**3.2 Interfacial properties**

vary dramatically from one another. The surface energy of the cores decreased to

As shown in **Table 3** (**Figure 4**), the 0.2 and 0.4 wt% ABSN-treated cores displayed lower water contact angle, and the ethylene glycol droplet completely

> **Ethylene glycol**

Droplet infiltration

Droplet infiltration

Droplet infiltration

0.20% OSSF 110.12 27.54 24.66 2.55 1.80 6.53 0.40% OSSF 110.71 32.14 22.83 2.49 1.84 5.76

*Contact angle and surface energy of artificial cores after adsorption equilibrium in ABSN and OSSF solutions*

*Contact angle of water on artificial cores (room temperature). (a) Untreated, (b) treated by 0.20 wt% ABSN,*

**(mJ/m2 )**

, which indicated that OSSF could greatly change the wettability from

**energy/ (mJ/m2 )** **Standard error**

**Ethylene glycol**

**Standard error**

**Ethylene glycol**

**Surface energy**

**Distilled water**

— ——

— ——

— ——

**Surface energy**

**Distilled water**

— ——

— ——

— ——

20–25 mJ/m<sup>2</sup>

**Table 2.**

**Figure 3.**

**Table 3.**

**172**

*(T = 150°C, pH = 9).*

*and (c) treated by 0.20 wt% OSSF.*

**Concentration/wt% Contact angle/ (°) Surface energy/**

**Ethylene glycol**

spreading

spreading

spreading

0.20% OSSF 104.53 39.19 28.05 1.87 2.14 4.13 0.40% OSSF 107.48 48.50 26.49 1.33 2.39 1.32

*Contact angle and surface energy of reservoir cores after adsorption equilibrium in ABSN and OSSF solutions*

**Distilled water**

0.0 13.47 Droplet

0.20% ABSN 8.75 Droplet

0.40% ABSN 6.42 Droplet

*(T = 150°C, pH = 9).*

hydrophilic to highly hydrophobic.

*21st Century Surface Science - a Handbook*

0.00 Droplet

0.20% ABSN Droplet

0.40% ABSN Droplet

**Concentration/wt% Contact angle/° Surface**

**Distilled water**

infiltration

infiltration

infiltration

To evaluate the surface activities of OSSF and ABSN in a high-temperature basic environment, the surface tension of solutions and fluid filtrates was measured after aging at 150°C for 16 h. In **Figures 5** and **6**, both 0.2–0.4 wt% ABSN and OSSF could decrease the surface tension under high temperature. Meanwhile, OSSF was better at reducing surface tension, meaning that it could better reduce filtrate adsorption and aqueous phase trapping damage in the rock.
