CAJ | 학술논문

国内气体钻井技术仍处于发展阶段,井内流场分布及工艺参数研究方面还不成熟,尤其是在气体钻井过程中发生偏心时环空内的流场分布变化研究较少.基于流体动力学方法,利用FLUENT软件对气体钻井时环空内气固两相流场进行了数值模拟研究,模拟发现偏心环空中岩屑流速偏离对称分布,在倾斜井眼中有明显增加,最大速度在环空厚度较大处发生;钻柱旋转使环空压降增大,而随井斜角的增大,压降逐渐减小;偏心环空的岩屑浓度较大,随钻柱旋转速度的增大先增后减,而随井斜角的增大而增大.数值模拟气体钻井形象直观地反映了井内各参数的分布情况,为进一步设计技术参数提供了有效的依据.
국내기체찬정기술잉처우발전계단,정내류장분포급공예삼수연구방면환불성숙,우기시재기체찬정과정중발생편심시배공내적류장분포변화연구교소.기우류체동역학방법,이용FLUENT연건대기체찬정시배공내기고량상류장진행료수치모의연구,모의발현편심배공중암설류속편리대칭분포,재경사정안중유명현증가,최대속도재배공후도교대처발생;찬주선전사배공압강증대,이수정사각적증대,압강축점감소;편심배공적암설농도교대,수찬주선전속도적증대선증후감,이수정사각적증대이증대.수치모의기체찬정형상직관지반영료정내각삼수적분포정황,위진일보설계기술삼수제공료유효적의거.
Gas drilling technology is being developed in China, research on distribution of flow and parameters of gas drilling is still in the rough, especially the research on the distribution of flow properties in eccentric annulus. Based on the computation fluid dynam-ics method, the gas-cuttings flow properties in eccentric annulus are simulated by FLUENT. The velocity of cuttings is asymmetrical in eccentric annulus and it increases obviously in inclined borehole. The maximum velocity occurrs in the major eccentric annulus. The pressure fall increases when drill string revolves, and it drops gradually with the augment of deviation angle. The concentration of cut-tings gets higher in eccentric annulus. It first increases and then decreses while the rotation speed gets higher. And it increases with the augment of deviation angle. Numerical simulation of gas drilling reflects the distribution of all borehole parameters vividly and directily, providing an effective basis for further parameters design.