渤海海域莱北低凸起新近系岩性油藏成藏模式及勘探实践

Exploration advances and accumulation model for Neocene lithological reservoirs in Laibei Low Uplift, Bohai Sea area

温宏雷 杨海风 杨波 王利良 涂翔 李志强

WEN Honglei YANG Haifeng YANG Bo WANG Liliang TU Xiang LI Zhiqiang

中海石油(中国)有限公司 天津分公司 渤海石油研究院, 天津 300459

Bohai Oilfield Research Institute, Tianjin Branch Company, CNOOC China Ltd., Tianjin 300459, China

莱北低凸起位于渤海海域的南部，受两大富烃凹陷夹持，构造演化复杂，断块圈闭破碎，油气成藏规律复杂，长期没有商业发现。通过对莱北低凸起各个构造20余口钻井实钻数据及各项参数的统计分析，探讨莱北低凸起油气成藏主控因素，结合近期的勘探发现，进一步总结莱北低凸起新近系岩性油藏成藏模式。汇聚类型决定油气在凸起上的富集区带，莱北低凸起的东西段分别发育“断层汇聚型”富集带和“构造脊汇聚型”富集带；油源断裂活动性控制油气的垂向运移效率，当已钻井所在圈闭运移断层的断距大于80 m时，浅层普遍获得较好的油气发现；断砂配置关系制约油气向储层充注的效率，当断砂接触面积大于10×103 m2时，新近系圈闭普遍能有较好的油气丰度及烃柱高度。运用建立的成藏模式对莱北低凸起新近系未钻岩性圈闭进行了综合分析，筛选出23个有利目标砂体，在后续的钻探中获得成功，证实了该成藏模式的有效性，并在莱北低凸起获得重大突破，找到了第一个亿吨级商业性油田——垦利6-1油田。

The Laibei Low Uplift locates in the southern part of Bohai Sea area, and is sandwiched by two major hydrocarbon-rich sags with a complex structural evolution history. The broken fault block traps and the model of hydrocarbon accumulation are still unclear. It is the single uplift (low uplift) without commercial development in the Bohai Sea area. Combined with recent drilling data, a "convergence-transportation-filling (CTF)" model of the Neocene lithological reservoir formation in the Laibei Low Uplift was proposed. The type of convergence determines the enrichment zone of oil and gas on the uplift, and the zones of "fault convergence type" and "structural ridge convergence type" enrichment are developed in the eastern and western sections of the Laibei Low Uplift. The vertical migration efficiency of oil and gas appeared to be determined by the activity of oil source fault. When the fracture slip of the migration fault in the drilled trap is greater than 80 m, the shallow layer is generally found to be a better reservoir of oil and gas. The relationship between fault and sand restricts the filling efficiency of oil and gas. When the contact area of fault and sand is greater than 10×103 m2, the Neocene traps generally have a better oil and gas abundance and hydrocarbon column height. By the using of established reservoir forming model, a comprehensive analysis of the undrilled lithological traps of Neogene strata was carried out by this study, 23 favorable target sand bodies were suggested and have been proved to be successful. The effectiveness of the reservoir forming model has been validated, and the first large-scale commercial oil field, i.e., Kenli 6-1 oil field, on the Laibei Low Uplift has been accordingly developed.

“十三五”国家科技重大专项 2016ZX05024-002;中海石油（中国）有限公司科技项目 YXKY-2017-TJ-01

https://doi.org/10.11781/sysydz202201102