柴西南区岩性油气藏地质特征及控制因素

吴颜雄; 薛建勤; 施奇; 杨芸; 刘君林; 马凤春; 李翔; 王艳清

doi:10.11781/sysydz202401022

柴西南区岩性油气藏地质特征及控制因素

doi: 10.11781/sysydz202401022

吴颜雄^{1, 2,},
薛建勤²,
施奇^{1, 2},
杨芸^{1, 2},
刘君林²,
马凤春²,
李翔³,
王艳清⁴

1.
青海省高原咸化湖盆油气地质重点实验室, 甘肃敦煌 736202
2.
中国石油青海油田分公司, 甘肃敦煌 736202
3.
中国石油勘探开发研究院西北分院, 兰州 730020
4.
中国石油杭州地质研究院, 杭州 310023

基金项目:

国家科技重大专项 2016ZX05046-006

中国石油天然气股份有限公司重大科技专项 2016E-01

详细信息

作者简介:
吴颜雄(1982-), 男, 正高级工程师, 从事油气地质勘探综合研究工作。E-mail: wyxqhyjy@petrochina.com.cn

中图分类号: TE122.3
计量
- 文章访问数: 142
- HTML全文浏览量: 63
- PDF下载量: 35
- 被引次数: 0
出版历程
- 收稿日期: 2023-06-20
- 修回日期: 2023-12-05
- 刊出日期: 2024-01-28

Geological characteristics and controlling factors of lithologic reservoirs in southwestern Qaidam Basin

WU Yanxiong^{1, 2
,},
XUE Jianqin²,
SHI Qi^{1, 2},
YANG Yun^{1, 2},
LIU Junlin²,
MA Fengchun²,
LI Xiang³,
WANG Yanqing⁴

1.
Qinghai Provincial Key Laboratory of Plateau Saline-Lacustrine Basinal Oil & Gas Geology, Dunhuang, Gansu 736202, China
2.
Qinghai Oilfield Branch Company Ltd., PetroChina, Dunhuang, Gansu 736202, China
3.
Northwest Branch of Exploration and Development Research Institute, PetroChina, Lanzhou, Gansu 730020, China
4.
Hangzhou Research Institute of Geology, PetroChina, Hangzhou, Zhejiang 310023, China

摘要

摘要: 近年来，柴达木盆地在咸化湖相滩坝砂中发现了多个“小而肥”的岩性油气藏。为了拓展岩性油气勘探规模、发现新的目标及区带，支撑油田规模增储上产，利用岩心、测井和地震资料，开展岩性油气藏成藏条件综合分析。通过解剖已发现岩性油气藏特征，明确控制因素，指出了岩性油气藏勘探接替领域。结果表明，柴西南区具备形成岩性油气藏的四大有利条件：一是发育继承性的七个泉—红柳泉、砂西—跃进、扎哈泉—乌南三大稳定的古斜坡，利于油气聚集成藏；二是临近红狮和扎哈泉两个生烃中心，油源条件优越；三是咸化湖盆发育大型辫状河三角洲、广覆式分布的滨浅湖滩坝砂及藻席—灰云坪沉积，形成碎屑岩和碳酸盐岩两种互补型的储集体；四是发育多种疏导体系，纵向上可以形成多套含油层系。受古构造、沉积、成岩等多因素控制，柴西南区发育砂岩上倾尖灭型、砂岩透镜体型、物性封堵型和白云石化成岩圈闭四种类型岩性油气藏。岩性油气藏受古构造、优质源岩和有效储层三因素控制。古构造决定岩性圈闭的类型和油气运移方向；优质烃源岩控制岩性油气藏的分布及规模；有效储层控制岩性油气藏的富集。综合评价指出，辫状河三角洲前缘砂体是古近系下干柴沟组下段岩性勘探的有利区，主要分布在砂西、尕斯、乌南向盆内的倾末端；白云石化成岩圈闭是古近系下干柴沟组上段岩性勘探的有利区，主要分布在环红狮凹陷周缘；广覆式分布滩坝是新近系上干柴沟组、下油砂山组岩性油气藏勘探的有利区，主要分布在英雄岭、尕斯、扎哈泉、乌南等地区。这一认识支撑了切探2井、尕斯新层系等岩性勘探获得一系列重大突破，可为柴西南区岩性油气藏的下一步勘探提供指导。
- 成藏条件 /
- 控制因素 /
- 岩性油气藏 /
- 勘探潜力 /
- 柴达木盆地
Abstract: In recent years, several small and rich lithologic oil and gas reservoirs have been discovered in the saline lacustrine beach bar sand in the Qaidam Basin. In order to expand the exploration scale of lithologic oil and gas reservoirs, find new exploration targets and zones, and increase storage and production of oilfields, based on coring, logging and seismic data, the controlling factors of oil and gas accumulation in lithologic reservoirs are defined, and some exploration succeeding fields of lithologic reservoirs are pointed out. The results show that: The southwestern Qaidam Basin has four favorable conditions for the formation of lithologic reservoirs. The first is the development of three stable ancient slopes, namely, the Qigequan-Hongliuquan, Shaxi-Yuejin, and Zahaquan-Wunan, which are inherited and conducive to the accumulation of oil and gas. The second is the proximity of two hydrocarbon generation centers, Hongshi and Zahaquan, with superior oil source conditions. The third is that the salt lake basin developed large braided river delta, widely distributed shoal-bar sand and algal hill-gray cloud flat deposits, forming two complementary types of reservoirs of clastic rock and carbonate rock. The fourth is the development of a variety of drainage systems, which can form several sets of oil-bearing strata vertically. Controlled by paleo-structural, sedimentary and diagenetic factors, there are four types of lithologic reservoirs in the southwestern Qaidam Basin: updip pinching out, sandstone lens, physical sealing and dolomitization trap. Lithologic reservoirs are controlled by three factors: paleo-structure, high-quality source rock and effective reservoir. Paleo-structure determines the type of lithologic traps and the direction of hydrocarbon migration. The high-quality source rock controls the distribution and scale of lithologic reservoirs and effective reservoir controls the accumulation of lithologic reservoirs. Comprehensive evaluation shows that the braided river delta front sand body is a favorable area for the exploration of lithologic reservoirs in the lower Ganchaigou Formation of the Lower Paleogene, mainly distributed in the basin dip end of Shaxi, Gasi, and Wunan. The dolomitization trap is a favorable area for exploration of lithologic reservoirs in the upper member of lower Ganchaigou Formation of Paleogene, mainly distributed around the Hongshi Sag. The widely distributed beach bar is a favorable area for lithologic oil exploration in the upper Ganchaigou Formation and lower Youshashan Formation of Neogene, mainly distributed in Yingxiongling, Gasi, Zhahaquan, Wunan, and other areas. This understanding supports a series of major breakthroughs in lithologic exploration, such as well Qietan 2 and the new series of Gasi, with important guiding significance for further exploration of lithologic reservoirs in the southwestern Qaidam Basin.
- reservoir formation condition /
- controlling factor /
- lithologic reservoir /
- exploration potential /
- Qaidam Basin
注释:

