Study On The Reservoir Characteristics And Development Measures In Es2 Of Low Fault Zone In Chengbei

The low fault area in Chengbei is located in the beach area of the southern Dagang Oilfield.It reports controlled reserve and predicted reserve of 140 million tons,which is one of the key areas for oilfield exploration and development.Aiming at the difficulties of thin interbedded development and poor physical properties in this area,this paper mainly studies the characteristics of Es2 of the low fault area in Chengbei and proposes development strategy.Through the analysis of the basic geological characteristics and the geological characteristics of the study area,the sedimentary microfacies are analyzed to control the distribution characteristics of the reservoirs;the previous research results are modeled to establish the three-dimensional geological model of the study area;then,the mining parameters based on the reservoir engineering theory are developed through the geological parameters of typical blocks.Research on the developed plan,at the same time,based on the real geological model,using the reservoir numerical simulation technology to carry out reasonable development strategys and optimization of exploitation parameters for the study area,and finally carry out prediction research on the actual block.The three-dimensional geological model is constructed with the explained geological data,including the structural,fault,sedimentary facies and reservoir physical parameters(porosity,permeability,saturation,net-to-gross ratio,etc.)model,which lays a foundation for numerical simulation work.Then,in the feasibility study of the development method,compared by depletion and artificial replenishment energy water injection development.In the feasibility study of water injection development,the reasonable injection-production ratio and water injection timing were optimized respectively,and the numerical simulation of injection-production ratio was taken as the lower limit value.It is considered that the low-level injection-production ratio of the low fault area in Chengbei should reach 1.0-1.5 or even higher.The mining ratio should be greater than 1.2;the most suitable water injection method for the low fault grade in northern Chengbei is to inject water for 3 months.It is recommended to develop the reservoir by means of advanced water injection(3 months ahead).Then,the research and development of the development well network was carried out in three different well areas.The numerical simulation results show that the reasonable well pattern in the well area is suitable at 16-25 wells/ km2.Combined with the development principles,rational development methods,well placement methods,well spacing and other indicators discussed in the reservoir engineering,four development strategies were preliminarily designed,all of which are five-point vertically wells.For the prediction analysis and evaluation of the oil production and comprehensive water cut index parameters of each scheme,it is preferred that the scheme 4 is the best development plan,the cumulative oil recovery is 11.3378 million tons,the comprehensive water cut is 85.40%,and the oil recovery is 21.35%.According to the actual situation of the study block and the numerical simulation results,it is preliminarily suggested that the Es2 of the low fault section in the northeastern part of the reservoir will be developed after fracturing operation of the vertical well injection of the five-point well pattern and the 400 m × 100 m well pattern,and consider the water injection for the first 3 months.Appropriately increase the ratio of injection to production is 1.2:1.The results of this study will provide some guidance for the production of 5 million tons in Dagang Oilfield within 15 years.