丙烯酰胺类聚合物在储层岩石表面的吸附行为

Adsorption Behavior of Acrylamide Polymers on Reservoir Rock Surface

杨玉坤 李骏涵 于明 杨嗣民 敖宏丹 罗平亚 林凌

YANG Yukun LI Junhan YU Ming YANG Simin AO Hongdan LUO Pingya LIN Ling

研究聚合物在油气储层岩石表面的吸附滞留对于工作液配方优化、提升非常规油气藏经济效益具有重大 意义。为分析储层岩石与丙烯酰胺类聚合物的吸附作用，采用淀粉-碘化镉法间接测定了部分水解聚丙烯酰胺 （HPAM）、部分水解丙烯酰胺/二烯丙基二甲基氯化铵共聚物（HPAD）和丙烯酰胺类疏水缔合聚合物（HAP）在页 岩、煤岩和砂岩表面的吸附量，量化了吸附时间、聚合物浓度、温度和矿化度对3 种聚合物在岩石表面吸附行为的 影响。结果表明，HPAM和HAP在岩石表面的吸附更符合准二级吸附动力学模型，而HPAD则更符合准一级吸 附动力学模型。与HPAD和HAP相比，HPAM平衡吸附量更大。3 种聚合物在储层岩石上的吸附过程都更符合 Freundlich 吸附模型。达到吸附平衡所需时间与聚合物、储层岩石种类密切相关。HPAM在3 种岩石表面的吸附 会达到饱和，而HPAD和HAP的吸附量随着时间推移而增加。温度升高，会导致解吸附加剧，从而导致吸附量下 降；溶液矿化度升高，聚合物的溶解度降低，导致吸附量增加。聚合物在储层表面的持续吸附是其在工作液中消 耗的主要原因。HPAD和HAP可能会由于其在储层岩石表面的持续吸附，导致有效浓度过低而使工作液失效。

The adsorption and retention of polymers on the surfaces of oil and gas reservoir rocks play a significant role in the optimization of drilling fluid formulations and enhancing the economic benefits of unconventional oil and gas reservoirs. In this study，the adsorption of partially hydrolyzed polyacrylamide（HPAM），partially hydrolyzed poly（acrylamide/ diallyldimethylammonium chloride）（HPAD），and hydrophobically associating polyacrylamide（HAP）on shale，coal rock，and sandstone surfaces was indirectly measured by starch cadmium iodide method. The adsorption quantities were quantified. The effects of adsorption time，polymer concentration，temperature，and salinity on the adsorption behavior of the three polymers on rock surfaces were analyzed. The results indicated that the adsorption of HPAM and HAP on rock surfaces conformed more closely to the pseudo-second-order adsorption kinetic model，while that of HPAD adhered more closely to the pseudo-first-order adsorption kinetic model. Compared with HPAD and HAP，HPAM exhibited a higher equilibrium adsorption capacity. The adsorption processes of all three polymers on reservoir rocks better fit the Freundlich adsorption model. The time required to reach adsorption equilibrium was closely related to the polymer and the type of reservoir rock. The adsorption of HPAM reached saturation on the surfaces of all three rock types，while the adsorption of HPAD and HAP increased over time. An increase in temperature intensified desorption，resulting in a decrease in adsorption quantity. Conversely，an increase in salinity reduced the solubility of polymers， leading to an increase in adsorption quantity. The continuous adsorption of polymers on reservoir surfaces was the main reason for their consumption in drilling fluids. The sustained adsorption of HPAD and HAP on reservoir rock surfaces might result in the failure of drilling fluids due to their low concentrations.

10.19346/j.cnki.1000-4092.2024.02.005