Study On The Layers Subdivision And Reconstruction Technology Of Z Block In Lamadian Oil Field In Extra High Water Cut Period

After more than 40 years development and adjustments, Lamadian oil field has achieved good results. After entering extra high water cut period, from the view of layers, well long, high permeability, contradiction between layers, the thickness of oil layer varies greatly. From the perspective of development effect, the layers have high water content, low water content difference between the layers, the remaining oil is scattered, inefficient and ineffective injection production cycle is serious. Therefore, the adjustment of individual wells or layers is difficult to achieve a fundamental improvement in scale. It is necessary to carry out the scale of the layer of well pattern adjustment to find remaining oil and improve water flooding development effect.In this paper, Z block in Lamadian oilfield as the research object. Through comprehensive analysis of development status and the formation of recombinant technology policy limits by numerical simulation, including permeability ratio and effective thickness, to determine the principle of layer division.Then the paper puts forward three kinds of restructuring plans. According to the actual situation of the field, the adjustment plan of layers is confirmed. After the geological model and numerical simulation model are established, the distribution of remaining oil in the block is obtained based on the history matching. According to the principle of well pattern adjustment, combined with the adjustment of the layer system, four kinds of well pattern are put forward, and the optimal solution is obtained by numerical simulation: that one encryption number 8 wells all as water injection wells, drilling new oil wells, constitute 212 m five spot areal well pattern, mining Gâ… 6~Gâ…¡3 layers; secondary encryption number 1 injection and production well all as water injection wells, drilling new oil wells, constitute 212 m five spot areal well pattern, Mining Gâ…¡4 and the fellowing layers.The plan is divided into two sets of layers, using two sets of 212 m five point method of well net, drilling 54 new oil wells, and the stage of recovery is 6.04%.When the crude oil prices is $70 / barrel(3149 yuan/ton), after-tax financial internal rate of return is 20.2%, investment recovery period is 3.9 years, the effect of economic forecast is best, and development effect gets a higher level.