P645 WELL DYNAMIC FRACTURING BY PRESSURE PULSES DAVID W. YANG 1 and RASMUS RISNES 2 Abstract 1 A new experimental set-up has been developed which can be utilised to study the dynamic fracturing by pressure pulses. The set-up employs a falling weight to impact on a piston that compresses the borehole fluid and transmits dynamic pressurisation to the simulated wellbore. The fracture pattern can directly be observed and examined after the impacting test. Altogether 63 tests have been conducted by using the developed set-up. Experimental results have proven a critical pressurisation rate at which multiple fractures begin to evolve. The