Carbonate rock oil and gas reservoir-forming geological process reconstruction method based on dating technology

Abstract

The invention provides a carbonate rock oil and gas reservoir forming geological process reconstruction method based on a dating technology. The method comprises the following steps: obtaining a rock sample in which carbonate diagenetic minerals are rich in hydrocarbon inclusions and the carbonate diagenetic minerals and asphalt have an associated relationship as a rock sample for reconstruction analysis of a work area oil and gas reservoir-forming geological process; identifying host minerals rich in hydrocarbon inclusions in a rock sample for analysis, performing isotope dating and cluster isotope testing to obtain the absolute age of the host minerals rich in the hydrocarbon inclusions, wherein the obtained absolute age data represents the time of a main reservoir forming period of an oil and gas reservoir; identifying carbonate diagenesis minerals associated with asphalt in the rock sample, and obtaining the absolute age of the carbonate diagenesis minerals through isotope dating so that the filling and cracking time of the crude oil is determined; and based on the crude oil filling, the cracking time and the main reservoir-forming time, reconstructing the oil and gas reservoir-forming geological process.

Description

technical field [0001] The invention belongs to the technical field of carbonate oil and gas reservoir evaluation in petroleum and natural gas geological exploration, and in particular relates to a method for reconstructing geological process of carbonate rock oil and gas accumulation based on dating technology. Background technique [0002] Reconstruction of the geological process of oil and gas accumulation is one of the bottleneck technical problems faced by oil and gas exploration and evaluation, especially the reconstruction of the geological process of oil and gas accumulation in ancient marine carbonate rocks in the lower structural layers of superimposed basins in China; The determination of is the key to solving the reconstruction of the geological process of hydrocarbon accumulation. The methods commonly used in the past to determine the time of oil and gas accumulation include geological comprehensive analysis method, inclusion homogeneous temperature method, diag...

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Problems solved by technology

The inclusion uniform temperature method is mainly based on the inclusion capture temperature to determine the hydrocarbon generation and expulsion temperature of source rocks, combined with the analysis of structure-burial history and basin thermal history, qualitatively judges the time of oil and gas accumulation, due to the instability and composition of organic matter in hydrocarbon inclusions The difference leads to a large change in the homogeneous temperature, while the stability of the homogeneous temperature of brine inclusions is relatively high. Therefore, the gas-liquid two-phase brine inclusions that coexist with hydrocarbon inclusions are generally used as test objects. Only when there are hydrocarbon inclusions and gas-liquid two-phase brine inclusions, can the homogeneous temperature of gas-liquid two-phase brine inclusions represent the trapping temperature of hydrocarbon inclusions. It is difficult to promote the application of samples that meet such harsh conditions

Moreover, using the comprehensive geological analysis method and the uniform temperature of inclusions to invert the formation time of oil and gas reservoirs requires reliable paleogeothermal models and burial history models, and there will be many uncertainties due to differences in geological understanding

The isotopic dating methods of diagenetic minerals have been reported, including illite K(Ar)-Ar, apatite or zircon U-Th / He dating to quantitatively determine the time of oil and gas accumulation, but they are mainly applicable to clastic rock and igneous rock reservoirs. Moreover, due to the limitation of geological understanding, there is a large uncertainty

The rhenium-osmium isotope dating method is mainly used for direct dating of oil and gas products (bitumen, crude oil). Although it can be used to quantitatively analyze the generation and cracking time of oil and gas, due to the possibility of resetting the Re-Os isotope system during oil and gas migration and transformation However, the geological meaning of Re-Os isotopic age is still different, and rhenium-osmium dating has very strict requirements on samples, and the detection success rate is low, so it is difficult to popularize

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