泥岩掉块层位还原技术研究与应用

Research and application of reduction technology of mudstone landslide horizon

泥岩掉块是井壁稳定性的一项重要评价指标,但常规录测技术难以识别泥岩差异,无法确定泥岩掉块深度。为实现井壁失稳井段的稳定性程度评价,提出了利用元素录井和数学算法相结合实现泥岩掉块定量化、智能化层位还原方法。基于元素录井定量分析泥岩矿物成分,建立单井元素地层剖面,通过获取泥岩掉块的矿物成分,利用由欧氏距离法、曼哈顿距离法和调整余弦相似度法组成的相似度评价法建立井壁失稳掉块精准分析模型,根据掉块分布的集中度评价井壁稳定性情况,为钻井施工方案优化提供指导。该方法在锦州25油田4口井中成功应用,钻井工期较前期实施井缩减了1.2 d,表明具有较好的推广应用价值。

Mudstone landslide is an important evaluation index of wellbore stability,but conventional logging technologies are difficult to identify mudstone differences and determine mudstone landslide depth.In order to evaluate the stability degree of borehole wall instability section,a quantitative and intelligent horizon reduction method of mudstone landslide by combining element logging and mathematical algorithm is proposed.Based on the quantitative analysis of mudstone mineral composition by element logging,the element stratigraphic profile of single well is established.By obtaining the mineral composition of the mudstone landslide,an accurate analysis model of borehole wall instability landslide is set up by using the similarity evaluation method composed of Euclidean distance method,Manhattan distance method and adjusted cosine similarity method.Evaluate the wellbore stability according to the landslide distribution tendency,so as to provide guidance for the optimization of drilling construction scheme.This method has been successfully applied in four wells of Jinzhou 25 oilfield,and the drilling period is reduced by 1.2d compared with the previous implementation wells,indicating that it has good popularization and application value.