The Study On Architecture Analysis And Remaining Oil Distribution Of The First Segment Of Fu’ning Formation In Gaoji Oilfield

Most of major oilfields in China which were discovered at high water-cut stage right now, but oil recovery is comparatively low that about30%. The research shows a lot of remaining oil with different scale and distributes can be found in the long term water flooded reservoirs. The remaining oil generally distributed but accumulation in some certain areas and controlled by the reservoir architecture, so the study of reservoir architecture and the remaining oil distribution pattern controlled by them are very significant.Gaoji oilfield is located in Chenqiao and Jinbei village of Jinhu town in Jiangshu province, in the middle of the western slope which belong to the secondary stuctual belt in Dongtai depression, bordering the Cuizhuang oilfield to the south, Liuzhuang oil and gas field to the north, Sanhe subsag to the east,Jianhu uplift to the west, that is fault nose and broken nose group formatting unde.r the background of slope structure. In this paper, taking the first segment of Funing formation of Gaoji oilfield as a case,aimed at reservoir geological and development characteristics of gaoji oilfied, under the comprehensive analysis of reservoir geological logging reservoir petrology analysis test sedimentology geostatistics and sequence stratigraphy,using the comprehensive geological analysis technology,and the theory of petroleum geology modern sedimentology reservoir geology petroleum development geology and sequence stratigraphy, using the method of scale analysis and model fitting, the architecture of the reservoir is precisely anatomized, the systemic analyzing method of delta reservoir inner architecture is established, and the remaining oil distribution patterns controlled by the different hierarchy architecture are summarized, which will help to study the characteristics of the simillar reservoir in the other oil fields.With the knowledge of high-resolution sequence stratigraphy, taking many factors into account, such as denudation and deletion of Strata, degradation of stream, sand bodies stacking, changes of Sedimentary micro-facies, and development factors, an accurate sequence frame of the scope of the entire area was established. The Eifl is divided into two groups,19small layers.On the basis of high-resolution stratigraphic correlation, single layer and oil sand body arecorrelated within this frame, taking modern deposition and outcrop study as a guidance, a few architecture hierarchies, including composite sand body, single sand body, single genetic sand body and Progradation body are identified in the research area.In the process of the single sand body recognition and research, a set of research methods has been put forward, adopting the method of relative depth that is from small intraformational sandstone roof surface to the small layer formation top boundary of sand top, combined with the flat combination of sedimentary microfacies and profile maps of sedimentary microfacies from various visual angles, and taking a comprehensive study in single phase distribution of sand body. The scale of the single sand body is recognized by using log data of dense spacing wells and the boundary point reasonable combination of the single sand body is using rule that is something which is similar adjacent. The reservoir configuration unit is depicted and represented fine under the guidance of a mode of space combination of the single sand body. A set of methods which is about identification and anatomical of the single sand body has been put forward, according to previous research results, determining relationship of the width-to-thickness ratio of the single sand body, being based on the sand body width, thickness trend and vertical sequence to identify the single sand body, using experience formula, geological model, and small well spacing materials determining progradating body, the scale of progradating surface and its occurrence, guiding the internal structure analysis of the single sand body in the key well area,and at last give a dynamic verification for it. In the study of stochastic simulation, using results of sedimentary microfacies and logging processing and adopting the modeling phasing methods build the structure model and reservoir parameter model through the sequential indicator simulation method. On this basis, using Petrel software and multistage modeling phasing methods, we have established the reservoir architecture3D model of the underwater distributary channel sand body system and analysed the distribution characteristics of intercalation in the research area.On the basis of architecture anatomy and dynamic data analysis, build the remaining oil distribution patterns model controlled by different hierarchy architecture units, stacked channel,single channel and inner architecture of single channel, are summarized, analyzing the microfacies, rhythm, the structural plane (intercalation) controlling the factor of remaining oil distribution in details.