强水敏油藏防膨技术研究及应用

RESEARCH AND APPLICATION OF ANTI-SWELLING AGENT IN STRONG WATER SENSITIVITY RESERVOIR

针对强水敏油藏储层特征,从防膨率、腐蚀率、破碎率和配伍性实验筛选了四种防膨剂,现场应用结果可知单一加入防膨剂难以满足油田需要。通过正交试验方法优化筛选出防膨效果最佳的配方:2.5%KCl+0.8%FA-367+1%ZJ-1+1%XH-F3,其防膨率达到86.06%。动态防膨实验表明岩心渗透率的伤害率从37.6%下降到8.21%,防膨作用明显。现场应用实验表明,该防膨体系对黏土稳定性较好,能很好满足强水敏油藏注水开发需要。

According to the characteristics of strong water sensitivity reservoir,an optimum anti- swelling formulation was proposed in the paper. Based on anti- swelling rate,corrosion rate,crushing rate and compatibility,four anti- swelling agents were elected. The experimental result showed that it was difficult to meet the requirement of anti- swelling in oilfield by single anti- swelling agent. So an optimum anti- swelling formulation was screened out through orthogonal experiment, containing2. 5% KCl,0. 8% FA- 367,1% ZJ- 1 and 1% XH- F3.The anti- swelling rate of this formulation was up to 86. 06%.Moreover,the dynamic anti- swelling experiment was used to measure the varieties of the core damage rate. It suggested that core permeability damage rate was 37. 6% without the anti-swelling system but decreased to 8. 21% with the anti- swelling system and the anti- swelling effect was obvious. Field application proved that this anti- swelling system was beneficial to stabilize the clay. All these evidences showed that this formulation was well suitable for injecting water development in strong water sensitivity oilfield.