改进型铝合金钻杆对岩屑运移仿真分析  

Simulation Analysis of Cuttings Migration in Improved Aluminum Alloy Drill Pipe

作　　者：王志亮 夏成宇[1] 张震 李郑涛 张新红[1] Wang Zhiliang;Xia Chengyu;Zhang Zhen;Li Zhengtao;Zhang Xinhong(School of Mechanical Engineering,Yangtze University;Shale Gas Research Institute,PetroChina Southwest Oil and Gas Field Company)

机构地区：[1]长江大学机械工程学院,湖北省荆州市434023 [2]中国石油西南油气田公司页岩气研究院

出　　处：《石油机械》2021年第10期17-23,共7页China Petroleum Machinery

基　　金：国家自然科学基金项目“深水无隔水管钻井涡动对钻柱动态响应研究”(51405032);页岩油气国重实验室开发基金项目“硬塑性岩层空化射流高频多维冲击破岩机理及应用研究”(20-YYGZ-KF-GC-16)。

摘　　要：在川渝地区的钻井过程中,岩屑运移能力始终是影响钻进效率的主要因素之一。由于传统钢钻杆与钻井液密度相差较大,使得钢钻杆在重力作用下会偏向井口下部,在钻杆底部的岩屑因流速较低会沉积形成岩屑床,最终将造成卡钻或机械钻速降低等问题,严重影响钻进成本。为了提高页岩气井内岩屑运移能力,通过对比3种不同材料钻杆的物理参数,得出铝合金钻杆具有低密度、抗腐蚀及高强度等性质的结论。为使铝合金钻杆整体所受重力小于钻井液的浮力,对其结构进一步改进,并采用理论分析与数值计算,验证了其可浮性。最后利用有限元仿真在Fluent中建立铝合金钻杆与传统钢钻杆的三维井眼环空岩屑沉降模型,对比分析了两者在改变岩屑粒径、井斜角、机械钻速和排量等因素下对环空内岩屑质量的影响。最终表明改进型铝合金钻杆相比传统钢钻杆可以更有效地减少环空内岩屑质量。该研究成果对提高川渝地区页岩气井内的岩屑运移能力与钻井经济效益具有重要的现实意义。In the process of drilling in Sichuan-Chongqing area,the cuttings migration ability is always one of the main factors affecting drilling efficiency.Due to the large difference between the density of traditional steel drill pipe and that of drilling fluid,the steel drill pipe would be leaned to the bottom of the wellhead under the action of gravity,the cuttings at the bottom of the drill pipe would deposit and form cuttings bed due to the low flow rate,and finally result in sticking or reducing of ROP,which seriously affects the drilling cost.In order to improve the cuttings migration ability in shale gas wells,the physical parameters of 3 different materials of drill pipes were compared,concluding that the aluminum alloy drill pipe has low density,corrosion resistance and high strength characteristics.In order to make the overall gravity suffered by the aluminum alloy drill pipe less than the buoyancy of the drilling fluid,its structure was further improved,and theoretical analysis and numerical calculation were conducted to verify its floatability.And finally,the finite element simulation was used to build the 3D annular cuttings settlement model of aluminum alloy drill pipe and traditional steel drill pipe in Fluent to compare and analyze the influence of them on the cuttings mass in the annulus under the conditions of changing the particle size of cuttings,hole deviation angle,ROP and displacement,indicating that the improved aluminum alloy drill pipe can more effectively reduce the cuttings mass in the annulus than the traditional steel drill pipe.The research results have important practical significance for improving the cuttings migration ability in shale gas wells and the economic benefits of drilling in the Sichuan-Chongqing area.

关 键 词：铝合金钻杆 钢钻杆 岩屑运移 数值模拟 对比分析 

分 类 号：TE921[石油与天然气工程—石油机械设备]