Experimental Research On Physical Simulation Of The Dual Laterolog For Fracture-cavernous Formation

At present, carbonate fracture-cavity reservoirs with well reservoir capacity and ability to penetrate, has become an important research topic of common concern at home and abroad. Since fracture-cavity reservoirs with strong heterogeneity, obvious anisotropy, logging response characteristics is very complex, making fracture-cavity recognition become a difficult and hot academic issue. The key to evaluate cave reservoir is determine the type of filling material and extent. Research of cavity spatial scale, filling degree and filling type via dual laterolog physical simulation method, to provide an experimental tool for the evaluation of carbonate fracture-cave recognition.In order to expand the use of dual laterolog method to identify the fracture-cave reservoir. This thesis based on the dual laterolog theory, aims to the main research of physical model design principle and experimental techniques method for the dual laterolog response to fractured-cavernous formation. And explore the characteristics of laterolog resistivity by changing the experimental cave model’s space dimension and resistivity etc.A downscale model system is established in lab. The first step is to study the theory on design for the physical model, and analyze the relationship between the physical model and experimental prototypes, including borders, spatial condition, time scale, geometric dimensions, electrical parameter. And based on the above principles, to carry out the design and manufacture of the experimental models, also the design and manufacture of downscale dual laterolog tool. Downscale physical model theory of fracture-cave formation, including the analysis of experimental prototypes, follow by mathematical method in physical principles of dual laterolog response to the cave model with different filling degree or different filling material. Downscale experimental apparatus includes a down-hole logging electrode system, ground electric circuit, oscilloscopes, computer control systems, etc. Former simulation test design includes the main factors affecting the effectiveness of the cave reservoirs. Namely the way of control and implementation to the resistivity of filling materials and filling degree.Experimental simulation of the dual laterolog response for the changes geometry and resistivity in the cave model, and numerical simulation space geometry, filling resistivity, filling level of the borehole cave. Numerical simulation of dual laterolog deep and shallow response for different radial caves and different location, and the response for fractured-cavernous combination with the crack of different angle includes 0°, 90°, and inclined crack, also the relationship between the dual laterlog response to combination of fracture and cave and the fracture aperture. Cite examples to study the deep and shallow laterolog response of different filling levels caves.The research of downscale fracture-cave formations physical simulation devices and experimental method and technology, enhance the understanding of the dual laterolog response to fractures and caves in fractured-cavernous formation. The study also provide an experimental basis for identification and evaluation for carbonate fracture-cave reservoir.