含盐钻井液中粘土粒度分布研究

PARTICLE SIZE DISTRIBUTION FOR CLAY IN SALINE DRILLING FLUIDS

用激光粒度仪测定了含单一处理剂的海水钻井液及不同含盐量（０—３６％ＮａＣｌ）的盐水钻井液中粘土颗粒的粒度分布。在海水钻井液中细颗粒含量剧烈减少，粗颗粒含量剧烈增加，平均粒径增大，处理剂减效或失效。随着盐含量的增加，细颗粒含量缓慢减少，粗颗粒含量缓慢增加，平均粒径缓慢增大，盐含量超过１２％后，这一变化趋势有所加剧。用碱金属、碱土金属离子对粘土颗粒表面双电层和水化层的压缩作用和粘土颗粒的分散和聚集作用讨论了粒度变化的机理。

The particle size distribution of Wiomings clay and Minghuazhens formation clay in mixture in seawater drilling fluids treated with one of commonly used mud additives (thinner FCLS, filtrate loss controller MV CMC, viscosifier PAC141, coagulant PAM) and of Anqiu's clay for mud in salt water drilling fluids (0—36% NaCl) is determined by using a Shimazus lazer diffraction particle size analyzer with Weibull's distribution index and average particle diameter given. These mud additives loss their functions partially or completely in the fluids. The mechanisms involved in the distribution changes are discussed in terms of clay particle dispertion/gathering.