构造成岩作用及其油气地质意义

Structural diagenesis and its petroleum geological significance

沉积储层的形成演化受沉积作用、构造作用和成岩作用共同的影响,其中沉积作用是基础,构造作用和成岩作用是关键。根据控制沉积储层形成演化的主要地质因素,本文提出了构造成岩作用概念及其内涵,分析了构造成岩作用在致密低渗透储层及其天然裂缝有效性定量评价中的应用。构造成岩作用是指沉积岩层从松散沉积物到固结形成沉积岩石及之后的过程中所发生的构造和成岩相互作用,它主要研究沉积物沉积以后构造变形与沉积物物理、化学变化的相互作用关系,既包括构造变形方式和变形强度对沉积储层成岩作用及流体的影响,还包括成岩作用和流体对构造变形的影响。构造成岩作用控制了含油气盆地沉积储层的形成演化过程以及有效储层的分布规律,利用构造成岩作用研究可以为致密低渗透油气储层质量评价、天然裂缝及其有效性评价提供有效的途径。

The formation and evolution of sedimentary reservoirs is controlled by sedimentation,tectonism and diagenesis,of which sedimentation is the foundation,and tectonism and diagenesis are the keys.Based on the main geological factors controlling formation and evolution of sedimentary reservoirs,the concept of structural diagenesis and its implications are put forward in the paper.Then the application of structural diagenesis in quantitative evaluation of tight and low-permeability reservoirs and effectiveness of natural fractures is analyzed.Structural diagenesis is referred to structural and diagenetic interaction occurring in the process of change from loose sediments to the formation of consolidated sedimentary rocks.Structural diagenesis is the study of the relationships between structural deformation and physical and chemical changes to sediments,including both the influences of structural deformation mode and deformation intensity on diagenesis and fluid,and the influences of diagenesis and fluid on structural deformation in sedimentary reservoirs.Structural diagenesis controls the formation and evolution processes of sedimentary reservoirs and distribution of effective reservoirs in petroliferous basins.So the study of the structural diagenesis can provide an effective way for evaluation of reservoir quality,natural fractures and fracture effectiveness in tight and low-permeability reservoirs.