Igneous intrusions are common features within rifted sedimentary basins. With advances in technology, exploration has progressed into more complicated petroleum systems where sediments are segmented and altered by networks of dykes and sills. Magmatism increases temperatures and fluid pressures within adjacent sedimentary host rocks. This can lead to mobilisation of mineral-rich hot fluids through pores and fractures, which alters the host rock microstructure via both mineralisation and dissolution. However, few studies have quantified the impact of intrusions on reservoir quality, specifically on host rock pore networks and their ability to conduct fluid. This study uses a combination of plug porosity and permeability, optical, SEM and cathodoluminescence microscopy and XRD to investigate the mineralogical and reservoir quality changes to sandstones within thermal aureoles. In contrast to published models, associating igneous bodies with reduction of reservoir quality in the host rock, our analyses of two intruded sandstones show that alteration and mobilisation of pore filling minerals and clays can also result in enhancement of porosity and permeability at the intrusion-host rock contact. This study identifies the microstructural and chemical changes which produce these reservoir characteristics and discusses the implications of these processes on reservoir quality and fluid migration in intrusion-rich sedimentary basins.

火成岩侵入是裂谷沉积盆地中的常见特征。随着技术的进步，勘探已经发展到更加复杂的石油系统，在这些系统中，沉积物通过堤坝和坎的网络进行分割和改变。岩浆作用增加了邻近沉积基质岩石中的温度和流体压力。这可能导致富矿热流体通过孔隙和裂缝动员，从而通过矿化和溶解作用改变了宿主岩石的微观结构。但是，很少有研究量化入侵对储层质量的影响，特别是对宿主岩孔网络及其导流能力的影响。这项研究结合了塞子孔隙率和渗透率，光学，扫描电镜，阴极荧光显微镜和X射线衍射研究热敏极内砂岩的矿物学和储层质量变化。与已发表的模型相反，将火成岩与宿主岩中的储层质量降低联系起来，我们对两种侵入式砂岩的分析表明，孔隙填充矿物和黏土的改变和动员还可以提高侵入岩体的孔隙度和渗透率。摇滚接触。这项研究确定了产生这些储层特征的微观结构和化学变化，并讨论了这些过程对富含入侵的沉积盆地中储层质量和流体运移的影响。我们对两种侵入式砂岩的分析表明，孔隙填充矿物和黏土的改变和运动也可以提高侵入体与岩体接触时的孔隙度和渗透率。这项研究确定了产生这些储层特征的微观结构和化学变化，并讨论了这些过程对富含入侵的沉积盆地中储层质量和流体运移的影响。我们对两种侵入式砂岩的分析表明，孔隙填充矿物和黏土的改变和运动也可以提高侵入体与岩体接触时的孔隙度和渗透率。这项研究确定了产生这些储层特征的微观结构和化学变化，并讨论了这些过程对富含入侵的沉积盆地中储层质量和流体运移的影响。