摘要
应用微量元素方法进行油气地球化学勘探,国内外学者已进行过大量的尝试,并且取得了一系列成果。对于油气田上方地表土壤中产生的微量元素分布异常的原因,主要有"电场作用理论"和"烃类垂向微运移理论"两种理论假说。大量实践证明,地下数百米,甚至几千米的微量元素能够近乎垂直地迁移至地表,在油气藏正上方生成某种晕状异常。地球化学晕的宽度接近下伏油气藏在地表的投影宽度。因此,可以根据油气田上方土壤中微量元素的分布特征,分析油气分布规律和进行含油气远景评价。通过对大庆喇嘛甸油田B层土壤中微量元素分布特征的研究,认为铀(U)、锶(Sr)两种元素可以作为油气的指示元素。油田上方土壤中铀元素含量一般呈现微弱的低值异常,而在油田边缘出现高值异常。锶元素在油田上方土壤中表现为高值异常。根据地表土壤中元素的分布异常,可以确定油藏边界位置,为油气勘探提供了一个新方法。
Abatraet：Domestic and foreign scholars have done plenty of research work to study the application of trace elements method in oil and gas geochemical exploration and have obtained a series of achievements. There are two theoretical hypotheses can be used to explain the abnormal distribution of trace elements in surface soil over hydrocarbon reservoir, namely ＂the electric field theory＂ and ＂the vertical micro-migration theory of hydrocarbon＂. A large number of practices prove that trace elements can be transported vertically from the deep of hundreds to thousands miters to the ground surface and form geochemical halo in the soil over oil and gas reservoirs. The size of geochemical halo in surface soil is close to the vertical projection of reservoirs on the earth＇ s surface. Therefore, we can analyses the hydrocarbon distribution and evaluate the oil and gas potential according to the distribution characteristics of trace elements in surface soil of oil and gas field. By researching the distribution characteristics of trace elements in B horizon soil in the Lamadian oilfield, Daqing area, it shows that U and Sr are indexes elements for predictions of oil and gas. There appears low anomaly value of uranium content in surface soil over the oil reservoir and high value anomaly over the margin of it. On the contrary, strontium content shows high abnormal value in surface soil over the reservoir. According to the geochemical element anomalies in surface soil, the reservoir boundary can be determined, which suggest a new way for oil and gas exploration. Key words： trace element; surface soil; oil and gas geochemical exploration; Lamadian oilfield
出处
《地质论评》
CAS
CSCD
北大核心
2013年第1期183-192,共10页
Geological Review
关键词
微量元素
地表土壤
油气化探
喇嘛店油田
trace element
surface soil
oil and gas geochemical exploration
Lamadian oilfield
