Geologic Reservoir Characteristic And Reserve Estimate Of Kazakhstan Kumkol South Oil Field

Kumkol South Oil Field include six reservoirs(M?,M?,the U?,the U? U? and U?).Two of them are Cretaceous reservoirs(M? and M?),and four of them are Jurassic reservoirs(U?,the U?,U? andUIV).All the reservoirs are divided into four layer series of development.The study focus on the second layer series of development(the U?,the U?)and development of the third layer system(U?).At present,Kumkol South Oil Field need to design the program of fine injection,but the existing geologic result can not meet the require of fine injection,sush as:1)Geologic zonation can not meet the require of scrutiny.Now the subject reservoir is divided into 3 sublayers,and each of them contain one more single sandbody.How to correlation each sandbody,whether they can connect on horizontal direction,and pattern on flat need to do more study.2)Fine fault and micro-structure do not get enough awarness.Along with the deeper and deeper development,the early structural map revealed more and more problems.One is that the local structure and fault need to study again as the well pattern enctypted and dynamic date enriched,the original contour line and major fault can not meet the require of oil field development and management during the medium-after time;second,the more and more date show that waterflood efficiency controled by structure factor,especially the micro-structure and fine faults whose amplitude less the 10 metres,the same time the distribution of remaining oil is mutually related with single sandbody's micro-structural feature,also the fine faults have deep influence to do analysis of waterflood response.So,the study of micro-structure and fine faults are urgent.3)There is no study of sedimentary facies.But the sedimentary facies control the distribution of reservoirs,it also have guide contribution of geologic model,numerical model,reservoir forcasting,study of remaining oil distribution,as well as well pattern design and injection direction.So it must do sedimentary facies study.4)For the waterflooding of reservoir,it need to do study of oil/water interface and to calculate reserves.In view of the above peoblems,this study developed based on three-dimensional seismic data,combined with geology,well logging,drilling,development data and as well as the results of previous studies.1)Stratigraphic division and correlation studied on earlier work,to establish stratigraphic system pursuanting to marker bed,lithologic association,sedimentary cycle,logging and seismic.In the stratigraphic system,finding resistant claystone,analysing genetic axiom to divise and correlate single sandbody,and combining with well,logging,and seismic inversion to analyse the distribution of single sandbody.2)It make the structural map by establishing velocity field,generate horizon velocity,doing time-depth conversion,differential correcting using well data.coherence cube,time slice,spectral decomposition,curvature to discriminate fine fault.3)According to core,sedimentary structure,claystone color,and uniting regional geolog:ic setting,lithologic association,logging to identify sedimentary microfacies;using seismic and logging to study profile facies;to study sandbody's distributiong with seismic attribute,logging,then,to study the sedimentary microfacies on flat.And also analyse the sedimentary microfacies how to control the physical property distribution.4)For calculationg reserves accurately,this study established log interpretation chart,and th cutoff of oil layer.Defined OWC and study oil distribution according to log interpretation and testing data.On the base of reservoir awareness,it calculate and estimate reserve using volumetric method as the units are sandbodies and the norm is "SEC criterion for reserve estimate".5)It study reservoir petrological feature,physical property feature,pore space characterization,hydrosyalite content according to rock slice,poroperm analysis,cast slice and X-diffraction dataThere are some new recognition of this reservoir by the study:1)Region of interest is a large arch structure and with a series of micro structure.The fault system make up of two major fault whose aligement is N-W,and some associated fine fault.2)There are total 7 sandbodys of Object2,Object3,for 5 of them are in Object2,and others are in Object3.3)The sedimentary facies is delta front with the main sedimentary microfacies are underwater distributary channels,channel mouth bars,sand sheets and some interchannels.The sourse was from north,and the physical propertyof underwater distributary channels and channel mouth bar is better than sand sheets.