Formation conditions and hydrocarbon accumulation model of deep low to ultra-low permeability gas reservoirs of Y Structure in Central Anticline Belt, X Sag, East China Sea Shelf Basin
-
摘要:
油气勘探证实东海X凹陷中央背斜带深层低渗-特低渗砂岩储层蕴含丰富的天然气资源，而针对低渗-特低渗储层油气资源的地质认识尚不深入，极大地制约了东海油气增储上产。Y构造是X凹陷最大反转背斜构造，通过对烃源岩特征、储层物性和成岩作用等的深入分析研究，并结合其热史-埋藏史，重点阐明了气藏主力产层花港组砂岩的低渗-特低渗演化过程、低渗-特低渗化影响因素与储层成岩-成藏耦合关系。研究表明，Y构造在龙井运动反转期剥蚀量超过1 200 m，说明花港组砂岩储层13 Ma曾经历历史最大埋深与最高温度，易形成低渗-特低渗砂岩储层。根据研究区砂岩储层致密化程度及演化特征，可以将气藏划分为花港组H3砂层组成藏未特低渗气藏、H4—H5边成藏边特低渗气藏和H8—H12先特低渗后成藏之气藏。在此基础上，结合油气成藏过程分析，建立了中央背斜带“花港组垂向两期充注、龙井组调整运移”成藏模式。
Abstract:Oil and gas exploration has confirmed that the deep low to ultra-low permeability sandstone reservoirs in the central anticline of the X Sag in the East China Sea contain abundant natural gas resources. However, the geological understanding of oil and gas resources in low-permeability to ultra-low permeability reservoirs is not yet deep, which greatly restricted the increases of oil and gas reserves and production in the East China Sea. The Y Structure is the largest inversion anticline structure in the X Sag. Through in-depth analysis on the characteristics of source rocks, reservoir properties, and diagenesis, combined with its thermal burial history, we elucidated the evolution process of low to ultra-low permeability sandstones in the main production layer of the gas reservoir, and clarified the impact factors on the low to ultra-low permeability and the coupling relationship between reservoir diagenesis and reservoir formation. Results show that during the reversal period of the Longjing Movement, the amount of the thickness eroded from the Huagang Formation in the Y Structure exceeded 1 200 m, indicating that the sandstone reservoir of the Huagang Formation experienced the maximum burial depth in history and the highest temperature in 13 Ma, making it easy to form low to ultra-low permeability sandstone reservoirs. According to the degree of densification and evolutionary characteristics of sandstone reservoirs in the research area, three sets of the gas reservoirs were recognized: the H3 sand layer of the Huagang Formation composed of low-permeability gas reservoirs, the H4-H5 reservoir formed while forming ultra-low permeability gas reservoirs, and the H8-H12 reservoir formed first and then ultra-low permeability gas reservoirs. On this basis, combined with the analysis of the process of oil and gas reservoir formation, a reservoir formation model of “two-stage vertical filling in Huagang Formation and adjustment-migration in Longjing Formation” was established in the central anticline belt.
-
-
表 1 Y构造天然气甲烷稳定碳同位素及成熟度表
Table 1. Stable carbon isotope and maturity of natural gas methane in Y Structure
井号 深度/m 层位 样品 δ13C1/‰ δ13C2/‰ δ13C3/‰ 天然气成熟度 甲烷 乙烷 丙烷 YY-1 4 085～4 105 花下段H7 DST −34.4 −28.3 −27.1 1.48 2 933～2 938.5 花上段H2 DST −32.1 −25.4 −23.4 1.62 YY-3d 3 008 花上段H3 MDT −32.5 −25.6 −23.0 1.59 3 269 花上段H4 MDT −31.9 −25.9 −23.8 1.24 1 393.98 龙井组 MDT −39.6 −25 −23.6 1.08 1 482.72 龙井组 MDT −38.1 −25.0 −23.6 1.27 H井 3 873～3 903 花上段 DST −30.5 −24.7 −23.5 1.72 3 462～3 491
3 493～3 507花上段 DST −30.7 −24.0 −23.1 1.71 Z井 3 769～3 799 花上段H3 DST −30.9 −24.0 −24.0 1.69 3 709～3 739 花上段H3 DST −29.8 −23.8 −23.6 1.77 3 447.2～3 456.1 花上段H2 DST −29.2 −23.3 −22.3 1.81 3 177 ～3 181 /
3 186～3 199花上段H1 DST −29.9 −23.5 −22.7 1.76 4 240～4 352.76 花上段H5 DST −30.4 −25.3 −23.3 1.73 3 673～3 705 花上段H3 DST −31.3 −26.0 −25.5 1.67 3 570 花上段H2 DST −29.6 −23.4 −22.3 1.78 注：*天然气成熟度计算公式：δ13C1（‰）≈58.67×lnRo－44.37[20]。 
下载: 导出CSV
-
[1] 周心怀. 西湖凹陷地质认识创新与油气勘探领域突破[J]. 中国海上油气,2020,32(1):1-12.
