近期渤海海域油气勘探的新突破

Recent new breakthroughs in hydrocarbon exploration in Bohai sea

通过勘探研究思路转变、地质认识创新及作业技术进步,近期渤海油田在盆地边缘小凹陷、中深层轻质高产油气、浅层重质油产能、潜山油气勘探等多个区域和领域实现了新的突破。重新认识凹陷生排烃能力,完善渤海海域新近系浅水三角洲沉积模式,提出断裂性质、结构、活动性等三因素联合控藏模式,明确了油气差异富集规律;提出陡坡带区域盖层下构造-地层(岩性)圈闭勘探理念,建立陡坡带"源-汇"时空耦合富砂机理,指导了中深层优质储层预测;建立渤海海域首个特稠油油藏模式,运用特稠油热采测试技术组合,实现了产能突破;明确花岗岩储层成因机理,提出花岗岩储层垂向分带序列和半定量评价标准,创新花岗岩潜山"似层状"油藏模式,丰富了潜山油藏类型。这些重大突破带动了渤海海域近期一系列大中型油气田的发现,使该区域新增储量稳步增长,所取得的认识及技术经验可为今后勘探提供指导。

In Bohai oilfields, new breakthroughs have recently been made in several aspects, such as small mar- gin sag, middle-deep high-yield light oil and gas, shallow heavy oil capacity and buried-hill hydrocarbon, through changing ways of thinking, innovating in geological knowledge and improving operation technology. Firstly, the hydrocarbon generation-expulsion capacity of a sag was revaluated, the Neogene deposition model of shallow delta was improved and a hydrocarbon accumulation model controlled by three factors, i.e. fault property, structure and activity, was presented, making the pattern of differential hydrocarbon entrapment clear. For the steep slope zones, an exploration concept to look for structural-stratigraphic （lithologic） traps below the regional seal and a sand enrichment mechanism by spatial-temporal coupling of “source-sink” were established, which have directed the prediction of excellent middle-deep reservoir rocks. For the extra-heavy oil, its first accumulation model was established, and its breakthrough in productivity was made by using a combination of its thermal recovery and test techniques. For the granite reservoir rock, its origin, vertical zon- al sequence and semiquantitative evaluation criterion were identified, and an innovated accumulation model of “quasi-bedded” buried hill granite has added a new type of buried hill reservoir. These major breakthroughs have promoted the recent discovery of several large and major fields in Bohai sea, with the added reserves in- creasing steadily, which will provide guidance for the future exploration.