[经] cost per well drilled
píng jūn yī kǒu jǐng de zuàn jǐng chéng běn ㄆㄧㄥˊ ㄐㄩㄣ ㄧ ㄎㄡˇ ㄐㄧㄥˇ ㄉㄜ˙ ㄗㄨㄢˋ ㄐㄧㄥˇ ㄔㄥˊ ㄅㄣˇ