深水气井测试清井诱喷瞬态流动模拟
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摘要
在深水气井测试作业中,由于缺乏对实际放喷过程中井筒内流态、压力、温度变化的准确认识,无法判断清井诱喷关键参数设计是否合理。为此,基于所建立的井筒多相流瞬态流动模型,以实际深水测试气井为研究对象,进行清井诱喷瞬态数值仿真模拟,真实再现实际工况下井筒内驱替工作液流动情况,量化清井诱喷过程中沿程压力、温度剖面非稳态变化,并对清井诱喷关键参数进行敏感性分析。研究结果表明:(1)模拟油压与实测油压的最大误差在±5%左右,拟合效果较好,验证了模型的准确性及可靠性;(2)清井时间随油嘴尺寸减小而递增;(3)诱喷液垫越高,气体从井底流出的初始速度越快,激动压力越大,清井诱喷时间越短;(4)在保障地面处理设备安全、平稳运行及经济有效的前提下,应尽可能采用大油嘴、大管径测试管柱并设定合理的诱喷液垫高度以完成清井诱喷。结论认为,该研究成果成功实现了深水气井测试清井放喷瞬态流动过程的模拟,对测试工作制度、测试管柱及设备的设计和选型,保证深水测试安全等都具有指导意义。
The change of flow pattern, pressure and temperature inside the wellbore in the actual process of blowout is not understood accurately, so it is unable to judge whether the key parameters of induced flow in well cleanup during deepwater gas well test are designed rationally. In this paper, the testing of an actual gas well was taken as the research object. Based on the transient flow model of wellbore multiphase flow, transient numerical simulation was conducted on the induced flow in well cleanup to truly reproduce the flowing situation of displacement fluid in the borehole under the actual operating condition. The unsteady-state change of pressure and temperature profiles along the depth in the process of induced flow in well cleanup was quantified. Besides, sensitivity analysis was performed on the key parameters of induced flow. And the following research results were obtained. First, the maximum error between the simulated tubing pressure and the measured value is about ±5%, which indicates good fitting. It is verified that the model is accurate and reliable. Second, the cleanup time increases with the decrease of choke size. Third, the higher the flow inducing liquid cushion is, the faster the gas initially flows out of the bottom hole, the higher the excitation pressure is and the shorter the cleanup time is. Fourth, the induced flow in well cleanup shall be supplied with large choke, large-diameter test string and rational liquid cushion height as much as possible while ground treatment equipments are kept safe, smooth, economical and effective. In conclusion, these research results promote the successful simulation on the transient flow process of induced flow in well cleanup during deepwater gas well tests, and they can be used as a guidance for the formulation of testing system, the design and type selection of test strings and equipments and the guarantee of deepwater testing safety.
The change of flow pattern, pressure and temperature inside the wellbore in the actual process of blowout is not understood accurately, so it is unable to judge whether the key parameters of induced flow in well cleanup during deepwater gas well test are designed rationally. In this paper, the testing of an actual gas well was taken as the research object. Based on the transient flow model of wellbore multiphase flow, transient numerical simulation was conducted on the induced flow in well cleanup to truly reproduce the flowing situation of displacement fluid in the borehole under the actual operating condition. The unsteady-state change of pressure and temperature profiles along the depth in the process of induced flow in well cleanup was quantified. Besides, sensitivity analysis was performed on the key parameters of induced flow. And the following research results were obtained. First, the maximum error between the simulated tubing pressure and the measured value is about ±5%, which indicates good fitting. It is verified that the model is accurate and reliable. Second, the cleanup time increases with the decrease of choke size. Third, the higher the flow inducing liquid cushion is, the faster the gas initially flows out of the bottom hole, the higher the excitation pressure is and the shorter the cleanup time is. Fourth, the induced flow in well cleanup shall be supplied with large choke, large-diameter test string and rational liquid cushion height as much as possible while ground treatment equipments are kept safe, smooth, economical and effective. In conclusion, these research results promote the successful simulation on the transient flow process of induced flow in well cleanup during deepwater gas well tests, and they can be used as a guidance for the formulation of testing system, the design and type selection of test strings and equipments and the guarantee of deepwater testing safety.
