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

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.