摘要: |
针对常规电阻率方法识别低对比度油层比较困难的问题,从自然电位产生机理入手,分析了淡水和盐水钻井 液条件下自然电位异常幅度的影响因素、含油饱和度与自然电位异常幅度之间的联系。结果表明,适当的盐水钻井 液条件下油层自然电位呈小幅度正异常或小幅度负异常,与水层自然电位呈大幅度正异常有很大差异。采用合理 设计钻井液性能、调整测井环境的方法,通过及时测井,得到正异常幅度自然电位,利用油层与水层的自然电位异常 幅度之间的差异,实现了低对比度油层的准确、有效识别。冀东油田低对比度油层的识别评价应用实例表明,该技 术是提高低对比度油层识别精度的一种有效手段。 |
关键词: 优化设计 钻井液电阻率 自然电位 低对比度 油层评价 |
DOI: |
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基金项目::中石油股份公司科技攻关项目(030169-4) |
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A new method for identifying low-contrast reservoir based on optimizing design of drilling fluid properties |
CHENG Xiang-zhi1,FAN Yi-ren1,ZHOU Can-can2,ZHOU Feng-ming3
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(1. Faculty of Geo-Resource and Information in China University of Petroleum,Dongying 2570619 Shandong Province, China;2. Well Logging and Remote Sensing Technology Department,Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China ;3. Research Institute of Exploration and Development, Jidong Oilfield y Tangshan 063004, Hebei Province, China )
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Abstract: |
Aimed at the problem that the low-contrast pay is more difficult to recognize by the conventional resistivity method, the influence factors of the spontaneous potential (SP) anomaly magnitude under the fresh & the brine drilling fluid and the relationship between saturation and the SP anomaly magnitude were analyzed by the mechanism of SP. The results show that the oil layer has low amplitude normal or negative anomaly SP and the water layer has large amplitude positive anomaly SP under the brine drilling fluid. The fluid performance was reasonably designed to adjust logging environment of well drilling, and the positive anomaly SP was obtained by prompt logging, then the low-contrast pay was accurately and effectively recognized by using the difference of the SP anomaly magnitude between oil layer and water layer. The technique was extensively applied in recognizing the low-contrast reservoir Jidong Oilfield,which shows that the technique is an effective way of recognizing the low-contrast reservoir. |
Key words: optimization design drilling fluid resistivity spontaneous potential low contrast reservoir evaluation |