The Dynamic Stability Loop (DySL) by PSL Systemtechnik was designed to test long-term stability of umbilical chemicals in the lab at very stringent conditions. The DySL combines up to six loops for measurements of long-term changes of viscosity and tube blocking tendencies at pressurized conditions.
The test facility consists of up to 6 high pressure pumps, circulating the product sample through a hot and a cold bath under pressurized condition. Each flow cycle is providing extreme stress on the product by continuous changes of flow and non-flow, high and low pressure and hot and cold environment conditions and simulates umbilical line conditions. Two capillaries per line are integrated to check for viscosity changes, e.g. by limited product stability or by emulsification / demulsification processes. Furthermore two filters per line allow to execute filter blocking tests. If required, the filter frits can be replaced or cleaned externally, fast and easy. An increase in differential pressure between the inlet and the outlet of the test capillary indicates a risk of umbilical plugging due to viscosity changes or wall depositioning effects.
In both conditions, in the hot bath as well as in the cold bath, the viscosity and the filter blocking tendency is continuously measured by monitoring differential pressure and checking for any long-term pressure changes. User defined settings of absolute pressure, back pressure and temperatures allows simulating a wide range of umbilical conditions, starting from on-shore up long tie back deepwater applications.
In respect to extensive testing demands, the Dynamic Stability Loop is specially designed for multiple loop test runs. It comprises up to 6 test loops for parallel testing of different alternative oilfield chemicals or different product types. Each loop is operated separately. Cleaning and refill is possible while other loops are still running. Measurement capillary and filter plates can be replaced by user. If required, tests can be performed for up to 30 days and more.
Only a small amount of sample is needed (< 20 ml) to fill a test loop. The sample media can be pumped in a closed loop or an open loop. In an open loop the sample is always pumped back to the reservoir. This allows the reservoir fluid to be pumped. Thus, the sample amount can be increased up to a maximum of 500 ml. In a closed loop only the amount of sample in the loop (Ø10 ml) is pumped.
Data examination with software
The software WinDySLenables a comfortable control of the instrument and simple data-acquisition. Different additional recording options are selectable to analyze various aspects of an experiment. The software also provides an integrated tool to execute a quick calibration of the pressure sensors to balance long-term shift of sensor readings.