The “Blair Witch Project” filmmakers are betting that audiences will come back for more scary fare not once, but twice, with two planned sequels to the surprise movie hit of 1999, according to industry reports. Work on the first sequel is slated to begin in February; it’s being scheduled for a Halloween 2000 release, with “Blair Witch” writers-directors Eduardo Sanchez and Daniel Myrick serving as consultants (they’re currently working on their follow-up, “Heart of Love”). Just where the story will go remains to be seen (the movie’s three main characters met a grim fate at the end of the original). The movie’s three stars, Heather Donahue, Michael Williams and Josh Leonard, could appear in the second film, a prequel to the first movie, which will begin production in the Fall of 2000. Simultaneous production on two film sequels was also announced recently for another ’99 hit, “The Matrix.”