钻探工程2024，Vol.51Issue(z1)：90-95,6.DOI:10.12143/j.ztgc.2024.S1.013
基于非球形岩屑的高压CO2喷射钻井携岩试验研究
Experimental study of rock cutting-carrying for high-pressure CO2 jet drilling based on non-spherical rock cuttings
摘要
Abstract
In unconventional reservoir exploitation,underbalanced gas drilling technology overcomes the shortcomings of conventional drilling such as low drilling speed,long well construction period and low efficiency,and one of the key constraints to the gas drilling technology is the high efficiency of rock cuttings transport at the bottom of the well when drilling in deep formations.Since the gas drilling rock cuttings transport research mostly adopts spherical instead of real non-spherical rock cuttings,ignoring the influence of non-spherical contour on rock chip transport,resulting in the inaccurate characteristics of bottomhole jetting rock cuttings transport.In this paper,the non-spherical rock cuttings are produced by cutting sandstone with a PDC drill bit,and a PDC drill bit and high-pressure CO2 jetting test platform are set up to investigate the effects of the sphericity φ of the rock cuttings,the jetting pressure,the rotational speed of the drill bit,and the volume of the rock cuttings on the rock transport.The results show that:the axial velocity of the non-spherical rock cuttings fluctuates greatly when they rise,and their start-up speed is faster than that of the spherical rock cuttings,but the velocity decays faster;with the increase of the value of φ,the axial velocity of the rock cuttings decreases and then increases in the wellbore,and the axial velocity of the rock cuttings decreases and causes the poor transport efficiency when the value of φ is in the range of 0.6～0.65;the axial velocity of the rock cuttings increases significantly with the increase of the CO2 injection pressure,and the increase of axial velocity of rock cuttings at the distance of 35 mm from the bottom of the well can reach 221%;the increase of drill rotational speed increases the axial velocity of rock cuttings significantly close to the bottom of the well,and the average velocity is stable at 11.88 m/s when the rotational speed of the drill bit is in the range of 70～80 r/min,which shows a better effect of rock carrying;the axial velocity decreases and then increases with the increase of rock cuttings'volume.The above study systematically elucidates the rock-carrying characteristics of PDC bit jet drilling,and provides a theoretical basis for the application of CO2 and other gas jet drilling technologies.关键词
非常规储层/欠平衡气体钻井/喷射携岩/岩屑球形度/PDC钻头Key words
unconventional reservoir/underbalanced gas drilling/jetting rock cutting-carrying/rock cuttings'sphericity/PDC drill bit分类
能源科技引用本文复制引用
杨显鹏,涂杰,蔡灿,曾琪,魏怀洲,蒲治成,陈浩..基于非球形岩屑的高压CO2喷射钻井携岩试验研究[J].钻探工程,2024,51(z1):90-95,6.基金项目
国家自然科学基金青年基金项目"超临界CO2循环喷射压裂作用下干热岩储层缝网形成与增渗机理研究"(编号:52004236) （编号:52004236）
国家自然科学基金重点项目"海相页岩水平井超临界二氧化碳压裂机理与一体化模拟研究"(编号:52234003) （编号:52234003）
油气藏地质及开发工程国家重点实验室开放基金"高压CO2射流-非平面齿复合破岩机理及喷嘴布置设计研究"(编号:PLN202237) （编号:PLN202237）
四川省科技厅创新创业苗子工程重点项目"干热岩井超临界CO2射流-PDC齿复合破岩机理及配套钻头设计"(编号:2021JDRC0114) （编号:2021JDRC0114）
