Unconventional natural gas fracturing effect evaluation and productivity prediction method based on principal component analysis

Abstract

The invention discloses an unconventional natural gas fracturing effect evaluation and productivity prediction method based on principal component analysis. The method comprises the following steps: 1) establishing an unconventional natural gas fracturing effect evaluation and productivity prediction evaluation database; 2) standardizing the original data; 3) calculating a covariance matrix; 4) solving a characteristic value and a characteristic vector; 5) calculating a variance contribution rate and an accumulated variance contribution rate, and determining the number of principal components;6) determining m vectors of the principal component, and outputting a new data sample; 7) establishing a multiple linear regression model according to the new sample, and performing fitting simulation test on the established multiple linear regression model; 8) performing fitting simulation inspection; and 9) carrying out shale gas fracturing effect evaluation and productivity prediction by usingthe established multiple linear regression model. According to the method, the problems of low linear relevancy and data redundancy of original data, artificial subjective factors caused by the factthat an existing evaluation method needs a large amount of sample data and expert scoring and the like can be well solved, and the accuracy of unconventional natural gas fracturing effect evaluation and productivity prediction is improved.

Description

Technical field:

[0001] The invention belongs to the technical field of unconventional natural gas development and quantitative prediction models, and specifically relates to unconventional natural gas fracturing effect evaluation and productivity prediction technology. Background technique:

[0002] Shale gas, tight sandstone gas, and coalbed methane are unconventional natural gas. At present, the state attaches great importance to the development and utilization of shale gas. At the same time, my country's demand for natural gas is strong, and shale gas is bound to become an important supplement to the current natural gas resources. The exploration and development of shale gas is undoubtedly of great social and economic significance. Accurate evaluation of shale gas fracturing effects and productivity prediction is of great significance for guiding shale gas exploration and development.

[0003] With the continuous improvement of extraction technologies such as seismic at...

Examples

Embodiment 1

[0051] Step 1. It is known that multiple wells in a shale gas block in western Chongqing have achieved production breakthroughs. Collect representative well reservoirs and production data with the fracturing section as a unit, and establish a database for shale gas fracturing effect evaluation and productivity prediction. The database mainly It is composed of reservoir geological parameters and fracturing construction parameters. In this embodiment, the data include acoustic time difference, construction displacement, natural gamma ray, total hydrocarbon and slick water volume, brittleness index, segment spacing, compensation density, total organic There are 11 factors including carbon, total sand addition and total gas content, as shown in Table 1.

[0052] Table 1 Database of shale gas fracturing effect evaluation and productivity prediction

[0053]

[0054]

[0055] Step 2, shale gas fracturing effect evaluation and productivity prediction database standardization

...

Embodiment 2

[0115] In this example, the fracturing data of 25 stages of a certain well in the Yuxi shale gas block were collected. The database is mainly composed of reservoir geological parameters and fracturing construction parameters. In this embodiment, the data include acoustic time difference, construction displacement, natural gamma ray, total hydrocarbon and slick water volume, brittleness index, segment spacing, compensation density, The 11 factors of total organic carbon, total sand addition and total gas content are shown in Table 11.

[0116] Table 11 Database of shale gas fracturing effect evaluation and productivity prediction

[0117]

[0118]

[0119] Among the fracturing data of 25 stages in this embodiment, the fracturing data of the first 16 stages were selected to establish a production capacity prediction model, and the fracturing data of the last 9 stages were used to predict and evaluate the production capacity. The shale gas fracturing effect evaluation and ...

Technical field:

[0001] The invention belongs to the technical field of unconventional natural gas development and quantitative prediction models, and specifically relates to unconventional natural gas fracturing effect evaluation and productivity prediction technology. Background technique:

[0002] Shale gas, tight sandstone gas, and coalbed methane are unconventional natural gas. At present, the state attaches great importance to the development and utilization of shale gas. At the same time, my country's demand for natural gas is strong, and shale gas is bound to become an important supplement to the current natural gas resources. The exploration and development of shale gas is undoubtedly of great social and economic significance. Accurate evaluation of shale gas fracturing effects and productivity prediction is of great significance for guiding shale gas exploration and development.

[0003] With the continuous improvement of extraction technologies such as seismic at...

Examples

Embodiment 1

[0051] Step 1. It is known that multiple wells in a shale gas block in western Chongqing have achieved production breakthroughs. Collect representative well reservoirs and production data with the fracturing section as a unit, and establish a database for shale gas fracturing effect evaluation and productivity prediction. The database mainly It is composed of reservoir geological parameters and fracturing construction parameters. In this embodiment, the data include acoustic time difference, construction displacement, natural gamma ray, total hydrocarbon and slick water volume, brittleness index, segment spacing, compensation density, total organic There are 11 factors including carbon, total sand addition and total gas content, as shown in Table 1.

[0052] Table 1 Database of shale gas fracturing effect evaluation and productivity prediction

[0053]

[0054]

[0055] Step 2, shale gas fracturing effect evaluation and productivity prediction database standardization

...

Embodiment 2

[0115] In this example, the fracturing data of 25 stages of a certain well in the Yuxi shale gas block were collected. The database is mainly composed of reservoir geological parameters and fracturing construction parameters. In this embodiment, the data include acoustic time difference, construction displacement, natural gamma ray, total hydrocarbon and slick water volume, brittleness index, segment spacing, compensation density, The 11 factors of total organic carbon, total sand addition and total gas content are shown in Table 11.

[0116] Table 11 Database of shale gas fracturing effect evaluation and productivity prediction

[0117]

[0118]

[0119] Among the fracturing data of 25 stages in this embodiment, the fracturing data of the first 16 stages were selected to establish a production capacity prediction model, and the fracturing data of the last 9 stages were used to predict and evaluate the production capacity. The shale gas fracturing effect evaluation and ...

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