北部湾盆地海域油气勘探历程与启示

Offshore Petroleum Exploration History and Enlightenment in Beibu Gulf Basin

分析钻井、地震、储量、产量等历史数据,总结勘探成果、勘探领域、石油地质理论,将北部湾盆地海域勘探历程划分为3个阶段。早期探索阶段(1960-1995年),钻井证实北部湾盆地具备良好的烃源岩和生储盖组合,明确了北部湾盆地的基本构造特征,划分了二级构造单元;20世纪80年代的对外合作高潮,为下一步油气勘探奠定了良好基础。涠西南凹陷突破及滚动勘探阶段(1995-2010年),以涠洲12-1油田为代表一批油田的发现和成功评价,北部湾盆地海域累计探明石油储量突破1×10^(8) t;面对涠西南凹陷满凹含油但油田规模较小的难题,提出滚动勘探战略,实现了储量升级和增加。乌石凹陷突破及新领域探索阶段(2010年至今),以乌石17-2油田为代表一批油田的发现和成功评价,证明乌石凹陷是北部湾盆地继涠西南凹陷之后又一被证实的富烃凹陷,开启了北部湾盆地勘探的新局面;同时对潜山油气藏等新领域积极探索,为后续的可持续发展积蓄力量。

The paper analyzes the historical data of drilling,seismic survey,reserves and production,summarizes the offshore exploration achievements and targets and petroleum geology theory,then divides the offshore exploration process in the Beibu Gulf basin into three stages:(1)Early exploration stage(1960-1995).Drilling results proved that there are good source rocks and source⁃reservoir⁃cap assem⁃blages in the Beibu Gulf basin,the basic structural characteristics was understood,and the secondary tectonic units were divided.Early ex⁃ploration results laid a good foundation for further oil and gas exploration during 1980s when there was a high tide of foreign cooperation.(2)Breakthrough to the Weixinan sag and progressive exploration stage(1995-2010).The discovery and successful evaluation of a number of oilfields represented by Weizhou 12⁃1 firstly contributed to the cumulative proven geological reserves of oil in the Beibu Gulf basin ex⁃ceeding 100 million tons.Facing the condition that the Weixinan sag is full of oil but the average size of the oilfields in the sag is relatively small,a progressive exploration strategy was put forward,which broke the bottleneck and realized the upgrading and increase of reserves.(3)Breakthrough to the Wushi sag and exploration into new areas(since 2010).The discovery and successful evaluation of a number of oil⁃fields represented by Wushi 17⁃2 proved that the Wushi sag is another hydrocarbon⁃rich sag that has been confirmed by drilling data follow⁃ing the breakthrough of the Weixinan sag.This opened a new prospect in the Beibu Gulf basin.Meanwhile,the exploration to new targets such as buried⁃hill reservoirs led to the identification of a number of pre⁃Paleogene carbonate reservoirs which are potential contribution to sustainable development.