| The L block of P oilfield has strong heterogeneity and belongs to a medium to low permeability reservoir.Currently,it has entered a stage of medium to high or even extremely high water content,with a water content of 96.6% and a recovery rate of only 33.57%.There are currently problems in this block,such as incomplete injection and production well networks,low water drive utilization and reserve control,and poor water injection effectiveness.Therefore,in response to the current situation of high water content and low recovery development in this block,it is necessary to carry out well pattern adjustment and further improve recovery rate based on the characteristics of medium to low permeability and heterogeneous reservoirs.Through extensive literature research and on-site production dynamic and static data,binary composite flooding was selected as a subsequent oil recovery technology,and numerical simulation methods were used to optimize and adjust the well pattern and various injection parameters.Based on the geological characteristics of Block L and the dynamic and static parameters of reservoir development,the design and optimization of binary composite flooding scheme in Block L are carried out through reservoir numerical simulation.Firstly,use Petrel software to establish a three-dimensional geological model of the target block to reflect the true underground reservoir structure,and establish a sedimentary facies model and attribute model.Then,the geological model is imported into the eclipse software to establish a numerical simulation model.The remaining oil is fitted using the eclipse software to verify the accuracy of the geological model and perform water drive history fitting.The final geological reserve error is 1.35%,which meets the accuracy requirements of the geological model.The fitting accuracy of the entire area reaches over 85%,and the fitting accuracy of a single well reaches over 90%.Use software to generate 3D views and fit results to analyze the causes,types,and influencing factors of residual oil distribution.Propose reasonable comprehensive well network adjustment deployment suggestions,develop new well network design and development plans,and ultimately determine the optimal well network adjustment plan for Block L as the reverse seven point well network hole filling plan under the ultimate well spacing.Finally,numerical simulations were used to optimize the injection parameters of binary composite flooding,including injection volume,injection concentration,slug method,injection speed,and chemical agent dosage.After conducting binary composite flooding on the basis of well pattern adjustment through numerical simulation of the block,the results show that:(1)polymer molecular weight:20 million;(2)Injection rate: 0.13 PV/a;(3)Pre segment: 0.02 PV+1600 mg/L(P),main segment: 0.3 PV+1800 mg/L(P)+0.2 wt%(S),secondary segment: 0.2 PV+1800 mg/L(P)+0.2wt%(S),post segment: 0.3 PV+1600 mg/L(P).The final recovery rate of the entire area increased by 16.47%,with an increase of 28.5% in oil production × 104 t,with a maximum decrease in water content of 13.61%,the development effect and economic benefits are both good,providing a basis for injection production adjustment in the later stage of similar oilfield development. |
