油气化探异常双因素评价方法——以渤海湾盆地济阳坳陷临南—钱官屯地区为例

Double-factor evaluation for oil and gas geochemical anomalies:A case study of Linnan-Qianguantun areas,Jiyang Depression,Bohai Bay Basin

以往对化探异常的评价往往仅侧重化探指标,较少考虑地质因素,因此评价结果缺乏地质条件支撑。以济阳坳陷临南—钱官屯地区为例,采用趋势面法对有效指标酸解烃甲烷、顶空气甲烷、游离气甲烷和物理吸附气甲烷进行单指标异常提取,再采用叠合法圈定综合异常。评价综合异常时既从化探指标角度进行评价,又结合研究区地质特征进行地质评价,化探评价与地质评价相结合形成异常评价交会图。评价结果与勘探实际吻合程度较高,表明建立的化探—地质双因素油气化探异常综合评价方法具有良好的应用效果。该评价方法可实现对化探综合异常的全面评价,具有良好的应用前景。

In the past,the evaluation of geochemical anomalies often only focused on geochemical indicators,with less consideration of geological factors,so the evaluation results lacked geological support.Taking the Linnan-Qianguantun areas of Jiyang Depression as an example,some effective indicators such as acidolysis methane,headspace methane,free methane and physically adsorbed methane were identified by a single indicator anomaly.Then,the comprehensive anomaly was obtained by a superposition method.An anomaly evaluation intersection diagram was made combining geochemical indicators with the geological characteristics of the study area.The evaluation results were in good agreement with the actual results,indicating that the double-factor evaluation for oil and gas geochemical anomalies provides good prospect evaluation.It provides a technical means for the comprehensive evaluation of comprehensive anomalies.