Abstract: The technology of Chemical Shallow Profile modification is an important means in adjustment on water injection structure. The GaoTaiZi reservoirs in the Daqing oilfield of China are mainly delta frontal facies sedimentation, there are many fine layers in longitudinal profile with 92 sedimentary units. With GaoTaiZi reservoir entering into high water-cut period and its development time prolonged, the problems of contradiction between longitudinal zones are becoming more and more prominent. But the thickness of separation layers are less than 0.4m, the room for layers subdivision of injection wells is very small, it becomes difficult to carry out oilfield development and modification.
Combined with the sedimentary characteristic of river-delta reservoir and the study result of flow unit, Vadose feature of delta frontal facies sedimentation reservoir in Daqing Oilfield is studied in this paper. Whether the chemical shallow profile modification effects are good or bad is mainly determined by the distribution of ancient current. The paper studies the distribution rule of ancient current and carries out reservoir description. It classifies the ancient current in sedimentary microfacies (single sandbody), carries out chemical shallow profile modification in ancient current, perfects the relationship of injection and production well in ancient current and improves development effects.
After chemical shallow profile modification, adjustment effect is different in oil wells of various vadose directions, base on this principal?profile modification mode in main flow zone of sedimentation system of delta frontal facie in the Daqing oilfield is set up, the thought and ways of selecting wells and layers in delta frontal facies to carry through profile modification is put forward. great economic and technology effect is get and it has wide application prospect.
Background information of regional geological characteristics This region is located on middle Saertu anticline structure. On vertical section plane it is divided into 4 oil reservoirs formation 26 (subzone) packages 92 small beds. In development we divided it into G I, G II, G III, G IV four bed system and use inverted 9-spot square pattern exploitation. Here GaoTaizi formation has the characteristics of have several oil reservoirs, the permeability among them is quite different And oil reservoir is seriously heterogeneous.
Detailed l reservoir comparison and division and Research on Vadose Geological Charatceristic Based on S+Ppay zone with 92 vertical sedimentary units and subdivision 4 sedimentary microfacies: distriburary fluvial sandbody, tabulated sheet sand, untabulated sheet sand, under water mud. combined study results both at home and abroad, drawing out sedimentary microfacies distribution maps and typical sandbody section maps, distributing different types of fluvial-deltaic secimenrary microdacies and sandbody macroditribution at different sedimentary conditions, showing geometric shape of different sandbody, distribution rule and their connection type with other sandbodies, setting up 4 types fluvial-deltaic fine geological models There are 5 types in delta front facies, they are inner delta front branch sandbody model, inner delta front branch-massive transitional sandbody model, inner deltaic massive sandbody model, outer delta front stable sheet sandbody model and outer delta front unstable sheet sandbody model.