注聚调驱井聚合物堵塞物的矿物复合结构形貌及组成特征

Mineral morphology and composition characteristics of the plugging materials in polymer flooding

胜利油田渤19区块注交联聚合物开采多年后,因注入水的水质不达标导致聚合物过度交联形成强凝胶,造成聚合物注入区块许多油水井的堵塞。对现场聚合物垢样品所做的化学组分、表面元素能谱及红外光谱的研究表明,垢的主体结构由交联的聚丙烯酰胺组成,交联体吸收了大量水分,在交联体内小环境中因富集而形成氯化物矿物晶体无机垢结构,而在成垢的过程中又将地层内的一些粘土矿物包裹于交联体内,形成具有聚合物-矿物复合结构的强胶凝态物质,严重影响聚合物注入—调剖—驱油过程中的聚合物溶液的流动。

By the comprehensive analysis of the cases of polymer flooding and profile control in the Block B19 in Shengli Oilfield,it is suggested that the main factor causing plugging in B19 was the injecting water that did not meet the standards of water flooding,which caused the excessive cross-links of the injecting polymer and the formation of strong gelatinous material.The chemical analysis,the energy spectroscopy and the IR spectroscopy were used to investigate the mineral morphology and main compositions of gel scales.It was shown that the gel scales are composed of cross-linked polyacrylamide（PAM）,in which a mass of water have been absorbed.The chloride mineral crystals as the inorganic scale material were gradually enriched and formed the inorganic scale structures in vivo environment of cross-linked polymeric inclusions.Moreover,some clay minerals from the formation were wrapped into the polymeric inclusions,eventually leading to the formation of the strong gelatinous materials with the complex polymer-mineral structural characteristics,which seriously affected and even obstructed the flow path of the polymer solution in polymer profile control and polymer flooding.