Lithologic Reservoirs ›› 2026, Vol. 38 ›› Issue (5): 149-158.doi: 10.12108/yxyqc.20260514

• PETROLEUM EXPLORATION • Previous Articles     Next Articles

Evaluation of fault sealing and trap effectiveness of Kaiping Sag, Pearl River Mouth Basin

CAI Junjie1(), LI Yaqi2,3, GAO Zhongliang1, JIANG Fujie2,3(), JIANG Dapeng1, NIU Peng1, HAO Mianzhu1   

  1. 1 Shenzhen Branch, CNOOC (China) Co., Ltd., Shenzhen 518054, Guangdong, China
    2 State Key Laboratory of Petroleum Resources and Exploration, China University of Petroleum (Beijing), Beijing 102249, China
    3 School of Geosciences, China University of Petroleum (Beijing), Beijing 102249, China
  • Received:2025-12-17 Revised:2026-01-27 Online:2026-09-01 Published:2026-09-04
  • Contact: JIANG Fujie E-mail:caijj3@cnooc.com.cn;jiangfj@cup.edu.cn

Abstract:

Due to the low exploration degree and the complex fault system of Kaipingnan Oilfield, it is urgent to clarify the differential fault sealing and trap effectiveness. Based on the review of fault system characteristics and trap types, the vertical and lateral sealing capacities of faults in four major structural belts within the study area were systematically evaluated by using the shale smear factor (SSF) method and the shale gouge ratio (SGR) attribute. Integrating trap closure amplitude, hydrocarbon column height, trap area and predicted effective trap area, grading and classification criteria for trap effectiveness evaluation were established, and the effective trap range was determined. The results show that: (1) The fault system in Kaiping Sag exhibits multi-phase activity characteristics. Wenchang Formation mainly develops NEE to near EW trending faults, while Enping Formation develops NNE, near EW and NW trending faults. Trap types mainly include antithetic fault traps, cross-fault block traps, and self-sealing traps. (2) The critical value of SSF for vertical sealing of fault in oil-bearing intervals of Kaiping Sag is 2.3. SSF values in 11-3 and 11-4 structural belts are less than 2.3, indicating good vertical fault sealing conducive to hydrocarbon preservation. In contrast, SSF values in the northern area (11-1 structural belt) and the western slope (10-1 structural belt) exceed 2.3, suggesting that cap rocks have been damaged and with leakage risk. The lower limit SGR value for lateral fault sealing is 26%. The average hydrocarbon column heights that can be sealed by trap-bounding faults in 11-3 and 11-4 structural belts are 90 m and 75 m, respectively. The lateral sealing capacity of trap-bounding faults in 11-3 structural belt is slightly higher, with small traps scale (trap area rangs from 0.28 km2 to 6.76 km2, predicted effective trap area is 0.22-2.90 km2), but exhibit relatively large closure amplitudes (being 32-296 m, over 60% of samples exceeding 50 m). (3) According to trap effectiveness, traps in the study area are classified into three levels from high to low: Level Ⅰ, level Ⅱ, and level Ⅲ. 6 level Ⅰ traps developed in 11-3 and 11-4 structural belts, accounting for over 60% of all evaluated traps, and there are 7 level Ⅱ traps. Among them, trap B1 and trap E1 in 11-3 structural belt are priority targets for exploration deployment.

Key words: shale smear factor (SSF), shale gouge ratio (SGR), fault sealing, fault system, trap effectiveness, trap grading evaluation, Kaiping Sag, Pearl River Mouth Basin

CLC Number: 

  • TE5

Fig. 1

Structural zone division of Kaiping Sag (a) and comprehensive stratigraphic column (b),Pearl River Mouth Basin"

Fig. 2

Rose diagram of fault trends in different periods of Kaiping Sag"

Fig. 3

Distribution of growth index of typical faults in different periods of Kaiping Sag"

Fig. 4

Displacement-depth curves of typical fault in Kaiping Sag"

Fig. 5

Distribution of traps and faults in 11-4 structural belt (a) and 11-3 structural belt (b), Kaiping Sag"

Table 1

Classification of trap types of Kaiping Sag"

