油田堵漏剂微胶囊技术的研究

Study on Microencapsulation Technology of the Lost Circulation Material for the Oil Field

由于高吸水性固体颗粒吸水后体积会增加几十倍乃至更大,所以以它为芯材制备微胶囊有一定的难度.本实验就是以高吸水性固体颗粒为芯材,选择合适的壁材来制备微胶囊.实验以流化床喷涂法(现今已被广泛应用)制备油田堵漏剂微胶囊,结果证实了壁材的可适用性.此外还探讨了壁材的流量、压缩空气的流量、喷嘴高度及颗粒大小对微胶囊壁厚及表面形态的影响.确定了微胶囊制备的最佳工艺条件为:壁材流量Q=122mL·h-1,压缩空气流量q=0.76m3·h-1,喷嘴高度H=11.5cm,芯材粒径为dP=0.454mm,在此条件下的最佳壁厚度为:190～200μm.

The volume of highly-water-absorbed solid particles increases greatly after they absorb water. Thus, they are very difficult to be microencapsulated. In this paper, highly-water-absorbed solid particles were used as core materials, and the harden fat (HF) as the appropriate wall-material was chosen to produce the microcapsules. Fluidized-bed spraycoating method was chosen to produce the lost circulation material microcapsules for the oil field. The applicability of the wall material HF was verified. The effects of the flowrate of the wall-material and the pressed air, the height of the nozzle and the size of the core-material on the capsule wall thickness as well as the surface characteristics of the microcapsule, were studied. The optimal process parameters to produce lost circulation material microcapsules for the oil field were determined as follows: the flowrate of the wall-material Q =122mLh-1, the flowrate of the pressed air q =0.76m3h-1, the height of the nozzle H=11.5cm, the size of the core-material dp=0.454mm. The optimal membrane thickness obtained under those optimal parameters mentioned above is 190~200mm.