The Research Of Adaptive Plugging System In High Salinity Reservoir In The Underground

The ion concentration of high salinity reservoirs is high,the requirement for salt of the plugging agent is high,conventional systems exist the problems that the performance of plugging agent is poor,the intensity of block is poor,the valid of measure is short.In this paper,according to the characteristics of high salinity reservoirs and existing problems of the agent,we had developed the emulsion plugging system and gel plugging agent system for the high salinity reservoirs which can resist high salt and high metal ions,they have good stability.The emulsion plugging system applies to the total salinity concentration of 5000mg/L²5000mg/L,it could produce the largest amount of precipitation in the concentration of 20000mg/L,it is suitable for the concentration of Ca²⁺、Mg²⁺ higher than 5000mg/L,the blocking rate can reach 95%⁹8%;the gel plugging agent system applies to the lowest total salinity concentration range from 95000mg/L to 14000mg/L,it is suitable for the concentration of Ca²⁺、 Mg²⁺ in the lowest range of 5000mg/L⁷000mg/L,10000mg/L¹3000mg/L or more formations,the blocking rate can reach 94%⁹9%.The mechanism of the adaptive plugging system were discussed,the emulsion plugging system through the emulsion reach the first block,after the emulsion broke up,the reaction produced precipitation as the second block and enter into large pores selectively,the gel plugging agent system reach the block through the formation of gel,through the chemical and physical effects with the metal ion in the high salinity reservoir,they achieve the effective plugging to the high permeability layer and large pore.The adaptive plugging process is optimized by changing the composition of the system,designing a suitable means of implantation process in the specific formation of large pore achieve the plug in the appropriate time and appropriate place and the role and mechanism is analyzed.The design of technology solutions and injection parameters are optimized,it aims to provide a set of adaptive plugging technology for high salinity reservoirs.