| 摘要: |
| 为了将随钻电阻率测井值的响应特征应用于深水钻井气侵早期监测方法中，对随钻电阻率测井值气侵响应规律进行研究。在分析测井值的环境影响因素基础上，设计套气侵模拟试验装置，研究随钻电阻率测井值在不同注气量下气体侵入井筒的响应特征。考虑如何排除地层岩性影响随钻电阻率测井值变化并结合钻井液录井资料的基础上，建立基于随钻电阻率测井的深水钻井气侵早期监测方法。试验结果表明：通过瞬时随钻电阻率测井值的脉动特征可进行井底环空流型识别，并拟合出了气体体积分数与无因次随钻电阻率测井值的关系式，拟合公式与试验数据的相对平均误差为5%，吻合程度较高；与常规泥浆池增量法相比，建立的方法可提前10 min监测到气侵发生，比隔水管气侵早期监测方法提前6 min监测到气侵发生。 |
| 关键词: 气侵早期监测 随钻电阻率 试验井筒 响应特征 气侵程度 |
| DOI：10.3969/j.issn.1673-5005.2017.06.011 |
| 分类号: |
| 基金项目:国家"973"计划项目（2015CB251200）；教育部长江学者和创新团队发展计划项目（IRT1086）；国家科技重大专项（2016ZX05028-001-003） |
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| Early gas kick detection based on the LWD resistivity in deepwater drilling |
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WANG Jinbo, SUN Baojiang, LI Hao, WANG Ning, WANG Zhiyuan, GAO Yonghai1,2
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1. School of Petroleum Engineering in China University of Petroleum, Qingdao 266580, China;2. CNOOC Research Institutes, Beijing 100027, China
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| Abstract: |
| When applying LWD resistivity for deepwater gas kick detection, it is not clear and difficult to identify the response characters of the LWD resistivity. In this research, a simulated wellbore was built in laboratory to study gas kicks during drilling, and to analyze the response characters of the LWD resistivity under different gas kick rates. A method of early gas kick detection was developed based on the LWD resistivity and drilling fluid log data with considerations of eliminating effects of rock formation. Based on the experimental results, a model correlating the dimensionless resistivity and kicked gas volume was formulated, and the impulse character of instantaneous LWD resistivity was used to identify the flow pattern of multiphase flow in wellbore. The results show that the average error between the experimental data and that predicted by the model is less than 5%. With application of this method for the detection of typical gas kicks in deepwater well, it is 10 minutes earlier than the conventional method of mud pit gain, and 6 minutes earlier than the method of early gas kick detection via bottom riser. The method of the LWD resistivity can detect a gas kick occurring in the wellbore earlier than the conventional overflow detection technique, which can provide useful data for the as kick control. |
| Key words: early gas kick detection LWD resistivity experimental wellbore response characteristics gas kick degree |
