CN-122014212-A - Coal-rock gas horizontal well EUR prediction method based on sensitive factor analysis and related device

Abstract

The invention discloses a coal-rock gas horizontal well EUR prediction method based on sensitive factor analysis and a related device, belonging to the technical field of oil-gas field development; the method comprises the steps of analyzing the correlation between all production factors and the EUR of the coal and rock horizontal well through historical data to obtain sensitive factors, constructing an EUR prediction model of the coal and rock horizontal well based on the sensitive factors, obtaining sensitive factor parameters of the coal and rock horizontal well to be predicted, inputting the sensitive factor parameters into the EUR prediction model of the coal and rock horizontal well, and predicting to obtain the EUR of the coal and rock horizontal well. According to the invention, a big data analysis means is introduced, a quantitative formula linearly fitted by a sensitive composite factor is selected as a coal-rock horizontal well EUR prediction formula, batch prediction of single-well EURs of the coal-rock horizontal well is realized, the prediction coincidence rate exceeds 93%, and the bottleneck that the existing coal-rock horizontal well is less in production well and short in production time and is difficult to predict is broken.

Inventors

• WANG SHUJIE
• XU YUNDONG
• ZHANG ZHENGTAO
• DU YAFENG
• CUI YUEHUA
• LIU ZHIJUN
• ZHANG FANG
• RAO QIAO
• WANG YIFEI
• LIU JIAOJIAO
• ZHANG BOJIE
• FEI SHIXIANG
• HU WEIWEI
• ZHENG XIAOPENG
• ZHANG ZHIGANG
• LU GUIYI
• Meng Peilong
• LI XIAOFENG
• FENG YANSONG
• WANG JINGJIAN
• WANG YE
• HE FENGPENG
• LUO WENQIN

Assignees

• 中国石油天然气股份有限公司

Dates

Publication Date

20260512

Application Date

20241112

Claims (10)

1. 1. The method for predicting the EUR of the coal-rock gas horizontal well based on the sensitivity factor analysis is characterized by comprising the following steps of: Analyzing the correlation between all production factors and the EUR of the coal-rock gas horizontal well through historical data to obtain sensitive factors; constructing an EUR prediction model of the coal-rock gas horizontal well based on the sensitive factors; And acquiring sensitive factor parameters of the coal-rock gas horizontal well to be predicted, inputting the sensitive factor parameters into an EUR prediction model of the coal-rock gas horizontal well, and predicting to obtain the EUR of the coal-rock gas horizontal well.
2. 2. The method for predicting the EUR of the horizontal well of the coal and rock based on the analysis of the sensitive factors according to claim 1, wherein the step of analyzing the correlation between all the production factors and the EUR of the horizontal well of the coal and rock by the historical data to obtain the sensitive factors specifically comprises the following steps: selecting a part of historical coal-rock gas horizontal wells with stable production and long production time, solving EUR, and collecting all production factor parameters of the historical coal-rock gas horizontal wells; based on big data analysis, the influence weight of each production factor on the EUR is evaluated, and the production factors strongly related to the EUR are obtained as sensitive factors.
3. 3. The method for predicting the EUR of a horizontal well of a coal and rock based on sensitive factor analysis according to claim 2, wherein the production factors comprise horizontal section length, coal and rock length, density, sand amount, total liquid amount, burial depth, coal and rock thickness, reservoir cap combination, coal and rock structure, gas content and average gas measurement.
4. 4. The method for predicting the EUR of the coal and rock gas horizontal well based on the sensitivity factor analysis according to claim 2, further comprising the steps of introducing the concept of a geological engineering composite factor based on the single factor analysis result and the knowledge, analyzing the influence of interaction among different production factors on the EUR of the coal and rock gas horizontal well, and evaluating the multi-factor sensitivity of the deep coal and rock gas EUR.
5. 5. The method for predicting the EUR of the gas horizontal well of the coal and rock based on the sensitivity factor analysis according to claim 2, wherein the sensitivity factors comprise the length of the coal and rock, the thickness of the coal and rock, the gas content, the total liquid amount and the sand adding amount.
6. 6. The method for predicting the EUR of the gas horizontal well based on the sensitivity factor analysis according to claim 1, wherein the EUR prediction model of the gas horizontal well is a prediction model established based on a linear_model.
7. 7. The method for predicting the EUR of the gas horizontal well based on the sensitivity factor analysis according to claim 1, wherein the expression of the EUR prediction model of the gas horizontal well is: EUR= -43835+955.4 x Ln (LHQ) +30789.3 x ln (S)/ln (W) +680.2 x ln (WS) in the formula, EUR represents the final recoverable gas well reserve, L represents the length of coal and rock, H represents the thickness of coal and rock, Q represents the gas content, W represents the total liquid amount, and S represents the sand addition amount.
8. 8. The utility model provides a coal gas horizontal well EUR prediction system based on sensitive factor analysis which characterized in that includes: The analysis module is used for analyzing the correlation between all production factors and the EUR of the coal-rock gas horizontal well through historical data to obtain sensitive factors; the modeling module is used for constructing an EUR prediction model of the coal-rock gas horizontal well based on the sensitive factors; The prediction module is used for acquiring sensitive factor parameters of the coal-rock gas horizontal well to be predicted, inputting the sensitive factor parameters into the coal-rock gas horizontal well EUR prediction model, and predicting to obtain the coal-rock gas horizontal well EUR.
9. 9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the steps of the method according to any of claims 1-7 when the computer program is executed.
10. 10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any one of claims 1-7.