地区 圈闭 控圈断层 圈闭类型 圈闭钻井
开平
凹陷
11-4
构造带
A块圈闭 自圈圈闭 S1、S3
B1块圈闭 F1 反向断层下盘圈闭 S2d
B3块圈闭 F3 反向断层下盘圈闭 S4
C块圈闭 F2 交叉断层圈闭 S5d
D块圈闭 F7 反向断层下盘圈闭 S6d
开平
凹陷
11-3
构造带
A块圈闭 F11-W 交叉断层圈闭 C1
F11-E C1
B1块圈闭 F13 交叉断层圈闭
F18
B2块圈闭 F12 反向断层下盘圈闭
C1-1块圈闭 F14 交叉断层圈闭
F15
C1-2块圈闭 F15 反向断层下盘圈闭
C2块圈闭 F14 反向断层下盘圈闭
E1块圈闭 F16 交叉断层圈闭
F17 交叉断层圈闭

Fig. 6

Bar chart of trap types of 11-3 structural belt and 11-4 structural belt, Kaiping Sag"

Fig. 7

Fracture deformation mechanism and growth evolution model of different brittle ductile rocks"

Fig. 8

Lithologic docking types and their sealing analysis methods"

Fig. 9

Evaluation of the sealing of the cap layer of the lower member of Paleogene Enping Formation in Kaiping Sag"

Fig. 10

SGR-AFPD plot of faults controlling drilled traps in 11-4 structural belt, Kaiping Sag"

Table 2

Evaluation of faults controlling traps in 11-4 structural belt and 11-3 structural belt, Kaiping Sag"

构造带 圈闭区块 控圈
断裂
SGR/% 可封闭
的烃柱
高度/m
断层可封闭含油范围的油水界面深度/m
11-4
构造带
B1块圈闭 F1 26~60 87.6 3 599.7
F1 66.9 3 674.7
F1 80.7 4 240.6
B3块圈闭 F3 35~60 73.5 3 433.5
C块圈闭 F2 35~70 75.0 3 362.0
D块圈闭 F7 35~75 67.3 3 257.3
11-3
构造带
A块圈闭 F11-W 40~60 82.0 3 390.0
F11-E 80.0 3 390.0
B1块圈闭 F13 35~70 89.3 3 509.0
F18 91.9 3 509.0
B2块圈闭 F12 35~60 93.5 3 314.0
C1-1块圈闭 F14 40~75 102.0 3 373.0
C1-2块圈闭 F15 40~60 101.3 3 351.0
C2块圈闭 F14 40~75 95.5 3 196.0

Table 3

Grading criteria for trap parameters of Kaiping Sag"

单项
得分
烃柱
高度/m
闭合
幅度/m
圈闭
面积/km2
预测有效
圈闭面积/km2
总分 圈闭
级别
1 < 75 < 50 < 2 < 1 < 1.5 三级
2 75~100 50~85 2~6 1~2 1.5~2.0 二级
3 > 100 > 85 > 6 > 2 ≥ 2.0 一级

Table 4

Comparison and grading for trap parameters of Kaiping Sag"

构造带 圈闭名称 闭合幅度 烃柱高度 圈闭面积 预测有效圈闭面积 综合
得分
圈闭定级
结果
圈闭钻井
数值/m 得分 数值/m 得分 数值//km2 得分 数值/km2 得分
11-4
构造带
C1(样本) 104 3 75.00 2 4.06 2 3.70 3 2.50 一级圈闭 S5d
B1(样本) 53 2 75.00 2 19.9 3 0.90 1 2.00 一级圈闭 S2d
D(样本) 61 2 67.36 1 8.2 3 3.26 3 2.25 一级圈闭 S6d
A(样本) 57 2 70.00 1 2.61 2 2.61 2 1.75 二级圈闭 S1、S3
B3(样本) 45 1 69.00 1 19.9 3 0.20 1 1.50 二级圈闭 S4
11-3
构造带
E1 296 3 100.45 3 4.61 2 0.50 1 2.25 一级圈闭 建议钻井
B1 135 3 89.39 2 6.76 3 2.90 3 2.75 一级圈闭 建议钻井
A(样本) 98 3 80.00 2 2.43 2 2.40 3 2.50 一级圈闭 C1
C2 85 2 95.58 2 1.48 1 1.10 2 1.75 二级圈闭
E2 46 1 105.00 3 0.65 1 0.40 1 1.50 二级圈闭
C1-2 32 1 101.27 3 0.53 1 0.32 1 1.50 二级圈闭
C1-1 44 1 101.27 3 0.51 1 0.30 1 1.50 二级圈闭
B2 50 2 93.45 2 0.28 1 0.22 1 1.50 二级圈闭

