耐高温抗高盐气藏水侵抑制剂性能及疏水改性作用机理

Performance and Hydrophobic Modification Mechanism of Water Invasion Inhibitor for High Temperature and High Salt Gas Reservoirs

陈 浩 侯宝峰 王 松 秦会娜 徐 薇 范海明 张富民

CHEN Hao HOU Baofeng WANG Song QIN Huina XU Wei FAN Haiming ZHANG Fumin

为提高气藏水侵抑制剂的耐温抗盐性、减缓对气藏的二次水侵污染，以甲醇为分散介质，通过表面张力、接触角、岩心自发渗吸含水饱和度、多孔介质气相渗透率的测定，研究了5种表面活性剂的表面活性、疏水改性效果、预防和解除水侵伤害能力；通过红外光谱、接触角、Zeta 电位和吸附层厚度的测定，分析最佳气藏水侵抑制剂改变气藏水湿性砂岩表面润湿性的作用机理。结果表明，5 种表面活性剂中，阳离子含氟双子表面活性剂（HB-1）具有较强的疏水改性能力以及良好的耐高温抗高盐性能，在180 ℃和矿化度为2.0×105 mg/L 的条件下老化24 h后，0.05% HB-1可将地层水表面张力降至21.0 mN/m。岩心经HB-1处理后，地层水在岩心表面的接触角由处理前的45.0°增至110.0°。HB-1能有效预防岩心水侵，可使岩心含水饱和度由处理前的77.4%降至8.1%；并可有效解除水侵伤害，使多孔介质气相渗透率由水污染后的29.9×10-3 μm2恢复到52.3×10-3 μm2。HB-1对水湿性砂岩表面疏水改性的作用机理为“吸附”。HB-1分子可在水湿性石英片表面形成厚度约为4.3 nm单层吸附疏水膜，且吸附膜厚度随着HB-1浓度的增大而增大；当HB-1质量分数达到0.1%时，吸附层之间的疏水作用逐渐形成紧密定向排列的双分子层结构，吸附达到饱和，Zeta电位（24.30 mV）和吸附膜厚度（4.3 nm）趋于稳定。

In order to improve the temperature and salt resistance of gas reservoir water intrusion inhibitors and mitigate secondary water intrusion contamination of gas reservoirs，methanol was used as dispersion medium. Through the measurement of surface tension，contact angle，spontaneous imbibition water saturation of cores，and gas-phase permeability in porous media，the surface activity，hydrophobic modification effects，and the ability to prevent and remove water invasion damage of five surfactants were studied. By measuring infrared spectrum，contact angle，Zeta potential and adsorption layer thickness，the mechanism by which the optimal gas reservoir water invasion inhibitor altered the wettability of gas reservoir water-wet sandstone surfaces was analyzed. The results showed that，among the five surfactants，the cationic fluorine-containing bicontinuous surfactant （HB-1） had strong hydrophobic modification ability as well as good high-temperature and high-salt resistance. After aging for 24 h at 180 ℃ and a salinity of 2.0×105 mg/L，the surface tension of formation water could be lowered to 21.0 mN/m at a HB-1 concentration of 0.05%. After the core was treated with HB-1，the contact angle of formation water on the core surface increased from 45.0° before treatment to 110.0°. Injecting HB-1 into the porous medium could effectively prevent water invasion into the core，which could reduce the water saturation of core from 77.4% before treatment to 8.1%. It could effectively relieve the damage of water invasion， and then restore the gas-phase permeability of porous medium from 29.9×10-3 μm2 after water contamination to 52.3×10-3 μm2. The mechanism of HB-1 on the hydrophobic modification of water-wet sandstone surface was“adsorption”. HB-1 molecules could form a monolayer adsorption hydrophobic film with a thickness about 4.3 nm on the surface of water-wet quartz sheet. Furthermore，the thickness of adsorption film increased with increasing dosage of HB-1. When the mass fraction of HB-1 reached 0.1% ，the hydrophobic interaction between adsorption layers gradually formed a tightly oriented bilayer structure，and then the adsorption saturated. At this time，the Zeta potential was stable at 24.30 mV，and the thickness of adsorbed film was finally maintained at 4.3 nm.

10.19346/j.cnki.1000-4092.2024.04.017