中国东部裂谷盆地变质基底中的油气前景——以辽河裂谷盆地基底变质岩潜山内幕油藏勘探为例

Oil and Gas Prospects in the Metamorphic Substrate of the Rift Basin in Eastern China—Taking the Exploration of the Buried Hill Inner Reservoir of Substrate Metamorphic Rock in the Liaohe Rift Basin as an Example

摘要: 辽河裂谷盆地，位于渤海湾盆地东北隅。伴随渤海湾盆地的发生发展，经历了多期次强烈的构造变动。特别是中生代以来，郯庐断裂走滑、拉伸应力(场)的强烈作用，形成多套裂缝系统叠加的储集体系和凹凸(隆起)相间分布的构造格局。构成裂谷盆地中受断层控制的潜山、凸起与生油凹陷(断陷)相伴或围绕分布的、有利于潜山油气藏形成的优越地质条件。在分析辽河裂谷盆地兴隆台潜山巨厚的“潜山内幕”油藏形成的主控因素和分布特点后，提出变质岩潜山内幕油藏成藏体系概念。“源、储、输、盖”等四大要素，构成基底变质岩潜山油藏不可或缺的成藏体系。有效耦合的成藏体系埋藏有多深，变质岩“潜山内幕”油藏埋藏就可能有多深；成藏体系中各要素的优劣、有效耦合程度，影响和控制了变质岩潜山油藏的分布特点和丰度；源岩的性质及含有物(水层、油层、生烃岩)不同，导致潜山内幕油藏分布的复杂性和隐蔽性：在纵向上，可能出现油、水层倒置或交互发育(ZG2)；也可能出现上部为水层或无任何油气显示现象。但都不能否认潜山内幕油藏的存在；在平面上，可能出现沿深大断裂作不规则的“团块”状分布。因此，按照变质岩成藏体系的有效耦合程度及源岩性质进行综合评价、部署。就能使我们对变质岩潜山“内幕油藏”的勘探，从偶然到必然、从被动到主动、从迷茫到清晰、从等待观望到主动出击的思想转变。同时，积极开展适应变质岩潜山内幕油藏勘探的技术创新；科学有序引进不受复杂地质条件影响、直接找油的“微轻子石油探测技术”。将大大提高变质岩潜山勘探的成功率和信心，推动和加快中国东部裂谷盆地变质岩潜山石油勘探工作向纵深发展。促进石油地质储量和产量再上新台阶；石油工业发展再创新辉煌。确保国家能源战略安全、缓解石油对外依存度具有重要的政治经济意义。

Abstract: Liaohe Rift Basin, is located in the northeast of Bohai Bay Basin. With the development of Bohai Bay Basin, it has experienced many periods of strong tectonic changes. Especially since the Meso-Generation, the strong effect of the radon fracture slip and stretch stress (field) has formed the structure pattern of the distribution between the storage system and the bump (uplift) phase of multiple sets of crack system superimposed and constitutes a buried hill controlled by faults in the Rift Basin, a bulge accompanied by a natural oil depression (break) or a superior geological condition that is conducive to the formation of the buried hill oil and gas reservoir. After analyzing the main control factors and distribution characteristics of the formation of the huge “subliminal mountain inside” reservoir in Xinglongtai buried hill in the Liaohe Rift Basin, the concept of the reservoir formation system of the sub-rock buried hill is put forward: “source, storage, transmission, cover” and other four elements, which constitutes the base of the deterioration rock buried hill reservoir indispensable storage system. How deep is the effective coupling of the reservoir system, how deep the reservoir of the “hidden mountain” reservoir of the metamorphic rock may be; The advantages and disadvantages of the elements in the reservoir system and the degree of effective coupling effect and control the distribution characteristics and abundance of the buried hill reservoir of the metamorphic rock. The nature and contents of the source rock (water layer, oil layer, hydrocarbon rock) are different, resulting in the complexity and concealment of the distribution of the buried hill reservoir: Upside down, oil, water layer inversion or interactive development (ZG2) may occur, or the upper layer may appear as a water layer or without any oil and gas display. But it cannot deny the existence of the hidden mountain inside the reservoir; the plane, irregular “mass” distribution along deep fractures may occur. Therefore, according to the effective coupling degree and the nature of source rock, the comprehensive evaluation and deployment are carried out according to the effective coupling degree of the metamorphic rock formation system. It can make us the credibility of the exploration of the “inside reservoir” of spoiled rock buried hill, from the chance to necessity, from passive to active, from confused to clear, from waiting to see to active attack of the ideological transformation. At the same time, actively carry out the technical innovation to adapt to the exploration of the inner reservoir of the metamorphic rock potential mountain; Scientific and orderly introduction of “micro-light sub-oil detection technology” is not affected by complex geological conditions and is directly oil-seeking. It will greatly improve the success rate and confidence of the exploration of metamorphic rock potential mountains, and promote and accelerate the development of oil exploration of metamorphic rock potential mountains in the Rift Basin in eastern China and promote oil reserves and production to a new level, oil industry development and brilliant innovation. It is of great political and economic significance to ensure the national energy strategic security and ease the dependence of oil on the outside world.