Development Optimization By Perforations Adding Between Layers For Fault Block Oil Reservoirs

The principal sedimentation type is continental sedimentation in the eastern oil fields of our country which contains multiple layers.There are great differences between the multiple layers The flow characteristics of oil-water two phase are different in multilayer reservoirs.It makes the interlayer interference become a inevitable problem in the process of oilfield development.The optimization of perforations adding is one of efficient measures to induce interlayer interference.So far there is no implementation approach that is feasible for development optimization by perforations adding between layers.The optimization of perforations adding was studied in allusion to fault block oil reservoirs that would be of great importance in inducing interlayer interference,realizing vertical equilibrium displacement and improving the effect of development for this type of reservoirs.The concept model was established to study the affecting factors including length of banded oil layer,crude oil viscosity,permeability,reservoir thickness,stratigraphic dip,pressure coefficientetc and liquid producing rate on the perforated degree by using numerical simulation method.Based on optimization of perforated degree,two-layer reservoir model was established,and the orthogonal test was designed to do sensitivity analysis by using numerical simulation method in order to study on the affecting factors including permeability,length of banded oil layer,reservoir thickness,viscosity of oil and pressure coefficient.The numerical simulation research was carried out to study on influence of the main factors on open time.The charts of optimal perforated degree and optimal open time was made under a certain daily fluid production rate by Watson interpolation algorithm.The research shows that the main affecting factors of the perforated degree include length of banded oil layer,crude oil viscosity,permeability,reservoir thickness and liquid producing rate.The optimal perforated degree could be appropriately reduced with the increase of permeability,the decrease of the length of banded oil layer or the decrease of crude oil viscosity.The optimal perforated degree first increases and then decreases with the increase of reservoir thickness and liquid producing rate.The limit of optimal perforated degree can be determined by pseudo-filtration resistance with the range between0.27×10~3mPa·s/μm~2 and 26.50×10~3mPa·s/μm~2.The main affecting factors of multiple layers open time include the length of banded oil layer,permeability and viscosity of oil.The bigger the factor contrast is,the greater the reservoir heterogeneity is,the later the open time is for the reservoir which has finer property or greater energy,the more the increased range of recovery ratio is;The boundaries of technique and tactic for optimization of multiple layers open time was determined by the pseudo-filtrational resistance ratio with the range between0.023 and 43.88.Based on the multiclass classification method of SVM and support vector machine regression algorithm,the software of optimization of perforations adding for fault block oil reservoir can be used to determine parameters of reservoir development quickly and effectively.