Study On The Distribution Law And Development Strategy Of Remaining Oil In The 3 Area Of Gangxi Oilfield

Gangxi Oilfield has entered the stage of high water cut development.The remaining oil is highly dispersed and the production decreases rapidly.The study of remaining oil distribution is of great significance to guide the comprehensive potential tapping and development adjustment of the oilfield.In this paper,core,logging,seismic and production dynamic data are used to study the fine division and comparison of small layers,reservoir internal configuration anatomy and reservoir heterogeneity.By using the methods of equal elevation correlation,time unit correlation,facies-controlled correlation and three-dimensional closed stratigraphic correlation of skeleton section,the backbone correlation section is established to divide sand bodies.The internal configuration of the reservoir was studied for the fluvial facies sedimentary development.The multi-stage channel superposition and truncation relationship in the composite meandering belt was divided into five types : overlapping type,isolated type,cutting superposition type,superposition type and composite type in the vertical direction.In the process of river sedimentation,the interlayer heterogeneity is serious due to the influence of lateral migration of river channel.Based on the above research,a three-dimensional geological model of the reservoir is established,and the remaining oil distribution law of the three areas of Gangxi Oilfield is studied by using the reservoir numerical simulation method,and the next development adjustment countermeasures are put forward.Due to the difference of sedimentary factors in the third area of Gangxi Oilfield,the distribution of sand bodies presents two forms : banded and continuous.The sedimentary rock interface of channel controls the scale of reservoir.Interlayer heterogeneity and intralayer heterogeneity have important influence on fluid flow and development.The distribution of remaining oil is affected by both reservoir factors and development factors.On the plane,the distribution of remaining oil is affected by recovery degree,fault development,lithologic boundary of sand body and sporadic small sand body,and the remaining oil is scattered on the plane.In the vertical direction,the distribution of remaining oil is mainly affected by sedimentary rhythm,interlayer and reservoir utilization imbalance.The remaining oil is relatively enriched at the top of the sand body and the unproductive layer affected by the interlayer.According to the distribution law of remaining oil in the third area of Gangxi Oilfield,based on the principle of combining secondary development with tertiary oil recovery,and aiming at fully releasing the potential of polymer flooding,the development and adjustment countermeasures of deploying new wells with standard five-point well pattern are proposed.After the overall implementation of the scheme,the polymer flooding effect is fully exerted,the recovery factor is further improved,and the technical reference for further improving the recovery factor of the old oilfields in Dagang Oilfield and Bohai Bay area is provided.