引文
[1]徐朝阳.井筒多相流瞬态流动数值算法及响应特征研究[D].成都:西南石油大学,2015.Xu Chaoyang.Research on the numerical algorithm for transient multiphase flow and response characteristics of flow parameters in wellbore[D].Chengdu:Southwest Petroleum University,2015.
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[4]赵广慧,刘丹丹,王维旭,刘静,赵博.深水钻机K型井架稳定性数值模拟研究[J].西南石油大学学报(自然科学版),2017,39(3):158-164.Zhao Guanghui,Liu Dandan,Wang Weixu,Liu Jing&Zhao Bo.Numerical simulation study on the stability of K-type derrick for deep-water drilling rigs[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(3):158-164.
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[6]何玉发,李紫晗,张滨海,高飞,李莹莹.深水气井测试临界携液条件的优化设计[J].天然气工业,2017,37(9):63-70.He Yufa,Li Zihan,Zhang Binhai,Gao Fei&Li Yingying.Design optimization of critical liquid-carrying condition for deepwater gas well testing[J].Natural Gas Industry,2017,37(9):63-70.
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[8]魏文倩,孙宝江,王粤,高永海,刘晓兰.基于OLGA的深水混输管道及井筒水合物风险分析[J].油气储运,2016,35(4):356-362.Wei Wenqian,Sun Baojiang,Wang Yue,Gao Yonghai&Liu Xiaolan.Risk assessment for hydrates in deepwater multiphase pipelines and boreholes by using OLGA[J].Oil&Gas Storage and Transportation,2016,35(4):356-362.
[9]喻西崇,李清平,安维杰,邬亚玲.海底混输管道停输和再启动瞬态流动规律研究[J].工程热物理学报,2008,29(2):251-255.Yu Xichong,Li Qingping,An Weijie&Wu Yaling.Shutdown and restart transient flow characteristics study in offshore multiphase pipeline[J].Journal of Engineering Thermophysics,2008,29(2):251-255.
[10]陈林,余忠仁.气井非稳态流井筒温度压力模型的建立和应用[J].天然气工业,2017,37(3):70-76.Chen Lin&Yu Zhongren.Construction and application of a wellbore temperature and pressure model for unsteady flow in gas wells[J].Natural Gas Industry,2017,37(3):70-76.
[11]Hamid K.Comparison of correlations for predicting wellbore pressure losses in gas-condensate and gas-water wells[C]//Canadian International Petroleum Conference,10-12 June 2003,Calgary,Alberta,Canada.
[12]杨胜来,魏俊之.油层物理学[M].北京:石油工业出版社,2015.Yang Shenglai&Wei Junzhi.Reservoir physics[M].Beijing:Petroleum Industry Press,2015.
[13]李士伦.天然气工程[M].北京:石油工业出版社,2000.Li Shilun.Natural Gas Engineering[M].Beijing:Petroleum Industry Press,2000.
[14]Chung C,Marian D,Napalowski R,Thomson J.Dynamic well clean-up flow simulation for field start-up planning in the Pyrenees development,offshore Western Australia[C]//SPE Asia Pacific Oil and Gas Conference and Exhibition,18-20 October2010,Brisbane,Queensland,Australia.
[15]Krogh E,Mjaaland S&Sletfjerding E.Dynamic flow simulation of a well clean-up operation at the Asgard Field[C]//SPE Annual Technical Conference and Exhibition,4-7 October 2009,New Orleans,Louisiana,USA.
[2]陈阳.深水钻井气侵期间井筒多相流流动规律研究[D].成都:西南石油大学,2016.Chen Yang.Study on multiphase flow law during the gas erosion in deepwater drilling[D].Chengdu:Southwest Petroleum University,2016.
[3]付强,魏纳,孟英峰,孙万通,郭平.深水钻井天然气水合物井筒多相流动模型及敏感性分析[J].中国海上油气,2016,28(4):107-113.Fu Qiang,Wei Na,Meng Yingfeng,Sun Wantong&Guo Ping.Model of wellbore multiphase flow and its sensitivity analysis during drilling in deep water natural gas hydrate reservoirs[J].China Offshore Oil and Gas,2016,28(4):107-113.