ZHOU X H. Geological understanding and innovation in Xihu Sag and breakthroughs in oil and gas exploration[J]. China Offshore Oil and Gas,2020,32(1):1-12.
[2] 张迎朝,邹玮,陈忠云,等. 东海陆架盆地西湖凹陷中央反转构造带古近系花港组气藏“先汇后聚”机制及地质意义[J]. 石油与天然气地质,2023,44(5):1256-1269. doi: 10.11743/ogg20230514
ZHANG Y Z,Zou W,CHENG Z Y,et al. The mechanism of “convergence ahead of accumulation” and its geological significance for gas reservoirs in Paleogene Huagang Formation across the central inverted structural zone of Xihu Depression,East China Sea Shelf Basin[J]. Oil & Gas Geology,2023,44(5):1256-1269. doi: 10.11743/ogg20230514
[3] 刘金水,张国栋,刘云. 西湖凹陷A洼陷异常高压封存箱成因机制与控藏作用[J]. 中国海上油气,2023,35(3):25-33.
LIU J S,ZHANG G D,LIU Y. Origin mechanism of abnormal high-pressure compartment in A sub-sag of Xihu Sag and its controlling effect on reservoir formation[J]. China Offshore Oil and Gas,2023,35(3):25-33.
[4] 倪智勇,张紫东,李思澎,等. 西湖凹陷平湖斜坡构造带油藏成藏期次厘定[J]. 石油科学通报,2022,7(3):281-293. doi: 10.3969/j.issn.2096-1693.2022.03.026
NI Z Y,ZHANG Z D,LI S P,et al. The oil accumulation period in the Pinghu slope tectonic belt of the Xihu Sag[J]. Petroleum Science Bulletin,2022,7(3):281-293. doi: 10.3969/j.issn.2096-1693.2022.03.026
[5] 王欣,李峰,沈娇,等. 西湖凹陷杭州斜坡带平湖组沉积体系及演化[J]. 油气地质与采收率,2022,29(4):57-68.
WANG X,LI F,SHEN J,et al. Evolution of sedimentary system of Pinghu Formation in Hangzhou slope belt,Xihu Sag[J]. Petroleum Geology and Recovery Efficiency,2022,29(4):57-68.
[6] 沈文超,邵龙义,周倩羽,等. 西湖凹陷古近系平湖组泥质岩地球化学特征及其地质意义[J]. 地质学报,2022,96(6):2078-2093.
SHEN W C,SHAO L Y,ZHOU Q Y,et al. Geochemistry of argillaceous rocks of the Eocene Pinghu Formation from Xihu Depression in East China Sea Basin and its geological significance[J]. Acta Geologica Sinica,96(6):2078-2093.
[7] 蒋一鸣,何新建,唐贤君,等. 钓鱼岛隆褶带物质构成及东海西湖凹陷原型盆地东边界再认识[J]. 地球科学,2019,44(3):773-783.
JIANG Y M,HE X J,TANG X J,et al. Material composition of Diaoyu Islands folded zone and reanalysis of eastern boundary of prototype basin of Xihu Sag in East China Sea[J]. Earth Science,2019,44(3):773-783.
[8] 刁慧,邹玮,李宁,等. 东海盆地西湖凹陷武云亭构造油气来源与成藏模式[J]. 地质科技通报,2020,39(3):110-119.
DIAO H,ZOU W,LI N,et al. Hydrocarbon origin and reservoir forming model of Wuyunting Structure in Xihu Depression,East China Sea Basin[J]. Bulletin of Geological Science and Technology,2020,39(3):110-119.
[9] 张宙,何新建,唐贤君,等. 东海盆地西湖凹陷构造圈闭特征及其油气藏类型[J]. 海洋地质前沿,2022,38(3):27-35.
ZHANG Z,HE X J,TANG X J,et al. Structural trap characteristics and reservoir types in Xihu Sag,East China Sea Basin[J]. Marine Geology Frontiers,2022,38(3):27-35.
[10] 李天军,黄志龙,郭小波,等. 东海盆地西湖凹陷平北斜坡带平湖组煤系原油地球化学特征与油-源精细对比[J]. 石油与天然气地质,2022,43(2):432-444. doi: 10.11743/ogg20220215
LI T J,HUANG Z L,GUO X B,et al. Geochemical characteristics of crude oil from coal measure source rocks and fine oil-source correlation in the Pinghu Formation in Pingbei slope belt,Xihu Sag,East China Sea Shelf Basin[J]. Oil & Gas Geology,2022,43(2):432-444. doi: 10.11743/ogg20220215
[11] 蒋一鸣,刁慧,曾文倩. 东海盆地西湖凹陷平湖组煤系烃源岩条件及成烃模式[J]. 地质科技通报,2020,39(3):30-39.
