煤层气排水对河流生态环境影响风险评价

Risk Assessment of Impact of Coalbed Methane Drainage on River Ecological Environment

煤层气排水有着复杂的水质特点,在非正常工况下的排水对于河流生态环境有着不利影响,因此需要进行风险评价。通过野外调查和水样采集,分析排水水质和环境现状,然后对河流廊道以及河流水质进行预测,采用模糊综合评价法进行风险评价,分析排水对河流生态环境的影响。评价结果表明,河流廊道和河流水质均会受到排水的影响,不同排水阶段的风险在较轻风险和中度风险之间,风险排序为钻井废水>压裂废水>返排废水>煤层气产出水>集气站排水,针对风险提出了风险防控的建议。

The water quality characteristics of coalbed methane drainage are complex,and the drainage under abnormal working conditions has adverse impacts on the river ecological environment,so it is necessary to carry out risk assessment.Through field investigation and water sample collection,the drainage water quality and environmental status are analyzed,and then the river corridor and river water quality are predicted.The fuzzy comprehensive evaluation method is used for risk assessment to analyze the impact of drainage on the river ecological environment.The evaluation results show that both the river corridors and river water quality will be affected by drainage,and the risks in different drainage stages are between light risks and moderate risk,and the risk ranking is drilling wastewater>fracturing wastewater>returning wastewater>coalbed methane produced water>gas gathering station drainage.Suggestions for risk prevention and control are put forward.