轮古东走滑断裂破碎带结构及与油气关系

The structure of crushed zone near the Lungudong strike slip fault and its relationship with the gas and oil

利用最新处理完成的轮古东300 km2叠前深度偏移地震资料,多手段识别出轮古东气田发育3期4组断裂。断裂控制了裂缝走向与裂缝发育密度,裂缝主要为高角度（45°~75°）构造窄裂缝,沿裂缝存在溶蚀,走向主要为NESW。纵向上,一间房组裂缝发育密度最大（14条/100 m）,其次为鹰山组（6条/100 m）和良里塔格组（4条/100 m）;平面上,裂缝主要分布在主干断裂周边1 km范围内,随着距断裂距离增大,裂缝发育强度（裂缝线密度）呈指数降低。在此基础上,综合考虑主干断裂及伴生裂缝发育特征,将轮古东断裂破碎带平面上划分为“羽状破碎带、转换破碎带、斜列破碎带、复合破碎带”4种结构,羽状破碎带分布面积最广,是油气最富集的区域,是目前高效井的集中分布区,围绕羽状破碎带的钻探为走滑断裂控储控藏研究和寻找新的油气富集区域提供了新思路。

Using the latest seismic data of 300 km2 depth migration before stack in Lungudong, the authors identified three stagesand four groups of fractures in Lungudong gas field by various means. The strike and compactness of the fractures are controlled byfaults. The fractures are mainly high angle（45°-75°）narrow fractures. Corrosion is developed along the fractures, and the dominantstrike is NE-SW. In the longitudinal field, the fractures of Yijianfang Formation has maximum density（14 fractures per 100 m）,followed by the compactness of the fractures of Yingshan Formation （6 fractures per 100 m） and the compactness of the fractures of Lianglitage Formation （4 fractures per 100 m）. In the plane field, fracture is mainly distributed in the area within 1 km of the mainfaults. With the increasing distance from the fault, the degree of fracture development （linear density of fractures） decreases with thetendency of index number. On such a basis, the authors have comprehensively considered developmental characteristics of mainfractures and accompanying fractures. In the plane field, crushed zones of Lungudong fault are divided into pinnate crushed zone,transform crushed zone, echelon crushed zone,and composite crushed zone. The area of pinnate crushed zones is the largest andmost gas and oil spots are concentrated here, and high- efficiency wells are centrally distributed in this area at present. Theexploration drill holes around the pinnate crushed zone offer a new train of thought for the study of strike slip fault controlling oiland gas reservoir and finding new rich domains of gas and oil.