正牵引构造对冲积扇储层内部构型的控制作用

针对同生逆断层上盘发育的正牵引构造与冲积扇储层内部构型耦合关系不明的情况，利用岩心、露头、密井网及地震等资料，采用井震结合、标志层与目的层高程差、构型层次分析及地质综合分析等方法，从正牵引构造的基本特征出发，探讨了其控制下冲积扇储层内部构型的差异分布特点。研究表明：（1）正牵引构造有4个基本特征：呈不对称的背斜隆起形态、不同位置隆起幅度存在差异且具有累积效应、常与张性构造和不整合伴生、具有继承性发育且分布范围渐变的特点；（2）正牵引构造引起的差异隆起的沉积底形控制了冲积扇砂砾岩体的分布样式，冲积扇砂砾岩体构型要素在空间上分布与已有冲积扇沉积模式差异较大，即不再遵循辐向距扇根部位距离相等的位置具有大体相同的构型属性的规律；（3）正牵引构造控制了沉积物可容空间的大小，抬升隆起导致其发育部位可容空间不断降低，而其侧翼的则不断增加。同时，其隆起的沉积底形影响了古水流的流向，最终改变了冲积扇储层内部构型的分布格局，不再遵循沿辐向上构型要素类型与规模渐变的基本特征。

Controlling effect of normal drag structure on the internal reservoir architecture in an alluvial fan

The coupling relationship between the normal drag structure developed in the hanging wall of a contemporaneous reverse fault and the internal reservoir architecture in alluvial fan, based on core, outcrop, dense well and seismic data is unclear. Well-to-seismic calibration, elevation differences between key and target strata, hierarchy bounding surface analysis and comprehensive geological analysis have been used to clarify this relationship. The differential distribution characteristics of internal reservoir architecture under the control of normal drag structure were studied. Research shows:(1) Normal drag structure has 4 essential features:asymmetrical anticline uplift morphology, uplifted extent difference exists in different places with cumulative effect, extensional tectonic and unconformities often appear, successive development and distribution range gradually change. (2) The bed form of differential uplifting caused by normal drag structure controlled the dispersion and filling with sandy conglomerate, which was different from the traditional mode, that is, different architecture may appear at the same distance to the fan root. (3) Normal drag structure controlled sediment accommodation space. Uplift made the space decrease, and on the wings increase instead. On the other hand, uplifting sedimentary bed form affected the direction of paleocurrent and changed the distribution of internal architecture in an alluvial fan reservoir. Architecture element type and scale no longer changed along the radial direction.