ConocoPhillips $2,694,932 Westlake Chemical Corp $1,572,466 Schlumberger Ltd $1,432,373 Oasis Petroleum Inc. $562,460 ConocoPhillips $2,694,932 Westlake Chemical Corp $1,572,466 Schlumberger Ltd $1,432,373 Oasis Petroleum Inc. $562,460