贵州省赫章县含煤地层测井曲线特征及变化规律

Contrast of Coal Seam Well Logging Trace Features and Coal Seam Variation Pattern in Hezhang County Area, Guizhou Province

赫章县含煤地层为二叠系上统长兴组和龙潭组上部。由于两组地层的岩性组合特征及含煤特征的不同,在测井曲线的反映也不同。长兴组主要为钙质砂岩或石灰岩(如标志层1、2、3),三侧向视电阻率测井曲线呈高幅值箱状异常反映,自然伽马测井曲线呈低幅值箱状异常反映;龙潭组主要为泥质粉砂岩、泥岩,自然伽马测井曲线多处出现高幅值单峰或尖峰状异常反映。综合各煤矿的测井曲线典型响应特征,可以确定区内典型标志层位9个,其中长兴组含煤地层5个,龙潭组含煤地层4个。通过对境内测井曲线的对比发现,西部长兴组煤层发育较龙潭组好,但向东及南部长兴组煤层发育逐渐变薄或尖灭,而龙潭组煤层发育情况与其正好相反。

Coal-bearing strata in the Hezhang County have upper Permian Changxing Formation and upper part of Longtan Formation.Since the different rock association characteristics and coal-bearing properties of two formations, thus different images on logging traces. In Changxing Formation is mainly calcareous sandstone or limestone（such as horizon marker 1, 2 and 3）, on laterolog-3 apparent resistivity logging traces present high amplitude box type anomalous reflex, on gamma-ray logging traces present low amplitude box type anomalous reflex. In Longtan Formation is mainly politic siltstone, mudstone, on gamma-ray logging traces present many high amplitude unimodal or spike anomalous reflexes. Colligated typical response features on logging traces from Hezhang coalmines have found out identifiable 9 typical horizon markers, in which, 5 in Changxing Formation coal-bearing strata, 4 in Longtan Formation coal-bearing strata. Through logging traces correlation has found that Changxing Formation coal seam development is better than Longtan Formation in western part, but toward east and south coal seams in Changxing Formation gradually thinning even lens out, while for Longtan Formation on the contrary.