Distribution and origin of groundwater methane in the Wattenberg oil and gas field of northern Colorado.
Distribution and origin of groundwater methane in the Wattenberg oil and gas field of northern Colorado.
复制标题
科罗拉多州北部瓦滕贝格油气田地下水甲烷的分布和来源。
DOI：
10.1021/es404668b
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发表时间：
2014
影响因子：
11.4
通讯作者：
K. Carlson
中科院分区：
文献类型：
--
作者：
Huishu Li;K. Carlson
公众对科罗拉多东北部瓦滕伯格油田油气井钻井和压裂造成的潜在环境污染的担忧正在增加。令人关切的问题之一是石油、天然气或采出水迁移到地下水含水层，导致饮用水污染。由于甲烷是天然气的主要成分，而且可以溶解并随地下水迁移，因此含水层中的杂散气体引起了人们的关注。了解石油和天然气活动（如钻井和压裂）对环境影响的第一步是确定其发生、位置和来源。在这项研究中，地下水甲烷数据已收集到一个相对较新的规定在科罗拉多进行了分析。78%的地下水威尔斯井中检出了溶解性甲烷，平均浓度为4.0 mg/L，范围为0 ~ 37.1 mg/L。在地下水威尔斯井中发现的甲烷中，95%以上被归类为微生物来源，在含水层中测得的产出气体和溶解甲烷的C和H同位素特征之间的重叠最小。油气威尔斯的密度和油气威尔斯的距离对甲烷浓度都没有显著影响，表明其他重要因素也影响甲烷的生成和分布。在两个含水层威尔斯井中检测到热成因甲烷，表明产层的潜在污染途径，但微生物源气体是Wattenberg油田溶解甲烷的主要来源。
Public concerns over potential environmental contamination associated with oil and gas well drilling and fracturing in the Wattenberg field in northeast Colorado are increasing. One of the issues of concern is the migration of oil, gas, or produced water to a groundwater aquifer resulting in contamination of drinking water. Since methane is the major component of natural gas and it can be dissolved and transported with groundwater, stray gas in aquifers has elicited attention. The initial step toward understanding the environmental impacts of oil and gas activities, such as well drilling and fracturing, is to determine the occurrence, where it is and where it came from. In this study, groundwater methane data that has been collected in response to a relatively new regulation in Colorado is analyzed. Dissolved methane was detected in 78% of groundwater wells with an average concentration of 4.0 mg/L and a range of 0-37.1 mg/L. Greater than 95% of the methane found in groundwater wells was classified as having a microbial origin, and there was minimal overlap between the C and H isotopic characterization of the produced gas and dissolved methane measured in the aquifer. Neither density of oil/gas wells nor distance to oil/gas wells had a significant impact on methane concentration suggesting other important factors were influencing methane generation and distribution. Thermogenic methane was detected in two aquifer wells indicating a potential contamination pathway from the producing formation, but microbial-origin gas was by far the predominant source of dissolved methane in the Wattenberg field.