复杂结构井井眼清洁技术研究进展

Research progress of hole cleaning in complex structure well

复杂结构井在海洋油气田、老油田和低渗透油气田开发中应用广泛，但该井型的大斜度井段和水平井段易出现井眼清洁问题，造成卡钻等事故，从而影响机械钻速和井下安全，制约了复杂结构井技术的发展。文中分别从井眼清洁的主要影响因素、数学模型及岩屑床清洁工具等方面，对井眼清洁技术进行了系统综述。通过分析井眼清洁的主要影响因素，结果表明，井斜角在30～60°时岩屑床最难清除，增加环空流速、钻杆转速和调整钻井液性能，可在一定程度上提高井眼清洁效果。此外．分析了描述岩屑运移规律的经验模型、分层理论模型及岩屑床清除工具，并对未来井眼清洁数学模型和井眼清洁技术发展趋势进行展望，为今后深入研究井眼清洁问题提供了参考。

Abstract： Complex structure well is widely used in the development of marine oilfield, old oilfield and low permeability oilfield. However, the poor hole cleaning in the highly-deviated sections and horizontal sections leads to sticking pipe and other accidents,which affects the rate of penetration and downhole safety and restricts the technology development of complex structure well. In this paper, a systematic review on main influencing faetors, mathematic model of hole cleaning and cuttings bed removing tool is conducted. Analysis of main influential factors of hole cleaning shows that cuttings bed is difficuh to be removed for the hole angles between 30°-60°, and increasing of annular veloeity and drillstring rotation, and adjusting of drilling fluid property can optimize the hole cleaning to some extent. Moreover, we analyze the empirical models and theoretical models which reveal the rule of cuttings transport, and analyze the cuttings bed removing tool, and predict the development trend of mathematic model and hole cleaning technique, which may provide a reference for the future research in hole cleaning.