Fig. 11

Evaluation results of favorable trap classification of 11-4 structural belt (a) and 11-3 structural belt (b),Kaiping Sag"

[1] 印朋. 我国发现首个深水深层亿吨级油田[J]. 企业观察家, 2024,(3):38-39.
YIN Peng. China’s first deep-water oil field of 100 million tons has been discovered[J]. Enterprise Observer, 2024,(3):38-39.
[2] 刘小兵, 窦立荣, 万仑坤, 等. 全球深水油气勘探开发业务发展及启示[J]. 天然气与石油, 2022, 40(4):75-83.
LIU Xiaobing, DOU Lirong, WAN Lunkun, et al. Business development and inspiration of global deep water exploration and development[J]. Natural Gas and Oil, 2022, 40(4):75-83.
[3] 徐长贵, 高阳东, 刘军, 等. 南海陆缘“拆离-核杂岩型”盆地发现与油气地质条件:以南海北部开平凹陷为例[J]. 地学前缘, 2024, 31(6):381-404.
XU Changgui, GAO Yangdong, LIU Jun, et al. Discovery of “detachment-core complex type” basins offshore the northern South China Sea and their oil and gas geological conditions:A case study of the Kaiping sag in the northern South China Sea[J]. Earth Science Frontiers, 2024, 31(6):381-404.
[4] WEBER K J, MANDL G, PILAAR W F, et al. The role of faults in hydrocarbon migration and trapping in Nigerian growth fault structures[R]. Houston,Offshore Technology Conference, 1978.
[5] LINDSAY N G, MURPHY F C, WALSH J J, et al. Outcrop studies of shale smears on fault surfaces[M]. London: The International Association of Sedimentologists, 1993, 15:113-123.
[6] YIELDING G, FREEMAN B, NEEDHAM D T. Quantitative fault seal prediction[J]. AAPG Bulletin, 1997, 81(6):897-917.
[7] 杨海长, 曾清波, 纪沫, 等. 珠江口盆地深水区开平凹陷拆离型裂陷石油形成条件与勘探方向[J]. 石油学报, 2023, 44(6):933-947.
YANG Haizhang, ZENG Qingbo, JI Mo, et al. Accumulation conditions and exploration direction of crude oil in detachment rift of Kaiping sag in deep water area of Pearl River Mouth Basin[J]. Acta Petrolei Sinica, 2023, 44(6):933-947.
[8] BRADLEY D C. Passive margins through earth history[J]. Earth-Science Reviews, 2008, 91:1-26.
[9] 张志业, 何登发, 李智, 等. 珠江口盆地开平凹陷边界断层三维几何学与运动学[J]. 地球物理学报, 2018, 61(10):4296-4307.
ZHANG Zhiye, HE Dengfa, LI Zhi, et al. 3D geometry and kinematic of the boundary fault in the Kaiping Depression,Pearl River Mouth Basin[J]. Chinese Journal of Geophysics, 2018, 61(10):4296-4307.
[10] 李智, 张志业, 何登发, 等. 珠江口盆地开平凹陷构造单元划分与平面复原[J]. 海洋地质前沿, 2023, 39(7):70-78.
LI Zhi, ZHANG Zhiye, HE Dengfa, et al. Tectonic division and plane restoration of Kaiping Sag,Pearl River Mouth Basin[J]. Marine Geology Frontiers, 2023, 39(7):70-78.
[11] 庞雄, 郑金云, 梅廉夫, 等. 先存俯冲陆缘背景下南海北部陆缘断陷特征及成因[J]. 石油勘探与开发, 2021, 48(5):1069-1080.
PANG Xiong, ZHENG Jinyun, MEI Lianfu, et al. Characteristics and origin of continental marginal fault depressions under the background of preexisting subduction continental margin,northern South China Sea,China[J]. Petroleum Exploration and Development, 2021, 48(5):1069-1080.
[12] 蔡嵩, 彭光荣, 陈兆明, 等. 珠江口盆地开平凹陷古近系构造特征及构造演化分析[J]. 海洋地质与第四纪地质, 2023, 43(2):106-118.
CAI Song, PENG Guangrong, CHEN Zhaoming, et al. Paleogene tectonic evolution of Kaiping Sag,Pearl River Mouth Basin[J]. Marine Geology & Quaternary Geology, 2023, 43(2):106-118.
