Research On Natural Decline Trend And Slow Down Countermeasure Of Xian He Fault Block Reservoir

Reservoir decline trend is very important for reservoir development,which is the important reserence of reservoir development level evaluation,development planning,development scheme design and adjustment.The major reservoir of Xian he oil production plant is fault block oil reservoir,which is already at middle or past development period.The degree of recovery now has reached to 34.5%,and the average water cut is about 96.2%.All the reasons including complex block tectonics,fragmented distribution remaining oil and uneven use of layers can lead to obvious water swept and instable produce.In order to enhance the oil recovery of fault block oil reservoir,natural decline trend need to be studied,and confidences the development static,plans the proper adjustment.Based on Xian He fault reservoir development,reasonable classification of fault block oil reservoir is carried out,and the natural decline law of different fault reservoirs is studied.The simplified analytical model of phase permeability index is established,and the influence of different elements on the change law of natural decline is studied,such as water cut,oil-water viscosity ratio,relative permeability curve and production rate.The concept model of simple fault block oil reservoir is built,and the influence of the factors such as displacement mode,heterogeneity and well pattern is studied.Combined with the field practice,the effect of t new well production and measure production on the change of natural decline rate is studied.According to geology and development characteristics of different fault block reservoir and main influence factors of natural decline,the technical countermeasures to slow natural decline of different fault block reservoirs is proposed,and applied in the typical reservoir,which natural decline is slowed down.Technical system which be built to slow down natural decline is very useful for the similar fault reservoirs.