【摘要】 目的选用固壁性能好的高聚物类无固相钻井液,以确保复杂地层孔壁稳定性和钻孔工程质量,提高钻进效率.方法在分析聚乙烯醇、聚丙烯酰胺等水溶性高分子聚合物吸附成膜机理的基础上,通过正交实验优选出水溶性高分子聚合物无固相钻井液主剂与交联剂组分,测试该钻井液的漏斗黏度、API失水量、旋转黏度和胶结砂样的能力,并分析各影响因素的相关性,判断钻井液的流变性.结果该钻井液表观黏度5.0×10-3~8.0×10-3Pa.s,API失水量6~20 ml/30 min,属于假塑性幂律流体,具有良好的剪切稀释作用;在岩石表面吸附速度快,对松散砂及风化碎石层的胶结能力强,能起到"下套管"的固壁作用;具有良好的絮凝钻屑聚沉的能力,维持体系无固相,显著提高破碎地层的岩矿心采取率.结论实验优选出的水溶性高分子聚合物无固相钻井液配方组成简单,施工现场配置方便,钻井液性能指标优良,确保复杂地层钻进工作的顺利进行.更多还原

【Abstract】 This paper focuses on selecting nice-featured solid-free drilling fluid of polymer in order to guarantee the stability of complicated stratum-hole wall and the quality of drilling project.Based on the mechanism of adsorption membrane formed by polyvinyl alcohol,polyacrylamide and other water-soluble polymer,the components of main reagent and cross-linking reagent on solid-free drilling fluid of water-soluble polymers are selected through the orthogonal experiment.Funnel viscosity of the drilling fluid,API water loss,rotation viscosity and the ability of cemented sand sample are tested to analyze the relevance of each factor and to determine the rheology of drilling fluid.The drilling fluid performance is as follows,of apparent viscosity,6~20ml/30min of API lost water,belonging to false plastic power-law fluid,which goes with good shearing and dilute effect;high adsorption rate on the surface of rock and strong cementing ability to loose sand and weathering rock layers,which plays an affirmative role of"casing the solid wall";good capability toward flocculating drilling cuttings together so as to maintain no solid-phase in slurry system,significantly improving on taking rate of the rock core in fragmentary layers.The solid-free drilling fluid of water-soluble polymers selected through orthogonal test is composed of a simple formula,also easy to confect in construction site.The excellent performance of drilling fluid ensures the successful work of drilling in complicated stratum.更多还原