石油与天然气地质 ›› 2022, Vol. 43 ›› Issue (2): 445-455.doi: 10.11743/ogg20220216

• 方法技术 • 上一篇    下一篇

深水盐下湖相碳酸盐岩缝洞地震预测

黄文松1(), 徐芳1, 刘成彬2, 黄继新1, 赵俊峰2, 郭松伟1, 李云波1   

  1. 1.中国石油 勘探开发研究院,北京 100083
    2.中油国际(巴西)公司,里约热内卢 巴西 22250-040
  • 收稿日期:2021-11-09 修回日期:2022-01-20 出版日期:2022-04-01 发布日期:2022-03-11
  • 第一作者简介:黄文松(1973—),男,高级工程师,油气田开发地质。E?mail: hwshws6@petrochina.com.cn

Seismic prediction of fractures and vugs in deep-water sub-salt lacustrine carbonates:Taking F oilfield in Santos Basin, Brazil as an example

Wensong Huang1(), Fang Xu1, Chengbin Liu2, Jixin Huang1, Junfeng Zhao2, Songwei Guo1, Yunbo Li1   

  1. 1.Research Institute of Petroleum Exploration&Development, PetroChina, Beijing 100083, China
    2.Brazil Petroleum and Gas Company, CNODC, Rio de Janeiro 22250-040, Brazil
  • Received:2021-11-09 Revised:2022-01-20 Online:2022-04-01 Published:2022-03-11

摘要:

桑托斯盆地F油田位于巴西深水区域的盐岩之下,具有埋藏深、岩性多样、非均质性强的特点。与常规的以孔隙型为主的储层和中国西部“串珠状”的大型溶洞储层不同,研究区碳酸盐岩为深水盐下湖相碳酸盐岩,其溶蚀孔洞孔径小、裂缝类型多,导致地震响应特征极其不明显,常规缝洞预测方法不适用。另外,受上覆巨厚盐岩层的影响,缝洞发育储层段的地震资料分辨率低,增加了利用叠后地震方法预测其分布规律的难度。因此,针对研究区缝洞发育特点,采取井震相结合的思路,以消除泥岩及火成岩岩性干扰为前提,首先进行地震资料优化处理,然后充分利用岩心、FMI测井等资料以及生产漏失等信息,综合分析地震异常可能表达的地质信息,探索了一套适用于深水盐下多种岩性发育背景的小尺度湖相碳酸盐岩缝洞储层地震预测方法。该方法明确了裂缝与孔洞的敏感地震属性,通过联合构造应力场进行裂缝预测,结合波阻抗、孔隙度及CGR等地震反演结果,开展溶蚀孔洞预测,取得了良好的预测效果,对湖相碳酸盐岩缝洞储层预测研究有借鉴意义。

关键词: 敏感地震属性, 地震反演, 碳酸盐岩缝洞预测, 深水盐下储层, 湖相碳酸盐岩, 桑托斯盆地, 巴西

Abstract:

The F oilfield, a deep-water sub-salt oilfield in the Santos Basin of Brazil, is characterized by deep burial, diverse lithology and strong heterogeneity. Unlike commonly-seen porous reservoirs and some large karst cave reservoir clusters in Western China, the reservoirs in the study area are deep-water lacustrine carbonate rocks with small vug size and various fracture types, resulting in extremely unclear seismic responses and wrong interpretations with conventional prediction methods for fractured-vuggy reservoirs. In addition, the massive salt layers overlaying the reservoirs also reduce the resolution of seismic data of well fractured and vuggy parts and pose challenges to the understanding of their distribution pattern through post stack seismic method. To deal with the problem, this study develops a workflow suitable for the seismic prediction of small fractured-vuggy carbonate reservoirs of diversified lithology against a deep-water sub-salt setting based on the development characteristics of fractures and vugs in the study area and a combination of well and seismic data analyses to eliminate the lithologic interference of mudstone and igneous rocks. It features in the optimization of seismic data and a quick responsiveness to geological information conveyed through seismic anomalies by making full use of core, FMI well-logging and production leakage information. Application to the prediction of dissolution pores and vugs has been proven positive as the method is capable of defining the sensitive seismic attributes of fractures and vugs to predict fractures by combining structural stress field and to predict vugs by combining seismic inversion results such as wave impedance, porosity and CGR. The study is of guiding significance to the prediction of lacustrine carbonate reservoirs with fractures and vugs.

Key words: sensitive seismic attribute, seismic inversion, prediction of carbonate fractures and vugs, deep-water sub-salt reservoir, lacustrine carbonates, Santos Basin, Brazil

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