How many are there in a book? http://greatlakesstudentloans.in.net www.greatlakesstudentloan.com Halliburton, a contractor involved in drilling the oil well that exploded in the Gulf of Mexico, destroyed computer simulations it performed in the months after the accident. Those simulations didn't bear out Halliburton's contention that BP PLC (BP, BP.LN), which owned the well, erred by not following its advice on using certain equipment, the Justice Department had said.