阅读说明：本技术 一种评价原位加热改质时页岩油储层有机质转化率的方法 (Method for evaluating shale oil reservoir organic matter conversion rate during in-situ heating modification ) 是由 陈方文 丁雪 卢双舫 郑强 谭雅文 于 2020-06-11 设计创作，主要内容包括：一种评价原位加热改质时页岩油储层有机质转化率的方法,属于石油开发领域。该方法评价原位加热改质开采页岩油时页岩油储层有机生成烃类转化率。步骤为：①从页岩油储层岩心样品的同一深度选取7份样品作为平行子样品；②将这7个平行子样品进行洗油、烘干处理；③分析这7个平行子样品的有机碳含量；④将7个平行子样品分别放入温度为200℃、300℃、400℃、500℃、600℃、700℃和800℃马福炉中；⑤30天后将7个平行子样品从马福炉取出,做洗油、烘干处理后分析有机碳含量；⑥依据7个平行子样品有机碳含量变化,评价该套页岩油储层在不同加热改质温度下有机质的转化率。(A method for evaluating the organic matter conversion rate of a shale oil reservoir during in-situ heating modification belongs to the field of petroleum development. The method evaluates the conversion rate of the organic generated hydrocarbons of the shale oil reservoir when the shale oil is extracted by in-situ heating modification. The method comprises the following steps: selecting 7 samples from the same depth of a shale oil reservoir core sample as parallel subsamples; washing the 7 parallel sub-samples with oil and drying; analyzing the organic carbon content of the 7 parallel sub-samples; fourthly, respectively placing the 7 parallel sub-samples into muffle furnaces at the temperature of 200 ℃, 300 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃ and 800 ℃; taking out 7 parallel sub-samples from the muffle furnace after 30 days, performing oil washing and drying treatment, and analyzing the organic carbon content; sixthly, evaluating the organic matter conversion rate of the set of shale oil reservoirs at different heating and modifying temperatures according to the organic carbon content change of 7 parallel subsamples.)

1. A method for evaluating the organic matter conversion rate of a shale oil reservoir during in-situ heating modification is characterized by comprising the following steps:

step 1: selecting 7 samples from the same depth of a shale oil reservoir core sample as parallel sub-samples, wherein the mass of each parallel sub-sample is about 20g, and the unit of the mass of each sample is g;

step 2: carrying out oil washing treatment on the 7 parallel sub-samples to remove liquid hydrocarbon in the samples, and then carrying out drying treatment to remove organic solvent and pore water;

and step 3: the organic carbon contents of the 7 parallel subsamples are respectively analyzed, and the organic carbon contents of the 7 parallel subsamples are respectively TOC₁ ⁰、TOC₂ ⁰、TOC₃ ⁰、TOC₄ ⁰、TOC₅ ⁰、TOC₆ ⁰And TOC₇ ⁰The unit of organic carbon content is%;

and 4, step 4: placing the 7 parallel sub-samples into muffle furnaces at 200 deg.C, 300 deg.C, 400 deg.C, 500 deg.C, 600 deg.C, 700 deg.C and 800 deg.C, respectively;

and 5: after 30 days, taking out 7 parallel subsamples from the muffle furnace, respectively carrying out oil washing treatment on the 7 parallel subsamples to remove liquid hydrocarbon in the samples, then carrying out drying treatment to remove organic solvent and pore water, and then respectively analyzing the organic carbon content of the 7 parallel subsamples, wherein the organic carbon content of the 7 parallel subsamples is TOC₁、TOC₂、TOC₃、TOC₄、TOC₅、TOC₆And TOC₇The unit of organic carbon content is%;

step 6: according to the change characteristics of the organic carbon content of 7 parallel subsamples, the organic matter conversion rate of the shale oil reservoir during in-situ heating modification is evaluated according to the following formula

In the formula, F_Organic-iIs heated at a temperature of number iThe organic matter conversion rate of the shale oil reservoir is expressed in unit; TOC_i ⁰The method comprises the steps of (1) after oil washing and drying operations are carried out, putting a parallel sub-sample into a muffle furnace with the temperature number i, wherein the unit of the organic carbon content is; TOC_iThe method comprises the following steps of (1) taking out a muffle furnace with the temperature number of i, carrying out oil washing and drying operations, and then, paralleling the organic carbon content of a sub-sample, wherein the unit of the organic carbon content is; i =1,2, … 7, numbering muffle furnaces at 200 ℃, 300 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃ and 800 ℃ in that order.

Technical Field

The invention relates to a method for evaluating the organic matter conversion rate of a shale oil reservoir during in-situ heating modification, and belongs to the technical field of petroleum exploration and development.

Background

Shale oil refers to petroleum resources contained in shale layer systems mainly made of shale, and comprises petroleum resources in compact carbonate or clastic rock adjacent layers and interlayers in the shale layer systems. The successful exploration area of the North American shale oil belongs to marine strata, such as a Barken group, an eagle beach group, a Barnit group and the like, the shale oil exploitation effect is obvious by utilizing technologies such as horizontal wells, hydraulic staged fracturing and the like, and the external dependence of American crude oil is obviously reduced. This is one of the key factors in the success of the north american shale oil revolution. However, the shale oil resource in China is mainly enriched in a continental basin, and the effect of applying horizontal wells and hydraulic fracturing technology is not ideal. Shale oil drilling and large-scale hydraulic staged fracturing are high in cost, however, the oil yield of shale oil wells is far from having economic benefits under the background of high investment, and therefore the development process of shale oil in China is very slow.

