川东北YB地区须家河组裂缝特征及主控因素

Controlling factors and fracture characteristics of Xujiahe Formation reservoir
in YB Area, northeastern Sichuan Basin

何志勇 刘海涛 肖伟

中国石化勘探南方分公司研究院，四川 成都 610041

Research Institute, SINOPEC Exploration Southern Company, Chengdu 610041, China

川东北YB地区须家河组储层为低孔、低渗的致密砂岩储层，裂缝的存在极大地改善了储层的储渗空间，提高了单井产能。综合分析研究区的构造特征、演化特征、岩心资料及成像测井资料进行认为，须家河组储层裂缝以构造缝为主，倾向NW，西北部地区以中低角度缝为主，中东部地区以高角度缝为主。西北部地区裂缝发育主要受控于九龙山背斜带，在背斜翼部转折端和倾没端裂缝较发育；中东部地区裂缝发育主要受控于断层，沿大型断层呈南北向条带分布，断层上盘及构造高陡部位裂缝较为发育。裂缝发育主控因素包括构造幅度、构造部位、岩石类型和岩性组合等，其中，构造幅度、岩石类型为西北部裂缝的主控因素；构造部位、岩性组合为中东部裂缝的主控因素。

The reservoir of Xujiahe Formation in YB Area of northeast Sichuan Basin is a tight sandstone reservoir characterized by low porosity and low permeability. However, the existence of fractures greatly improves the reservoir space and the production capacity of single well. Through analyzing the tectonic characteristics, evolution characteristics, core data and FMI imaging logging data in study area, it is considered that the fractures of reservoir are primarily tectonic fractures with the dip direction of NW and have middle and low angle in the northwestern work area and high angle in the central and eastern region. Fractures in the northwestern work area is mainly controlled by the Jiulong Mountain anticline belt, and develop well in the wing twist end and pitching end of anticline; while in the central and eastern work area, they are mainly controlled by fault, resulting in north-south strip along the major fault and develop well in the upper wall and high-steep parts of structure. The controlling factors of fracture development mainly include structure amplitude, tectonic position, rock type and lithological combination, in which the structure amplitude and rock type are main controlling factors of the fractures in the northwestern work area, while the tectonic position and lithological combination are main controlling factors of the fractures in the central and eastern work area.

10.6056/dkyqt201401007