四川盆地二叠系永探1井火山岩气井完井测试井壁稳定性实验  

Experimental study on wellbore stability during volcanic gas well test:A case study on Well Yongtan 1 in the Permian of the Sichuan Basin

作　　者：唐庚 龚浩 徐家年[2] 周朗 张华礼 张林 TANG Geng;GONG Hao;XU Jianian;ZHOU Lang;ZHANG Huali;ZHANG Lin(Engineering Technology Research Institute,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China;College of Petroleum and Natural Gas Engineering,Chongqing University of Science&Technology,Chongqing 401331,China;Engineering Technology Department,PetroChina Southwest Oil&Gasfield Company,Chengdu,Sichuan 610051,China)

机构地区：[1]中国石油西南油气田公司工程技术研究院 [2]重庆科技学院石油与天然气工程学院 [3]中国石油西南油气田公司工程技术处

出　　处：《天然气工业》2022年第3期91-98,共8页Natural Gas Industry

基　　金：中国石油天然气股份有限公司西南油气田公司重大科技专项“四川盆地二叠系火成岩钻完井及储层改造技术研究”(编号:2019ZD01-05)。

摘　　要：四川盆地二叠系永探1井火山岩气井,在完井试油过程中地层垮塌,返出大量火山岩碎屑,堵塞井筒及地面流程,严重影响了完井测试。为进一步优选后续完井方式,高效开发此类气藏,在分析储层岩石矿物组分、微观孔隙结构、岩石力学参数的基础上,基于Von-Mises剪切破坏理论,进行了完井试油及生产过程中井壁稳定性的研究。研究结果表明:(1)工区火山岩下部储层黏土矿物含量高,裂缝、微裂缝发育,经工作液作用后,易发生黏土矿物膨胀、颗粒分散、运移,引起井壁失稳;(2)不同工作液影响了岩石力学参数,进而影响到井壁稳定性,经改性聚磺试油工作液作用后的储层,直井井壁上岩石最大剪切应力均方根存在大于井壁岩石剪切强度均方根的井壁不稳定点;(3)火山岩下部储层火山岩碎屑产出的临界日产量为1.13×10^(4)m^(3);(4)模拟气井日产量介于1.42×10^(4)~28.35×10^(4)m^(3)时,折算年碎屑产出量介于270.3~2183.2 kg,折算井筒沉砂高度介于12.7~102.5 m,易对生产造成影响。结论认为,实验室结果为此类火山岩气藏的高效开发奠定了基础,火山岩气井完井试油及生产过程中,应通过优化工作液配方、控制生产压差、优选完井方法等方式保障井壁稳定,充分发挥气井产能。During the completion test of Well Yongtan-1(volcanic gas well)in the Permian of the Sichuan Basin,the formation collapsedand a large amount of volcanic debris returned,which blocked the wellbore and surface flow and finally impacted the well completion test seriously.In order to optimize the following completion mode and develop similar gas reservoirs efficiently,this paper analyzes reservoir rock mineral compositions,micro pore structures and rock mechanical parameters.Then,the wellbore stability in the process of completion test and production is researched based on Von-Mises shear failure theory.And the following research results are obtained.First,the lower volcanic reservoir in the work area has high clay mineral content and developed fractures and micro fractures.After the action of working fluid,clay mineral expansion,particle dispersion and migration occur easily,resulting in wellbore instability.Second,different working fluids influence rock mechanical parameters,and then impact the wellbore stability.In the reservoir treated by the modified polysulfonate well test working fluid,there is a wellbore instability point on the wall of the vertical well where the root mean square of maximum rock shear stress is greater than that of rock shear strength.Third,the critical gas production for the production of volcanic rock debris in the lower volcanic reservoir is 1.13×10^(4)m^(3).Fourth,when the daily production of simulated gas well is between 1.42×10^(4)m^(3)and28.35×10^(4)m^(3),the converted annual debris production is in the range of 270.3-2183.2 kg,and the converted shaft sand setting height is12.7-102.5 m,which can impact the production easily.In conclusion,the experimental results lay a foundation for the efficient development of similar volcanic gas reservoirs.In the completion test and production process of volcanic gas wells,wellbore stability shall be maintained by optimizing the working fluid formula,controlling the production pressure difference and optimizing the completion method,so as to giv

关 键 词：四川盆地 火山岩气井 井壁稳定 火山碎屑 完井 试油 增产 临界压差 临界产量 

分 类 号：TE257[石油与天然气工程—油气井工程]