Oil-water Distribution Of Wuerxun Oilfield In Hailar Basin

Wuerxun oilfield is located in new Bargu left banner of hulun buir city,Inner Mongolia.With the further exploration and development,Wuerxun oilfield has become the main target production block of Daqing oilfield.Lots of dynamic and static data of Wuerxun oilfield has been accumulated after three-year development,whereas,here comes some problems in the procedure of development.Take an example,in December,2010,24 wells of 101 wells were high-water-cut oil-producing wells after putting into production.What's worse,some wells are purely wet producer.It indicates that the oil-water distribution law of Wuerxun oilfield has not been fully identified.Based on the material of recent years,the paper has reanalyzed the structural features and reservoirs distribution characteristics,reenacted plate of oil-water layers identification,in addition,analyzed the controlling factors of oil-water layer distribution,and eventually confirmed the development potential of the oilfield.The main difficulty of the Wuerxun oilfield oil-water layer identification is the lithological and physical properties differences of each block.The lithology of the south block is coarse-grained and the content of conglomerate is higher than that of the north central.The dominant lithology of the central block is fine-medium sand and conglomerate is rare.However,the dominant lithology of the north block is silt sand.The south and central block belong to low porosity,super-low permeability reservoir,but the north block is low porosity,low permeability reservoir.According to the different lithological and physical properties of each block,the study enacts plate of oil-water layers identification,and practical application shows that plate meets the requirements of the oil-water layer identification.The oil-water distribution of Wuerxun oilfield is mainly controlled by two factors.The first factor is distribution of source rocks and oil-gas migration system.For example,due to structure trap,structural-lithological trap of the N1 layer is near to the oil source,which gets priority to capture oil and gas and comes to a good oil and gas accumulation.The other factor is the closure of fault.If hanging wall is an anticline or platform,the displacement pressure of the fault is large.Under the circumstances,the effect of closure is well.On the contrary,if hanging wall is a monocline,the displacement pressure is low,and the fault is not sealed.On the basis of previous analysis,the result shows that N1 of Wu 108-112 east block is of great development potential.The main reasons are as following:Firstly,the structural appearance of the block is a nose structure,which is low in the east and high in the west.Otherwise,the nearby faults are sealed.Secondly,N1 is located in the junction of fan deltaic front and deep lake,and sand content of N1 is 15?30%.Lastly,oil-gas shows well in the three wells nearby.