Development Adjustment Of The Loose Sandstone Reservoir With Complex Faults And Edge-bottom Water In Overseas G Oilfield

The G oilfield is a typical loose sandstone reservoir with complex faults and edgebottom water.The edge-bottom water continuously provides energy to product oil,but it’s also easy to result in rapidly rising and high water cut.The G oilfield is put into production at 2004 and has many production problems now,such as high water cut,low oil recovery,worse effects of measures and low producing degree of low-productivity layers.So the development plan needs to be changed to increase the recovery factor.The geological characteristics,production performance,numerical simulation and development adjustment of G oilfield are studied by petroleum geology,reservoir engineering method,3D geological modeling and numerical simulation technology.The research of the geological characteristics of G oilfield shows that it has a large formation thickness,well developed faults,large reservoir differences,strong heterogeneity,and large longitudinal differences of fluids.By reservoir engineering method,the analysis of the production performance shows that the most oil wells have high water cut currently,which restricts the oilfield production.The monthly decline rate of single well is 0.83%.The reasonable well spacing density is calculated and the result shows that the well pattern can be reasonably infilled.The predicted ultimate recovery is 14.1% by four kinds of water drive curves.Based on keeping the physical characteristics of G oilfield,a conceptual model of a reservoir with edge-bottom water has been established to study the effects of height and thickness of perforation,aquifer,and interlayers on the law of water cut increasing.After rational up scaling of geological model of G oilfield,an actual numerical model of G oilfield is established,and the results of history match show that the model can be used in project prediction because it conforms to the reality well.By reservoir simulation technology,the influencing factors of water invasion are analyzed and the remaining oil distribution area of the G oilfield is determined.Furthermore,the targeted strategies are designed,such as adjusting perforation horizon,infilling wells and drilling horizontal wells.The development indicators of strategies are predicted,compared and optimized,that will provide useful guidance for the next step in the development of the G oilfield development plan.