Study and Field Test on a High Temperature Plugging Agent for the Thermal Recovery of Heavy Oil in Fengcheng Oilfield, Xinjiang

Underground and surface steam channeling were easily encountered during thermal recovery of heavy oil in Fengcheng Oilfield, Xinjiang, and it seriously affected the productivity level and caused surface pollution. To solve this problem, research on a high temperature plugging agent for thermal recovery of heavy oil was carried out. Oil soluble phenolic resin OSR was synthesized with phenol and formaldehyde as main raw materials and organic amine as catalyst. A new phenolic epoxy resin type of high temperature plugging agent, HTD, was developed with epoxy resin, organic silicone coupling agent and diluents. Under simulated heavy oil reservoir conditions in the laboratory, HTD was mixed with quartz sand in certain particle size for filling, compaction and high-temperature maintenance. In addition, high-temperature gelling and curing experiments were conducted. Temperature resistance, and high temperature curing performance and plugging effect were evaluated followed by field tests on three wells. The experimental results showed that HTD could resist high temperature over 300 ℃ and its compressive strength was greater than 12 MPa when combined with quartz sand at a temperature above 180 ℃. The plugging rate of high permeability core was greater than 99.5% at 220–300 ℃ with a breakthrough pressure gradient over 35 MPa/m. In field tests, steam channeling was blocked and production by steam huff and puff came back to normal with the pressure of 3.5–5.5 MPa. Two years later, oil production rose to 62.12 t/d with an average daily increase of 22.7 t, achieving sound economic benefits. Research results show that HTD has excellent temperature resistance and plugging performance and can effectively block surface and underground steam channeling. HTD has a good application value, for it can expand steam sweep volume and improve oil well productivity, showing a long validity period.