[4]赵广慧,刘丹丹,王维旭,刘静,赵博.深水钻机K型井架稳定性数值模拟研究[J].西南石油大学学报(自然科学版),2017,39(3):158-164.Zhao Guanghui,Liu Dandan,Wang Weixu,Liu Jing&Zhao Bo.Numerical simulation study on the stability of K-type derrick for deep-water drilling rigs[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(3):158-164.
[5]何家雄,卢振权,苏丕波,张伟,冯俊熙.南海北部天然气水合物气源系统与成藏模式[J].西南石油大学学报(自然科学版),2016,38(6):8-24.He Jiaxiong,Lu Zhenquan,Su Pibo,Zhang Wei&Feng Junxi.Source supply system and reservoir forming model prediction of natural gas hydrate in the deep water area of the northern South China Sea[J].Journal of Southwest Petroleum University(Science&Technology Edition),2016,38(6):8-24.
[6]何玉发,李紫晗,张滨海,高飞,李莹莹.深水气井测试临界携液条件的优化设计[J].天然气工业,2017,37(9):63-70.He Yufa,Li Zihan,Zhang Binhai,Gao Fei&Li Yingying.Design optimization of critical liquid-carrying condition for deepwater gas well testing[J].Natural Gas Industry,2017,37(9):63-70.
[7]Bendiksen KH,Maines D,Moe R&Nuland S.The dynamic twofluid model OLGA:Theory and application[J].SPE Production Engineering,1991,6(6):171-180.
[8]魏文倩,孙宝江,王粤,高永海,刘晓兰.基于OLGA的深水混输管道及井筒水合物风险分析[J].油气储运,2016,35(4):356-362.Wei Wenqian,Sun Baojiang,Wang Yue,Gao Yonghai&Liu Xiaolan.Risk assessment for hydrates in deepwater multiphase pipelines and boreholes by using OLGA[J].Oil&Gas Storage and Transportation,2016,35(4):356-362.
[9]喻西崇,李清平,安维杰,邬亚玲.海底混输管道停输和再启动瞬态流动规律研究[J].工程热物理学报,2008,29(2):251-255.Yu Xichong,Li Qingping,An Weijie&Wu Yaling.Shutdown and restart transient flow characteristics study in offshore multiphase pipeline[J].Journal of Engineering Thermophysics,2008,29(2):251-255.
[10]陈林,余忠仁.气井非稳态流井筒温度压力模型的建立和应用[J].天然气工业,2017,37(3):70-76.Chen Lin&Yu Zhongren.Construction and application of a wellbore temperature and pressure model for unsteady flow in gas wells[J].Natural Gas Industry,2017,37(3):70-76.
[11]Hamid K.Comparison of correlations for predicting wellbore pressure losses in gas-condensate and gas-water wells[C]//Canadian International Petroleum Conference,10-12 June 2003,Calgary,Alberta,Canada.
[12]杨胜来,魏俊之.油层物理学[M].北京:石油工业出版社,2015.Yang Shenglai&Wei Junzhi.Reservoir physics[M].Beijing:Petroleum Industry Press,2015.
[13]李士伦.天然气工程[M].北京:石油工业出版社,2000.Li Shilun.Natural Gas Engineering[M].Beijing:Petroleum Industry Press,2000.
[14]Chung C,Marian D,Napalowski R,Thomson J.Dynamic well clean-up flow simulation for field start-up planning in the Pyrenees development,offshore Western Australia[C]//SPE Asia Pacific Oil and Gas Conference and Exhibition,18-20 October2010,Brisbane,Queensland,Australia.
[15]Krogh E,Mjaaland S&Sletfjerding E.Dynamic flow simulation of a well clean-up operation at the Asgard Field[C]//SPE Annual Technical Conference and Exhibition,4-7 October 2009,New Orleans,Louisiana,USA.