黄骅坳陷断裂发育特征及其对新生古储型潜山成藏控制作用

“新生古储”型潜山是大港油田潜山勘探的重要领域并取得了勘探突破，多期断裂演化控制了新生古储潜山类型多样性及成藏条件多样性。通过系统分析坳陷控山断裂的静态、动态特征，恢复断裂发育对潜山山系形成的控制作用，针对古生界内幕碳酸盐岩与碎屑岩储层物性特征和成储机制、烃源岩特征及源-储配置关系等成藏要素系统分析，区划潜山类型，指出不同类型潜山勘探潜力层系及分布区。研究结果表明：(1)现今断裂具有多走向、多性质的特征，受控于多期次叠合演化的结果。其主要为四个期次：T₃时期近EW和NW(W)逆断，J₁₊₂继承发育；J₃+K₁初期挤压逆冲形成NNE(近SN)向逆断-转换断层；至K₁为负反转发育阶段，形成负反转断层；E时期受伸展作用控制，形成NE(E)向伸展断层。(2)“两期挤压成山-一期块断成山”成山过程，内幕储层经历“早成岩期—表生期—中成岩期—晚成岩期”多期成岩作用，奥陶系碳酸盐储层为中孔-中渗储层，碎屑岩储层为中-低孔隙、中-低渗储层。(3)在孔二段和沙三段优质烃源岩发育的条件下，源-储对...

Fault characteristics and fault control of hydrocarbon accumulation in “new source,old reservoir” type buried hills of the Huanghua depression

The “new source, old reservoir” type buried hills are an important exploration target in the Dagang Oilfield, Hunanghua depression where an exploration breakthrough is made recently. Controlled by multi-stage fault evolution this type of buried hills is diverse in reservoir types and hydrocarbon accumulation conditions. In this study, the static and dynamic characteristics of the hill-controlling faults are systematically analyzed, and the fault control on the formation of buried-hill reservoirs is revealed. Based on a systematic analysis of the influencing factors in reservoir formation, such as physical properties/reservoir-forming mechanisms of Paleozoic carbonate and clastic reservoirs, source-rock properties, and source-reservoir configurations, the buried-hill types are delineated, and the potential exploration strata and distribution area for each type are identified. Results show (1) the current fault system has the multi-direction, multi-property characteristics resulted by multi-stage superposition evolution. The fault system develops through four main stages: near-EW and NW (W) reverse faults of T3 period continue development in J₁₊₂; NNE (near-SN) thrust-transition fault forms by extrusion thrust in J₃+K₁; the above thrust-transition fault undergoes negative inversion in K₁; and NE (E) extension fault forms in the Cenozoic E period. (2) The buried hill experienced “two-stage extrusion, one-stage block faulting” orogenesis, and the inner reservoir experienced multi-stage diagenesis (early-, supergene, middle- and late-diagenesis). The Ordovician carbonate reservoir has medium porosity/permeability, and the clastic reservoir has medium-low porosity/permeability. (3) With high-quality source-rock developing respectively in the 2^nd and 3^rd members of the Kongdian and Shahejie formations, source-reservoir configuration becomes an important factor controlling the formation of buried-hill reservoirs, and five source-reservoir configuration types are formed under fault control. (4) According to source-rock property, source-reservoir configuration and internal structural style, the “new source, old reservoir” type buried hills are divided into three categories and seven subcategories. The buried hills have a ring-shaped planar distribution, and the potential exploration area includes three zones: Ordovician strata in the multi-stage structural superposition area; middle-low strata in the basin margin; and deep strata connected to the high buried-hill source rocks outside the basin.