李万东,吴阳,兰小林. 厄瓜多尔东部油区平衡法悬空水泥塞固井技术[J]. 石油钻探技术,2022, 50(4):83-89. DOI: 10.11911/syztjs.2022032
引用本文: 李万东,吴阳,兰小林. 厄瓜多尔东部油区平衡法悬空水泥塞固井技术[J]. 石油钻探技术,2022, 50(4):83-89. DOI: 10.11911/syztjs.2022032
LI Wandong, WU Yang, LAN Xiaolin. Cementing technologies of balanced off-bottom cement plugs in Eastern Ecuador [J]. Petroleum Drilling Techniques,2022, 50(4):83-89. DOI: 10.11911/syztjs.2022032
Citation: LI Wandong, WU Yang, LAN Xiaolin. Cementing technologies of balanced off-bottom cement plugs in Eastern Ecuador [J]. Petroleum Drilling Techniques,2022, 50(4):83-89. DOI: 10.11911/syztjs.2022032

厄瓜多尔东部油区平衡法悬空水泥塞固井技术

Cementing Technologies of Balanced Off-Bottom Cement Plugs in Eastern Ecuador

  • 摘要: 为了解决厄瓜多尔东部油区打水泥塞作业成功率不高的问题,研究了作业中影响水泥塞稳定性及质量的各种因素,采取针对性措施,形成了厄瓜多尔东部油区平衡法悬空水泥塞固井技术。针对水泥塞与下部钻井液所形成界面不稳定的问题,研制了低密度高强水泥浆和反应性支撑液;针对打水泥塞钻杆与井筒环空间隙过窄导致水泥塞质量不合格的问题,设计了插管工具;针对打水泥塞钻杆下端开口造成水泥浆向下喷射、与钻井液混合严重的问题,研制了分流器工具;针对钻杆内缺乏隔离塞及现有工具成本高、操作复杂等问题,研制了海绵球塞工具。室内试验表明,低密度高强水泥浆密度1.74 kg/L,24 h抗压强度22.5 MPa,满足作业要求;反应性支撑液密度1.44 kg/L,动切力48 Pa,胶凝强度49 Pa,能够有效支撑上部水泥浆;设计的插管、分流器和海绵球塞等工具,能够解决水泥塞放置过程中的质量问题。 现场应用表明,厄瓜多尔东部油区平衡法悬空水泥塞固井技术应用效果良好,能够大幅提高作业成功率,可推广应用。

     

    Abstract: Because the setting cement plugs applied in Ecuador oil field have a low success rate, this study explored the factors that influence the stability and quality of cement plugs during operation. It also took targeted measures to develop the cementing technologies of balanced off-bottom cement plugs in Eastern Ecuador. Specifically, low-density and high-strength cement slurry and viscous reactive pills were prepared to solve the problem of the unstable interface between a cement plug and the lower drilling fluid. A drill pipe with a inserted pipe was designed to address unqualified cement plugs due to the excessively narrow annular gap between the drill pipe and the wellbore. A flow diverter was developed to deal with the severe mixture of slurry and drilling fluid caused by the downward slurry spraying due to the lower open end of the drill pipe. Then, sponge balls were prepared to tackle the shortcomings such as no isolation plug in the drill pipe, as well as high costs and complex operations of existing tools. Laboratory tests show that the high-strength cement slurry with a low density of 1.74 kg/L and a compressive strength of 22.5 MPa for 24 h could satisfy the requirements of operations. The viscous reactive pills, with a density of 1.44 kg/L, a yield stress of 48 Pa, and a gel strength of 49 Pa, could effectively support the upper cement slurry. All of the above-mentioned tools can solve quality problems in the cement plug placement. The field application in Eastern Ecuador shows that the developed cementing technologies perform well and can greatly raise the success rate of operations, and thus, it can be widely popularized and applied.

     

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