['Typical', 'surfactants', 'in', 'the', 'oilfield', 'services', 'industry', 'are', 'alkylphenol', 'ethoxylates', ',', 'e.g.', 'nonylphenol', 'ethoxylate', '(', 'NPE', ')', '[', '14,15,30,106,107', ']', '.']