海上底水稠油油藏氮气泡沫压锥技术研究与应用

基于QHD32-6油田西区底水稠油油藏底水锥进控制水淹的需要,分析了氮气泡沫压锥堵水敏感性因素,研制了氮气泡沫压锥液。模拟分析表明,注氮20 d、表活剂溶液质量浓度10 g/L、气液比2∶1、焖井2～5 d时压锥堵水效果最好;室内评价实验表明,起泡剂YS-FA150与生产污水、地层水及水源井水之间的配伍性较好;起泡剂的泡沫半衰期为3 871 s,排液半衰期215 s,气液比为2∶1的泡沫体系的阻力因子高达90,饱和起泡剂的岩心渗透率恢复率可达99.8%。现场应用结果表明,新研制的氮气泡沫压锥液能有效地抑制底水沿高渗透部位的锥进,试验井含水率由92.8%下降到62.5%,日产液量降低60 m3,日产油量增加22 m3,累积增油3 500 m3,综合效益显著。氮气泡沫压锥技术适合底水油藏锥进后进一步提高产量,具有较好的应用前景。

Research and application of nitrogen foam coning control technique for heavy oil reservoir with bottom water in offshore oilfield

The sensitivity elements of nitrogen foam coning-control fluid are analyzed,and the nitrogen foam coning-control fluid is developed to meet the demand for controlling bottom water coning the heavy oil reservoir in Qinhuangdao 32-6 oilfield in Bohai Bay.The simulation analysis indicates that effect of exclusion of water is best when the nitrogen is injected for 20 days,mass concentration of surface acting agent is 10 g/L,gas fluid ratio is 2∶1,soak time is 2 to 5 days.Laboratory evaluation shows that the foaming agent YS-FA150 has better compatibility with produced water,formation water and aquifer water,with foam half-life of 3 871 s,drain half-life of 215 s;the foam system with gas-liquid ratio of 2∶1 has the resistance factor up to 90;the saturated foaming agent can make core permeability recovered 99.8%.The field application shows that the new Nitrogen foam coning-control fluid can restrain the bottom water coning along the high-permeability zone effectively and gave good performance in a tested well,with the water cut reduced from 92.8% to 62.5%,the fluid production decreased by 40 m3 per day,the oil output increased by 22 m3 per day,and the cumulative oil increment of 3 500 m3,presenting the obvious overall benefit.The technology can enhance the oil production further after bottom water coning reservoir and has good application prospects.