新型聚酰胺-胺树枝状聚合物页岩抑制特性研究

树枝状聚合物由于其独特的分子结构和特性,近年来日益受到关注。聚酰胺-胺（PAMAM）作为研究最为成熟的树枝状聚合物,目前已在各领域得到应用,并在油田化学方向发挥潜力。采用抑制膨润土造浆实验、页岩滚动分散实验和粒度分布测试综合评价不同代数聚酰胺-胺树枝状聚合物的抑制性,借助表面张力、Zeta电位测试和X-射线衍射等表征测试了不同代数聚酰胺-胺的特性。结果表明,不同代数（G0~G5）聚酰胺-胺树枝状聚合物均具有优良的抑制性,其中G0和G5抑制性优于传统的KCl和国外聚胺Ultrahib。不同代数树枝状聚合物在黏土层间的吸附状态与其浓度有关,低浓度下为单层吸附,高浓度下为双层吸附。聚酰胺-胺树枝状聚合物表面胺基密度高,水溶液中部分质子化后,通过静电作用、氢键作用等强吸附在泥页岩表面,降低黏土水化斥力,排挤出层间水分子,抑制泥页岩水化分散。 

Shale Inhibition Characteristics of a New Polyamide-Amine Dendrimer

Dendrimers, because of their unique molecular structures and characteristics, have been receiving more and more attention in recent years. Polyamide-amine (PAMAM), the most understood dendrimer, has been widely used in many felds, including oilfeld chemistry. In a recent study, the inhibitive capacity of PAMAM with different generations was evaluated through bentonite yield test, hot rolling test and particle size distribution test etc. Using surface tension tester, Zeta potentiometer and X-ray diffraction tester, PAMAMs of different generations were characterized. It has been shown that PAMAM s of different generations (G0-G5) all have superior shale inhibitive capacity, better than that of KCl and Ultrahib (a polyamine product used as a shale inhibitor). The adsorption of PAMAMs in between the layers of clay is related to their concentrations. At low concentrations, the adsorption is monolayer adsorption; at higher concentrations, the adsorption becomes double-layer adsorption. PAMAM has high intensity of amine base at its surface, and after partial protonation in water, it is adsorbed on to the surface of clay particles through electrostatic force and hydrogen bond, reducing the hydration repulsion of clay particles and squeezing interlayer water molecules out of clay, thereby inhibiting the hydration and dispersion of shales.