国外保护油气层技术新进展--关于暂堵机理和方法的研究

针对近年来国外在钻井液、完井液中通过加入暂堵剂对储层进行有效保护的研究进展进行了综述，重点介绍了实施暂堵的原理和一些新的方法，即（1）碱溶性微米级纤维素暂堵技术，这种暂堵剂能够对井壁进行快速封堵，减少钻井液中的固相和滤液侵入储层；（2）固相颗粒多组分滤失模型，利用该模型，可分别预测储层岩心受钻井液污染和反排后的损害深度及对渗透率的损害程度，又可用于对钻井液中固相的粒度分布状况进行优化设计，减轻固相对储层的损害；（3）反排时泥饼的清除机理，用初始流动压力的数学模型计算，初始流动压力随渗透率下降而增大，并随损害深度增加而增大，同时初始流动压力与反排速度呈线形增长的关系；（4）孔喉网络模型，可用于模拟微粒运移、沉积及发生堵塞的过程，并可优选暂堵剂尺寸，虽天然的多孔介质并不具有规则的结构，但可通过一个网络结构代替；（5）高渗储层暂堵技术，高渗储层的主要损害因素是固相侵入，因此需使用暂堵剂来形成低渗透泥饼，以防止固相和滤液进一步侵入。总之，油气层保护技术还需要进一步向前发展。

Advances in overseas technology of formation damage control--Investigations on the mechanisms and methods of temporary plugging

This article summarizes the overseas research development for controlling the damage by means of using the temporary plugging additives in the drilling & completion fluids in recent years. Especially, it focuses on the principle of temporary plugging and some new methods, i. e. , micrometer degree alkali cellulose for temporary plugging technique, using it the well wall can be plugged rapidly, and the invasion of solid phase and filtrate of drilling fluid into formation can be prevented; the filtrate model of multi-component solid phase fine particle in which not only the damage degree and depth of reservoir and permeability after reverse discharging can be predicated respectively, but also the distributive state of solid phase in drilling fluid can be designed optimistically; the mechanism of cleaning out mud cake during reverse discharging and using mathematic model to calculate the initial flowing pressure, result shows that the initial flowing pressure increase with the reducing of permeability and the increasing of damage depth, meanwhile, it is in linear increasing with reverse discharging velocity; using pore throats net model to simulate the processes of fine migration, aggradation and plugging and to optimize the size of temporary plugging agent; temporary plugging techniques for high permeable reservoir, due to the main factor of damage in high permeable reservoir is solid phase incursion, it needs to use temporary plugging agent to form low permeable mud cake to prevent the incursion of solids and filtrate fluids, etc. . It is necessary to further develop the technology of formation damage control.