The Fine Description Of Reservoir And The Distributing Of Remaining Oil Of Yuancheng Oilfield

Today,oilfields of the world have come into high water-cut stage. But there are still large amounts of remaining oil stored in place. How to characterize the distribution of remaining oil and enhance oil recovery is the main purpose of the current exploration and exploitation activities. In order to realize this purpose, it is necessary to describe finely reservoir and study the distribution of remaining oil.After collecting and re-processing of the data related with geological background, core observation, drilling, logging, lab analysis and so on, this paper uses a multi-discipline theories and research methods such as stratigraphy, sedimentology, reservoir engineering, and well logging geology to study the structural framework, micro-structures, sedimentary facie, reservoir heterogeneity and flow units of the reservoirs. In this way, this paper establishes 3D quantitative reservoir geological model under the sedimentary facie controlling. Taking YuanQing 64 well area as a case study, this paper studies the distribution of remain oil, predict the production index using the technology of reservoir numerical simulation in both qualitative and quantitative ways on the base of matching production history. The main conclusions can be summarized as follows:1. According to the principle of deposition cycles and isochronic correlation, the division and correlation of substrata was carried out on the wells of field.The distribution of formation in Qing 64 area is large, the thickness is stable. The structure is a low vault structure formed by effect of differential compaction for the different compaction ratio of sand shale. Its shape is not regular, long axial toward to north-west, there are two high point which is consistent in different fine formations, all this provide that the development of structure is remarkable secession.2. Analyzing the background and characteristics of sedimentary and core, the micro facie of the formation are studied. The conclusion is that this area are mainly braided river sedimentary system, micro facie are mainly braided channel, inner-channels, natural dyke and alluvial flat, braided channel is the mainly sedimentary micro facie. the sedimentary facie determine the distribution of sand body in plane area.3.The distribution of the main oil-bearing sandstone reservoir is different between the subzone. The research of the reservoir heterogeneity reveals that grain size distribution of in-layer sandstone is positive rhythm. The distribution of reservoir property is coincided with the distribution of litho.4 .The relationship between depositional micro-facie and flow unit reveal thatâ… flow unit distribute in braided channel,â…¡flow unit distribute in inner-channel and natural dyke,â…¢flow unit distribute in alluvial flat . 5. The study of the four physical property relationship show that reservoir physical property are effected by lithologic character, the reservoir physical property become poor when the grain size become fine or clay content increase, the reservoir parameters secondary interpretation model established. Give the standard of recognizing oil or water, established the 3D geology model with depositional facie controlling.6. The reasonable of development well pattern is studied using the reservoir engineering and reservoir numerical simulation technology, the result reveal that the remaining oil is effected by low structure, reservoir,sedimentary facie, bottom water coning and other development factors. There are abundant remaining oil where the area is Reservoir injection-production faultiness, higher of the structure and the pressure balance area, then give the corresponding adjustment program and development technology policy.