| Considering the mining of heavy oil reservoir with high water cut, it is often difficult tochoose the measures like working in the water avoidance sidetracking, layer exchange and filllayer. And in the case of the differential effect of these measures, chemical water shutofftechnology in previous years has played a good role. It can boost yield dramatically and lowerwater cut increasing speed, but with the enlarge of the oil well flooding radius, the watershut-off effect of chemical water plugging and profiling technology is becoming less efficientin recent years. Analysis was believed that high temperature resistant plugging agent is unableto enter the reservoir in deep, cannot form a continuous closure strips wells belt, and dealswith a small radius. Therefore, the development of cheap and efficient high-temperatureplugging agent series with wide applicability to meet the site needs has a far-reachingpractical significance.The project is aimed at developing a modified tannin extract+nitrogen foam-based hightemperature blocking agent to solve the problems in heavy oil reservoir with high watercontent caused by edge and bottom water onrush, and also carrying out its performanceevaluation. Modified tannin extract chemical water shutoff technology is a selective blockingagent with modified tannin extract-based and cross-linked by water-soluble phenolic resin,featured by easy to pump and blocking ability, high temperature resistance, long shelf life.Nitrogen foam with steam injection can effectively block the high permeability layer,improve the steam swept volume, and enhance oil recovery. According to the characteristicsof the modified tannin extract chemical blocking agent, the conditions for well selection,construction parameters were optimized to ensure the success rate and efficiency of measures.There has the vital significance for the studies of this project to better solve the issues in theproduction and improve the comprehensive benefits of oilfield. |
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