Evaluation of Remaining Oil Potentialities and Well Performance for Thick Layers’ High Water Cut Stage in Beierxi Developing Area
|School||Northeast University of Petroleum|
|Course||Petroleum and Natural Gas|
|Keywords||high water cut stage distribution of remaining oil improve recovery thicklayer|
The East Block of Beierxi area is located in the Saertu pure oil field of changyuan,Daqing, which belongs to large rivers’depositional system of Laxi. At present, the East Blockof Beierxi has run into the high water cut stage with96.3%of the composite water cut,58.8%of the reserve recovery, which is charactered with highly watered out degree of all blocks,obvious interlaminar contradiction, and scattered distribution of remaining oil. Hereby, thereare big challedges to redevelop the remaining oil.This paper has established the fine geological modeling, and preceded the accurategeologic description towards every sedimentation unit combined with the thick layers’dynamic and static data of the East Block of Beierxi in Sabei. Among them, the reserveproportion of PI2and PI5+6is very big, accoMPanying with the widely distribution ofchannel sand and high drilling encounter rate. It has made the prediction by the method ofnumerical simulation aiming at the distribution law of the remaining oil on the basis ofgeological modeling. The remaining oil mainly assists in the low-permeability, thin and poorlayer, river edge or the interstream sand. The watered out degree of all sedimentation unit isvery serious, the oil saturation is rather low, and the interlaminar contradiction is very obvious,so it’s troublesome to redevelop the oil remaining.This paper based on fuzzy logic comprehensive judgment method, introduce this methodfrom mechanics to math model selection. Based on this system, combined it with the realblock, screen appraisement indexs from geologic, development, dynamic analysis and someother aspects, then establishe the math modal, and give the important weight, so present aclear and operational method for well classification in reservoir of high water cut stage.It alsohas quantitatively evaluated the remaining oil potentialities in high water cut stage bymultiple fuzzy comprehensive evaluations considering the characteristics of reservoirheterogeneity and the influential factors of producing data. And it has established thequantizing model for the analysis of remaining oil potentialities, completed the quantitativedescription towards the result of the qualitative analysis. Moreover, it has classified the PIgroup into there potential area and provided the reference for remaining oil potentialities inhigh water cut stage according to the qualitatively coMParative analysis of six sedimentationunits prior to Polymer Flooding and now.It has manufactered six projects after Polymer Flooding which are separate zone waterinjection, layered proration, Corresponding to the injection-production, profile modification,water plugging, fracturing, divide perforation, cyclic waterflooding, subdivision waterinjection together with water plugging, cyclic waterflooding together with water plugging,profile modification together with fracturing and subdivision water injection together withprofile modification,and subdivision water injection with profile modification and waterplugging according to the characteristics of all the sediment units,based on the conclusion ofthe remaining oil distribution law and type of high layers in high water cut stage in the East Block of Beierxi of Sabei. And it has also made the numerical simulation forecast towards theproduction performance index. The forecast results show that all the mentioned projects cancontrol the ascending velocity of the water cut differently, relieve the interlaminarcontradiction and improve the recovery of thick layers. The best project is subdivision waterinjection with profile modification and water plugging, which can decrease the water cut by5.17%and improve the recovery by3.32%. Next is the project subdivision water injectionwith profile modification, which can decrease the water cut by4.83%and improve therecovery by2.72%. The result indicates that we can limit the ascending velocity of the watercut effectively, relieve the interlaminar contradiction and improve the reserve recovery furtherby virtue of implementing various technologies for redeveloping remaining oilsimultaneously.