Study On Potential And Technical Countermeasures Of Reperted Fracturing Stimulation For Horizontal Wells In Block YP

With the continuous deepening of petroleum exploration and development,the proportion of low permeability reservoirs is increasing year by year.Low permeability oil and gas reserves will be the main resource base for increasing storage and production in a long period of time in China.The low permeability reservoir in YP block has the characteristics of low permeability reservoir,at the same time,it has low production or low output after single well construction,and the increase of output is not good after the unfit fracture parameters.Therefore,it is urgent to study the potential of increasing production and the optimization of fracture parameters for fracturing stimulation in this block.In this paper,the following research has been carried out on the potential of repeated fracturing of horizontal wells in YP block elastic development:(1)experimental research and evaluation on the characteristics of single well reservoir in YP block;(2)inversion of first fracture fracture,fracture parameters,analysis of the cause of fracture failure;(3)establishing fine reservoir numerical simulation of well YP1-4 Model,using historical fitting method to verify the simulation results,and calculate the remaining reserves of single well;(4)carry out the evaluation of the potential of repeated fracturing stimulation,forecast and track the result of the production of the single well,and follow the effect of the transformation;(5)the optimization of the fracture parameters for the production of the horizontal wells in the YP block,and(6)will increase the production potential.The combination of force research method and optimization of fracture parameters is applied to the actual production wells in the blocks,and the results of the transformation are tracked.Through this study,the following conclusions and understandings have been reached:(1)through the numerical simulation of the single well reservoir in YP block,it is shown that the accuracy of the simulation results is 7.2%and even higher after the reservoir heterogeneity,stress sensitivity and start-up pressure are considered,and(2)the large gap gap between the fractured clusters is the main reason for the initial fracturing of the YP block;(3)through the YP1-4 well It is known that the well bottom pressure of the well is reduced from 19.5MPa to 16.6MPa after three years of development,the energy retention of the formation is above 85%,the oil saturation of the cluster distance rises from 46.1%to 48%,and has a good material base.It is suggested to carry out the remolding formula of the new filling pressure new seam,and the actual daily production of 11.7t/d has achieved good results.The effect of increasing production and transformation,(4)reservoir geological parameters,initial fracturing cracks and formation energy retention are the main factors affecting the refracturing.According to the statistical analysis of the permeability of YP block,it is known that the permeability is better after the transformation of the 2.3mD reservoir,and the selection of the refracturing area is the amount of each cluster of sand and the total liquid amount of each cluster for the first fracturing.At the minimum level of the whole horizontal section,(5)through the optimization of the fracture parameters of the increase in production and transformation,it is found that the area of increasing production and transformation of the cluster spacing 30m is beyond 100 of the well bore,and the area of energy conservation is over 60%.It is suggested that the old seams be lengthened to 300 meters,and the oil-bearing saturation in the zone between the clusters is 70m and 100m.More than 48%,it is suggested that the new method of pressure relief should be used for reconstruction.With the results of this study,two wells have been constructed,and the output of N255-P338 well is 1.1t/d.After the old seam lengthening and the replacement of the new joint,the oil production is 7.1t,and the cumulative oil increases by 1359t in 210 days.The output of Z52-P70 well before the transformation is 1.3t/d,the old seam lengthened 1,and the new seams are reformed for half a year,and the stable production capacity is 7.2t/d for half a year and 6 mines are mined.The cumulative oil increase of 1527t in two wells shows that the research results can provide theoretical and practical guidance for the study and reconstruction of the potential of refracturing stimulation in the horizontal well of the YP block.