基于压力响应释放的水基钻井液用靶向微胶囊润滑剂  

Targeted pressure-response encapsulated lubricants for water-based drilling fluids

作　　者：刘均一 宋华[1] 陈二丁[1] 夏晔 LIU Junyi;SONG Hua;CHEN Erding;XIA Ye(Drilling Technology Research Institute,Sinopec Shengli Petroleum Engineering Co.,Ltd.,Dongying,Shandong 257100,China)

机构地区：[1]中国石化胜利石油工程有限公司钻井工艺研究院

出　　处：《天然气工业》2023年第12期91-99,共9页Natural Gas Industry

基　　金：中国石化石油工程公司科技课题项目“囊装钻井液润滑剂的研究与应用”(编号:SG19-73K)。

摘　　要：常规水基钻井液用润滑剂有效浓度低,持效润滑性不足且消耗量大。为此,基于微胶囊结构与靶向释放的润滑剂研制新思路,以改性脲醛树脂为壁材,油基润滑剂为芯材,通过原位聚合反应,研制了一种基于压力响应释放的靶向微胶囊润滑剂(T-LUBE);并采用红外光谱、扫描电镜、原子力显微镜、极压润滑、四球动态摩擦磨损等实验方法,表征了T-LUBE的微胶囊特征与持效润滑性能,揭示了T-LUBE的关键作用机理。研究结果表明:①T-LUBE是一种“核壳”结构的微胶囊,抗温150℃,与钻井液配伍性能良好,加量3%时极压润滑系数降低率可达80%以上;②T-LUBE具有受压释放、靶向润滑特性,微胶囊释放临界摩擦压力为28.3 N·m,在井下高摩阻、大扭矩环境下,微胶囊可持续受压释放出润滑剂,实现对井下关键部位的靶向润滑,并保证较高的润滑剂浓度,从而充分发挥持效润滑作用;③研制的T-LUBE已在中国石化胜利油田现场试验3口井,试验井段摩阻同比降低率都在30%以上,钻井液润滑剂总用量降低40%以上,效果良好。结论认为,该新型靶向微胶囊润滑剂可为大位移井、长水平井等复杂结构井的高效钻井施工提供技术支撑,对于实现安全、优质、高效的油气钻井具有重要的理论和现实意义。The conventional lubricants for water-based drilling fluids have the disadvantages of low effective concentration,short continuous lubrication and great consumption.Based on the new idea of developing a lubricant by combining microcapsule structure and targeted release,this paper develops a tar geted pressure-response encapsulated lubricant(T-LUBE)with modified urea-formaldehyde resin as the wall material and oil lubricant as the core material by means of in-situ polymerization.In addition,the microcapsule characteristics and continuous lubrication of T-LUBE are characterized and the key mechanisms of T-LUBE are investigated by means of infrared spectroscopy,scanning electron microscopy,atomic force microscopy,extreme pressure lubrication,and four-ball dynamic friction and wear experiments.And the following research results are obtained.First,T-LUBE is a kind of microcapsule with a"core-shell"structure,which can resist the temperature up to 150℃and exhibits excellent drilling fluid compatibility.When 3wt%T-LUBE is used,the extreme pressure lubrication coefficient can be reduced by above 80%.Second,T-LUBE has the characteristics of pressure-response release and targeted lubrication with the critical point of microcapsule releasing friction pressure of about 28.3 N•m.When encountering high friction and large torque in the downhole conditions,the microcapsule releases lubricant continuously under the pressure,enabling the targeted lubrication of downhole key parts and ensuring higher lubricant concentration.Thus,continuous lubrication is exerted fully.Third,T-LUBE has been tested on site in 3 wells of the Sinopec Shengli Oilfield,and the results are good.The friction in the test section decreases by more than 30%and the total consumption of drilling fluid lubricant reduces by more than 40%.In conclusion,this newly developed lubricant can provide technical support for the efficient drilling of complex structure wells such as extended reach wells and long horizontal wells,and is of great theoretical and practica l

关 键 词：水基钻井液 润滑剂 微胶囊 压力敏感 靶向润滑 现场试验 

分 类 号：TE254[石油与天然气工程—油气井工程]