Sand control and water drainage by ultrasonic atomization for gas recovery from hydrate reservoirs

Abstract:

Hydrate reservoirs have the characteristics of weak consolidation， high clay content and low permeability， which is prone to lead to serious problems of wellbore and reservoir instability, low gas production and sand production during drilling and production. Sand production is a bottleneck which restricts the safe and efficient exploitation of hydrate. The existing sand control technology of NGH reservoir mainly comes from the sand control methods commonly used in conventional petroleum exploitation， and the contradiction between sand control precision and permeability enhancement is prominent. This paper proposes a gas recovery method with ultrasonic atomization for sand control and water drainage for hydrate reservoirs， which can effectively block sand greater than 10 microns，and produce water in the form of mist with small droplets of about 5 microns， so as to realize continuous production of water and gas. Preliminary simulation experiments were carried out based on an experimental simulation evaluation device. Results show that the method is feasible and water mist can be produced continuously through the cone holes of the atomizing plate. However， the atomization device needs to be further optimized due to the presence of mud contents； otherwise the mud contents will seriously affect atomization. The preliminary work can provide a new idea for sand control and gas recovery enhancement in hydrate reservoirs.

Key words:hydrate;sand control;drainage;gas production;ultrasonic atomization