大牛地气田奥陶系马家沟组各标志层元素录井特征分析及应用

Element logging characteristics analysis and application of each marker bed of Ordovician Majiagou Formation in Daniudi Gas Field

通过全面梳理大牛地气田奥陶系马家沟组的划分方案和各标志层,除公认的4个标志层之外新增5个标志层,共确定了9个标志层,自上而下分别为马五14底部凝灰质标志层K 1、马五22白云岩标志层K 2、马五41白云岩标志层K 3、马五5黑灰岩标志层K 4、马五7含灰白云岩标志层K 5、马五9灰质白云岩标志层K 6、马四段厚层灰岩标志层K 7、马二段白云岩标志层K 8、马一段泥质粉砂岩标志层K 9,同时分析总结了每个标志层的岩性特征、元素录井特征和测井特征。利用元素录井数据对新钻井XH 1井马家沟组进行了标志层识别,利用识别出的标志层完成了元素录井小层划分工作,其结果比现场录井地层划分结果更详细、准确,与测井分层结果较一致。这表明在暂无测井资料的情况下,利用元素录井进行标志层识别、层位划分是可行可信的,值得在录井现场推广运用。

Based on a comprehensive analysis of the division scheme and each marker bed of Ordovician Majiagou Formation in Daniudi Gas Field,in addition to 4 recognized marker beds,5 new marker beds are added,and 9 marker beds are determined.From top to bottom,they are tuffaceous marker bed K 1 at the bottom of Ma514 subzone,dolomite marker bed K 2 of Ma522 subzone,dolomite marker bed K 3 of Ma541 subzone,black limestone marker bed K 4 of Ma55 sub-member,calcium carbonate bearing dolomite marker bed K 5 of Ma57 sub-member,limy dolomite marker bed K 6 of Ma59 sub-member,thick limestone marker bed K 7 of Ma 4 Member,dolomite marker bed K 8 of Ma 2 Member,and argillaceous siltstone marker bed K 9 of Ma 1 Member.At the same time,the lithologic characteristics,element logging characteristics and well-logging characteristics of each marker bed are analyzed and summarized.The marker bed of Majiagou Formation in XH 1 well of new drilling is identified by element logging data.The identified marker beds have been used to complete the subzone division of element logging,and the results are more detailed and accurate than that of the field mud logging stratigraphic division,which is consistent with the results of well logging stratification.This indicates that it is feasible and reliable to use element logging to identify marker beds and divide horizons in the absence of log information,so it is worth popularizing and applying in the mud logging site.