摘要
鄂尔多斯盆地延长组中上组合发育多期次前积体,高精度三维地震部署以后,前积体地震反射特征更加清晰,为前积体的精细研究打下了良好资料基础。本次研究首次利用三维地震资料对前积体结构进行精细解剖,在明确前积体砂体“三段式”展布规律基础上,认为前积体下坡折带砂体向下和长7源岩接触,向上在中斜坡带相变为泥岩,具备形成岩性油藏条件,并据此首次提出前积体岩性油藏概念。本文针对前积体岩性油藏,通过精细的前积格架解释以及储层预测,明确了前积体内部砂体沿坡折呈朵叶状展布,多个朵叶体沿着长7湖盆坡折带叠置发育,使得砂体在平面上呈现出北西—南东向条带式展布,并且多期前积体控制形成多期砂带。与传统的长6致密油藏等厚划分方案相比,前积体岩性油藏模式更加合理,更加符合等时沉积地质规律。近期,油田公司针对前积体岩性油藏采取平行—垂直坡折带方向部署实施两口风险井位,均已经获得勘探突破,试油获得高产工业油流,证实了前积体岩性油藏石油富集程度高,勘探潜力大。前积体岩性油藏的认识以及勘探突破意义重大,改变了鄂尔多斯盆地传统长6致密油等厚水平分布的认识,为延长组致密油勘探开发以及储量发现提供了全新的研究思路。
The upper and middle members of the Yanchang Formation in the Ordos Basin have developed multiple progradation bodies.After the deployment of high-precision 3D seismic,the seismic reflection characteristics of the progradation bodies were clearer,laying a good data foundation for the detailed study of the progradation bodies.This study was the first time to use the 3D seismic data to conduct a detailed analysis of the progradation body structure.Based on the clear understanding of the“three-stage”distribution pattern of the progradation body sand bodies,the sand bodies in the lower slope break zone of the progradation body were in contact with the source rock of the Chang 7 member at the bottom and transformed into mudstone at the top in the middle slope zone,thus having the conditions to form lithologic oil reservoirs.Based on this,the concept of“progradation body lithologic oil reservoirs”was proposed for the first time.This paper focused on the“progradation body lithologic oil reservoirs”,through detailed progradation framework interpretation and reservoir prediction,it was clear that the sand bodies in the progradation body were distributed in a flower-like pattern along the slope break,and the multiple flower-like bodies were superimposed along the slope break of the Chang 7 member lake basin,resulting in a northwest to southeast strip-like distribution of the sand bodies on the plane,and the formation of multiple sand belts was controlled by multiple progradation bodies.Compared with the traditional equal-thickness division scheme of the Chang 6 tight oil reservoirs,the“progradation body lithologic oil reservoirs”model was more reasonable and more in line with the isochronous sedimentary geological laws.Recently,the oilfield company has deployed two risk wells which were parallel and perpendicular to the slope break direction for the“progradation body lithologic oil reservoirs”.Currently,both well A and well B had achieved exploration breakthrough and obtained high-yield industrial oil flow during the test,confirming that the progradation body lithologic oil reservoirs had a high degree of oil enrichment and great exploration potential.The recognition and exploration breakthrough of the“progradation body lithologic oil reservoirs”were of great significance,changing the traditional understanding of the equal-thickness horizontal distribution of Chang 6 tight oil in the Ordos Basin and providing a new research idea for the exploration and development of tight oil in the Yanchang Formation and the discovery of reserves.
作者
冯许魁
沈亚
杨洋
开百泽
强敏
赵雨
邹义
郭斌华
梁家昌
韩均安
Feng Xukui;Shen Ya;Yang Yang;Kai Baize;Qiang Min;Zhao Yu;Zou Yi;Guo Binhua;Liang Jiachang;Han Jun'an(Changqing Branch of Research Institute,BGP Inc.,CNPC,Xi'an 710021)
出处
《地质科学》
2026年第1期110-119,共10页
Chinese Journal of Geology(Scientia Geologica Sinica)
基金
中国石油东方地球物理勘探有限责任公司油气勘探新领域综合研究项目(编号:2023YQX10111)资助。
关键词
前积反射
前积体岩性油藏
致密油
延长组
鄂尔多斯盆地
Progradation reflection
Progradation body lithologic oil reservoir
Tight oil
Yanchang Formation
Ordos Basin
