Reservoir Characteristics And Development Technology Policy Of Chang 9 Reservoir In Block D Of Jiyuan Oilfield

The oil and gas exploration and exploitation area of Jiyuan Oilfield is located in Shaanxi Province,Gansu Province and Ningxia Hui Autonomous Region,covering an area of 9752 square kilometers.In order to clarify the characteristics of Chang 9 reservoir in Jiyuan oilfield and provide the basic geological basis for the next step of reservoir development,it has reference significance for the development of Chang 9 reservoir in the future.This research enriches the understanding of the four-property relationship of Chang 9 by perfecting the criteria of sub-bed Division of Chang 9 in Jiyuan oilfield.Based on the existing core,logging data,production performance and test data of Chang 9 oil-bearing formation in Block D,The basic methods of stratigraphy are studied,the method and principle of substratum division and correlation of Chang 9 oil-bearing formation in Jiyuan oilfield are determined,and the isochronous stratigraphic framework of Chang 9 in Block D is established.Based on the data of core analysis and testing,the reservoir types and Pore structure are summarized,and the thickness map,physical property distribution map,pore structure and physical property relation map of each sand group are worked out,study the reservoir plane,inter-reservoir and intra-reservoir Heterogeneity,make clear the reservoir development characteristics and reservoir distribution characteristics.On this basis,from the pressure system,injection-production system and other aspects of the development of technical policy is reasonable evaluation,summarized the regularity of understanding.The static geological data of reservoir description in the study area are comprehensively used,the corresponding development technical policy is made by reservoir engineering method,and the relevant charts of reservoir engineering are established.Based on the evaluation of development effect,the reasonable development technical limit under the current water cut and pressure condition is put forward.According to the production characteristics of single well and well group of oil and water well,the corresponding stable production countermeasures are put forward from different aspects.At the same time,the reservoir flow units are characterized by SPSS software,and the development units are divided according to the results and production dynamics.It is found that the sedimentary environment of Chang 9 oil-bearing formation in Block D is mainly deltaic front subfacies,which can be further divided into sedimentary microfacies such as underwater distributary channel,estuary bar,interdistributary bay and river flank,with strong heterogeneity in each small layer,wide distribution of Chang 9 interval layers and low vertical connectivity between each layer,through the analysis and study of the characteristics of the Chang 9 reservoir,the content of feldspar and quartz in the four small layers of Chang 9 is close to each other,and in the cuttings,the content of extrusive rock,quartzite and phyllite slate is high,the detrital compositions of each layer vary greatly,and the compositions of different fluid properties rock layers are obviously different.The Chang 91 sandstone in Block D is of large thickness and belongs to two-stage or multi-stage channel superimposed sand body.The lithology is fine sandy medium sandstone and silty with low shale content.The filler is mainly kaolinite and the pore-throat structure is mainly dissolved pore-intergranular Pore.According to the physical properties and development status,the Chang 9 reservoir in Chang 9 formation of Chang 911-1 is divided into four types of reservoir flow units:A,B,C and D.Based on the analysis of development technology policies such as declining and effective effect,the pressure of Chang 9 reservoir in Block D is kept low,the effective displacement system has not yet been fully established,the water injection intensity in the south is low,and the middle and north are high,at the same time,combined with the main factors that affect the effect of oil development,the measures such as non-correspondence of small beds and poor water absorption in profile are taken to control the reservoir,which has played a positive role in stabilizing the production of the reservoir and confirmed the evaluation of the effect of the technical policy for the overall development of the reservoir.