MODELLING AIR PERFORATORS FOR SERVICEABILITY

摘要

Perforating is important to oil and gas production. It is accomplished by detonating a plurality of shaped charges packaged inside a sealed tubular carrier of the perforating gun run into an oil or gas well. While the metallic jets generated from the detonated shaped charges create passages for oil or gas flowing from reservoir into well, the detonation may also cause damage or swell to the carrier in addition to the perforated holes. A split or over-swollen carrier will be stuck inside the well. It will obstruct production and is commonly regarded as a catastrophic failure. Therefore, it is necessary to have a reliable method to accurately predict the post-detonation conditions of the carrier before a perforating job is carried out. In this paper, we developed an energy based model to simulate the swell of perforator carriers after service used for gas wells. A serviceability or failure criterion was proposed and verified by both computational and experimental results. The model and serviceability criterion yield very good results consistent and confirmed to the data collected by laboratory tests.