Evaluation Method For Water Flooding Development Effect In Extra High Water Cut Period

Water injection development is a commonly used method in oil fields.At this stage,many oil fields in China have entered a special high water cut period.The daily oil and oil recovery rate of single wells has dropped sharply,and the underground water storage rate of injection water is getting smaller and smaller.The water-oil ratio has increased sharply,and the stage water-flooding effect has deteriorated.The inefficient and inefficient circulation has become a production problem that effectively restricts the remaining oil in the layer.The evaluation of the development effect at this stage is an important means to clarify the direction of the next step and determine the adjustment measures.The original evaluation index standard has not been applied to the development stage of extra high water cut.Therefore,we urgently need to study the index system,evaluation index standards and comprehensive evaluation methods for the evaluation of oilfield development effects in extra high water cut period to better guide the rational and efficient development of oil fields.Based on the principle of water injection,such as water injection,water injection,fine water injection and effective water injection,this paper selects 10 indicators suitable for the evaluation of development effect in extra high water cut period,which are water discharge reserve control degree,water quality compliance rate and injection.Mining ratio,stratigraphic energy maintenance level,water flooding reserve utilization degree,water content rising rate,dispensing rate,sub-injection pass rate,remaining recoverable reserve oil recovery rate,natural decline rate;reference oil and gas industry standard and mine extra high water cut period The statistical data of each indicator was used to correct the original index standard,and the evaluation index standard corresponding to the extra high water cut period of the water flooding reservoir was determined.The weight coefficient of each index was obtained by the grey correlation analysis method,and the oilfield water was applied by fuzzy comprehensive evaluation method.The development effect of the flooding development was comprehensively andobjectively evaluated,and finally applied to the evaluation of the development effect of the ultra-high water cut period in the G block of D oilfield,and reasonable suggestions were given for the subsequent development.