Abstract:

The main reservoirs in Bohai have the characteristics of serious reservoir heterogeneity, large injection rate of single well and low cementation strength of rock. Due to the long-term water injection and polymer flooding, the rock structure has been destroyed and the dominant channel of water flow has been formed. This problem has caused the inefficient and ineffective circulation of the injected water. In this paper, we evaluated the gelling time, the plugging effect and the reservoir adaptability of the new inorganic geopolymer gel plugging agent by the static gelling test and the core displacement test. The results show that it is easy to adjust the curing time of the inorganic geopolymer gel. The curing time is adjustable between 20 ~ 480 hours. Based on the plugging experiments of the sandpack pipe, the plugging rate of the inorganic geopolymer gel was over 99 %. While the plugging experiment of a double pipe parallel model composed of the sandpack pipe and artificial homogeneous core bring us a plugging rate of high permeability layer more than 98 %. The permeability of the low permeability layer is almost unchanged. Therefore, the inorganic geological polymer gel has the advantages of plugging the large channel but not for the small pores. It is suitable for the plugging of the zones with ultra high permeability or the large channels in the reservoir.

Key words: inorganic geopolymer gel, gelling time, plugging rate, start-up pressure, reservoir damage