MDT压力测试影响因素分析及应用

Analysis of Influence Factors on MDT Pressure Testing and Its Application

模块式动态地层测试器(MDT)的在个别油田应用不理想。对其应用情况的统计分析揭示,测量失败与地层物性、岩性、井孔质量以及泥浆性能等因素有关。例如,高GR、高泥质、泥饼质量差的地层易发生超压;密度大、物性差的地层易发生干测试;井眼不规则、储层异常致密、声波时差偏小则易导致座封失败。在分析和应用测试资料前,要从分析压力恢复曲线入手,先行剔除失效测点和异常测点,方可提高应用效果。

The successful rate of MDT logging in several oilfields is not so good. The statistics and analysis of it indicate that the failures of MDT are related to petrophysical property and lithology of the reservoir, irregular borehole, as well as mud performance. For example, over-pressured is frequent in formations with high GR, high shale content and bad mud cake; dry test is frequent in formations with high density and unsatisfactory petrophysical property; while irregular borehole, abnormal compact formation and small slowness of AC frequently cause failure of packer setting. It is important to analyze the pressure recover curve firstly, and then to reject the invalid or abnormal test data before analyzing and applying MDT information, so that the application effect of MDT would be improved.