Shale oil reservoirs in China belong to reservoirs with low porosity, ultralow permeability, rich organic matters and strong plasticity, the capacity obtained by means of the pore fluid pressure of the reservoirs is rapidly reduced, and the single well recovery ratio is very limited. Horizontal well staged hydraulic fracturing and other technologies are successful in North America, but obviously 'water and soil are not uniform' in China, and the high-investment drilling and fracturing cost and oil yield are seriously unbalanced. The shale oil in-situ heating modification technology is that heating the shale oil reservoir can reduce viscosity, pressurize, increase permeability, increase yield and reduce cost of shale oil, and is expected to break through the technical bottleneck of shale oil exploitation. The kerogen remaining during heating of the shale oil reservoir is further cracked and converted to liquid and gaseous hydrocarbons. In the process of heating, modifying and exploiting the shale oil, how the conversion rate of hydrocarbon generated by organic matters of a shale oil reservoir changes with the reservoir temperature and the variation thereof are key parameters for development and evaluation of in-situ heating, modifying and exploiting the shale oil. At present, the domestic scholars often catalyze shale reservoir samples with different degrees of thermal maturity, then mainly focus on the pore structure specific diagnosis change of the samples, less analyze the conversion rate of organic matters under various temperature conditions, and the temperature of catalysis and the like are limited to a certain extent; or the golden tube is used for thermal simulation experiments, but the operation process of using the golden tube for thermal simulation experiments is complex and high in cost.

Therefore, the method for evaluating the organic matter conversion rate of the shale oil reservoir during in-situ heating modification is provided, and the organic matter conversion rate of the shale oil reservoir under the temperature conditions of different heating modified shale oils is evaluated through the change characteristics of the organic carbon content of the sample under different temperature conditions, so that basic parameters are provided for evaluating in-situ heating modified mining shale oils.

Disclosure of Invention

The purpose of the invention is: the method for evaluating the conversion rate of the organic matters of the shale oil reservoir during in-situ heating modification is provided, and quantitative evaluation of the conversion rate of hydrocarbons generated by the organic matters of the reservoir in the in-situ heating modification shale oil exploitation process under different temperature conditions is realized. The defects of complex operation and high cost of the prior art and the method are overcome.

The technical scheme adopted by the invention is as follows: the method for evaluating the organic matter conversion rate of the shale oil reservoir during in-situ heating modification is characterized by comprising the following steps of:

step 1: selecting 7 samples from the same depth of a shale oil reservoir core sample as parallel sub-samples, wherein the mass of each parallel sub-sample is about 20g, and the unit of the mass of each sample is g;

step 2: carrying out oil washing treatment on the 7 parallel sub-samples to remove liquid hydrocarbon in the samples, and then carrying out drying treatment to remove organic solvent and pore water;

and step 3: the organic carbon contents of the 7 parallel subsamples are respectively analyzed, and the organic carbon contents of the 7 parallel subsamples are respectively TOC₁ ⁰、TOC₂ ⁰、TOC₃ ⁰、TOC₄ ⁰、TOC₅ ⁰、TOC₆ ⁰And TOC₇ ⁰The unit of organic carbon content is%;

and 4, step 4: placing the 7 parallel sub-samples into muffle furnaces at 200 deg.C, 300 deg.C, 400 deg.C, 500 deg.C, 600 deg.C, 700 deg.C and 800 deg.C, respectively;

and 5: after 30 days, taking out 7 parallel subsamples from the muffle furnace, respectively carrying out oil washing treatment on the 7 parallel subsamples to remove liquid hydrocarbon in the samples, then carrying out drying treatment to remove organic solvent and pore water, and then respectively analyzing the organic carbon content of the 7 parallel subsamples, wherein the organic carbon content of the 7 parallel subsamples is TOC₁、TOC₂、TOC₃、TOC₄、TOC₅、TOC₆And TOC₇The unit of organic carbon content is%;

step 6: according to the change characteristics of the organic carbon content of 7 parallel subsamples, the organic matter conversion rate of the shale oil reservoir during in-situ heating modification is evaluated according to the following formula

In the formula, F_Organic-iThe organic matter conversion rate of the shale oil reservoir is obtained when heating modification is carried out at the temperature with the number of i, and the unit of the organic matter conversion rate of the shale oil reservoir is; TOC_i ⁰The method comprises the steps of (1) after oil washing and drying operations are carried out, putting a parallel sub-sample into a muffle furnace with the temperature number i, wherein the unit of the organic carbon content is; TOC_iThe method comprises the following steps of (1) taking out a muffle furnace with the temperature number of i, carrying out oil washing and drying operations, and then, paralleling the organic carbon content of a sub-sample, wherein the unit of the organic carbon content is; i =1,2, … 7, numbering muffle furnaces at 200 ℃, 300 ℃, 400 ℃, 500 ℃, 600 ℃, 700 ℃ and 800 ℃ in that order.

The invention has the beneficial effects that: the invention discloses a method for evaluating the conversion rate of organic matters of a shale oil reservoir during in-situ heating modification, and provides a quantitative evaluation method for the conversion rate of hydrocarbons generated by organic matters of the reservoir in the in-situ heating modification shale oil exploitation process under different temperature conditions, so that the quantitative evaluation of the conversion rate of hydrocarbons generated by organic matters of the reservoir in the in-situ heating modification shale oil exploitation process under different temperature conditions is realized. The defects of complex operation and high cost of the prior art and the method are overcome.

Drawings

FIG. 1 is a flow chart of the present invention.

The specific implementation mode is as follows: