LAUSR

AbstractAs one of the important additives in the process of petroleum’s exploitation, the gel breaker is a key factor to determine whether the exploitation can be completed successfully. Here, a novel porous SiO2 aerogel microsphere loaded with ammonium persulfate (aAPS) with obvious delay-releasing performance under higher temperature and pressure was synthesized by the process of sol–gel and water-in-oil (W/O) inverse emulsion polymerization. The obtained gel breaker was characterized by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR). The releasing rate of ammonium persulfate of gel breakers under different conditions was determined by pH meter method. The results show that the loading of APS is about 53 wt% and the releasing rate is significantly affected by temperature and time. The whole process showing the preparation and the release process of aAPS is illustrated in Fig. 1. Porous silica aerogel microspheres were prepared by sol-gel and water-in-oil (W/O) inverse emulsion polymerization. During the drying process, ammonium persulfate precipitates are still present in these pores when the solution evaporates in the microsphere and then are successfully obtained by the silica aerogel loaded with ammonium persulfate. During the release process, ammonium persulfate has a concentration difference in the interior of the microsphere and in the environment of the system. Under this concentration difference, APS gradually diffuses into the environment of the system. The presence of the network skeleton of silica aerogel microspheres can greatly prolong the diffusion path of ammonium persulfate, hindering the mutual diffusion and penetration of ammonium persulfate and water molecules, so the breaker has a certain delay release.HighlightsThe preparation of a novel silica aerogel-based gel breaker by a simple and industrialized method.The releasing rate of the gel breaker can reach about 65% at the temperature of 70 °C.The gel breaker has obvious delay-releasing performance under high temperature and pressure, which can reach about 120–130 min when the temperature reaches up to 70 °C.SiO2 as an environmentally friendly material, instead of polymer materials, greatly reduces the pollution to the environment.