1) 所有作者声明不存在利益冲突。

1) 利益冲突声明/Conflict of Interests

2) 作者贡献/Authors’Contributions

2) 吴颜雄、施奇参与论文写作和修改；薛建勤、王艳清提供修改意见；杨芸、刘君林提供样品和资料支持；马凤春、李翔参与文章设计及讨论。所有作者均阅读并同意最终稿件的提交。

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图 1 柴西南区地理位置(a)及其新生界地层综合柱状图(b)

Figure 1. Geographical location map (a) and composite bar chart (b) of southwestern Qaidam Basin

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图 2 柴西地区古近系烃源岩总有机碳含量分布

Figure 2. Total organic carbon content distribution of Paleogene source rocks in western Qaidam Basin

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图 3 咸化湖相烃源岩生烃模式

据参考文献[25]修改。

Figure 3. Hydrocarbon generation model of saline lacustrine source rocks

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图 4 柴西地区早上新世(N₂¹)时期下渐新统(E₃¹)古构造

Figure 4. Paleostructures of Lower Oligocene in western Qaidam Basin during early Pliocene

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图 5 柴西地区各层段沉积相平面分布

Figure 5. Plane distribution of sedimentary facies of each layer in western Qaidam Basin

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图 6 水槽实验模拟不同盐度条件陆源碎屑搬运距离

Figure 6. Flume experiment simulating terrigenous debris transport distance under different salinity conditions

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图 7 柴西南区岩性油气藏储层储集空间类型

a.七6-5井，2 449.04 m，E₃¹，辫状河三角洲前缘水下分流河道，粉砂岩，粒间孔和溶蚀孔，铸体薄片；b.七102井，2 464.16 m，E₃¹，辫状河三角洲前缘水下分流河道，细砂岩，粒间孔和溶蚀孔，铸体薄片；c.扎401井，3 274.43 m，N₁，滨浅湖滩坝，中细砂岩，粒间孔和溶蚀孔发育，铸体薄片；d.扎平1井，3 136.2 m，N₁，滨浅湖滩坝，细砂岩，粒间孔和溶蚀孔，铸体薄片；e.七34井，E₃¹，3 136.61 m，辫状河三角洲前缘水下分流河道，细砂岩，粒间孔和溶蚀孔，铸体薄片；f.扎2井，3 236.2 m，N₁，滨浅湖滩坝，细砂岩，粒间孔和溶蚀孔，扫描电镜；g.跃新4-6井，3 380.40 m，E₃²，滨浅湖，藻灰云岩，溶蚀孔隙，铸体薄片；h.狮41-6-1井，E₃²，3 857.9 m，浅湖，泥晶灰云岩，晶间孔和溶蚀孔，铸体薄片；i.狮41-2井，4 080 m，E₃²，白云石晶间孔，扫描电镜。

Figure 7. Effective reservoir types of lithologic reservoirs in southwestern Qaidam Basin

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图 8 柴西南区岩性圈闭类型

a.砂体上倾尖灭型：水下分流河道砂体沿物源或某一方向发生尖灭，前端为泥质沉积，后期构造抬升，形成上倾尖灭；b.砂岩透镜体：滨浅湖滩坝砂，周围被泥岩所包围，形成透镜体；c.物性封堵型：横向稳定的砂体后期受原始沉积和后期成岩作用影响，造成物性差异，形成物性封堵；d.白云石化成岩圈闭：碳酸盐岩的白云石化程度差异较大，白云石化强，孔隙发育，物性好，相反周围物性差，形成成岩圈闭。

Figure 8. Types of lithologic traps in southwestern Qaidam Basin

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图 9 柴西南区岩性圈闭及岩性油气藏分布模式

Figure 9. Distribution patterns of lithologic traps and reservoirs in southwestern Qaidam Basin

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图 10 柴西地区七个泉下渐新统岩性油气藏接力式分布模式

Figure 10. Relaying distribution pattern of lithologic reservoirs in Lower Oligocene, Qigequan area, western Qaidam Basin

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