High Energy Gas Fracturing Pressure Profile Transmission

摘要

A monitor system has been successfully developed to measure and record the transient pressure profile during multiple radial fracturing (MRF) propellant stimulations of natural gas wells. The system consists of a downhole device that houses pressure transducers, data transmission cables to the surface, and signal conditioning and recording equipment at the wellhead. The development effort included design, fabrication and test activities. Use of the monitor was demonstrated in three stimulation events conducted in Devonian shale gas wells. The downhole package was assembled from commercially available hardware and a few custom components. The monitor is about 17 feet long by 1-11/16 inch diameter. Two piezoelectric crystal pressure transducers are spaced five feet apart in the monitor. Coaxial cables (one per transducer) run from the monitor to the surface, periodically fastened to an armored wireline. A quality instrumentation tape deck is used to record the data. The measured frequency response of the system is flat to 40 kHz. A series of 55 design tests were run in an above-ground fixture to evaluate components and design alternatives. Two oil wells about to be plugged and abandoned were then employed to run six deep well tests of the monitor where commercial propellant stimulation charges were fired. Deployment procedures for the monitor were worked out in these tests.