稠油火驱油藏封堵气窜用腐殖酸钠冻胶的研制OA北大核心CSTPCD

Sodium humate was used as gelling agent to prepare gel.The stability of sodium humate gel under the conditions of high temperature,high pressure,and the presence of flue gas was investigated.The variation law of gel strength during high-temperature heat treatment was analyzed through rheological experiments.The sealing ability of the gel was evaluated via physical simulation testing.The form of the gel was observed by Cryo-SEM,and the feasibility of using sodium humate gel for sealing gas channeling during fireflooding was discussed.The experimental results showed that by using sodium humate as gelling agent and adjusting the gelation time by selecting the catalyst,the temperature-resistant gel suitable for different temperature conditions such as 120,150,180℃can be formed.Meanwhile,the gelation time can be adjusted from 10 h to 75 h,and the dehydration rate is lower than 20%after heat treatment for 90 d.The gel exhibits good stability under high temperature,high pressure,and the presence of O2 and CO2.The breakthrough pressure gradient of the gel formed by 10%(w)sodium humate and 1.2%(w)water-soluble phenolic resin can reach 3.95 MPa/m in 0.94 μm2 sandpacks,showing a strong sealing ability.