The PUMA is a compact, efficient modular system for controlling the temperature of mission-critical drilling fluids – boosting both the efficiency and safety of drilling hole operations at relatively low cost.     Drilling high-pressure/high-temperature wells for oil and gas is often both risky and complicated. Temperature fluctuations, combined with the pressures associated with deep hole drilling, result in severe axial and tangential stresses at the borehole wall. At the same time, the drilling mud is heated by a combination of pressure and mechanical friction, and this heat is circulated by drilling action. This alters the basic rheology of the drilling fluids, affects the service life and accuracy of in-hole measuring devices, and can place the safety of drilling teams at risk. Using a PUMA system to provide effective control of the temperature of drilling fluids considerably reduces the risks involved in such operations. It also reduces operating costs due to extended elastomer service life and less wear and tear on the mud. In addition, fewer additives are needed, since the rheological properties of the drilling mud are kept much more stable. The PUMA mud temperature control system is a complete skid-mounted module that uses advanced plate heat exchanger technology to continuously cool the drilling mud, under stringent control. The system has a proven track record in oil and gas installations, where it has demonstrated an impressive impact on drilling efficiency. It also results in greater endurance and accuracy for in-hole measuring devices such as Monitor While Drilling (MWD) equipment and other logging tools, and makes it possible to use these at greater depths.