Method and device for predicting oil-gas quantity produced by in-situ development of shale oil

Abstract

The invention provides a method and a device for predicting oil-gas quantity produced by in-situ development of shale oil, and the method comprises the following steps: obtaining an original total organic carbon content TOC value, a vitrinite reflectance Ro value and an original hydrogen index HI value of shale to be measured; obtaining the in-situ development output oil gas quantity of the to-be-measured shale according to the original TOC value, the Ro value and the original HI value of the to-be-measured shale, and a pre-established shale oil in-situ development output oil quantity prediction model and a shale oil in-situ development output gas quantity prediction model. The shale oil in-situ development output oil quantity prediction model and the shale oil in-situ development output gas quantity prediction model are pre-established according to output oil gas quantity data obtained by performing thermal simulation experiments on a plurality of different shale samples and originalTOC values, Ro values and original HI values of the shale samples. According to the technical scheme, quantitative prediction of the oil-gas quantity produced by in-situ development of the shale oil is realized, and the prediction precision and efficiency of the oil-gas quantity produced by in-situ development of the shale oil are improved.

Description

technical field [0001] The invention relates to the technical field of petroleum exploration, in particular to a method and device for predicting the amount of oil and gas produced by in-situ development of shale oil. Background technique [0002] Shale refers to medium-to-low maturity shale with high total organic carbon content (TOC) and low vitrinite reflectance (Ro), including generated petroleum hydrocarbons and unconverted organic matter. Due to the low degree of thermal evolution of medium-low maturity shale oil, undeveloped pores in shale, and difficulty in fluid flow, it is impossible to achieve commercial-scale development with the existing horizontal well volume fracturing technology. Medium and low maturity shale can be developed using in-situ conversion technology, which converts unconverted organic matter in medium and low maturity shale into oil and gas through in-situ heating, and combines the in-situ converted oil and gas with the retained A technology for ...

AI Technical Summary

Problems solved by technology

[0005] In the prior art, the four schemes for evaluating the oil and gas produced by shale all have defects: one is to use the H / C evaluation method for the produced oil and gas. C is not only time-consuming but also expensive. In addition, in the process of kerogen separation, hydrous silicate rocks will be precipitated, which will release hydrogen during combustion, resulting in abnormally high H / C. Silica gel contamination can be identified by microscopy and analyzed. It can be disposed of with hot hydrochloric acid, but silicon fluoride is insoluble in acid, resulting in large errors in the measurement of H / C, and the evaluation accuracy is not high

The second is the open system simulation experiment, which cannot be pressurized and cannot simulate the actual formation conditions. The sample size is small, the error is large, and the temperature rises quickly. It cannot truly reflect the thermal maturation process of source rocks, and the retained oil and gas volume under formation conditions cannot be obtained.

The third is the simulation experiment of high temperature and high pressure hydrocarbon generation and expulsion in a semi-open system, using crushed loose samples, in which there is a large space in the sample, the amount of retained oil and gas obtained is inaccurate, and cannot truly reflect the thermal maturity of source rocks under formation conditions During the process, the amount of retained oil and gas and the amount of removed oil and gas have not realized variable pressure to obtain data, so it is impossible to truly obtain the evaluation of shale hydrocarbon generation, retained hydrocarbons and produced hydrocarbons

The fourth is the simulation of hydrocarbon generation in a closed system—the gold tube simulation experiment, which cannot simulate the hydrocarbon expulsion process. The generated oil and gas have secondary cracking, the sample amount is small, the error is large, and the temperature rises quickly, which cannot truly reflect the thermal maturity process of the source rock; System hydrocarbon generation simulation—autoclave simulation experiment, which cannot simulate hydrocarbon expulsion and retained oil and gas, the furnace wall is thick, it is difficult to accurately measure the temperature, and the pressure control is difficult. Without constant pressure experiments, the probability of secondary hydrocarbon generation and cracking of oil and gas is high The speed is fast and cannot truly reflect the thermal maturation process of source rocks

[0006] In summary, the existing shale oil in-situ development output oil and gas volume prediction scheme cannot quantitatively predict the oil and gas output in shale oil in-situ development, and the prediction accuracy and efficiency are low

For the above problems, no effective solution has been proposed

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