Reservoir Modeling Study On Fracture-cave Carbonate In Tahe Oilifeld

The Ordovician carbonate reservoir in the Tahe Oilfield is a large fracture&cavesystem formed by supergene karstification. The maltiphasic karstification and thecollapse of karst cavities lead to complex reservoir space and a highly heterogeneousof reservoir. So, quantitative evaluation and characterization of the reservoircharacteristics is more difficult. As technology advances and to meet the needs ofexploitation, it is necessary to make accurate description and build refined threedimensional geological models. Based on the carbonate reservoir in in4district ofTahe Oilfield, combining with interdisciplinary studies, this thesis discussed themethod to build single-well model, two-dimensional models and three dimensionalgeological models.First of all, the article analyzes the geological characteristics of the Ordoviciancarbonate reservoir in Tahe Oilfield. It takes geology, logging, high-resolution3Dseismic data and dynamic production data as guidance, and makes full use of welldata. Then the article combines deterministic modeling methods with stochasticmodeling methods following the step of single well model--two dimensionalmodel-three dimensional model. Finally, geological model and property model offracture-cave carbonate reservoir of this area are established.The author comes to the following conclusion and understanding through aboveresearch:1. Geological modeling of fracture-cave carbonate reservoir is a verycomprehensive work, which needs various information and should follow the way ofintegrative modeling method;2. Combining deterministic modeling with stochasticsimulation, we can greatly reduce uncertainly and increase reservoir modelingprecision;3. Based on the logging data, combining with well drilling, output and acidfracturing data, the author divided the reservoir to cave reservoir(unfilled cave,half-filled cave, filled cave), fracture reservoir and cave-fracture reservoir. At thesame time, three karst belts are recognized and single well geological models are built;4. By analyzing seismic attribute and cavity reservoir, the article describes thecorrelativity between RMS, acoustic impedance data and cave reservoir, buildsseismic probability model of cave reservoir as well;5. By utilizing “SequentialIndicator Simulation” method and restraining of the seismic property data, the authorbuilds the cave reservoir model and property model;6. This article improves theinterpretation precision of fracture parameter through FMI and core data. Figuring up big size fracture models and property model by ant body tracking technique andempirical equation. Reservoir geological modeling establishment is subject toperson’s understanding about geological conditions of reservoir, and to person’sfamiliarity degree of modeling theory and software, among which geologicalknowledge is the most important and basic factor.