关井过程防喷器胶芯的冲蚀性能研究  

Erosion Resistance of Rubber Core of BOP Ram During Shut-in Process

作　　者：胡四海 赵广慧[1] 张川 刘涛 贾宇喆 马封安 HU Sihai;ZHAO Guanghui;ZHANG Chuan;LIU Tao;JIA Yuzhe;MA Feng'an(School of Mechanical Engineering,Southwest Petroleum University,Chengdu 610500,China;Chengdu Aerospace Mould&Plastic LLC,Chengdu 610100,China;Sichuan Baoshi Machinery Drilling Equipment Co.,Ltd.,Sichuan Deyang 618399,China)

机构地区：[1]西南石油大学机电工程学院,成都610500 [2]成都航天模塑有限责任公司,成都610100 [3]四川宝石机械钻采设备有限责任公司,四川德阳618399

出　　处：《表面技术》2024年第23期159-168,共10页Surface Technology

基　　金：中国石油天然气集团有限公司关键核心技术攻关项目(2021ZG08)。

摘　　要：目的预测井涌或井喷发生时关闭防喷器闸板对胶芯的冲蚀,为评估关井后胶芯的密封性能提供依据。方法首先依据橡胶试件的冲蚀试验,基于LM优化算法反演分析确定丁腈橡胶的冲蚀模型参数,将所确定的冲蚀模型通过UDF嵌入Fluent软件,建立关井过程中防喷器半封闸板附近流场的数值模型,计算密封胶芯的冲蚀性能,研究关井全过程胶芯材料去除量与关井时长的变化规律。结果得到了丁腈橡胶材料的改进Finnie冲蚀模型参数,该冲蚀模型预测的试件冲蚀率随冲击角的变化与试验数据的最大相对误差仅为5.77%,可用于模拟丁腈橡胶构件的冲蚀性能。在防喷器关阀过程中,携岩钻井液对胶芯的冲蚀主要发生在端面边缘处的岩屑高速碰撞区。胶芯的冲蚀率与钻井液的含砂量呈线性正相关,与钻井液的流速呈非线性正相关。随着闸板开度的减小,冲蚀率呈现指数增长。在文中的参数条件下,当闸板开度分别为104、26、6 mm时,胶芯的材料去除率分别为1.52、5.22、28.3 mm^(3)/s,表明在关井后期闸板即将关闭前,胶芯受到的冲蚀最严重。在关井全过程中,胶芯的材料去除量随着关井时长的增加而增加,关井时长分别为3、8 s时对应的胶芯体积去除量分别为5.04、13.43 mm^(3)。结论在井涌或井喷发生时,关闭防喷器闸板的时机和时长对于处置事故至关重要,需综合评价关井时长对井口动载荷和胶芯冲蚀量的影响,制定科学的关井预案,以保障井筒、地面装备和施工人员的安全。A large amount of fluid carrying rock debris rapidly flows out of the well when a blowout or well kick occurs.During the process of closing the blowout preventer(BOP)ram,solid particles in the drilling fluid will erode the rubber core of the ram.To address this issue,the work aims to determine the optimal erosion model for nitrile rubber and predict the erosion amount of the rubber core quantitatively,so as to provide a basis for evaluating the sealing performance of the rubber core after shut-in.Firstly,based on the erosion test of rubber specimens,the optimal parameters of the erosion model suitable for nitrile rubber material were obtained through inversion analysis by the Levenberg-Marquardt(LM)optimization algorithm.Then,this erosion model with optimal parameters was assigned to the elements of the sealing rubber core via a user defined function(UDF).A numerical model of the flow field near the BOP pipe ram was established during the shut-in process by Fluent.Finally,the erosion resistance of the rubber core was simulated,and the variation of the removal of the rubber core material with the duration of shut-in was discussed.As a result,an improved Finnie erosion model was determined by which the relationship between the erosion rate and impact angle was calculated for the rubber specimens.The maximum relative error between the predicted results and the experimental ones was only 5.77%.It could be used to simulate the erosion resistance of nitrile rubber components.By the improved Finnie model,the erosion resistance of the sealing rubber core of BOP ram was calculated during the shut-in process.It was found that the erosion of the rubber core by rock-carrying drilling fluid mainly occurred at the lip edge,the high-speed collision zone of cuttings.The erosion rate of the rubber core was linearly positively correlated with the sand content and nonlinear with the flow rate of the drilling fluid.As the opening of the ram decreased,the erosion rate grew exponentially.Under the parameter conditions proposed,when th

关 键 词：防喷器半封闸板 密封胶芯 冲蚀模型 反演分析 关井过程 

分 类 号：TE92[石油与天然气工程—石油机械设备]