[13] 吕彩丽, 张功成, 杨东升. 珠江口盆地珠二坳陷文昌组构造差异性与动力学成因机制[J]. 地学前缘, 2017, 24(6):333-341.
LYU Caili, ZHANG Gongcheng, YANG Dongsheng. Differential structure and dynamic mechanism of Wenchang Formation in the Zhu II Depression of the Pearl River Mouth Basin[J]. Earth Science Frontiers, 2017, 24(6):333-341.
[14] THORSEN C E. Age of growth faulting in southeast Louisiana[J]. Gulf Coast Association of Geological Societies Transactions, 1963, 13(2):103-110.
[15] KOLEDOYE B A, AYDIN A, EYAL Y. A new process-based methodology for analysis of shale smear along normal faults in the Niger Delta[J]. AAPG Bulletin, 2003, 87(3):445-463.
[16] 付广, 吴伟. 乌尔逊—贝尔凹陷油气成藏模式及其主控因素[J]. 岩性油气藏, 2015, 27(1):14-20.
FU Guang, WU Wei. Oil-gas accumulation models and their main controlling factors in Wuerxun-Beier Depression[J]. Lithologic Reservoirs, 2015, 27(1):14-20.
[17] TISSOT B P, WELTE D H. Petroleum Formation and Occurrence[M]. Berlin,Heidelberg:Springer-Verlag, 1978.
[18] 杨为华. 松辽盆地双城断陷白垩系营城组四段致密油成藏主控因素及模式[J]. 岩性油气藏, 2024, 36(4):25-34.
YANG Weihua. Hydrocarbon accumulation model and main controlling factors of tight oil of the fourth member of Cretaceous Yingcheng Formation in Shuangcheng fault depression,Songliao Basin[J]. Lithologic Reservoirs, 2024, 36(4):25-34.
[19] SEGALL P, POLLARD D D. Mechanics of discontinuous faults[J]. Journal of Geophysical Research, 1980, 85(B8):4337-4350.
[20] 吕延防, 黄劲松, 付广, 等. 砂泥岩薄互层段中断层封闭性的定量研究[J]. 石油学报, 2009, 30(6):824-829.
LYU Yanfang, HUANG Jinsong, FU Guang, et al. Quantitative study on fault sealing ability in sandstone and mudstone thin interbed[J]. Acta Petrolei Sinica, 2009, 30(6):824-829.
[21] 张新顺, 王建平, 李亚晶, 等. 断层封闭性研究方法评述[J]. 岩性油气藏, 2013, 25(2):123-128.
ZHANG Xinshun, WANG Jianping, LI Yajing, et al. A comment on research methods of fault sealing capacity[J]. Lithologic Reservoirs, 2013, 25(2):123-128.
[22] 吕延防, 王有功, 付广, 等. 珠江口盆地珠一坳陷断层圈闭钻探风险性评价[J]. 石油学报, 2011, 32(1):95-100.
LYU Yanfang, WANG Yougong, FU Guang, et al. Evaluation of the drilling risk of fault traps in the Zhu Ⅰ Depression in the Pearl River Mouth Basin[J]. Acta Petrolei Sinica, 2011, 32(1):95-100.
[23] 付广, 王浩然, 胡欣蕾. 断层垂向封闭的断-储排替压力差法及其应用[J]. 石油学报, 2014, 35(4):685-691.
FU Guang, WANG Haoran, HU Xinlei. Modification and application of fault-reservoir displacement pressure differential method for vertical sealing of faults[J]. Acta Petrolei Sinica, 2014, 35(4):685-691.
[24] 付广, 史集建, 吕延防. 断层侧向封闭性定量研究方法的改进[J]. 石油学报, 2012, 33(3):414-418.
FU Guang, SHI Jijian, LYU Yanfang. An improvement in quantitatively studying lateral seal of faults[J]. Acta Petrolei Sinica, 2012, 33(3):414-418.
[25] 付广, 宿碧霖, 历娜. 一种利用断层岩泥质含量判断断层侧向封闭性的方法及其应用[J]. 岩性油气藏, 2016, 28(2):101-106.
FU Guang, XU Bilin, LI Na. A method of judging lateral sealing of fault by mudstone content of fault rock and its application[J]. Lithologic Reservoirs, 2016, 28(2):101-106.
[26] 付广, 郎岳, 胡欣蕾. 反向和顺向断裂侧向封闭油气的差异性研究[J]. 岩性油气藏, 2014, 26(6):28-33.
