鄂尔多斯盆地滑北隆起旬探1井寒武-奥陶系试气存疑

Question on Cambrian-Ordovician Testing for Gas from Well Xuntan-1 of Weibei Uplift in Ordos Basin

旬探1井是鄂尔多斯盆地南缘渭北隆起北坡旬邑断块上的一口区域探井，钻探结果表明：该井区存在张夏组鲕滩型储层、亮甲山组上部溶蚀孔洞型储层、上下马家沟组层间岩溶膏模孔型储层，特别是上马家沟组三-四段中下部和下马家沟组三段的层阃岩溶带等重要勘探层系。同时在平凉组、马家沟组、张夏组都遇到较好的油气显示。但试气结果不佳。通过对旬探1井地质工程资料的研究分析以及所存在问题的揭示，认为试气失利的原因除地质因素外．很大程度上与当时的钻井、试气工艺技术条件不足有关。

The well Xuntan-1 is a regional exploratory well located on the Xunyi fault block of northern slope of Weibei（North of Wei river） uplift th the southern margin of Ordos basin. Drilling exploration results thow that there are Zhangxia Formation reservoirs of oolitic beach type, Upper Liangjiashan Formation reservoirs of dissolved-pore type, and Upper and Lower Majiagou Formation reservoirs of rater-strata karst gypsum-mould pore type. especially the important exploration bed set of inter-strata karst zones of the mid-lower parts of the Third-Fourth Members of Upper Majiagou Formation and the Third Member of Lower Ma.jiagou Formation, in the well Xuntan 1 area. Meanwhile in the Pingliang, Majiagou, and Zhangxia Formations meet good oil/gas show. But the results of testthg for gas are not good. The reason seems, to a great extent, to be related to insufficiency of conditions of drilling and testing-for-gas technology of the day, in addition to the geological factor. Therefore, the author analyzes the causation of failure of testing for gas on the well Xuntan 1.