Study On Logging Evaluation Method Of Carbonate Reservoir In Longwangmiao Formation In Gaosi - Moxi Area

Longwangmiao formation gas reservoir in the Gaoshiti-Moxi area is currently the focus of exploration and development in Sichuan Provence. Reservoir in this area is a multiple-porous media reservoir with strong heterogeneity, which resulted in many problems and difficulties in technology of logging evaluation in reservoir type division, quantitative calculation of reservoir parameters and the identification of fluid properties.Based on the analysis of the reservoir characteristics, using the conventional logging data and combining core analysis, imaging logging, with array acoustic logging data, this paper deals with the logging evaluation at four aspects:reservoir identification, reservoir parameter modeling, fluid property recognition, control factors of reservoir effectiveness analysis.Studies showing:①Application effect of three porosity model is good, which can effectively identify fracture and cave. On the basis of characteristic value of well logging curve reservoir can be effectively identified; Reservoir can be divided into three patterns which are caved, fracture-cavern and fracture-pore reservoirs, and different pattern’s distribution is regular.②Porosity interpretation models of sub-types of reservoirs is established by core analysis data demarcating porosity log curves, and the models have good correlation; Combining conventional logging data with nuclear magnetic logging data to calculate the reservoir permeability, improves the interpretation accuracy of permeability; Water saturation is calculated by Archie formula with m and n determined by experiment.③Among the six kinds of methods for identifying fluid properties in different area, the dual laterolog has universality.④On the basis of cut-off value, the paper evaluates electric characteristic of different effective reservoir, analyzes the relationship between lithology, pore throat structure, permeability, sedimentary faces, location and reservoir effectiveness, which ensures the characteristics of effective reservoir and provides an important theoretical basis for production of oilfield.This paper would propose a feasible well logging evaluation method. For the next step of reservoir evaluation, oil-test section of selection and calculation of reserves, the paper provides more accurate logging basis.