四川盆地普光地区深层地下油田卤水溶解性有机质组成特征研究

Study on the Compositional Features of Dissolved Organic Matter in a Deep Underground Oilfield Produced Brine in the Puguang Area of Sichuan Basin

采用C18、PPL、HLB三种固相萃取材料对四川盆地普光地区一处油田卤水中的DOM进行了富集分离并采用FTIR和Py-GC/MS对所分离的DOM进行了表征。结果表明,PPL和HLB的组合吸附剂对油田卤水DOM的富集效率较好,C18富集效率最低。所研究油田卤水DOM中主要含有有机酸、含硫化合物、芳香族化合物、碳水化合物、脂肪族化合物以及含氮有机物等。其中含硫有机物和有机酸所占比例较多。这可能是由于该区域海相层系中发育着多种类型的含硫物质,可通过生物地球化学作用而生成种类繁多的含硫有机物。而有机酸作为微生物生长的营养物质,又在一定程度上促进了含硫有机物的形成。通过比较发现,地质条件/成因以及水质参数等因素都会影响油田卤水DOM的组成特征。针对不同地域及不同形成机制的油田卤水中DOM的结构组成做系统性研究,可为后续DOM的有效处理提供科学依据。

Three solid phase extraction materials,C18,PPL and HLB,were used to isolate dissolved organic matter(DOM)from an oilfield produced brine in the Puguang area of the Sichuan Basin.The isolated DOM were characterized by FTIR and Py-GC/MS.The results showed that the combined adsorbents of PPL and HLB has the highest extraction efficiency for DOM in the oilfield produced brine,while C18 has the lowest extraction efficiency.The research oilfield produced brine DOM mainly contained organic acids,sulfur-containing compounds,aromatic compounds,carbohydrates,aliphatic compounds and nitrogencontaining organic compounds.Among them,sulfur-containing organics and organic acids accounted for a large proportion.This phenomenon may mainly attribute to the existence of various sulfur-containing substances in marine strata of this area,which can produce a wide variety of sulfur-containing organics through various biogeochemical reactions.The organic acids,which can serve as nutrients for microbial growth,can further promote the formation of sulfur-containing organic compounds to a certain extent.By comparison with other studies,it is found that geological conditions,geological origins,and water quality parameters will affect the compositional characteristics of oilfield produced brine DOM.Systematically studies on the structural compositions of oilfield produced brine DOM in different regions with different formation mechanisms can provide scientific supports for the effective treatments of DOM in sequential studies.