Obtaining frequently occurring phrases using Word2Vec
You may use gensim phrase vectorizer module available in Python.
You need to give threshold value which is some sort of pmi of words. The higher this value less are the number of phrases the default is 10. You can play around with this value to get results for your data.

phrase_threshold = 1
bigram = Phrases(sentences,threshold=phrase_threshold)

This is based on this based on the skipgram paper by Tomas Mikolov.