FU Guang, LANG Yue, HU Xinlei. Research on differences of lateral sealing between transoid fault and cisoid fault[J]. Lithologic Reservoirs, 2014, 26(6):28-33.
[27] KNIPE R J, FISHER Q J, JONES G, et al. Fault seal analysis:Successful methodologies,application and future directions[J]. Norwegian Petroleum Society Special Publications, 1997, 7:15-38.
[28] 高阳东, 彭光荣, 陈兆明, 等. 珠江口盆地开平凹陷深水古近系勘探重大发现及意义[J]. 石油学报, 2023, 44(7):1029-1040.
GAO Yangdong, PENG Guangrong, CHEN Zhaoming, et al. Breakthrough and significance of deep-water Paleogene exploration in Kaiping sag,Pearl River Mouth Basin[J]. Acta Petrolei Sinica, 2023, 44(7):1029-1040.
[29] 付晓飞, 宋宪强, 王海学, 等. 裂陷盆地断层圈闭含油气有效性综合评价:以渤海湾盆地歧口凹陷为例[J]. 石油勘探与开发, 2021, 48(4):677-686.
FU Xiaofei, SONG Xianqiang, WANG Haixue, et al. Comprehensive evaluation on hydrocarbon-bearing availability of fault traps in a rift basin:A case study of the Qikou Sag in the Bohai Bay Basin,China[J]. Petroleum Exploration and Development, 2021, 48(4):677-686.
[30] 何贵松, 何希鹏, 高玉巧, 等. 中国南方3套海相页岩气成藏条件分析[J]. 岩性油气藏, 2019, 31(1):57-68.
HE Guisong, HE Xipeng, GAO Yuqiao, et al. Analysis of accumulation conditions of three sets of marine shale gas in southern China[J]. Lithologic Reservoirs, 2019, 31(1):57-68.
[31] 安天下. 地层圈闭油气成藏有效性评价方法:以渤海湾盆地济阳坳陷为例[J]. 科学技术与工程, 2020, 20(10):3919-3926.
AN Tianxia. An effective evaluation method for stratigraphic trap hydrocarbon accumulation:A case study of Jiyang Depression,Bohai Bay Basin[J]. Science Technology and Engineering, 2020, 20(10):3919-3926.
[32] 侯连华, 杨帆, 杨春, 等. 常规油气区带与圈闭有效性定量评价原理及方法[J]. 石油学报, 2021, 42(9):1126-1141.
HOU Lianhua, YANG Fan, YANG Chun, et al. Principles and methods for quantitatively evaluating the effectiveness of conventional petroleum zones and traps[J]. Acta Petrolei Sinica, 2021, 42(9):1126-1141.
[1] YANG Jinhai, YU Yixin, OUYANG Jie, XU Maguang, JIN Feng, ZHANG Yuhang, YU Lang. Structural framework and hydrocarbon accumulation models of Zhongjiannan Basin in the western edge of the South China Sea [J]. Lithologic Reservoirs, 2026, 38(3): 141-148.
[2] LI Bin, MIN Zhongshun, MENG Lingna, ZHANG Yuanli, YIN Jianfeng, ZHOU Peijie. A method for assessing fault lateral sealing based on high-resolution geological modeling: A case study of Archean buried hill reservoir in Xinglongtai structural belt of Liaohe Depression [J]. Lithologic Reservoirs, 2026, 38(1): 126-135.
[3] YAN Yuyang, XIONG Lianqiao, HE Youbin, CHEN Ying, ZHAO Zhongxiang, LIU Shengqian, LUO Jinxiong, FENG Bin. Source-to-sink system of Paleogene in Huizhou Sag of Pearl River Mouth Basin and its control on reservoir [J]. Lithologic Reservoirs, 2025, 37(5): 166-177.
[4] CHEN Xiao, MIAO Yun, LI Wei, XIE Mingying, SHI Hao, WANG Weifeng. Calculation method for reasonable oil-water well ratio in the edge water drive offshore sandstone oilfield [J]. Lithologic Reservoirs, 2025, 37(1): 194-200.