Description

Coal-rock gas horizontal well EUR prediction method based on sensitive factor analysis and related device Technical Field The invention belongs to the technical field of oil and gas field development, and relates to a coal and gas horizontal well EUR prediction method based on sensitive factor analysis and a related device. Background The coal-rock gas is a novel unconventional natural gas in a source, has the characteristics of coexistence of a conventional reservoir and an unconventional reservoir, symbiosis of free gas and adsorbed gas, and complementation aggregation of self-source gas and self-source gas, and has high gas content, and large-scale exploitation is needed by means of horizontal well volume fracturing. In recent years, deep coal and rock gas exploration and development enter a brand new development stage, so that high attention and rapid follow-up in the natural gas industry are brought, coal and rock gas is promoted to become an important real field of natural gas storage and production increase, and the method has important significance for further guaranteeing energy safety. The 8# coal seam of the Erdos basin is widely distributed in a large area, the initial estimated resource amount exceeds 17 trillion square, and the exploration and development potential is huge. The method is characterized in that a basin coal-based stratum is not taken as a hydrocarbon source rock into an exploration sequence in the 60 th century, 3 middle-shallow source internal gas test well groups are opened up for 5# and 8# coals in the area of Daning-Ji county in the 90 th century, 40 wells are tested, the average test gas yield is about 1000 square/day, Y160 and M172 wells are selected in 2019-2021 to conduct risk evaluation and test production, the obtained test gas yield is 1670 square/day and 4713 square/day, deep coal and rock gas shows a certain exploration potential, the coal and rock gas exploration evaluation pace is comprehensively accelerated in the 90 th century in the 20 th century, the peak test gas yield of a horizontal well is 3.2-19.8 square/day, the cumulative gas yield of 4 wells exceeds thousands of square/day, and the exploration development achieves an important breakthrough. However, the buried coal and rock gas of the Erdos basin is 2000-3500 m, the difference of geological characteristic areas is obvious, and the difference of production characteristics of gas wells under different geology and process conditions is large. The final recoverable reserve (EUR) evaluation of the gas well is an important link in the coal bed methane scale development process, is an important basis for programming a coal bed methane development scheme, scientifically deploying gas well production and carrying out comprehensive adjustment, and needs to be continuously developed and evaluated. The coal-rock gas mainly adopts a method of mainly using a yield instability analysis method, and combines methods of empirical yield progressive subtraction, numerical simulation and the like to develop single well productivity and EUR prediction. The yield instability analysis method and the numerical simulation method have wide application range, but are complex to operate, the prediction accuracy depends on the input parameters of the model, and the experience yield progressive subtraction operation is simple and quick and convenient to apply, but the prediction result is greatly influenced by the fluctuation of data and the flowing stage. The method is only suitable for gas wells with longer production time, and cannot meet the requirement of batch prediction of mass development of a large number of newly built gas wells for deep coal gas scale. Disclosure of Invention The invention aims to provide a coal-rock gas horizontal well EUR prediction method based on sensitive factor analysis and a related device, so as to solve the technical problem that a final recoverable reserve prediction method of a gas well in the prior art is difficult to meet the batch prediction requirement of developing a large number of newly-built gas wells on a deep coal-rock gas scale. In order to achieve the purpose, the invention is realized by adopting the following technical scheme: In a first aspect, the invention provides a method for predicting EUR of a coal-rock gas horizontal well based on sensitive factor analysis, which comprises the following steps: Analyzing the correlation between all production factors and the EUR of the coal-rock gas horizontal well through historical data to obtain sensitive factors; constructing an EUR prediction model of the coal-rock gas horizontal well based on the sensitive factors; And acquiring sensitive factor parameters of the coal-rock gas horizontal well to be predicted, inputting the sensitive factor parameters into an EUR prediction model of the coal-rock gas horizontal well, and predicting to obtain the EUR of the coal-rock gas horizontal well. Further, the step of analyzing the correlation be