渤海浅部弱胶结地层力学特征与数字岩心仿真模拟

doi:10.3969/j.issn.1672-7703.2025.05.012

摘要/Abstract

摘要： 渤海海域浅部弱胶结地层因沉积年代新、成岩性差，取心样品松散不成形，导致常规岩石力学测试困难，不利于浅部层段钻井针对性设计。通过矿物综合表征、物理模拟实验及数字岩心建模，系统研究浅部地层的力学特征与破坏机制。采用XRD测试、铸体薄片分析及纳米压痕技术，揭示地层黏土矿物中蒙脱石占比达48.57%，具强水敏性，岩样胶结程度差、孔隙发育显著。物理模拟实验表明，随含水率从20%升至30%，岩样抗压强度由1.68MPa降至0.41MPa，弹性模量从22.1MPa 缩减至4.81MPa，破坏模式由脆性剪切破坏转为塑性变形，剪切带数量与宽度显著增加，剪胀效应增强。基于PFC6.0构建的数字岩心模型与物理实验结果高度吻合，不仅能还原试样从弹性变形到塑性破坏的动态过程，还通过细观损伤分析揭示了水分渗透导致颗粒间胶结力削弱的机制。首次建立渤海浅部弱胶结地层的数字岩心仿真模型，定量阐明含水率对地层力学特性的劣化规律，从“宏观力学响应—细观损伤演化”双尺度揭示水敏性致灾机理，为钻井液体系优化、井壁稳定性控制及防砂工艺设计提供了理论支撑，为海上弱胶结地层力学研究探索了新思路。

关键词: 渤海油田；浅部地层；弱胶结；数字岩心；岩石力学

Abstract: The shallow weakly consolidated strata in Bohai Sea area are characterized by new sedimentary age and poor diagenesis, resulting in loose and unformed core samples, and difficulty in conducting conventional rock mechanical tests, which is not conducive to the targeted drilling design in shallow sections. Through comprehensive mineral characterization, physical simulation experiments, and digital core modeling, the mechanical properties and failure mechanisms of shallow strata have systematically been analyzed. By using XRD testing, casting thin section analysis, and nanoindentation technology, the results show that montmorillonite accounts for 48.57% of the clay minerals in the formation, with strong water sensitivity, poor cementation degree, and well developed pores of rock samples. Physical simulation experiments indicate that as the water cut increases from 20% to 30%, the compressive strength of the rock sample decreases from 1.68 MPa to 0.41 MPa, the elastic modulus decreases from 22.1 MPa to 4.81 MPa, the failure mode changes from brittle shear failure to plastic deformation, the number and width of shear zones significantly increase, and the dilatancy effect enhances. The digital core model constructed based on PFC 6.0 is highly consistent with the physical experimental results, which can not only reproduce the dynamic process from elastic deformation to plastic failure of core samples, but also reveal the mechanism of weakening the interparticle bonding force caused by water infiltration through microscopic damage analysis. As a result, a digital core simulation model for shallow weakly consolidated formations in Bohai Sea area has been established for the first time, quantitatively elucidating the degradation law of increasing water cut on rock mechanical properties. The mechanism of water sensitivity induced disasters has been revealed from the dual scale of “macroscopic mechanical response–microscopic damage evolution”, which provides theoretical support for drilling fluid system optimization, wellbore stability control, and sand control process design, as well as new ideas for mechanical study of weakly consolidated formations in sea area.

Key words: Bohai Oilfield; shallow formation; weak consolidation; digital core; rock mechanics

中图分类号:

TE19

霍宏博,李红涛,汤柏松,杨昕昊,孙大林,何世明. 渤海浅部弱胶结地层力学特征与数字岩心仿真模拟[J]. 中国石油勘探, 2025, 30(5): 159-170.

Huo Hongbo,Li Hongtao,Tang Baisong,Yang Xinhao,Sun Dalin,He Shiming. Research on mechanical properties and digital core simulation of shallow weakly consolidated formations in Bohai Sea area[J]. China Petroleum Exploration, 2025, 30(5): 159-170.

