缩膨剂防膨和缩膨机理探究

Anti Swelling and Shrinkage Swelling Mechanism of Shrinkage Swelling Agent

对于泥质含量高、渗透率低的油藏,缩膨剂能起到降压、增注的效果,但尚无相关机理的研究报道。针对这一问题,考察了含有季铵、伯胺基团的缩膨剂(DSJ-1)加量对膨润土防膨率和缩膨率的影响,并对处理前后的膨润土进行了X射线衍射(XRD)、X射线荧光光谱(XRF)、Zeta电位、热重分析、粒度分布和光学显微镜表征,对DSJ-1的防膨和缩膨机理进行了分析。结果表明,在防膨处理过程中,DSJ-1主要吸附在膨润土表面,吸附量、Zeta电位对防膨率的影响最大;在缩膨处理过程中,DSJ-1主要吸附在晶层间,颗粒聚集体尺寸、Zeta电位影响缩膨率的大小。

For reservoirs with high mud content and low permeability,shrinkage swelling agent can reduce pressure and increase injection,but there are no research reports on the relevant mechanisms.In order to solve this problem,the influence of the dosage of shrinkage swelling agent(DSJ-1)containing quaternary ammonium and primary amine groups on the anti swelling rate and shrinkage swelling rate of bentonite was investigated.Then the bentonite before and after treatment was characterized by X-ray diffraction(XRD),X-ray fluorescence spectrum(XRF),Zeta potential,thermogravimetry,particle size distribution and optical microscope.The anti swelling and shrinkage swelling mechanism of DSJ-1 was analyzed.The results showed that during the anti swelling treatment process,DSJ-1 was mainly adsorbed on the surface of bentonite.The adsorption amount and Zeta potential had the greatest impact on the anti swelling rate.During the shrinkage swelling treatment,DSJ-1 was mainly adsorbed between crystal layers.The particle aggregate size and Zeta potential affected the shrinkage swelling rate.