JIANG Y M,DIAO H,ZENG W Q. Coal source rock conditions and hydrocarbon generation model of Pinghu Formation in Xihu Depression,East China Sea Shelf Basin[J]. Bulletin of Geological Science and Technology,2020,39(3):30-39.
[12] 刘英辉,蔡华,段冬平,等. 西湖凹陷平湖地区平湖组海侵体系域潮控三角洲-潮坪沉积特征及模式[J]. 海洋地质前沿,2022,38(1):33-40.
LIU Y H,CAI H,DUAN D P,et al. The sedimentary characteristics of tidal delta and tidal flat in transgressive system tract of Pinghu Formation in Pinghu area,Xihu Sag[J]. Marine Geology Frontiers,2022,38(1):33-40.
[13] 江东辉,杜学斌,李昆,等. 东海西湖凹陷保俶斜坡带平湖组“古地貌-古水系-古坡折”特征及其对沉积体系的控制[J]. 石油实验地质,2022,44(5):771-779,789. doi: 10.11781/sysydz202205771
JIANG D H,DU X B,LI K,et al. Distribution of sedimentary system multi-controlled by palaeo-geomorphology,water system and break during the deposition of Pinghu Formation,Baochu slope belt,Xihu Sag,East China Sea Shelf Basin[J]. Petroleum Geology & Experiment,2022,44(5):771-779,789. doi: 10.11781/sysydz202205771
[14] 陈春峰,徐东浩,张银国,等. 西湖凹陷中北部花港组上段浅水辫状河三角洲发育特征[J]. 海洋地质前沿,2024,40(10):39-48.
CHEN C F,XU D H,ZHANG Y G,et al. Shallow braided river delta in the upper Huagang Formation in the central-northern part of Xihu Sag,East China Sea Basin[J]. Marine Geology Frontiers,2024,40(10):39-48.
[15] 张迎朝,胡森清,刘金水,等. 东海盆地X凹陷天然气成藏条件与成藏模式[J]. 中国海上油气,2022,34(1):27-35. doi: 10.11935/j.issn.1673-1506.2022.01.004
ZHANG Y Z,HU S Q,LIU J S,et al. Gas accumulation conditions and mode in X Sag of East China Sea Basin[J]. China Offshore Oil and Gas,2022,34(1):27-35. doi: 10.11935/j.issn.1673-1506.2022.01.004
[16] 周心怀,徐国盛,崔恒远,等. 东海西湖凹陷中央反转构造带古近系花港组致密砂岩储集层裂缝发育特征与油气成藏关系[J]. 石油勘探与开发,2020,47(3):462-475. doi: 10.11698/PED.2020.03.03
ZHOU X H,XU G S,CUI H Y,et al. Fracture development and hydrocarbon accumulation in tight sandstone reservoirs of the Paleogene Huagang Formation in the central reversal tectonic belt of the Xihu Sag,East China Sea[J]. Petroleum Exploration and Development,2020,47(3):462-475. doi: 10.11698/PED.2020.03.03
[17] 李宁,徐振中,钟荣全,等. 西湖凹陷深层致密砂岩裂缝控制因素及发育模式:以中部洼陷带中南部W构造为例[J]. 海洋地质前沿,2024,40(10):19-28.
LI N,XU Z Z,ZHONG R Q,et al. Controlling factors and development patterns of fractures in deep tight sandstone in Xihu Sag,East China Sea Shelf Basin:a case study from W Structure in south central region of Central Depression Belt[J]. Marine Geology Frontiers,2024,40(10):19-28.
[18] 张武,邹玮,侯国伟,等. 西湖凹陷中部深层甜点气藏发育条件与分布预测[J]. 中国海上油气,2024,36(5):83-93.
ZHANG W,ZOU W,HOU G W,et al. Development conditions and distribution prediction of deep sweet spot gas reservoirs in the middle of Xihu Sag[J]. China Offshore Oil and Gas,2024,36(5):83-93.
[19] 沈伟锋,于仲坤,刁慧,等. 西湖凹陷热流演化史模拟及成藏意义[J]. 中国海上油气,2020,32(1):42-53.
SHEN W F,YU Z K,DIAO H,et al. Simulation of heat flow evolution history in Xihu Sag and its significance for hydrocarbon accumulation[J]. China Offshore Oil and Gas,2020,32(1):42-53.
[20] 程熊,侯读杰,赵喆,等. 西湖凹陷天然气成因及来源分析[J]. 中国海上油,2019,31(3):50-60.
CHENG X,HOU D J,ZHAO Z,et al. Analysis on the genesis and source of natural gas in Xihu Sag,East China Sea Basin[J]. China Offshore Oil and Gas,2019,31(3):50-60.
-
图(11)
表(1)
计量
- 文章访问数: 37
- PDF下载数: 5
- 施引文献: 0