A six-stage modeling method for the characterization of gas-water distribution in water-bearing carbonate gas reservoirs

Abstract

The invention discloses a modeling method used for representing the gas-water distribution of water-borne carbonate rock gas reservoir and relates to a six-stage modeling method. Based on the characteristics of a water-borne carbonate rock gas reservoir of the development of pores, cavities and crevices, the complex spatial combination types of the pores, cavities and crevices, the coexistence of layered edge water and uneven bottom water, the complex gas-water relations, etc., the invention proposes the six-stage modeling method of stratigraphic bedding plane structure modeling, sedimentary facies modeling, reservoir permeability medium facies modeling, gas-water interface modeling, fluid classification facies modeling and porosity, permeability and gas saturation property modeling, and the accurate quantitative representation of the gas-water distribution of water-borne carbonate rock gas reservoir in a three-dimensional space is realized. Compared with the water-borne carbonate rock gas reservoir model established by means of the conventional three-stage modeling method, the three-dimensional quantitative geological model of the gas-water distribution of water-borne carbonate rock gas reservoir is more accurate and reliable and can be widely used in each stage of the exploitation of water-borne carbonate rock gas reservoirs.

Description

technical field [0001] The invention relates to a six-stage gas reservoir modeling method, in particular to a six-stage modeling method for gas-water distribution characterization of water-bearing carbonate rock gas reservoirs. Background technique [0002] Carbonate gas reservoir reserves account for more than half of the international conventional natural gas reserves, and carbonate rocks are deposited in water bodies, and carbonate gas reservoirs with water exist widely at home and abroad. Therefore, carbon with water Quantitative characterization of gas-water distribution in salt rock gas reservoirs is particularly important. In addition to the impact of tectonic sedimentary evolution on the physical properties of carbonate rock reservoirs, diagenesis is particularly influential. Therefore, the sedimentary facies and the storage and seepage medium phases formed by diagenesis affect the spatial distribution of physical properties of carbonate rock reservoirs. law. It is...

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Problems solved by technology

[0005] The shortcomings of the traditional three-stage modeling method of structural modeling-sedimentary facies modeling-reservoir property modeling for the characterization of gas-water distribution in water-bearing carbonate gas reservoirs are reflected in the following three aspects: (1) Carbonate The storage and seepage medium of rock gas reservoirs is generally relatively complex, and its pore system is usually composed of pores, caves, and fractures of different origins, and various types of storage and seepage medium are combined in carbonate gas reservoirs. Medium phase is one of the main factors controlling the spatial distribution of gas reservoir physical property parameters, but traditional methods only focus on sedimentary facies modeling, relying on sedimentary facies-controlled methods to establish porosity-permeability attribute models obviously do not adopt storage-permeability medium phase-controlled porosity-permeability attribute models It can better highlight the actual characteristics of carbonate gas reservoirs; (2) It is precisely because of the simultaneous existence of multiple types of storage and seepage media that the gas-water relationship in water-carrying carbonate gas reservoirs is generally more complicated. Within a small area of ​​the reservoir, there are unique features such as the coexistence of edge and bottom water, and large differences in the gas-water interface, while traditional modeling does not have a modeling method specifically for the gas-water interface; (3) carbonate rocks with water The fluid saturation of gas reservoirs is not only affected by the gas-water contact, but also by the spatial distribution of fluids. Traditional modeling methods basically do not consider the control of the gas-water contact and fluid classification relative to gas saturation.

It can be seen that traditional modeling methods cannot be used to accurately characterize the gas-water distribution in three-dimensional space in carbonate gas reservoirs with water

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