Controlled Pulse Fracturing (CPF) is an emerging technology for stimulation of oil and gas producing formations. The CPF process uses an electrically ignited tool containing a solid propellant charge placed in the wellbore adjacent the zone requiring stimulation. Upon ignition, the CPF tool rapidly generates a high pressure gas pulse. This pulse of gas causes the rock to fracture and generates multiple, short (5-20 ft.) fractures, radiating from the wellbore. These fractures are partially propped by the scouring action of the high velocity gas which transports some of the formation particles down the induced fractures. The stimulated zone is usually contained within 3-6 ft. from the top and bottom of the tool. Another benefit of CPF is the reduction in pressure drop at the wellbore which can reduce solids dropping out of the flowing phase into the pore spaces (e.g., paraffin, scale, etc.) Although hundreds of CPF-type stimulations have been applied in oil and gas wells4,5,6 , little rigorous information on the actual success rates is available. Most of the stimulations have been attempted on low rate producers where a valid well test is almost impossible to acquire.7  Very little field data is available on the downhole pressure-time response during CPF stimulations. Also, mechanical aspects such as tool movement in the wellbore are poorly understood. In this paper, we will describe first the basis of the CPF stimulation technique. Laboratory results and field evidence will be presented to validate the theory. Applications of the CPF technique will be outlined. We shall discuss specific field cases on the following applications: 1) Penetrate past near wellbore damaged zones to ensure adequate connection with the formation (i.e. reduce skin), 2) Initiate connection of the wellbore to the zone to allow other stimulation fluids to efficiently and uniformly contact the formation (e.g., acid), and 3) Selectively stimulate isolated parts of a zone either to stay away from water producing zones or even out permeability profiles.

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