低渗透油藏微纳米乳液增注技术实验研究OA北大核心CSTPCD

Based on the good prospect of nano-materials for pressure reduction and injection of low-permeability reservoirs,a micro-nano emulsion used as injection enhancer was studied.The basic performance evaluation and injection parameter optimization of the micro-nano emulsion were carried out by using nano meter analyzer,contact angle meter,core displacement device,etc.The experimental results show that the micro-nano emulsion has a small particle size,certain adsorption and wettability-changing ability,which can change the wettability of the rock surface from strong water wetting to weak water wetting.It has good temperature resistance,anti-swelling performance,compatibility,and when the injection concentration is 0.5%(w),the oil-water surface tension can be reduced to a minimum of 0.60 mN/m.When the optimized process parameters are a single section of the plug stewing wells,injection concentration 0.3%(w),and injection flow 0.1 mL/min,the injection pressure is reduced by 16.87%.Based on the indoor research,6 wells were tested in the field,and the average injection pressure decreased by 1.8 MPa,the daily injection volume was increased by 35 m3,which lasted for 362 d,and provide theoretical basis for decompression and augmented injection with nano emulsion in low permeability reservoirs.