深水聚胺高性能钻井液试验研究

聚胺高性能钻井液是性能最接近油基钻井液的水基钻井液,在深水钻井领域具有广阔的应用前景。为降低钻井液成本,在研制聚胺强抑制剂的基础上,考虑水合物抑制及低温流变性等因素,通过优选处理剂,构建了适用于深水钻井的聚胺高性能钻井液体系,并对其进行了综合性能评价。结果表明,该钻井液可抗150 ℃高温,且低温流变性优良,2 ℃和25 ℃的表观黏度比和动切力比分别为1.36和1.14;其抑制页岩水化分散效果与油基钻井液相当,体现了其强抑制特性;在模拟1 500 m水深的海底低温高压(1.7 ℃,17.41 MPa)条件下,具备120 h抑制水合物生成的能力;抗钙、抗劣土污染能力较强;无生物毒性,能满足深水钻井环保要求。其主要性能指标基本达到了用于深水钻井的同类钻井液水平,可满足深水钻井要求。 

Experimental Study on High Performance Polyamine Drilling Fluid for Deepwater Drilling

High performance polyamine drilling fluid,a water-based drilling fluid,is similar to oil-based drilling fluid in performance,and has broad application prospects in the deepwater drilling.In order to break the technical monopoly of foreign companies and reduce costs,based on the development of a highly inhibitive polyamine shale inhibitor and taking consideration of low temperature rheology and hydrate inhibition,a high performance polyamine drilling fluid had been formed for deepwater drilling by selecting additives.The comprehensive evaluation results showed that the property of the drilling fluid is stable after hot rolling at 150℃.The ratios of apparent viscosity and yield point at 2℃and 25℃ were 1.36and 1.14respectively,which indicated that the drilling fluid was good in low temperature rheological property,and comparable with oil-based drilling fluid in shale inhibition,suggesting the drilling fluid is highly inhibitive.In a simulating condition of low temperature and high pressure(1.7℃,17.41MPa)at 1 500mwater depth,there would be no gas hydrate formed in the drilling fluid in 120hours.Moreover,it had good resistance to CaCl2(up to 1.0%) and cuttings(up to 8.0%)contamination.The EC50value of the drilling fluid was higher than 11 000mg/L,the drilling fluid could meet the environmental requirements of deepwater drilling without any biological toxicity.The primary performance indexes are largely to remain the same with that of polyamine drilling fluids used in overseas deepwater drilling operations,and can meet the requirement of deepwater drilling.