The seepage flow characteristics of hydrophobically associated polymers with different aggregation behaviours in porous media

Abstract

The polymer solution for oil displacement is subjected to strong shear action in practical application, and this action will affect its percolation characteristics in porous media. The effects of mechanical shearing on the solution properties and seepage characteristics of modified hydrophobically associated polymers and dendrimers with two different aggregation behaviours were studied. The results showed that mechanical shearing did not affect hydrophobic microzones. Polymers can re-associate to restore part of the network structure, thereby improving shear resistance (dendritic hydrophobically associating polymers > hydrophobically modified partially hydrolysed polyacrylamide). Polymers with ‘cluster’ aggregation behaviour enhanced solution performance, enabling them to establish higher resistance coefficient (RF) and residual resistance factor (RRF) in porous media but also bringing about injection difficulties. Increasing the injection rate would increase the injection pressure, but the established RF and RRF showed a downward trend. Mechanical shear pretreatment effectively improved the injectability of the polymer. To achieve polymer injection and flow control, pre-shearing polymer solution and low-speed injection can be used in field applications.

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 .…”

“…Currently, the most widely used polymer solutions for oil displacement in oilfields are partially hydrolyzed polyacrylamide (HPAM) and the hydrophobically associating polymer AP-P4 [ 21 , 22 , 23 , 24 ]. The use of dendrimer hydrophobically associating polymers (DHAPs) is one of the leading research methods to improve complex reservoir conditions [ 25 , 26 ]. Among them, the adsorption mechanism and influencing factors of HPAM are more prominent.…”

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).…”

Application and Optimization of the Rheological Model for a Hydrophobically Associating Dendrimer Polymer

“…Currently, the synthesis of polymer flooding agents mainly focuses on improving the performance of the solution by chemically modifying the molecular structure of the polymer and introducing functional groups to produce functional polymers [6][7][8]. More recent studies focus on the synthesis and characterization of the hydrophobic groups linked to polymers of dendritic structures [9]. Based on the synthesis of dendritic polymers, a large number of researchers have conducted comparative performance studies, and the results are shown in Table 1.…”