Bacterial contamination is a key concern for the oilfield industry. Biocides are used to control sulfate-reducing bacteria, slime-forming bacteria, iron-oxidizing bacteria and bacteria that attack polymers in drilling and completion fluids. High performance, broad-spectrum biocides are essential for the continued safe operation of oil and gas wells. The OS GIOCIDE and OS SAFE-GUARD are broad spectrum biocides based on glutaraldehyde and THPS chemistry. OS PRO-TECT O is an all-in-one combined corrosion inhibitor, biocide and oxygen scavenger. OS PRO-TECT H is an all-in-one combined corrosion inhibitor, biocide and H2S scavenger.