日青威盆地桃林地区白垩纪热流体活动特征及其对储层物性的影响

山东东部日青威盆地为近年来新发现的裂陷盆地，盆内广泛发育深水重力沉积岩并且有机质含量丰富，具有非常规油气勘探远景。为了查明盆地内热流体活动的发育特征及其对储层物性的改造作用，以桃林地区长玢岩及其围岩为研究对象，通过岩相学观察及X-射线衍射、流体包裹体、物性测试等实验分析方法，探讨了热流体活动特征及其对储层物性的影响。研究结果表明：闪长玢岩与围岩的岩性组合主要有2种类型：闪长玢岩+砂岩(下部)、闪长玢岩+角砾岩+火山碎屑岩+砂岩+粉砂岩(上部)；热流体活动对围岩的影响主要体现在独特的脉体特征、碎屑颗粒的热液蚀变、黏土矿物出现异常变化、流体包裹体均一温度出现异常高值4个方面；桃林地区热流体活动在砂岩储层中以横向运移为主，随着距离侵入体距离的增加，热流体对储层物性的影响减弱，但在地层中部出现物性相对好的区域，推测是多期次热流体以及次生断裂作为运移通道的叠加结果。

Characteristics of cretaceous thermofluid activity and its influence on reservoir physical properties in Taolin area,Ri-Qing-Wei Basin

Ri-Qing-Wei Basin in the eastern Shandong Province is a newly discovered rift basin in recent years; it is widely developed in deep-water gravity-flow sedimentary rocks and rich in organic matter. This basin has a potential for unconventional oil and gas exploration. To examine the developmental characteristics of thermal fluid and its effect on reservoir physical properties, diorite porphyrite and its surrounding rock in the Taolin area were selected and studied in experimental analysis methods including thin-section mirror observation, X-ray diffraction, fluid inclusion. Results show that thermal fluid had a strong effect on reservoir remolding. There are two lithological assemblages of diorite porphyrite and surrounding rock: diorite porphyrite + sandstone (lower) and diorite porphyrite + breccia + pyroclastic + sandstone + siltstone (upper). The characteristics of thermal fluid activity are mainly reflected in the unique characteristics of veins, hydrothermal alteration of clastic particles, abnormal changes of clay minerals, and abnormal high homogenization temperature of fluid inclusions. The thermal fluid movement in the Taolin area is mainly lateral migration in sandstone reservoir. With the increase of the distance from the intrusion, the influence from thermal fluid is weakened, but the area with relatively good physical property appeared in the middle of the formation, which is believed to be the superposition result of multi-stage thermal fluid activities and secondary fractures as migration channel.