低渗透油田微生物堵剂的多尺度封堵性能

Multi-scale Plugging of Microbial Plugging Agent in Low Permeability Oilfield

倪 军 王维波 王成俊 张 磊 李成勇

NI Jun WANG Weibo WANG Chengjun ZHANG Lei LI Chengyong

封堵低渗透油藏的多尺度水窜通道是提升这类油藏水驱开发效果的关键，开发了一种内源微生物堵剂，优化了其菌种发酵营养液配方，并基于室内静态实验表征了其基础物性，最后通过岩心动态实验评价了其封堵适应性。所优化的菌种发酵营养液配方为：1.0%～2.0%糖蜜+0.2%～1.0%硝酸钠+0.5%～2.0%磷酸二氢钾+ 0.2%～1.0%磷酸氢二钠+0.1%～0.5%硫酸铵+0.01%～0.1%工业酵母膏+0.01%～0.03%硫酸铁+0.01%～0.03%硫酸锰。在营养液中培养4 d后，微生物趋于稳定，形成的分散颗粒呈正态分布，粒径集中在 40～160 μm之间，粒度中值在 90 μm左右，且具有良好的抗剪切性、耐盐性及稳定性。初始态的微生物调堵剂能顺利进入低渗透岩心、非均质岩心和裂缝性岩心。进入岩心后，微生物基于其自生长特性与孔隙及裂缝介质匹配，对渗透率为5× 10-3 μm2 的岩心的封堵率达到 80%；对渗透率为5×10-3/100×10-3 μm2的非均质岩心的封堵率达 92%；对渗透率为5×10-3/300×10-3 μm2的非均质岩心的封堵率达95%。微生物堵剂对开度为30 μm的裂缝性岩心的封堵率达84%；对开度为80 μm的裂缝性岩心的封堵率接近90%。微生物堵剂既可以封堵不同尺度的多孔介质水窜通道，又可以封堵不同尺度的微裂缝水窜通道，具备封堵低渗透油田多尺度水窜通道的潜力。

The key to improve the effect of water flooding development of low permeability reservoir is to solve the problem of multi-scale water channeling in low permeability oil fields. An endogenous microbial plugging agent was developed and the formula of the fermentation nutrient solution for the plugging agent has been optimized. Subsequently，the basic physical properties of the plugging agent were characterized through indoor static experiments and the plugging adaptabilities of the plugging agent were evaluated through dynamic core experiments. The fermentation nutrient solution of the strain was consisted of 1.0%—2.0%molasses，0.2% —1.0% sodium nitrate，0.5% —2.0% potassium dihydrogen phosphate，0.2% —1.0% disodium hydrogen phosphate，0.1%—0.5% ammonium sulfate，0.01%—0.1% industrial yeast extract，0.01%—0.03% ferric sulfate and 0.01%—0.03% manganese sulfate. After cultivation in the fermentation nutrient solution for 4 days，the growth of microbial strains stabilized. The formed dispersed particles exhibited a normal distribution with particle sizes of 40—160 μm and a median granularity of about 90 μm. The prepared microbial plugging agent had good shear resistance，salt resistance and stability. The initial state of microbial plugging agent could be injected into the low-permeability core，heterogeneous core and fractured core with good injectivity. The microbial strains could grow and reproduce in the cores based on the characteristics of self-growth，and match with the spatial scale of pore media or fracture media，which could not only plug the porous medium with different scales， but also plug the micro-fractures with different scales. The plugging rate of the core with a permeability of 5×10-3 μm2 reached up to 80%. As for the heterogeneous parallel composite cores with the permeability of 5×10-3/100×10-3 μm2 and 5×10-3/300×10-3 μm2，the plugging rate reached up to 92% and 95%，respectively. For the fractured cores with an opening of 30 μm and 80 μm，the plugging rate reached up to 84% and 90%，respectively. The microbial plugging agents could plug both porous medium with the different scales and micro fractures with the different scales based on the characteristics of self-growth，thus possessing the potential to plug the multi-scale water channeling in low-permeability oil reservoir.

10.19346/j.cnki.1000-4092.2024.03.008