应用稀有气体同位素判识油田水淹现象——以辽河盆地黄沙坨油田为例

采集了辽河盆地黄沙坨油田注水开采所利用的水源井水、处理后的水源井水、注水井水和生产井原油样品,脱附了其中的水溶气和油溶气,测量了其3He/4He,4He/20Ne和40Ar/36Ar,发现它们可以判识生产井水淹现象和水淹程度。研究表明:(1)黄沙坨油田水源井、处理后的水源井水及注水井中水3He/4He4、He/20Ne和40Ar/36Ar均具有大气成因的特征;(2)黄沙坨油田原油40Ar/36Ar误差范围内与空气值接近,说明原油遭受了水淹,40Ar/36Ar可以成为油田遭水淹的示踪剂,但它与4He/20Ne之间没有线性关系,因此不能反映油田受水淹的程度;(3)黄沙坨油田原油4He/20Ne和3He/4He大于大气值,且两者呈较好的线性关系,说明其不但可以作为生产井油层遭受水淹的示踪剂,也可作为油层遭受水淹程度的指标。 

Identifying the phenomena of water flood in oil fields using noble gas isotope-exampled by the Huangshatuo Oilfield in the Liaohe Basin

The source water for water injection,source water after procession,water of an injection well,and oil crude of a production well were sampled and degassed.The 3He/4He,4He/20Ne and 40Ar/36Ar of the gases from the waters and oils were analyzed.We found that they can be used for identifying the phenomena and degree of water flood of a production well.Our research shows that the 3He/4He,4He/20Ne and 40Ar/36Ar of the source water for water injection,source water after procession and water of an injection well characterize an atmosphere source.The 40Ar/36Ar of crude oil in the Huangshatuo oil field is near that of the air in an error range,indicating that it was flooded by water and can be used as a tracer of water flood in an oil field,however it has no relation with 4He/20Ne and can not be used for reflecting the degree of water flood.The 4He/20Ne and 3He/4He of the oil from the Huangshatuo oil field were larger than those of air and they have a better liner relation,indicating they can be used for tracing water flood and its degree of an oil bed in a production well.