幂律流体中岩屑颗粒沉降速度实验

Cuttings particle settling velocity within power law fluid

 孙晓峰¹ 纪国栋² 冯松林³ 陈志学² 李显义² 曲从锋²

中国石油大学（北京）石油与天然气工程博士后科研流动站，北京 102200 中国石油集团钻井工程技术研究院，北京 102206 中国石油长庆油田分公司第六采油厂，陕西 榆林 719000

Post?-Doctoral Research Center of Oil and Gas Engineering, China University of Petroleum, Beijing 102200, China CNPC Drilling Research Institute, Beijing 102206, China No.6 Oil Production Plant, Changqing Oilfield Company, PetroChina, Yulin 719000, China

 钻井过程中，任何井型都需要钻井液有效携带岩屑上返，以保持井眼清洁；但由于岩屑颗粒与钻井液存在密度差，遇到接单根、停钻等工况，岩屑颗粒就会在钻井液中沉降。对于大斜度井和水平井，岩屑沉降后会堆积在造斜和水平井段，形成岩屑床，造成恶性井下安全事故，因此，深入研究岩屑颗粒在钻井液中的沉降规律十分重要。文中首先综述了不同形状、不同粒径的固体颗粒在牛顿流体中的阻力系数和沉降速度计算模型，分析了牛顿流体中固体颗粒雷诺数和阻力系数之间的关系；应用与研究固体颗粒在牛顿流体中沉降的相同方法，并通过室内实验，得到了不同粒径岩屑颗粒在幂律流体中的沉降速度模型、颗粒雷诺数与阻力系数之间的关系模型。

 Cuttings transport efficiency ought to be ensured for purpose of hole cleaning during the drilling operation for every well type. However, due to the density difference between cuttings particle and drilling fluid, cuttings particles will settle down in drilling fluid in operational mode of pipe connection or overhaul. For large deviation wells and horizontal wells, settling cuttings particles, which accumulate on the surface of direction interval or horizontal interval, will form cuttings bed that causes incident. Thus, a further study on the mechanism of cuttings particle settlement in drilling fluid is very important. In this research, several sorts of calculation model of for drag coefficient and settling velocity within Neotonian fluid, for cuttings particles of different shape or size, are reviewed first. Then, correlation between drag coefficient and particle Reynolds number within Neotonian fluid is analyzed. Thus, using the same research method by which cuttings particle settlement in Newtonian fluid is researched; calculation model for settling velocity of particles of different size and relation model for drag coefficient and particle Reynolds number are obtained.

10.6056/dkyqt201601027