[5] HE Yanbing, XIAO Zhangbo, ZHENG Yangdi, LIU Junyi, YI Hao, ZHAO Qing, ZHANG Yuexia, HE Yong. Hydrocarbon accumulation characteristics of Mesozoic Lufeng 7-9 buried hill in Lufeng 13 subsag transition zone,Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2023, 35(3): 18-28.
[6] HUANG Junli, ZHANG Wei, LIU Lihui, CAI Guofu, ZENG Youliang, MENG Qingyou, LIU Hao. Ternary seismic configuration interpretation technology of Paleogene Wenchang Formation in Panyu 4 depression, Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2023, 35(2): 103-112.
[7] YING Kaiying, CAI Chang'e, LIANG Yuqi, CHEN Hong, SHANG Wenliang, SU Guijiao. Vertical sealing of Paleogene faults and its control on reservoirs in Chaluhe fault depression, Yitong Basin [J]. Lithologic Reservoirs, 2023, 35(2): 136-143.
[8] HE Yong, QIU Xinwei, LEI Yongchang, XIE Shiwen, XIAO Zhangbo, LI Min. Tectonic evolution and hydrocarbon accumulation characteristics of Cenozoic in eastern Lufeng 13 subsag, Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2023, 35(1): 74-82.
[9] ZHANG Weiwei, LIU Jun, LIU Lihui, ZHANG Xiaozhao, BAI Haijun, YANG Dengfeng. Lithology prediction technology and its application of Paleogene Wenchang Formation in Panyu 4 depression,Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2022, 34(6): 118-125.
[10] LI Chengze, CHEN Guojun, TIAN Bing, YUAN Xiaoyu, SUN Rui, SU Long. Water-rock interaction in deep strata under high temperature and high pressure in Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2022, 34(4): 141-149.
[11] ZHANG Wei, LI Lei, QIU Xinwei, GONG Guangchuan, CHENG Linyan, GAO Yifan, YANG Zhipeng, YANG Lei. A/S control on spatiotemporal evolution of deltas in rifted lacustrine basin and its numerical simulation: A case study of Paleogene Wenchang Formation in Lufeng 22 subsag,Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2022, 34(3): 131-141.
[12] ZHAO Jun, HAN Dong, HE Shenglin, TANG Di, ZHANG Tao. Identification of fluid properties of low contrast reservoir based on water-gas ratio calculation [J]. Lithologic Reservoirs, 2021, 33(4): 128-136.
[13] XIANG Qiaowei, LI Xiaoping, DING Lin, DU Jiayuan. Formation mechanism and petroleum geological significance of Paleogene sandstone with high natural gamma value in Zhuyi Depression, Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2021, 33(2): 93-103.
[14] LUO Ze, XIE Mingying, LIANG Jie, TU Zhiyong, HOU Kai. Macro-correction method and application of seismic pseudo-well velocity point: a case study from M gas field in Pearl River Mouth Basin [J]. Lithologic Reservoirs, 2020, 32(3): 115-121.
[15] DU Xulin, DAI Zong, XIN Jing, LI Hailong, CAO Renyi, LUO Donghong. Three-dimensional water flooding physical simulation experiment of horizontal well in heavy oil reservoir with strong bottom water [J]. Lithologic Reservoirs, 2020, 32(2): 141-148.
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
No Suggested Reading articles found!
TRENDMD: