一种新型抗220℃高温深井水基钻井液体系室内研究

Laboratory Study on A New Type of Water-based Drilling Fluid of 220℃ High Temperature Resistance in Deep Wells

复杂地质条件下,钻井液性能极易发生破坏,因此深井钻井液的热稳定性一直是国内外钻井液研究的关键问题之一。为此研制出了一种新型的抗盐、抗钙、抗高温的深井水基钻井液体系(密度为2.4g/cm3),对该钻井液体系进行了常规性能评价以及高温性能评价;探讨了钻井液体系的油气层保护效果。结果表明,该水基钻井液体系抗温达到220℃;钻井液静置96h后,上、下密度差为0.033g/cm3,具有较好的沉降稳定性和抗盐性;在模拟动态条件下评价钻井液对油气层的保护效果,岩心渗透率恢复值达到90%以上,说明其保护油气层效果较好。

Under complex geological conditions,the rheological property of drilling fluid was easy to deteriorate,so the thermal stability of the deep well drilling fluid has always been one of the key problems of drilling fluid research at home and abroad.Therefore a new type of water based drilling fluid system with a density of 2.4g/cm3,which was salt resistant,calcium resistant and high temperature resistant,was developed.The performance of the drilling fluid system was evaluated and high temperature rheological property was studied.The reservoir protective effect was discussed.The results show that the water-based drilling fluid system can reach 30%salt resistance,2%calcium resistance,and resistance to temperature reaches 220℃,after it is held up for 96 h,the difference between upper and lower densities is 0.033g/cm3,it has a good sedimentation stability,the reservoir protection effect was evaluated under dynamic simulating condition,core permeability recovery is more than 90%,it indicates that the reservoir protection effect is good.