Development Of High-temperature-Resistant Profile Control Agents And Study Of Their Performance

After repeated high-temperature steam and hot water wash, the emergence of rising waterand other issues are getting more and more serious so far at Liaohe Oilfield, ShengliOilfield and other heavy-oil reservoirs. Although the current profile-control agents havesome effects in adjustment of the injection profile of120℃~150℃stratum, due to theirdecomposition above200℃, they can not meet the development of heavy oil withhigh-temperature water steam, especially the need of withstanding high temperature,nearly300℃, near the wellbore area. So there is an urgentneed to develophigh-temperature-resistant profile control agents for the development of these oilfields.This subject studied four kinds of high-temperature-resistant profile control agents,respectively taking sulfonated tannin, sodium lignosulphonate, sodium humate,nitro-sodium humate as fundamental agents, and taking cross-linker Ⅰ(compoundcrosslinker of phenol), cross-linker Ⅱ(compound crosslinker of aldehydes) and HPAM asaccessory ingredients. The ratio of every system was optimized through experiments, thentheir temperature-toleration properties were investigated respectively. Besides, theinfluences of salinity, temperature and pH on their gel properties were studied.The results show that the nitro-sodium humate system behaviors better intemperature-toleration property than sodium lignosulphonate system, which has bettertemperature-toleration property than sodium humate system and sulfonated tannin system.However, every system has its own suitable applied conditions.The initial viscosity of sulfonated tannin system is9.4mPa·s. It can withstand220℃,and it can be applied to formations of high salinity below12000ppm. Within80℃~200℃,temperature has little influence on its performance. Besides, its suitable used pH range is5~10.The initial viscosity of sodium lignosulphonate system is11.3mPa·s. It can tolerate240℃andits suitable salinity of formations is within10000ppm. Temperature has littleeffects on its performance in80℃~200℃. What’s more, its best suitable used pH rangeis from8to11.The initial viscosity of sodium humate system is10mPa·s. It can withstand220℃,and its suitable formation’s salinity is within14000ppm. Temperature has little influence on its gel performance within80℃~200℃. Its suitable applied pH range is from7to10.The initial viscosity of nitro-sodium humate system is9.5mPa·s. It can stand290℃,and its suitable formation’s salinity is in12000ppm. Similarly, temperature has littleinfluence on its gel performance within80℃~200℃. Its suitable applied pH range is from7to10.