腰英台油田青山口组储层裂缝特征研究

摘要

Yaoyingtai Oilfield is located in the central depression of Shongliao Basin,and the reservoir of Upper Cretaceous in Qingshankou Formation in the 1∼301 blocks of Yaoyingtai Oilfield is fractured low-permeability reservoir and develop fracture quite. This paper carries out systematical research about fractures through core observation,slices analysis,the imaging logging data and carbon and oxygen isotope analysis. The study shows that the fracture developed in Qingshankou Formation of Yaoyingtai Oilfield,and the highest degree of development in Qingshankou Formation is II sand set in No.1 section of Qingshankou Formation. Other findings include that the length of fracture distributes between 5∼15 cm and the width distributes between 0.1 1mm and the average density is 0.41 strips per meter. Most of fractures are full filled and the majority of fillings is calcite with fracture dip between 75◦∼90◦,the orientation of fracture has mainly 4 groups which includes NWW(280◦), NNW(345◦),NNE(18◦),NEE(76◦). While the width of micro-fracture rests under 0.5 mm and filled or half-filled by calcite and organics. The main fracture properties is shear fractures and other part of fracture properties is tension fracture. The fractures has two develop stages,one is formed in the late tectonic movement of the nenjiang formation,and another is formed in the late tectonic movement of MingShui formation.%腰英台油田位于松辽盆地南部中央拗陷区，其中的1号区块∼301号区块的上白垩统青山口组砂岩为裂缝性低渗储集层，裂缝较为发育。通过对岩芯的系统观测、薄片裂缝观察、测井资料解释、碳氧同位素测试等手段对裂缝进行了系统研究，结果表明：腰英台油田青山口组裂缝发育，其中发育程度最高的为青山口组一段II砂组；裂缝长度的主要分布在5∼15 cm，宽度主要分布在0.1∼1.0 mm，密度平均0.41条/米，大部分裂缝都被全充填，充填物以方解石为主，裂缝倾角主要分布于75◦∼90◦，裂缝方位主要共有4组，分别是NWW（280◦）向、NNW（345◦）向、NNE（18◦）向和NEE（76◦）向；微裂缝以宽度小于0.5 mm为主，被方解石或者有机质充填或者半充填，裂缝性质以剪切缝为主，部分发育张性缝；裂缝发育期次主要分为两期，分别为嫩江末期和明水末期。