基于非球形岩屑的高压CO_(2)喷射钻井携岩试验研究  

Experimental study of rock cutting‑carrying for high‑pressure CO_(2)jet drilling based on non‑spherical rock cuttings

作　　者：杨显鹏 涂杰 蔡灿[1,2,3,4] 曾琪 魏怀洲 蒲治成 陈浩 YANG Xianpeng;TU Jie;CAI Can;ZENG Qi;WEI Huaizhou;PU Zhicheng;CHEN Hao(High Pressure Jet Theory and Application Technology Laboratory,Southwest Petroleum University,Chengdu Sichuan 610500,China;College of Mechanical and Electrical Engineering,Southwest Petroleum University,Chengdu Sichuan 610500,China;Key Laboratory of Ministry of Education for Oil and Gas Equipment,Chengdu Sichuan 610500,China;State Key Laboratory of Oil&Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu Sichuan 610500,China;Dongfang Electric Corporation,Chengdu Sichuan 610500,China)

机构地区：[1]西南石油大学高压射流理论与应用技术实验室,四川成都610500 [2]西南石油大学机电工程学院,四川成都610500 [3]油气装备教育部重点实验室,四川成都610500 [4]油气藏地质及开发工程全国重点实验室(西南石油大学),四川成都610500 [5]中国东方电气集团公司,四川成都610500

出　　处：《钻探工程》2024年第S01期90-95,共6页Drilling Engineering

基　　金：国家自然科学基金青年基金项目“超临界CO_(2)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);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);油气藏地质及开发工程国家重点实验室开放基金“高压CO_(2)射流-非平面齿复合破岩机理及喷嘴布置设计研究”(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CO_(2)射流-PDC齿复合破岩机理及配套钻头设计”(编号:2021JDRC0114)。

摘　　要：在非常规储层开采中,欠平衡气体钻井技术克服了传统钻井钻速低、建井周期长和效率低等缺点,而气体钻井技术在深部地层钻进时井底高效携岩是制约上述问题的关键之一。由于气体钻井携岩研究中多采用球形代替真实非球形岩屑,忽略岩屑非球形轮廓对岩屑运移的影响,致使井底喷射携岩特性不准确。为此,本文采用PDC钻头切削砂岩所得真实岩屑制得非球形岩屑,搭建PDC钻头高压CO_(2)喷射携岩试验平台,探究岩屑球形度φ、喷射压力、钻头转速和岩屑体积对携岩的影响。结果表明:非球形岩屑上升时轴向速度波动大,且其启动速度快于球形岩屑,但速度衰减更快;随着岩屑球形度φ值的增加,岩屑在井筒内的轴向速度先减小后增加,当φ值在0.6~0.65范围内岩屑轴向速度降低导致运移效率变差;CO_(2)喷射压力增加对岩屑轴向速度增加显著,在距离井底35 mm处岩屑轴向速度增幅可达221%;钻头转速增加使得靠近井底段的岩屑运移速度提升显著,当钻头转速在70~80 r/min范围内,平均运移速度稳定在11.88 m/s,携岩效果较好;岩屑轴向速度随岩屑体积的增加呈现先减小后增大的趋势。上述研究系统阐明了PDC钻头喷射钻井携岩特性,为CO_(2)等气体喷射钻井技术应用提供了理论基础。In unconventional reservoir exploitation,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 CO_(2)jetting test platform are set up to investigate the effects of the sphericityφof 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 ofφ,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 ofφis in the range of 0.6~0.65;the axial velocity of the rock cuttings increases significantly with the increase of the CO_(2)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 cu

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 

分 类 号：TE248[石油与天然气工程—油气井工程] P634.5[天文地球—地质矿产勘探]