迟到时间校正创新性研究及在渤海油田的应用

Innovative Research on Lag Time Calibration and Its Application in Bohai Oilfield

摘要: 在现场钻井过程中，迟到时间的准确与否对地质录井及钻井工程都具有重大的意义，它是提高录井剖面符合率及油气发现率的重要保障，同时也是钻井工程准确监测的重要前提。迟到时间的影响因素较多，当前渤海地区主要运用投电石或标志物法，通过调整井眼扩大率来校正迟到时间，该方法在某些区块重难点井作业过程中往往无法满足剖面归位的要求。通过对渤海地区某一区块不同层段的多口井进行综合研究，发现该区块井眼扩大率在不同层位呈现出各自不同的特征，最终总结出迟到时间分层段计算方法。该方法在渤海油田进行了应用，录井剖面符合率与油气发现率都有较大的提高，取得非常好的效果。

Abstract: The accuracy of lag time was crucial to geological logging and drilling engineering in drilling process, which was the guarantee for improving the coincidence rate of profile of mud logging and the rate of oil and gas discovery, and also the important prerequisite for an accurate monitoring of drilling engineering. There existed many factors influencing the lag time. Currently, the lag time was calibrated by adjusting the reaming rate through throwing calcium carbide or markers. This method often could not meet the requirements of stratigraphic profile homing in the drilling process of important and difficult wells in some areas. A comprehensive research is carried out on different sections in multiple wells of a certain area in Bohai oilfield, the result shows that different intervals have different hole enlargement features, thus the method for calculating lag time by section is summarized. Application of the method in Bohai Oilfield improves that the coincidence rate of logging profile and oil and gas discovery rate are improved significantly.