基于二维螺旋周向涡流的破碎性油气层固井新技术  

A new cementing technology based on two-dimensional spiral circumferential vortex for fragile oil and gas layers

作　　者：闫振峰 魏凯[1,2] 翟晓鹏 付家文 齐奔[3] 李嘉诚 郑力会 YAN Zhenfeng;WEI Kai;ZHAI Xiaopeng;FU Jiawen;QI Ben;LI Jiacheng;ZHENG Lihui(National Engineering Research Center for Oil&Gas Drilling and Completion Technology//Yangtze University,Wuhan,Hubei 430100,China;Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering//Yangtze University,Wuhan,Hubei 430100,China;No.2 Cementing Company,CNPC Bohai Drilling Engineering Co.,Ltd.,Tianjin 300280,China;Sichuan Kehong Oil&Gas Engineering Co.,Ltd.,Chengdu,Sichuan 610066,China)

机构地区：[1]“油气钻完井技术”国家工程研究中心·长江大学 [2]“油气钻采工程”湖北省重点实验室·长江大学 [3]中国石油渤海钻探工程有限公司第二固井公司 [4]四川科宏石油天然气工程有限公司

出　　处：《天然气工业》2023年第5期71-77,共7页Natural Gas Industry

基　　金：中国石油天然气集团公司工程技术科技统筹项目“重点区块钻井提速与事故复杂预防技术攻关与应用”(编号:2018T-001-008)。

摘　　要：固井质量直接影响油气产量,优良的顶替效率是保证固井质量的先决条件。针对破碎性窄密度窗口地层固井存在大排量顶替易漏、小排量顶替效率低的技术难题,提出了螺旋顶替提高破碎性窄密度窗口固井质量的理念,用水平集法构建了水泥浆顶替前置液的追踪顶替界面数学模型,以典型固井工况参数为例,通过数值模拟方法研究了周向速度对顶替界面、顶替效率和接触时间的影响,形成了裸眼段二维螺旋(螺旋刚性扶正器)顶替固井技术。研究结果表明:①二维螺旋顶替时,顶替界面受周向速度的影响,“凸进”现象减缓,顶替界面较稳定,水泥浆接触地层时间延长,顶替效率提高;②相对于一维轴向顶替,二维螺旋顶替在原轴向波及范围内,增加了水泥浆周向波及,有助于将不规则井段内的被顶替液“旋出”,缩小滞留区,提高水泥浆胶结环境,驱净效果明显。结论认为,该技术在伊拉克米桑油气田现场应用,固井质量优质率从40%提升到60%,二维螺旋顶替固井技术稳定顶替界面和提高井壁驱净效果,二维螺旋周向波及顶替机理为解决破碎性窄密度窗口地层固井顶替的技术难题及研发螺旋注水泥工具提供理论支撑。Cementing quality has a direct impact on oil and gas production,and good displacement efficiency is the prerequisite to cementing quality.Cementing in the fragile strata with a narrow density window has the technical difficulties that high-rate displacement tends to result in leakage easily and low-rate displacement leads to low displacement efficiency.To solve these problems,this paper proposes the concept of applying spiral displacement to improve the cementing quality in the fragile strata with a narrow density window,and establishes a mathematical model tracking displacement interface of slurry displacing prepad fluid using the level set method(LSM).Then,based on the parameters of typical cementing conditions,the influence of circumferential velocity on displacement interface,displacement efficiency and contact time are studied by means of numerical simulation.Thus,the two-dimensional spiral(spiral rigid centralizer)displacement cementing technology for open hole is developed.And the following research results are obtained.First,during two-dimensional spiral displacement,the displacement interface is influenced by the circumferential velocity.As a result,the protruding phenomenon is weakened,the displacement interface is more stable,the contact time of slurry with the strata increases,and the displacement efficiency is improved.Second,different from one-dimensional axial displacement,two-dimensional spiral displacement makes slurry generate circumferential sweep in the original axial sweep range,which is helpful to"spin"the displaced fluid out of the irregular section,so as to reduce the detainment zone and improve the slurry bonding environment,achieving remarkable displacement and cleaning effect.In conclusion,field application of this technology in Missan Oilfield of Iraq increases the high-quality cementing rate from 40%to 60%.The core of two-dimensional spiral displacement cementing technology is to stabilize the displacement interface and improve the wall displacement and cleaning effect.The displacemen

关 键 词：钻井 水泥浆 固井 破碎性地层 窄密度窗口 盐膏层 二维螺旋顶替 固井质量 

分 类 号：TE256[石油与天然气工程—油气井工程]