The development of tight oil reservoir in the Ordos Basin is still in the experimental stage.Due to the tight reservoir and higher starting pressure gradient, effective flooding system is difficult to establish and pressure transmission is slow under conventional water injection development.Coupled with the existence of cracks and other advantages flowing channel,the contradiction of water injection is not effective or effective is also water flooding. Water flooding front and tracer monitoring data are used to study the characteristics and reasons of the development of tight oil reservoir.Volume fracturing test on injection well was carried out in a group of wells, the influence of artificial crack on the development effect is observed,the method changes the previous experience of oil well fractu-ring.The water flooding of oil well come from multiple directions at An 83 Chang 7 tight reservoir,the reason is that multi period fractures formed in the early geological process is superimposed on each other.Artificial fractures re-place natural fractures as the main flow channel after volume fracturing, the direction of water drive is changed, and water flooding effect is improved.This has an important guiding role to oil adjustment.

This paper first divides the stages of diagenesis by thermal evolution of organic and the distribution of clay for different structural zones in Chaluhe depression.Then,it analyzes the factors affecting diagenesis based on the analysis of structure,sedimentary facies,clay distribution,chemical property of underground water,and the micro character by thin section and SEM.The results show that the depth of the same diagenesis stage in the different sub-structures becomes shallow from southwest to northeast and that there are three secondary porosity zones in Liangjia,Wanchang and Botai district,two secondary porosity zones in Gudian slope,but not clear in Xin′anpu sub depression.They also reveal that the secondary porosity zones are greatly related with organic acid,unconformity surface,ground water infiltration,and the alkalescence corrosion in deep formation and the percentage of porosity damaged by compaction and cementation is different within different district and facies.

Based on the data of cores,thin slices,scanning electron microscope and x-ray diffraction,this paper studied the reservoir rock characteristics,diagenesis and pore evolution in Luxiang Fault Depression.It also analysed the burial history and thermal history using the BasinMod software,resumed the pore evolution history of Shuangyang Formation and calculated the oil-generatied peak period holding porosity firstly.The result reveals four diagenesis stages in Luxiang Fault Depression: compaction,cementation,metasomasis and dissolution.Compaction and cementation are the main cause for the porosity decrease.Before 36.5 Ma,the main diagenesis was compaction and cementation,with the porosity decreased by 13% of Shuangyang Group.In 36.5-30.0 Ma,organic material became mature,the diagenesis minerals dissolution of silicate and carbonate caused the porosity to increase to 25%.This provided secondary pore space for oil accumulation.After 10Ma,microfracture grew because of Shuangyang group temporary uplift,and deep hydrothermal fluid intruded along microfracture.Porosity decreased because of the recementation and mineral filling caused by deep hydrothermal fluid.

依据大量的薄片、扫描电镜、阴极发光和粘土矿物x衍射等资料,研究了鹿乡断陷储集层特征及成岩作用类型.结果表明,鹿乡断陷主要经历了压实、胶结、交代和溶解4个成岩阶段.压实和胶结作用是降低孔渗性能的主要因素,长石和方解石等成岩矿物的溶解作用与次生孔隙发育密切相关.依据储层中自生粘土矿物蒙皂石向伊利石转化的过程可划分为蒙皂石带、蒙皂石渐变带、第一迅速转化带,第二迅速转化带和第三迅速转化带.按照成岩阶段划分标准,将成岩阶段分为早成岩A期和B期,晚成岩A1期,晚成岩A2期和晚成岩B期.从早成岩B期到晚成岩A期是有机质成熟过程,粘土矿物转化、烃类热化学反应造成的酸性地层水介质使碎屑岩储层发育大量次生孔隙,是油气勘探的重点层段.

The characteristics and diagenetic types of Chaluhe reservoir were studied in terms of the data of drill cores,slices,scanning electron microscopy,X-ray diffraction.According to the criterion of division,the diagenetic phases are divided into early diagenetic A stage,B stage,and late diagenetic A stage and B stage,and the late diagenetic A stage is divided into A1 stage and A2 stage.By using the software of BasinMode,the burial history and thermal history of the primary structure were analyzed,and combined with the result of porosity evolution history,the reservoir diagenetic evolution was studied.The result is:before 30 Ma,the primary diagenesis was compaction and cementation.The porosity in the formation of Shanyang and Sheling reduced to 15% from 32% approximately,and that of Yongji and Wanchang reduced to 20% from 32% approximately;During the period of 30 Ma and 10 Ma,all the formations had been buried to the deepest depth and the feldspars in the sandstone formations of Shuangyang and Sheling began to dissolve,which caused the porosity to increase to 18%,providing space for the storage of oil and gas;but the porosity unchanged in the formation of Yongji and Wanchang during this period.Three diagenetic modes(alluvial fan,fan-delta,deep and half-deep lacustrine facies) are built in Chaluhe fault depression based on the study of burial history,thermal evolution history of organic,diagenetic evolution history,the rock type and sedimentary facies.

A calculation model for the low permeability reservoir in Baolang Oilfield is established based on the analysis and determination of the vital affecting factors for the permeability.While a relationship between porosity and permeability is built on the flow zone index(I_(FZ)) which characterizes the rock structure parameters.Accordingly,the discrimination fuction for the flow zone is established on the basis of logging data.Then,calculations are carried out on logging data and permeability parameters based on the identification of flow unit and the relationship between porosity and permeability.The 5 types of flow zones in Sangonghe Formation,Baolang Oilfied and the reservoir permeability controlled by I_(FZ) can meet the reservoir characterization in practice.

In order to understand the impact of pore evolution and diagenesis on reservoir petrophysical property of Baolang oilfield, reservoir rock property and diagenesis are studied by using methods of core and cuttings observation, thin section appraisal, X-diffraction analysis, and scanning electron microscope. According to the influence on petrophysical property, reservoir diagenesis is classified as destructive and constructive type. The influence of these 2 diagenesises on petrophysical property in the process of forming pore space is also analyzed.

河流砂体的研究已成为近几年储层研究的热点.本文总结前人研究成果的基础上,分析了河流相储层非均质研究的发展趋势及存在的问题.

油藏描述就是对油藏的各种参数进行三维空间的定量描述和表征,建立反映油藏构造、沉积、成岩、流体等特征的三维油藏地质模型.对具有中国陆相油藏特色的油藏描述技术的一些基本特点进行了总结.未来的油藏描述将进一步提高多学科协同分析的综合程度;进一步发展及应用高分辨率层序地层学;应用井间地震技术和四维地震技术监测油藏开采动态.