$re = '/<script(.*?)(?!<\/script>)(.*?)wrapperId={wrapper_id}(.*?)<\/script>/s';
$str = '<script type="text/javascript"> var blah; </script><script id="bleh" type="text/javascript" src="//domain/test.js?siteid=270606&testmode=0&banner360=1&banner=0&placementid=0&tp=3&wrapperId={wrapper_id}" > </script>';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php