参考文献

[1] 李回贵，李化敏，汪华君，等. 弱胶结砂岩的物理力学特征及定义[J].煤炭科学技术，2017,45(10):1-7.
Li Huigui, Li Huamin, Wang Huajun, et al . Physical and mechanical characteristics and definitions of weakly cemented sandstone [J]. Coal Science and Technology, 2017,45(10):1-7.
[2] 牛洪波，刘建刚，左卫青. 弱胶结地层水平井钻井技术探讨[J]. 石油钻探技术，2007,35(5):61-64.
Niu Hongbo, Liu Jiangang, Zuo Weiqing. Discussion on horizontal well drilling technology in weakly cemented formations [J]. Petroleum Drilling Techniques, 2007,35(5):61-64.
[3] 王冠民，庞小军，黄晓波，等. 渤海海域辽中凹陷南部古近系东营组三段重力流砂岩优质储层特征及成因[J]. 石油与天然气地质，2024,45(1):81-95.
Wang Guanmin, Pang Xiaojun, Huang Xiaobo, et al . Characteristics and origin of high-quality gravity-flow sandstone reservoirs in the 3rd member of the Dongying Formation，southern Liaozhong Sag， Bohai Sea [J]. Oil & Gas Geology, 2024,45(1):81-95.
[4] 徐长贵，周家雄，杨海风，等. 渤海海域油气勘探新领域、新类型及资源潜力[J]. 石油学报，2024,45(1):163-182.
Xu Changgui, Zhou Jiaxiong, Yang Haifeng, et al . New fields, new types and resource potentials of oil-gas exploration in Bohai Sea [J]. Acta Petroleum Sinica, 2024,45(1):163-182.
[5] Bin L, Yi X Z, Cun Z, et al . Characteristic strength and acoustic emission properties of weakly cemented sandstone at different depths under uniaxial compression [J]. International Journal of Coal Science & Technology, 2021,8(6):1288-1301.
[6] 卢欢，王清斌，杜晓峰，等. 低渗透储层类型划分及储层敏感性主控因素：以渤海海域古近系为例[J]. 石油学报，2019,40(11):1331-1345,1367.
Lu Huan, Wang Qingbin, Du Xiaofeng, et al . Lowpermeability reservoir types classification and reservoir sensitivity controlling factors:a case study of Paleogene in Bohai Sea [J]. Acta Petroleum Sinica, 2019,40(11):1331-1345,1367.
[7] Song Z, Ji H, Liu Z, et al . Study on the critical stress threshold of weakly cemented sandstone damage based on the renormalization group method [J]. International Journal of Coal Science & Technology, 2020,7(4):1-11.
[8] 尚辉，徐颖，倪苏黔，等. 不同含水状态对弱胶结砂岩压缩破坏特性的影响研究[J]. 武汉理工大学学报，2024,46(11):84-92.
Shang Hui, Xu Ying, Ni Suqian, et al . Study on the influence of different water-bearing states on the compression failure characteristics of weakly cemented sandstone [J]. Journal of Wuhan University of Technology, 2024,46(11):84-92.
[9] 张世忠，范钢伟，张东升，等. 应力—损伤—渗流耦合下采动弱胶结覆岩渗透性演化规律[J]. 采矿与安全工程学报，2024,41(6):1230-1240.
Zhang Shizhong, Fan Gangwei, Zhang Dongsheng, et al . Evolution law of permeability in mining-induced weakly consolidated overburden under stress-damage-seepage coupling[J]. Journal of Mining & Safety Engineering, 2024,41(6):1230-1240.
[10] 李回贵，李化敏，许国胜. 含水率对弱胶结砂岩力学特征的影响规律[J]. 采矿与岩层控制工程学报，2021,3(4):60-66.
Li Huigui, Li Huamin, Xu Guosheng. Influence of water content on the mechanical characteristics of weakly cemented sandstone [J]. Journal of Mining and Strata Control Engineering, 2021,3(4):60-66.
[11] 樊浩博，陈坤，赵梓宇，等. 新近系富水弱胶结砂岩力学及水稳特性试验研究[J]. 铁道科学与工程学报，2025,22(6):2622-2637.
Fan Haobo, Chen Kun, Zhao Ziyu, et al . Experimental study on the mechanical and water stability characteristics of Neogene water-rich weakly cemented sandstone [J]. Journal of Railway Science and Engineering, 2025,22(6):2622-2637.
[12] Zhao Z H, Liu H, Gao X J, et al . Meso-macro damage deterioration of weakly cemented red sandstone under the coupling effect of high-humidity and uniaxial loading [J]. Engineering Failure Analysis, 2023,143:1-13.
[13] 李小龙，李进，黄辉，等. 加载速率对弱胶结砂岩劈裂特性的影响研究[J]. 中国矿业，2023,32(2):165-172.
