CIBlockElement::SetPropertyValues

$update_el = array(
               "ID" => $ID_portal,
               "IBLOCK_ID" => $BLOCK_ID,
               "PROPERTY_VALUES" => array(
                  "id_system" => $ID_otrs,
                  "status" => 'На рассмотрении',
                  "otvet" => $up_el,
               ),
         );
      CIBlockElement::SetPropertyValuesEx($ID_portal, $BLOCK_ID, $update_el["PROPERTY_VALUES"]);