中国石油勘探 ›› 2021, Vol. 26 ›› Issue (5): 49-59.DOI: 10.3969/j.issn.1672-7703.2021.05.005

• 勘探案例 • 上一篇    下一篇

琼东南盆地BD21井深水区天然气勘探重大突破及意义

郭书生,廖高龙,梁豪,彭志春,王世越   

  1. 中海石油(中国)有限公司湛江分公司
  • 出版日期:2021-09-15 发布日期:2021-09-15
  • 作者简介:郭书生(1975-),男,河南洛阳人,1997年毕业于石油大学(华东)矿场地球物理专业,高级工程师,作业经理,主要从事地质作业管理及技术研究工作。地址:海南省海口市秀英区长滨三路8号巨制国际大厦,邮政编码:570100。
  • 基金资助:
    国家科技重大专项“大型油气田及煤层气开发”(2016ZX05026-002)。

Major breakthrough and signifi cance of deep-water gas exploration in Well BD 21 in Qiongdongnan Basin

Guo Shusheng, Liao Gaolong, Liang Hao, Peng Zhichun, Wang Shiyue   

  1. CNOOC Zhanjiang Branch Company
  • Online:2021-09-15 Published:2021-09-15

摘要: 琼东南盆地深水区油气资源丰富,前期已在深水西区乐东—陵水凹陷发现超千亿立方米大气田,但深水东区宝岛—长昌凹陷由于储层埋藏深、物性差,成藏地质条件认识不深入,导致深水东区勘探一直未获突破。近期部署在宝岛凹陷北部断阶带的风险探井BD21井在陵水组三段试获日产凝析油200.2m3、日产气73.12×104m3的高产油气流,实现了30多年来在深水东区勘探的首次重大突破。基于BD21井钻探成果,系统分析了宝岛凹陷北部断阶带油气成藏地质条件和富集规律。研究表明,宝岛凹陷发育崖城组规模烃源岩,成熟度高、生烃能力强;受神狐隆起控制,陵水组沉积期北部断阶带发育优质辫状河三角洲前缘储集体,储层厚度大、物性好;两期油气充注时期断裂活动性弱,构造演化与供烃时机匹配,储层和沟源断裂形成垂向+ 短侧向高效油气输导体系;区域性盖层覆盖了成藏系统内油气生成—运移—聚集全空间范围,油气运移输导封闭条件好。宝岛凹陷北部断阶带是有利的勘探方向,展现了深水斜坡区构造—岩性油气藏规模勘探潜力。

关键词: 琼东南盆地, 宝岛凹陷, 深水东区, 陵水组, 成藏条件, 重大突破

Abstract: The deep-water area of Qiongdongnan Basin has abundant oil and gas resources. A giant gas fi eld with resources of over 100 billion cubic meters has been discovered in Ledong-Lingshui Sag in the western deep-water area. While no breakthrough has been made in Baodao- Changchang Sag in the eastern deep-water area due to the great burial depth, poor reservoir physical properties and poor understanding of hydrocarbon accumulation conditions. Recently, a risk exploration Well BD21, located at the northern fault terrace zone in Baodao Sag, obtained high-yield condensate oil and gas production of 200.2m3/d and 73.12×104m3/d in the 3rd member of Lingshui Formation, which was a remarkable breakthrough in the eastern deep-water area in recent 30 years. Based on the drilling results of Well BD21, geological conditions and enrichment law of hydrocarbon accumulation are systematically summarized in the northern fault terrace zone in Baodao Sag. Study results show that a large-scale source rock of Yacheng Formation is developed with high maturity and strong capacity of hydrocarbon generation. The fault activity was weak during the two stages of hydrocarbon charging, and the tectonic evolution matched well with the timing of hydrocarbon supply. The high-effi ciency hydrocarbon migration pathways are formed by the combination of reservoir and faults which connect with source rock in both vertical and short-distance lateral directions. The regional caprock covers the whole spatial range of hydrocarbon generation, migration and accumulation, providing good sealing capacity. The northern fault terrace zone is favorable exploration target in Baodao Sag, which shows great potential of large-scale structural-lithologic oil and gas reservoirs in deep-water slope zone.

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