主客体组装型采油聚合物制备及低渗高含水油藏驱油机理

Most reservoirs in China are in the states of low permeability and high water cut after half a century of oil exploitation. The high molecular weight acrylamide polymers cannot be applied well under the low permeability while the high water cut might increase the usage of surfactant significantly. Therefore, it is important to construct a new product that could ensure the high concentration of the surfactant in crude oil gathering place, and make the chemical agent have certain viscoelasticityand relatively low molecular weight.The technology strategy of this study was that surfactant was assembled into the cavities of modified cyclodextrins (CDs) first. Then the copolymerization with acrylamide and hydrophobic monomer was conducted to prepare low molecular weight polymer.The main contents are followed: (1) hydrophobic response effect wouldgenerate between the polymer and the oil phase component, then the surface active agent would get a release rate and the effective concentration in the crude oil gathering place. (2) Assembly mechanism, thermodynamic parameter and kinetic equation between the cyclodextrin cavities and hydrophobic side groups on the polymer backbone. (3) Study on the polymer viscosity changes through core displacement experiments, analyse the shear mechanism of self-healing function and build the relationship equation of super molecular force and shear force.

经过了半个世纪的原油开采，在我国大多数油藏都处于低渗透和高含水状态。低渗使高分子量丙烯酰胺聚合物无法应用，高含水增加了表面活性剂使用量。如何构建一种采油新介质，既保证表面活性剂在原油聚集处有较高的浓度，不是大量分散在油藏水中，同时又使化学剂具有一定的黏弹性而分子量却不是很大。本研究采取的技术策略是：先将表面活性剂等组装到改性环糊精的内腔中，再与丙烯酰胺和疏水单体共聚制备低分子量的聚合物，通过原油聚集处疏水识别释放表面活性剂和再组装聚合物疏水侧基实现上述目的。研究：（1）该聚合物与油层中的油相组分发生疏水响应效应（非油部位不会发生疏水响应），表面活性剂得到释放和原油聚集处表面活性剂的有效浓度；（2）释放表面活性剂的环糊精内腔与聚合物主链上的疏水侧基组装机理、热力学参数和动力学方程；（3）通过岩心驱替实验研究不同剪切时聚合物黏度变化，分析剪切自修复作用机理，建立超分子和剪切作用关系方程。

为了构建聚合物-表面活性剂主客体超分子采油新介质体系，从而克服聚合物分子量与渗透率间的矛盾关系。研究工作从环糊精羟基性质出发，经重氮化等反应得到单6-氨基-单脱氧-β-环糊精，再通过酰胺键改性得到了单-6-丙烯酰胺基-单脱氧-β-环糊精不饱和单体和丙烯酰胺基瓜环单体，最后分别与丙烯酰胺共聚制备出了具有组装功能的主体环糊精聚合物和瓜环聚合物。利用聚合物的环糊精空腔疏水性质组装了阳离子型表面活性剂及瓜环组装离子性能等从而构建了任务书中的主客体超分子采油新介质体系。.进一步研究了油藏组分对环糊精组装的表面活性剂（客体）的疏水响应释放、流变学性能及高含水低渗透条件下的驱油效果，给出这种采油新体系疏水识别和剪切组装修复的驱油机理。.完成了计划书中的全部研究目标。