Description And Modeling Of Ordovician Karst Fracture-cavity Carbonate Reservoirs In Block 4 Of Tahe Oilfield

Carbonate reservoirs play an important role in the world's oil and gas reservoirs.In recent years,carbonate reservoirs have attracted more and more attention from experts and scholars,especially those with great potential for oil and gas fractured-vuggy carbonate reservoir.However,unlike the clastic reservoirs and the traditional carbonate reservoirs,the fractured-vuggy carbonate reservoir are highly heterogeneous and the development is very difficult.Tahe oilfield fractured-type carbonate reservoir is this highly heterogeneous reservoir,a variety of storage space,complex geological conditions,making the type of oil and gas reservoir become very difficult to exploit.This paper mainly studies the characteristics and types of reservoir in the Lower Ordovician carbonate fractured reservoirs in the in fourth blocks of Tahe Oilfield,and combines the logging and seismic data to establish the reservoir model of the study area by using petrel,While the reserves were calculated.The main part of Tahe Oilfield is the structure of No.2 Ai Xieke.On the plane,No.2 Ai Xieke structure is not standard gourd-like,the main stirke is the north to the east.The rupture of the study area is very developed,and the vast majority is the reverse fault.The extension is short,the plane is broken on the multi-main and oblique characteristics,broken distance is small.The carbonate matrix in fourth blocks in the Tahe oilfield cannot serve as reservoir space,the main reservoir space is the karst cave and fracture,and under the different ways,the reservoir space can constitute three types reservoir,fracture reservoir,fracture-cave reservoir,and cave reservoir.Those reservoirs have a trend of gradually worse from the top to bottom in the vertical,and the degree controlled by structure also become weak.To establish the training image,I choose the RMS attribute to do it,while the normalized RMS attribute is modeled as soft data,building the Three-dimensional Geological Model of fractured-vuggy Carbonate Reservoirs in Area 4 of Tahe Oilfield by Multi-point Statistical Algorithm.This model not only reflects the characteristics that the fractured-vuggy carbonate does not has the feature of "layer" in the longitudinal direction,but also conform the geological knowledge in the longitudinal direction,that is,the reservoir become worse from top to bottom?For the large scale fractures,using the ant-tracking for deterministic modeling.For the small scale fractures,using the cluster analysis to build the fracture intensity model,then build the small scale fractures model by random simulation.At last,the reserves of the Lower Ordovician fractured-vuggy carbonate reservoirs in the fourth blocks of Tahe Oilfield were calculated.The difference between the total reserves and the proven reserves of the State Reserve is only 6.84%.