岩性随钻实时识别方法——滑动窗口法研究

On a LWD Real-time Lithology Identification Method-Slip Window Method

利用随钻工程参数进行实时识别岩性研究,既有助于钻井过程中及时发现油气层,又能为及时的地层异常压力预报提供地质基础;与随钻测井相比,岩性随钻识别实时性更强,而且成本很低。动态滑动窗口法是一种随钻岩性识别方法,它利用有效信息窗口、参考信息窗口、区域信息窗口等途径寻找数据中的隐含信息,用以进行综合判别,且窗口是以自适应、自组织的方式随着钻深向下滑动,实现有效信息窗口的动态变更。该方法克服了传统静态岩性识别方法的局限,真正反映了整口井中地层性质和钻井施工均具有的复杂变化的整体中存在较稳定局部的非线性变化规律,可以有效地随钻实时识别复杂地层剖面的岩性,识别成功率大于80％。

Real-time lithology identification while drilling not only helps to find the oil-bearing layers, but also provides a geological basis for the abnormal formation pressure forecast. Compared with LWD, this kind of lithology identification method provides more exact real-time information and is more cost-effective. Dynamic slip window method is a while-drilling lithology identification method, which uses effective information window, reference information window, region information window to search default information in log data for comprehensive lithology identification. The windows slide down in the form of self-adaptation and self-organization to dynamically change the effective information window. This method conquers the localization of traditional static lithology identification method. Only by using the dynamic slip window method can the variation regulations( namely, 'some stable parts may exist in the complicated variational whole') in both the drilling process and formation properties of a well be really reflected. Consequently, lithologies of the complicated profiles can be effectively identified with 80% of success.