Rheochem is an oilfi eld services business that supplies drilling fluids to oil and gas companies in Australia and New Zealand. This drilling fluid, or mud, is a blend of chemicals that is used to help drill oil and gas wells which couldn't be drilled otherwise. It has many functions including control of formation pressure, lubricating the drill string, keeping the bit cool and maintaining borehole stability. Rheochem has taken the decision to move into oil and gas exploration. Its subsidiary Lochard Energy has acquired a 55% working interest in 12 wells in Texas as well as stakes in North Sea blocks.