新型高温高密度盐水钻井液研究

Study on a New High Temperature High Density Saltwater Drilling Fluid

针对中国高温高密度盐水钻井液普遍存在的"使用处理剂种类过多,加量过大,钻井液老化后HTHP造壁性和流变性难以控制,配制成本和维护成本居高不下"的难题,分析长期攻关而至今没能很好解决的原因,在此基础上提出了"以利用钻井液中处理剂高温交联作用为基础,结合使用优化重晶石级配以解决高密度钻井液黏度高、HTHP失水量大、且性能很难调控的难题,综合形成了高温高密度盐水钻井液研究"新的技术路线,并由此研发出性能好(HTHP失水量低,流变性良好……)而处理剂种类少(共4种)、总用量大幅度降低(仅为现用量的1/2~1/3)的高温高密度盐水钻井液体系,而且具有高温条件下使用性能越来越好,性能维护方便的潜力和趋势,为有效解决中国高温高密度盐水钻井液多年未能很好解决的技术难题,提供一条可行的途径。

Many problems exist in the use of high temperature high density saltwater drilling fuids, such as more additives （both type and quantity） that are used than necessary, HTHP fltration rate and rheology after aging becoming diffcult to control, and high costs in mixing and maintaining the property of the drilling fuid, etc. The reasons that these problems have been studied for a long term but remained unresolved are analyzed in this paper, and based on the analyses, a method has been presented to resolve the high viscosity, high HTHP flter loss and diffculties in controlling the properties of the drilling fuids, problems that are associated with the use of high density drilling fuids. This method, based on the high temperature crosslinking of mud additive, resolves the problems through optimized sizing of barite particles. A new technical clue has been presented for the study of high temperature high density saltwater drilling fuid, and based on the technical clue, a high temperature high density saltwater drilling fuid with excellent performance （low HTHP flter loss, good rheology…） was formulated with only 4 kinds of additives whose total amount was only 1/2-1/3 of the total amount of additives used in the high temperature high density saltwater drilling fuids presently in use. The high temperature properties of this new drilling fuid had the potential of becoming better after long time of using, and being easy to maintain. The study conducted and the drilling fuid formulated have provided a way of resolving the stubborn problems associated with the use of high temperature high density saltwater drilling fuids in China.