关键词: 纳米乳液, 储层保护,  , 页岩气, 水基钻井液

Abstract: Water sensitive damage and liquid trap caused by waterbased drilling fluid invasion are very prominent problems in the process of shale gas drilling and exploitation, which seriously affect drilling safety and production of shale gas well. According to the shale gas reservoir characterization and reservoir damage factor, based on nanoemulsion theory and basic reservoir protection principle, a novel nanoemulsion agents named SDME2 were developed by employing Gemini hyamine surfactant GTN, plus Tween 80, namyl alcohol and noctane as major raw materials. The results showed that the novel nanoemulsion agent could effectively reduce the surface tension of external fluid, increase contact angle, decrease water saturation in core, and increase recovery of low permeability reservoir permeability. The novel nanoemulsion agent was also conducive to shale gas desorption. Taking the newly developed shale gas reservoir protection agent as one of primary treatment agents, a new type of waterbased drilling fluid for shale gas reservoir protection was developed and its performance was good.

Key words: Nanoemulsion,    ,  Reservoir protection,    ,  Shale gas,    , Waterbased drilling fluid