{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:23:14Z","timestamp":1760059394491,"version":"build-2065373602"},"reference-count":34,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,6,11]],"date-time":"2025-06-11T00:00:00Z","timestamp":1749600000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"First-Class Discipline Collaborative Innovation Program of Heilongjiang Province","award":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"],"award-info":[{"award-number":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"]}]},{"name":"National Natural Science Foundation of China","award":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"],"award-info":[{"award-number":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"]}]},{"name":"Key Research and Development Program of Heilongjiang Province","award":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"],"award-info":[{"award-number":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"]}]},{"name":"The Postdoctoral Special Funding of Heilongjiang Province","award":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"],"award-info":[{"award-number":["LJGXCG2024-F02","42204131","2024ZX09C01","LBH-TZ2301"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Symmetry"],"abstract":"<jats:p>The implementation of lean drilling and completion design techniques is a pivotal strategy for the petroleum and natural gas industry to achieve green, low-carbon, and intelligent transformation and innovation. These techniques significantly enhance oil and gas recovery rates. In shale gas development, the shale brittleness index plays a crucial role in evaluating fracturing ability during hydraulic fracturing. Indoor experiments on Gulong shale oil were conducted under a confining pressure of 30 MPa. Based on Rickman\u2019s brittleness evaluation method, this study performed numerical simulations of triaxial compression tests on shale using the finite discrete element method. The fractal dimensions of the fractures formed during shale fragmentation were calculated using the box-counting method. Utilizing the obtained data, a multiple linear regression equation was established with elastic modulus and Poisson\u2019s ratio as the primary variables, and the coefficients were normalized to propose a new brittleness evaluation method. The research findings indicate that the finite discrete element method can effectively simulate the rock fragmentation process, and the established multiple linear regression equation demonstrates high reliability. The weights reassigned for brittleness evaluation based on Rickman\u2019s method are as follows: the coefficient for elastic modulus is 0.43, and the coefficient for Poisson\u2019s ratio is 0.57. Furthermore, the new brittleness evaluation method exhibits a stronger correlation with the brittleness mineral index. The fractal characteristics of crack networks and the relationship between symmetry response and mechanical parameters offer a new theoretical foundation for brittle weight distribution. Additionally, the scale symmetry characteristics inherent in fractal dimensions can serve as a significant indicator for assessing complex crack morphology.<\/jats:p>","DOI":"10.3390\/sym17060927","type":"journal-article","created":{"date-parts":[[2025,6,12]],"date-time":"2025-06-12T03:59:17Z","timestamp":1749700757000},"page":"927","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Weight-Based Numerical Study of Shale Brittleness Evaluation"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3871-6015","authenticated-orcid":false,"given":"Yu","family":"Suo","sequence":"first","affiliation":[{"name":"School of Petroleum Engineering, Northeast Petroleum University, Daqing 163318, China"},{"name":"Postdoctoral Resource Center, Daqing Oilfield Company Limited, Daqing 163458, China"},{"name":"Key Laboratory of Continental Shale Hydrocarbon Accumulation and Efficient Development, Northeast Petroleum University, Ministry of Education, Daqing 163318, China"},{"name":"Heilongjiang Province Key Laboratory of Oil and Gas Reservoir Fracturing and Evaluation, Daqing 163318, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Fenfen","family":"Li","sequence":"additional","affiliation":[{"name":"School of Petroleum Engineering, Northeast Petroleum University, Daqing 163318, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qiang","family":"Liang","sequence":"additional","affiliation":[{"name":"Research Institute of Exploration and Development, Petro China Changqing Oilfield Company, Xi\u2019an 710018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4918-8932","authenticated-orcid":false,"given":"Liuke","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Civil Engineering and Geomatics, Southwest Petroleum University, Chengdu 610000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liangping","family":"Yi","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Southwest Petroleum University, Chengdu 610000, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2815-5851","authenticated-orcid":false,"given":"Xu","family":"Dong","sequence":"additional","affiliation":[{"name":"Institute of Unconventional Oil & Gas, Northeast Petroleum University, Daqing 163318, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,11]]},"reference":[{"key":"ref_1","first-page":"11","article-title":"Thoughts on green and low-carbon oil and gas development engineering technologies","volume":"51","author":"Li","year":"2023","journal-title":"Pet. 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