Design And Optimization Of Polymer/Surfactant Flooding Scheme In Block N

As one of the important energy sources in China,the exploitation of oil is of great significance to the society.With most of the old oil fields in China entering the stage of high water cut,the conventional water drive method can not effectively exploit the crude oil in the reservoir,resulting in a large amount of remaining oil remaining in the reservoir.As a means of enhancing oil recovery,ASP flooding can replace the conventional water flooding method to continue to exploit the remaining oil in the reservoir,but its environmental unfriendliness has also attracted much attention.Compared with polymer/surfactant flooding is composed of polymer and surfactant,and its composition is relatively simple.However,polymer/surfactant flooding combined flooding can not only make up for the shortcomings of conventional water flooding technology and improve oil recovery,but also eliminate the damage of alkali to the formation.The actual field test shows that the oil displacement efficiency and oil well production have been significantly improved after the application of polymer/surface fiooding displacement technology.In order to guide the development and design of polymer/surfactant flooding accurately and effectively,this paper carried out the design and optimization of polymer/surfactant flooding scheme in N block by using numerical simulation method,combined with laboratory experiment and field data.Firstly,according to the development status and reservoir physical properties of block N,the Petrel software is used to establish the structural model and fault model to reflect the real structural state of underground reservoirs,and the sedimentary facies model and the attribute model under phase control are established.The accuracy of the model was checked by fitting.The historical data of actual oilfield development was used as the standard to modify and correct the model until the fitting accuracy met the requirements.The reserve fitting error was 0.071%,water cut error was 0.21%,cumulative oil production error was 0.028%,and the coincidence rate of single well was above 80%.In order to ensure that the oilfield prediction conforms to the actual situation and the results are accurate,the geological model of the test area is intercepted on the precise geological model,and the reservoir characteristics of the test area are consistent with the reservoir characteristics of block N.Secondly,Stars in the application of CMG numerical simulation prediction module of experimental zone binary flooding scheme and injection parameter optimization,respectively for binary flooding plan pre polymer slug,binary slug,protecting slug injection parameter optimization,the comparative analysis of different influence factors on the stage of recovery degree and the influence of the moisture content decreased,optimizing the reasonable scheme of slug,namely: PV2000mg/L(P)+0.3%(S),PV2000mg/L(P)+ 0.2%(S),PV2000mg/L(P)+ 0.2%(S),PV2000mg/L(P)+0.2%(S)0.2PV1600mg/L(P),the recovery degree of the optimized injection scheme is 17.39%,and the maximum reduction of water cut is 9.61 percentage points.Finally,based on field actual oilfield development situation,to the same drug price of asp flooding,the optimal scheme is used to numerically simulate the predictability,economic benefit comparison at the same time,found that the economic benefits and the development of the two options effect is very close,and considering the lye in ternary flooding brings to the formation of clay dispersion,migration,such as environmental unfriendly,Therefore,from the perspective of green and environmental protection,the Polymer/surfactant flooding development scheme of block N can be given priority.