测井计算钻井泥浆侵入深度的新方法研究

NEW METHOD OF CALCULATING DRILLING MUD INVASION DEPTH BY LOGS

用测井资料计算泥浆侵入深度主要是基于电阻率径向分布特征进行的 ,传统的方法主要有图版法、经验公式法。用测井资料计算泥浆侵入油气层深度是十分有效而直接的手段 ,用其间接地评价钻井泥浆污染油(气 )层的程度则是一项经济可行的新技术。文章在分析比较了传统的泥浆侵入校正方法的基础上 ,经过理论推导和应用介绍了一种直接利用深、中、浅电阻率组合测井资料计算泥浆侵入深度的新方法。通过对研究工区 10多口井的实际资料进行处理 ,泥浆侵入深度的解释结果与测试评价基本相符 ,应用表明 ,该方法不但可以求出钻井泥浆侵入深度 ,还可求出地层真电阻率 ,它优于传统的方法 ,对低侵、高侵和无侵三种情况都实用 。

It is a very effective and direct means to apply log data to calculating the depth of hydrocarbon reservoir′s being invaded by drilling mud and also a new,economic and feasible technique of indirectly evaluating the degree of the reservoir′s being damaged by drilling mud.On the basis of analyzing and contrasting the conventional corrective methods of mudinvasion depth,a new method of applying directly the deep-,mediam- and shallow-investigation resistivity combination logging data to calculating mud invasion depth is introduced in the paper through theoretical derivation and on-the-spot application.According to the results of processing the practical data collected from more than ten wells in research region,it was pointed out that the interpretation result of mud invasion depth is basically coincident with the test evaluation,so that the me thod can yet be regarded as a new way of calculating the depth of hydrocarbon reservoir′s being invaded by drilling mud.