泥饼强度影响因素研究

用ＦＣＰ－２０００泥饼针入度仪对吐哈油田常用聚合物泥浆和聚磺泥浆体系中影响泥饼质量的因素进行了系统研究．结果表明体系中固相颗粒的含量及其粒度分布对泥饼强度的影响最大．虽然作用机理不同，但起抑制和封堵作用的处理剂都能提高泥饼强度，而尤以含有钾铵基聚合物的泥浆的泥饼强度最大．实验中还发现一具有规律的异常现象，即压力增加时，泥饼致密层变厚，但其强度却降低．现场泥浆检测标明，钾铵基聚磺泥浆具有最好的泥饼强度，最高可达４００ｇ以上．对水基钻井液体系而言，一般泥饼强度为２００ｇ左右即能满足工程要求．

A Study on the Factors Influencing the Strength of Drilling Fluid Filter Cake

The strength of drilling fluid filter cake is one of the main parameters by which the quanlity of mud cake is evaluated.The factors influencing the quanlity of the filter cakes of the polymer mud and sulfonated polymer mud commonly used in Tuha Oil Field are studied with model FCP-200 filter cake penetrometer.The Experimental result shows that the contents of solid particles in the drilling fluids and their grain size distributions have a major influence on the quanlity of mud cake.It is shown that all drilling fluid additives which have inhibiting or sealing effect can increase the strength of mud cake although they have different effect mechanism,the strength of the filter cake of sulfonated ammonium potassium polymer mud is greatest,sometimes it can be more than 400g according to field tests in 17 wells.The mud cake strength of 200g can generally meet the requirements of drilling engineering.It is also observed in the experiments that the thickness of mud cake increases but its strength decrease with the increase of pressure.