Effect of microscopic aggregation behavior on polymer shear resistance

Abstract

The study of polymer aggregation behavior effect on shear resistance shed light on the synthesis of antishear polymer for oil displacement and enhances the application effect of polymer flooding. The effects of mechanical degradation on the properties of polymer solutions were studied by using partially hydrolyzed polyacrylamide (HPAM), hydrophobically modified HPAM (HMPAM), and dendritic hydrophobic associative polymers (DHAP), which are characterized by "granular," "chain," and "cluster" aggregation behavior, respectively. The results show that mechanical shearing can dramatically reduce the performance of polymer solution. The shearing resistance can be effectively enhanced by improving the polymer aggregation behavior. After being strongly sheared, hydrophobically associating polymers can still partially restore its network through hydrophobic association, therefore rebuild the solution viscosity. For DHAP, the broken molecular chains distribute more evenly in solution after shearing. In addition, the strength of reconstructed network structure of DHAP is better than that of HMAPM, which implies a better shear resistance. Furthermore, the hydrophobic association of linear polymers will increase their static adsorption on quartz sand. Meanwhile, DHAP with stronger spatial structure has less static adsorption, which is beneficial to maintain a higher polymer concentration in solution.

Adsorption Characteristics of Polymer Solutions on Media Surfaces and Their Main Influencing Factors

“…DHAP has a relative molecular weight of 6 million and a hydrophobic group content of 0.6 mol %. The specific synthesis steps have been reported in previous literature [ 11 , 25 , 26 ], and its molecular formula is shown in Figure 3 .…”

“…Different mathematical models were fitted based on the experimental data, and part of the adsorption mechanism was analyzed. The static adsorption experiment was conducted by the soaking method, using a UV spectrophotometer to determine the absorbance [ 11 ]. The specific steps were as follows: To prepare polymer solutions of different concentrations, 100 mL of polymer was placed in a wide-mouth bottle.…”

“…Rising adsorption capacity is accompanied by increasing adsorption retention capacity, the ability to reduce permeability, and the sweep ability of the subsequent fluid [ 8 , 9 ]. There are two main methods for the study of polymer solution adsorption: static and dynamic adsorption [ 10 , 11 , 12 , 13 ]. The determination of dynamic adsorption is based on the total amount of adsorption and retention, not on a single adsorption variable [ 14 , 15 , 16 , 17 ].…”

High Blocking Capacity of Fuzzy-Ball Fluid to Further Enhance Oil Recovery after Polymer Flooding in Heterogeneous Sandstone Reservoirs

“… 9 − 11 However, polymers have limited viscosity, which limits their ability to increase the sweeping volume. 12 , 13 Simultaneously, polymers have poor shear resistance, 14 salinity resistance, 15 and temperature resistance, 16 and viscosity was reduced further after injection into the reservoir. Furthermore, after water flooding, the reservoir will form a dominant channel for water flow, which will change the pore structure of the reservoir.…”

Effect of micro‐aggregation behavior on the salt tolerance of polymer solutions

“…The polymers used for the experiment were: (1) partially hydrolyzed polyacrylamide (HPAM), with a relative molecular weight of 20 million, hydrolysis degree of 26.3%, and solid content of 88.9% (Industrial Products), 32 the molecular formula of which is shown in Figure 1, Daqing oilfield production; (2) hydrophobically modified partially hydrolyzed polyacrylamide (HMPAM), with a relative molecular weight of 12 million, a degree of hydrolysis of 20%, and a hydrophobic group content of 1.2 mol%, the molecular formula of which is shown in Figure 2, self synthesis 33 ; (3) dendritic hydrophobically associating polymer (DHAP), with a relative molecular weight of 6 million, hydrolysis degree of 25%, hydrophobic group content of 0.6 mol%, and branching degree of 1, the molecular formula of which is shown in Figure 3. The specific steps of synthesis and the results of NMR analysis of the products are shown in refs 33 and 34 (Scheme 1).…”