海拉尔盆地苏德尔特构造带火山岩基底储层特征及成藏模式

海拉尔盆地苏德尔特构造带火山岩基底储层纵向差异明显，油气成藏规律复杂。通过岩心观察、裂缝描述、物性分析以及构造建模并结合勘探生产实践，认为苏德尔特构造带火山岩基底潜山储层纵向具有明显的“三分性”：顶部风化带,中层淋滤带和内幕致密带。顶部风化带发育风化缝,伴生构造缝,低孔—超低渗，属于孔—洞型储层；中部淋滤带以小缝为主，发育溶蚀孔洞,低孔—低渗，属孔_缝型储层；内幕致密带以微裂缝为主，构造缝发育，超低孔—低渗，属微裂缝型储层。裂缝储层主要集中在大型控洼边界断层附近，断阶带的中—浅层和断垒、断崖带的中—深层。苏德尔特构造带具有“断层—缝洞网—不整合”三元成藏模式，油气通过单向运移，双向运移以及“倒灌式”运移3种方式成藏。研究区的潜力勘探区为断垒(断崖）带的中—深层致密带以及边界断层附近的中—深层淋滤带和致密带储层。

Characteristics of the volcanic basement reservoirs and its hydrocarbon accumulation mode in Sudeert structural belt,Hailar Basin,China

The Sudeert structure belt in Hailar Basin has obviously vertical reservoir differences and various hydrocarbon accumulation patterns.Based on core,fracture feature,reservoir quality and structure modeling,as well as industry performance,the reservoir of Sudeerte structural belt is divided into three obvious parts,namely weathered -layer,leached-layer and the compact zone.The weathered-layer featuring great width and high inclination angle,which develops weathered and associated tectonic fracture,is classified as vuggy reservoir.The leached-layer,featuring irregular width and inclination angle and mainly composed of dissolution and leaching fissures,develops fractured-vuggy reservoir.The compact zone,made up of structural micro-fissures,cultivates tectonic fractures.The fractured zone of the studied area concentrates near the large border vault,in the shallow-middle layer of the fault horst and the middle-deep layer of the cliff.The unique fracture system and structure of the fault-block type buried hills form the ternary reservoir model(fault-fracture cave-unconformity) of the Sudeerte structural zone.The fault at the border migrates mainly along the unilateral direction of the source fault,and the oil/gas mostly concentrates in the three reservoirs of the near-fault zone;oil/gas in the step-fault zone mainly migrates downwards,and concentrates in the reservoirs at the border of cliff and fault horst.Therefore,the potential exploration zone of the Sudeerte structural zone should be the border of the large fault and the shallow-middle layer of the cliff and fault horst.