Research On Water Flooding Residual Oil Potential Evaluation And Development Plan Adjustment In Block M

After more than 50 years of water injection development,the comprehensive water of block M content reached 91.04%.After entering the ultra-high water-bearing period,the contradiction between the development layers is becoming more and more prominent,and the distribution of residual oil is scattered.By continuously increasing the digging potential of oil and water well adjustment measures,a good development effect has been achieved,and the potential for further adjustments has gradually decreased.On this basis,how to dig the remaining oil is the primary problem.Based on the detailed analysis of the geological characteristics and development history of M block,the geological model and numerical simulation model of the test area are established.On the basis of the historical fit,the oil layer utilization status,remaining oil planes and lengthways of each oil reservoir group were analyzed.The concept of easy-producing oil saturation limit is introduced,which was jointly evaluated with the injected pore volume multiple.Each sedimentary unit was evaluated and divided into four categories.According to the causes of remaining oil in various potential units,it is divided into 10 types,and define the remaining oil type and reserves distribution of each unit.(40),Ⅲ main remaining oil types of the potential units are non-injection type and non-injection type,the sum of reserves is 41.85% and 59.47%,respectively.Ⅱ,Ⅳ kinds of potential units are mainly interlayer interference type and poor water absorption type remaining oil,the proportion of reserves is 40.15% and 43.15%,respectively.Based on the potential evaluation results of residual oil potential evaluation and classification method proposed in this paper,according to the distribution of residual oil types of each potential unit,the experimental area is taken as the research object,combined with the current situation of block development and existing problems,the scheme design,simulation prediction and effect evaluation of two well network adjustment methods of well network thinning and encryption are carried out by numerical simulation method.The results show that the five-point method has the best effect in the well pattern thinning scheme,and the recovery rate increases by 2.76%.The encryption scheme(newly deployed a set of 120 m five-point method well pattern)has an increase of 4.23 percentage points compared with the original well pattern.The economic benefits are good under high oil prices.