几种水泥外加剂对地层伤害的机理研究

通过测定加有不同外加剂的水泥浆滤液离子组成、讨论滤液中颗粒尺寸分布、测定水泥浆液相电导，分析了加有不同外加剂的水泥水化历程；通过岩心流动实验考察了加有外加剂的水泥浆滤液对百色油田砂岩地层岩心的污染。实验结果表明：外加剂通过影响水泥水化历程改变滤液的离子组成和滤液中颗粒数量。在水泥浆中加入有机酸（酒石酸）可以改变滤液的离子组成，大大减轻滤液对地层渗透率的伤害。

MECHANIZMS OF RESERVOER PERMEABILITY DAMAGE CAUSED BY FILTRATE OF CEMENT SLURRY TREATED WITH DIFERENT ADDITIVES

The hydration process of the oil well cement of class G treated with different additives(dispersant.retarder,fluid loss controller and latex) are investigated by determing the changes in the cement filtrate composition,in the particle size distribution and in the liquid phase conductivity.Meanwhile.a series of permeability damage tests are rum on sandstone core samples from Baise Oil Field,Guangxi.Latex,being film-forming,causes the most severe pemeability damage.Other additives.capable interact with some cement constituents,lead to changing the concentrations of harmful ions which can form precipitotions and deposites from the filtrate in different directions.Tartaric acid decreases the amount of these dangerous ions and causes the least permeability damage.