淀粉基可降解暂堵剂制备及性能评价

Development and evaluation of starch-based biodegradable temporary plugging agent

以玉米淀粉和3种丙烯酸类单体为原料,通过接枝反应,在交联作用下聚合,同时混掺纳米碳酸钙,制备了一种环保型可降解暂堵剂STA-2。STA-2热稳定性优于淀粉,在土壤中可降解,吸水后具有“变形虫”的特点,对不同渗透率的岩心封堵性较强,具有“自适应封堵”特点,岩心渗透率恢复值可达85%以上。STA-2对水基钻井液流变性影响较小,可降低滤失量,改善储层保护效果。

Based on the characteristics of starch-based water absorbing resin,starch and three acrylic acid monomers were polymerized by grafting and crosslinking reaction,while mixing nano-calcium carbonate to prepare an environmentally friendly degradable temporary blocking agent,STA-2.STA-2 had better thermal stability than starch and was degradable in soil.With the characteristics of“amoeba”after absorbing water,STA-2 had good plugging performance for low permeability,medium permeability and high permeability cores.The core permeability recovery value was more than 85%,which indicated that STA-2 had self-adaptability to formation of different permeability.With addition of STA-2,water-based drilling fluid had good rheology,reservoir protection and plugging performance.