From answer from this page http://petanque.org/news/rules/105.shtml I understand, that I can play different boules, it's ok. But I want to know: may a have 4 boules during the play (in necessary 2 for point or 2 for shooting)?

The answer to your question can be found in the following excerpts from the official rules:

Article 1
In triples, each player uses 2 boules.
In doubles and singles, each player uses 3 boules.
No other version of the game is allowed.

Article 10 a – Changing of jack or boule
Players are forbidden to change the jack or a boule during a game except in the following cases:
1) The one or the other cannot be found, the search time being limited to 5 minutes.
2) The one or the other is broken: in this case the largest part is taken into consideration. If boules remain to be played, the aforementioned is immediately replaced, after measuring, if necessary, by a boule or a jack of identical or similar diameter. At the next end the player concerned can take a new complete set.

hello friends I think there must be 10 sets of new boule successful.that if players could have long boule.tq