Fracture-cavity type oil deposit analyzing method for water-flooding development and application thereof

Abstract

The invention relates to a fracture-cavity type oil deposit analyzing method for water-flooding development and application thereof. According to the method, history matching is conducted on a first geologic feature parameter of multiscale reservoir bodies constructing a multiscale reservoir body distribution conceptual model to obtain a second geologic feature parameter of the multiscale reservoir bodies constructing the finely drawn multiscale reservoir body distribution geologic model. In history matching, the independent representation multi-sided conductivity is adopted for dealing with the influence caused by connection position differences of different side fractures and caves on the oil water flowing rule; the virtual time step is adopted for reflecting the oil water replacement momentary balancing effect caused by oil water density difference; for anisotropy characters of the fractures, the tensor permeability of an arbitrarily fracture of the space is obtained by the adoption of conversion of a geodetic coordinate system and a space coordinates system. The fracture-cavity type oil deposit analyzing method for the water-flooding development is used for conducting fracture-cavity type oil deposit water-flooding development and decisions, the geologic model is more accurate, the flowing rule and the oil-displacement mechanism are more complete, and optimized decision through technologies and development effect predication are more accurate and reliable.

Description

technical field [0001] The invention belongs to the technical field of water injection development of fracture-cavity reservoirs, and relates to an analysis method of fracture-cavity reservoirs based on water injection development and its application. Background technique [0002] Some blocks in Tahe fracture-cave carbonate oilfield have implemented water injection to replace oil and fracture-cavity unit water injection development, and achieved good results, but the current recovery rate is only 13-15%, and the water content of some injection-production units has risen seriously , the difficulty of stabilizing oil and controlling water is gradually increasing, and it is necessary to continue to deepen water injection work to increase production and efficiency of old wells and improve oil recovery. Therefore, it is necessary to deeply analyze the problems and their causes in water injection development, understand the water injection development mechanism and water productio...

AI Technical Summary

Problems solved by technology

[0006] However, these methods also exposed some deficiencies when guiding field application: (1) Different from sandstone reservoirs, fractured-cavity reservoirs have great randomness in the spatial distribution of reservoirs, and the fluid flow law and water displacement mechanism are different. There are large differences, and the traditional sandstone reservoir research method is not applicable to fracture-vuggy reservoirs; (2) Fracture-vuggy media are different from continuous media, and conventional reservoir engineering methods are derived based on continuous media. Fracture-vuggy reservoirs lack guiding significance; (3) The connection relationship between fracture-vuggy media is complex, and the connection relationship determines the oil-water flow relationship in the reservoir. The existing multi-media numerical simulation and discrete fracture-vuggy network simulation have no Consider; (4) The filling degree of the cave medium is different. In the unfilled area, there is an instant equilibrium effect of oil-water replacement under the effect of oil-water density difference, which leads to the redistribution of the oil-water interface. In the filled area, the fluid flow is similar to that of a continuous medium The fluid flow in the fracture is different from the unfilled part, which is not involved in the existing multi-media numerical simulation and discrete fracture-cavity network simulation; (5) The fluid flow law in the fracture is high-speed non-Darcy flow, and there are extremely strong various The existing multi-media numerical simulation and discrete fracture-cavity network simulation are less involved; (6) The fracture-cavity reservoir space has the characteristics of uneven distribution of fractures and caves, different sizes and shapes , conventional modeling methods have poor adaptability, and only have high accuracy for large-scale caves and fractures

Images