Logging evaluation method and system for carbonate reservoir

Abstract

The invention provides a well logging evaluation method and system for a carbonate reservoir, and the method comprises the steps: obtaining the hole resistivity and the fracture resistivity of the reservoir based on the conductive characteristics of a carbonate reservoir matrix according to a separation processing strategy and set parameters, and determining the hole resistivity and the fracture resistivity of the reservoir after the fracture state of the current carbonate reservoir is judged. Calculating the fracture porosity according to the fracture resistivity, calling a matched permeability calculation model, adding the obtained fracture porosity and fracture opening data to calculate the fracture permeability of the reservoir, and performing logging evaluation on the current reservoir by integrating the fracture permeability and the hole permeability obtained by adopting a set algorithm. According to the scheme, conventional logging parameters and statistical analysis parameters are adopted, the problem that the precision deviation is obvious when a traditional logging evaluation technology is applied to the carbonate reservoir can be solved, on the basis that logging evaluation of various types of carbonate reservoirs is reliably achieved, intermediate theoretical parameters except the conventional parameters do not need to be calculated, and the calculation cost is reduced. And the timeliness of obtaining the evaluation result is improved.

Description

technical field [0001] The invention relates to the technical field of reservoir logging evaluation, in particular to a logging evaluation method and system for carbonate rock reservoirs. Background technique [0002] The carbonate reservoir space includes primary pores, lithological evolution pores, dissolution pores, caves and various fractures. The research results of typical carbonate oilfield reservoir space show that the primary porosity is very low, and whether fractures and dissolution pores are developed It is the primary factor for whether it can become an effective reservoir. For example, the carbonate formation in Tahe Oilfield, based on further research, according to various analysis data such as core observation, rock thin section, fluorescent thin section, etc., according to the scale, occurrence and genesis, carbon The effective storage space of the salt stratum can be effectively divided into different types. For example, the effective storage space of the c...

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Problems solved by technology

[0004] figure 2 An example diagram of the evaluation results of carbonate formation reservoirs using the above-mentioned dual-porous media model is shown in , according to figure 2 According to the information disclosed in the paper, during the evaluation process of the dual-porosity media model, a quantitative calculation method was developed for the two very important components (fractures and pores) of carbonate rock fracture-cavity reservoirs. There are big deficiencies in this method, which are mainly reflected in the following: the number of pores and fractures is divided as the reservoir evaluation standard, for example figure 2 In general, the porosity of pores in fractured reservoirs must be less than 2%, and the maximum level can only be Type II reservoirs, which is obviously inconsistent with the actual situation. It can be seen that the accuracy of reservoir evaluation results is not high; in addition, the evaluation method involves The evaluation elements are not comprehensive enough to form a continuous evaluation standard for the proportion of fractures and vugs in the reservoir. If the vug porosity is 5% of the reservoir and the fracture porosity is 0.04% (large vugs and small fractures), then it is impossible to effectively and clearly evaluate which of the two reservoirs is higher, and it is impossible to accurately deal with the problems from vugs to vugs to fractures to fractured reservoirs. Evaluation of continuous layer changes

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