Single Well Integral Injection-Production Test And Effects Evaluation In S-1 Area

With the increase of water cut in production wells,the lift energy consumption and the cost of water treatment increased gradually.When the economic limit is reached,it is necessary to shut production wells,thus affecting oil production.Single well integral injection-production technology can be used to separate oil and water from produced fluid.The separated water is injected into the reservoir through injection pump,and oil-water mixture with high oil content is lifted to the ground through production pump.Therefore,it is necessary to analyze and evaluate effect of Single well integral injection-production technology.The research results of this paper are as follows:Firstly,the fine geological modeling of the test area is completed.The sedimentary facies model and attribute model of 150 sedimentary units are established.The actual geological reserves in the test area are 5030.06?104t,and the geological reserves of the model are 5169.69?104t.Dynamic development indexes history fitting of the whole test area and 524 wells are completed.The remaining geological reserves of Gaotaizi oil layers are largest,which is 1310.13?104t,and remaining geological reserves of Putaohua oil layers are smallest,which is 465.3?104t.Therefore,the upper reservoir should be designed for exploitation and following reservoir should be designed for water reinjection which means Gaotaizi reservoir should be mined and Sa-Pu reservoirs should be reinjected.Secondly,design of the test scheme of injection and production technology in same well in South First Area is completed.According to the principle of test well selection,the test well number is determined as 17 wells in the central and western block of South First Area,9 wells near or within the fault zone and 8wells in non fault zone.For these wells,the upper reservoir should be designed for exploitation and the following reservoir should be designed for water reinjection which means Gaotaizi reservoir should be mined and Sa-Pu reservoirs should be reinjected.The recirculating section of the test well and the response well number are determined.Field test results show that in the test period,the recovery rate of the whole area is increased by 1.23%,and the water cut rate of single well is greatly reduced.Finaly,short-term and long-term development effect prediction of single well integral injection-production technology is completed.A method of simulating the injection and production wells is presented,and the short-term development effect is predicted.The results show that during test period,the cumulative oil production is 141.86?104t,and recovery rate is increased by 2.82%.Reservoir engineering method is used to predict the long-term development potential of 17 wells in the test area.The prediction results show that the development potential of single well integral injection-production technology is obviously higher than that of the water flooding potential.The development potential of the injection and production technology in the same well is about 2 times as much as that of the water flooding development.This paper puts forward a new method for predicting development effect of high water cut period: broken line method.This method is used to predict the long-term development of the test area.According to the results,before and after the implementation of single well integral injection-production technology,the recovery rate is 44.73% and 57.34% respectively.When the water content of the whole region reach 99.48% of the economic limit water cut of injection and production in the same well,the recovery rate increased by 12.61%.In summary,in reducing the water content and improving the recovery rate,single well integral injection-production technology shows great superiority,which made good effects in the field experiment,and this technique has a good application prospect.