Theboundaryintegralmethod(BIM)isusedtosimulatethe3-Dgasbubble,generatedwithinthetwobubblepulsationperiodsinproximitytoafreesurfaceinaninviscid,incompressibleandirrotationalflow.ThepresentmethodiswellvalidatedbycomparingthecalculatedshapesofthebubbleandthefreesurfacewithboththeexperimentalresultsandthenumericalonesobtainedbytheAxisymmetricBIMcode.Theexpansion,thecollapseofthegasbubbleandthefurtherevolutionofthereboundingnon-sphericalbubblearesimulated.Thevariousvariationpatternsofthefreesurfacespikeandthebubblecentroidfordifferentstandoffdistances,thebuoyancyparametersandthestrengthparametersareobtainedtorevealthenonlinearinteractionbetweenthebubbleandthefreesurface.Theamplitudeofthesecondmaximumbubblevolumeandthefourtypicalpatternsofthebubblejetandthefreesurfacespikeareexaminedinthecontextofthestandoffdistance.Thelargebuoyancyisusedtoelevatethespraydomeratherthanthefreesurfacespike.