Method of quantitatively evaluating space-time evolution of porosity during reservoir diagenesis evolutionary process

Abstract

The invention provides a method of quantitatively evaluating space-time evolution of porosity during a reservoir diagenesis evolutionary process. The method includes the following steps: (1) determining a diagenesis sequence and porosity change tendency of a reservoir, recognizing main diagenesis events that the reservoir experiences, and establishing a diagenesis evolutionary process; (2) simulating the diagenesis evolutionary process in several stages, and determining the diagenesis evolutionary process, diagenesis periods and diagenesis conditions; (3) performing diagenesis effect indoor tests in different diagenesis periods, and detecting fluid components, rock sample components and pore structures before and after the tests in the different diagenesis periods; (4) in complete correspondence with the tests, performing diagenesis effect numerical simulation in different diagenesis periods, and calibrating mineral dynamics computation parameters and specific surface area in the simulation; (5) extending the time of numerical simulation to actual diagenesis time of the reservoir and calibrating the model parameters again to establish a quantitative simulation system in which the porosity is evolved with time; and (6) simulating the evolutionary process of the reservoir in an area range, and establishing a quantitative simulation system that the porosity is evolved with space and time, thereby achieving quantitatively evaluating and prediction of the porosity with time in space.

Description

Technical field [0001] The invention relates to the field of petroleum exploration. In particular, the invention relates to a method for quantitatively evaluating the temporal and spatial evolution of porosity in the diagenetic evolution process of a reservoir. Background technique [0002] Oil and gas resources have increasingly become strategic resources closely related to national economy, social development and national security. Whether it is traditional conventional oil and gas with relatively mature technology, or emerging unconventional resources such as shale gas and coalbed methane with huge potential, they are all stored in the pores or fractures of the reservoir rock. If it is to be exploited effectively, it is necessary to clarify the rules of hydrocarbon accumulation, and to correctly evaluate the physical conditions such as the porosity and permeability of the reservoir. [0003] The distribution and physical properties of oil and gas resources are mainly affected a...

AI Technical Summary

Problems solved by technology

[0005] Regarding the study of porosity in the diagenetic process, on the one hand, the current technical scheme is based on geological data such as well points, and through theoretical analysis, petrological tests, and physical simulations, to simulate the history of sedimentary filling, burial, and heat source evolution to restore calcium The history of cementation, siliceous cementation, clay mineral cementation, feldspar mineral dissolution, etc., determine the typical diagenesis, strength and reservoir porosity changes in different periods, and determine the original pores of the reservoir based on petrological tests and other methods The increase and decrease of retained and secondary pores belong to qualitative or semi-quantitative analysis, and what is obtained is the overall curve of porosity. There is no quantitative analysis and evaluation of the evolution with time, and it cannot accurately provide a certain time or period during the diagenetic process. The specific value of porosity in a certain area

[0006] On the other hand, there are currently a small number of literatures that study diagenesis based on geochemical theories, and use thermodynamic calculations or numerical simulation methods to evaluate the transformation of porosity by a certain diagenesis, but these studies are all limited to a single typical diagenesis, such as the Baiyun Petrification and illite petrification belong to mechanism research and cannot predict the change of porosity in the actual diagenesis process

However, the actual diagenesis includes multiple diagenesis, and the process is extremely complex

At present, there is no technical solution that can quantitatively evaluate and predict the evolution of reservoir porosity over time and space during diagenesis based on comprehensive knowledge of geology, geochemistry, and computers

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