The Gordian Technology Of Extending Sand Control Life And Improved Oil Recovery In Polymer Injection Zone

About 80% of the polymer injection zone in Shengli Oil Field is unconsolidated sand reservoir, and sand control technology plays an important role in the recovery of polymer injection zone. Nowadays, in the polymer injection zone of Gudong, Gudao unconsolidated sand reservoirs have appeared some problems such as sand producing is getting worse, longevity of sand control is getting shorter, packing zone is plugging by polymer, pressure of the polymer injecting well is getting higher, etc. According to these problems, we need to find some methods to solve them. On the base of investigation and statistics to these problems, also with the theory analyzing and experiment research, we realized the specialty, from the micron migration and infiltrating fluid drafting aspect, of the sand producing mechanism in polymer injection zone oil wells, and discussed the relationship between different polymer concentration and oil well sand producing extent. Then, we analyzed the main reason which leads low fluid production in polymer injection zone. During this process, we pay our main effort on researching of the polymer plugging mechanism in sand control well, and found out that the both affection of the polymer attachment and micron bridge plug leads to plugging of sand control packing zone. In view of the problems appeared in polymer injection zone and base on the acknowledgement to sand preventing rule of different size packing gravel arrangement, we developed ranking pack new sand control process with which fiber is blending with gravel. With this new process, the function of sand preventing, sand steady and sand removing is obtained. At the same time, in order to accommodate more fluid production and enhance the polymer injection zone affection, we developed assorted sand control process for polymer injection zone oil wells. In order to solve the plugging near well bore, we developed new kind FSAY assay polymer plug breaking agent. We also developed new kind FSAF-1 assay sand control packing zone preventing agent which can inhibit the polymer plugging and prolong the plug breaking longevity. With the demonstration of the field experiment, these research outcomes successfully solved the tough sand control problems in polymer injection zone and formed an assay of sand control technologies which is suitable for polymer injection zone oil wells.