固相颗粒损害储层机理研究

Study on formation damage mechanism of solid particles

王富华1 王瑞和1 于 雷 朱宽亮 卢淑芹3 孔 枫4 刘玉明

中国石油大学石油工程学院，山东 东营 257061 胜利石油管理局钻井工艺研究院，山东 东营 257017 冀东油田分公司钻采工艺研究院，河北 唐山 063000 中海石油基地集团采油技术服务公司南海西部研究院，广东 湛江 524057

College of Petroleum engineering, China University of Petroleum, Dongying 257061, China Institute of Drilling Technology, Shengli Petroleum Administration Bureau, SINOPEC, Dongying 257017, China Institute of Drilling and Production Technology, Jidong Olifield Company, CNPC, Tangshan 063000, China Nanhai West Research Institute, Oil Base-Oilfield Technology Services Company, CNOOC, Zhanjiang 524057, China

在钻井、完井、井下作业及油气田开发全过程中，存在很多损害储层的因素，其中，入井工作液中的固相颗粒是一个不容忽视的重要因素。固相颗粒侵入储层的孔隙喉道，在孔隙喉道内滞留、沉积，堵塞油气流动通道，造成储层绝对渗透率下降。入井工作液中固相颗粒的种类很多，大致分为三大类：刚性颗粒、可变形球状颗粒和可变形纤维状颗粒。颗粒类型不同，堵塞机理也不同，主要原因在于颗粒的受力状态。作用在流动悬浮颗粒上的力分为3类：与吸附机理有关的力、与分离机理有关的力和与传输机理有关的力。理论研究表明，固相颗粒在孔隙内滞留的条件是与吸附机理有关的力大于或等于与分离机理有关的力。为进一步探讨固相颗粒侵入造成储层损害的机理，在室内对含不同类型固相颗粒的钻井液对岩心的损害程度进行了模拟评价。实验结果表明，不同类型的固相颗粒对岩心造成的损害率不同，其中，刚性颗粒损害率较低，可变形球状颗粒损害率较高，而可变形纤维状颗粒损害率没有明显的规律，彼此差别较大。

In the course of well drilling, completion, borehole operation and oilfield developing, there are many formation damaging factors, of which the effect of solid particles in the operating fluid is an important factor. The solid particles can entrain and detent and/or depose in pore and throat of formation. These can plug the percolation flow media and decrease the absolute permeability of reservoir. There are many kinds of solid particles in the operating fluid, which are composed of stiff particles, deformable particles and deformable fibrous particles. The different types of particles have different formation damage mechanisms due to the different force situation. There are three kinds of force acting on suspended particles, which include adsorption force, separation force and transmission force. Theory analysis shows that the solid particles will detent when adsorption force is greater than or equal to separation force. In order to study the mechanism of formation damage induced by solid particles, the damage degree of drilling fluids containing different types of solid particles to core is tested in laboratory. Theory study and experiment results show that the different types of solid particles create different damage ratios to the core, of which the damage ratio of stiff particles is low, the damage ratio of deformable particles is high, and there is no obvious law for deformable fibrous particles because the difference is large between them.