Development Potential Study Of Low-Permeability Heterogeneous Reservoirs Based On Reservoir Flow Unit

Noticing that it is difficult to adapt the varying parameters of1380block in Ganguyi oil field to the heterogeneous reservoirs conditions and the distribution of the remaining oil development potential is complex during at late stage of water flooding in this area, this paper conducted flow units classification and calculates the single-well controlled multiple reserve investigation based on many materials, including geological background, core, logging, analysis data and laboratory and production performance data of the reservoir, all of which are a combination of sedimentology, logging geology, development geology, well log interpretation technology, reservoir engineering and some other subjects. Then the location and the scale of the remaining oil development potential are clarified both on the plan and section.In this paper, on the basis of the basic geological research,8parameters that can fully reflect the reservoir geological features of the low-permeability and heterogeneous reservoir of this area are selected using gray integrated theory. Combined with the oil and gas testing capacity hierarchy and evaluation criteria, a comprehensive evaluation index system to classify the flow units is established. Then the reservoir is divided into three types of flow units, and that simplified the heterogeneous characterization of the reservoir. Relatively homogeneous flow units which fall into the same type are considered as a research unit to clarify that the I and II flow units are the "dessert" of the oil and gas reservoirs in this area. Single well controlled reserves calculation is applied to include oil-sand layers with similar effective reservoir thickness, physical properties and oil feature in a single well calculation unit. The single well controlled geological reserves, technically recoverable reserves and remaining recoverable reserves of each oil-sand layer are obtained. Remaining oil enriched well area, layer bit corresponding location and morphology and the corresponding flow units were determined through analysis of the single well remaining recoverable reserves distribution charts and the fitting diagrams of remaining recoverable reserves and flow units distribution. Finally, considering the remaining recoverable reserves and flow units type, and in accordance with the size of the remaining oil and reservoir properties, the target layer of the study area are divided into four levels developed potential area. Thus, the remaining oil enrichment area and reservoir quality of each single well are clarified in every layer, which points out the direction for tapping the latent remaining oil and the later efficient development of the oilfield in this area.