Li Xiaolong, Li Jin, Huang Hui, et al . Study on the influence of loading rate on the splitting characteristics of weakly cemented sandstone [J]. China Mining Magazine, 2023,32(2):165-172.
[14] 赵永川，杨天鸿，肖福坤，等. 西部弱胶结砂岩循环载荷作用下塑性应变能变化规律[J]. 煤炭学报，2015,40(8):1813-1819.
Zhao Yongchuan, Yang Tianhong, Xiao Fukun, et al . Variation of plastic strain energy in weakly cemented sandstone from western China under cyclic loading [J]. Journal of China Coal Society, 2015,40(8):1813-1819.
[15] An X, Lyu X, Sun J, et al . Mechanical behaviour and macromicro failure mechanisms of frozen weakly cemented sandstone under different stress paths [J]. Construction and Building Materials, 2024,449:138264.
[16] 宋朝阳，纪洪广，张月征，等. 不同粒度弱胶结砂岩声发射信号源与其临界破坏前兆信息判识[J]. 煤炭学报，2020,45(12):4028-4036.
Song Zhaoyang, Ji Hongguang, Zhang Yuezheng, et al . Identification of acoustic emission signal sources and precursor information before critical failure in weakly cemented sandstone with different grain sizes [J]. Journal of China Coal Society,2020,45(12):4028-4036.
[17] 宋朝阳，纪洪广，蒋华，等. 干湿循环作用下弱胶结砂岩声发射特征及其细观劣化机理[J]. 煤炭学报，2018,43( 增刊1):96-103.
Song Zhaoyang, Ji Hongguang, Jiang Hua, et al . Acoustic emission characteristics and mesoscopic degradation mechanism of weakly cemented sandstone under wet-dry cycling [J]. Journal of China Coal Society, 2018,43(S1):96-103.
[18] 张景科，刘盾，马雨君，等. 弱胶结砂岩水岩作用机制：以庆阳北石窟为例[J]. 东北大学学报( 自然科学版)，2022,43(7):1019-1032,1064.
Zhang Jingke, Liu Dun, Ma Yujun, et al . Mechanism of water-rock interaction in weakly cemented sandstone: a case study of the Northern Qinyang Grottoes [J]. Journal of Northeastern University (Natural Science Edition), 2022,43(7):1019-1032,1064.
[19] 苗胜军，杨鹏锦，黄正均，等. 多孔弱胶结岩石破裂的围压影响机制及压密—损伤本构模型[J]. 中国矿业大学学报，2023,52(2):229-240.
Miao Shengjun, Yang Pengjin, Huang Zhengjun, et al . Influence mechanism of confining pressure on the fracture of porous and weakly cemented rocks and a compaction-damage constitutive model [J]. Journal of China University of Mining and Technology, 2023,52(2):229-240.
[20] Zhao K, Wu W K, Zeng P, et al . Numerical and experimental assessment of the sandstone fracture mechanism by non-uniform bonded particle modeling [J]. Rock Mechanics and Rock Engineering, 2021,54(12):1-15.
[21] 张慧梅，陈世官，王磊，等. 扰动冲击下弱胶结红砂岩的能量耗散与分形特征[J]. 岩土工程学报，2022,44(4):622-631.
Zhang Huimei, Chen Shiguan, Wang Lei, et al . Energy dissipation and fractal characteristics of weakly cemented red sandstone under disturbance impact [J]. Chinese Journal of Geotechnical Engineering, 2022,44(4):622-631.
[22] 盛军，黄生远，徐立，等. 柴达木盆地尕斯库勒油田新近系储集层弱胶结砂岩应力敏感分析[J]. 矿物岩石地球化学通报，2018,37(5):932-942.
Sheng Jun, Huang Shengyuan, Xu Li, et al . Stress sensitivity analyses of weakly cemented sandstone of the Gasikule Oilfield Neogene reservoir in the Qaidam Basin [J]. Bulletin of Mineralogy, Petrology and Geochemistry, 2018,37(5):932-942.
[23] 邱守美，季鹏，徐蕾，等. 过筛管压裂技术在海上疏松砂岩油藏探索与实践[J]. 石油化工应用，2025,44(1):33-38.
Qiu Shoumei, Ji Peng, Xu Lei, et al . Exploration and practice of screen tube fracturing technology in offshore loose sandstone reservoirs [J]. Petrochemical Applications, 2025,44(1):33-38.
[24] 张明，李凡，刘光泽，等. 自主化一趟多层砾石充填防砂技术研究与应用[J]. 中国海上油气，2016,28(3):111-114.
Zhang Ming, Li Fan, Liu Guangze, et al . Research and application of independent multi-layer gravel filling sand control technology [J]. China Offshore Oil and Gas, 2016,28(3):111-114.