应用自然电位测井资料解释鱼卡煤田含水层

Iqe Coalfield Aquifer Interpretation Through Spontaneous Potential Well Logging

鱼卡煤田地层物性条件较好,区内干扰较小,自然电位曲线异常反映比较明显。根据化验分析报告,该区地下水和鱼卡河水,阳离子主要成份为Na^+,阴离子的主要成份为Cl^-,地下水与河水的总矿化度相差几十倍。该煤田含水层岩性一般为含砾粗砂岩或粗砂岩,自然电位曲线上表现为非常明显的负异常,绝对值与围岩差达20～100mV,与自然伽马曲线组合,曲线形态显示为不等体单边箱型。应用该项测井技术,在鱼卡煤田30个测井钻孔中共解释含水层44层,其中自然电位在含水层处反映达到优级的25份,占总数的83%。经二个抽水孔验证,划分的含水层位准确,成果质量可靠。

Strata physical nature is good for geophysical prospecting in Iqe coalfield, there are less interference in the area, while the spontaneous potential curve anomalies are clearly reflected. According to water quality analysis, main cation Na^＋ and anion Cl^- are reported for both groundwater and Iqe River water, but mineralization difference between them is scores of times. Water-bearing strata are generally pebbly grit stone or grit stone, which reflected on the spontaneous potential curves are clear negative anomalies, their absolute values different from surrounding rocks＇ can be 20-100mV, when combined with natural gamma ray curves are displayed as varying unilateral trunks. By the use of this logging technique, 44 aquifers were interpreted in 30 boreholes in Iqe coalfield, among them, excellent reflection of spontaneous potential at aquifers account for 83% in total. Two pumping tests have validated that interpreted horizons of aquifers are correct, result quality reliable.