dgffdggff"
}