be well aware 《of》
have a thorough [full, detailed] knowledge 《of》
be familiar 《with》
【形式ばった表現】 be well acquainted 《with》
know something fully [very well]
be fully [well, thoroughly] posted 《on, about, concerning》
be at home with 《things Japanese》
be well up in [on] 《current events》
have something at one's fingertips