国外微泡沫钻井液技术新进展及探讨

综述了近10年国外微泡沫钻井液技术的研究及应用进展，总结了国外在微泡沫微观机理及其体系流变性能等方面取得的认识。针对目前的技术现状，提出了微泡沫尺寸与地层孔隙喉道半径匹配关系认识不清、微泡沫引起的堵塞、室内评价与现场应用效果差异较大等几方面的问题。在此基础上，分别从微泡沫体系在多孔介质中的渗流规律及影响因素、微泡沫钻井液用化学剂、微泡沫钻井液制备方法3个层面，探讨了该技术的研究方向。即要建立数学模型定量描述微泡沫尺寸与多孔介质中匹配关系，从而为微泡沫在不同储层中的应用提供理论参考；研究微泡沫产生的"贾敏效应"对储层流体渗流能力的影响，避免微泡沫钻井液施工后可能引起的产液量下降问题；建立实验室与现场制备条件的对应关系，统一关于微泡沫钻井液的制备规范或标准。 

Micro Foam Drilling Fluid Technology Abroad: New Progress and Discussion

This paper summarizes progress made abroad on researches and application of micro foam drilling fluid in recent decade, including knowledge obtained about the micro mechanisms and rheology of micro foam drilling fluids. The authors present in the paper that, for the current technical status of the micro foam drilling fluids, the matching relationship between the sizes of foam and the sizes of pore throat is still not clearly understood; and there is a wide gap between laboratory evaluation on the blockage caused by micro foam and field application. Based on the problems presented above, the research direction of micro foam drilling fluid technology is discussed from three aspects, which are:the percolation flow pattern of micro foams in porous media and its affecting factors, chemical additives for micro foam drilling fluids, and the formulation method of micro foam drilling fluids. A mathematical model is needed to quantitatively describe the matching relationship between the sizes of micro foam and the sizes of pore throats in porous media, therefore to provide a theoretical reference for the application of micro foams in different reservoirs. The effects of "Jamin Effect" by the micro foams on the percolation flow capacity of reservoir fluids was studied to avoid the reduction of fluid production rate after operation with micro foam. Finally, the corresponding relation between laboratory experiment and field formulation conditions needs to be built up to unify the formulation criteria of micro foam drilling fluids.