Buried Giant Arc Structure System and Petroleum Exploration in Turpan-Kumul Basin, Northwest of China

Zhanlong, Yang ¹; Qilin, Chen ²
(1) Northwest Branch, Research Institute of Petroleum Exploration and Development, Lanzhou,, China. (2) Stratrgy Planning, Northwest branch, Research Institute of petroleum exploration and Development, Petrochina, Lanzhou, China.

Based on analysis of regional stress fields and structure distribution pattern in Yanshan and Himalayan periods, concluded that a huge arc structure belt mainly consisted of three local arc structure belts is buried in east-west direction in sedimentary cover of Turpan-kumul basin. With the symmetric central of stress break belt in the middle of basin, the petroleum geological features are comparable and symmetrical in west and east phases of the huge arc structure belt, which attached the three main hydrocarbon-rich sags (Shengbei, Qiudong, Xiaocaohu sag). The structure of Turpan-kumul basin is obviously characteristic on in different sections in west-east and various belts in north-south. The changing of regional and local stress fields are the main reason for the formation of this type of structure scheme. Because of the different slip within a stratum from north to south in middle to later Yanshan movement and Himalaya movement, the structure belt of the west piedmont section is mainly distributed in northwest-southeast and the east, northeast-southwest. The left and right cycles of stress fields in west and east sections result in the formation of arc structure belts in plane. There are three different arc structure belts formed within Turpan depression from north to south, which formed a huge arc structure belt within Turpan-kumul basin. The extrusion faults in EW development are good sealing elements of structure traps. The strike-slip in NS development are good hydrocarbon transporting elements of structure traps because they cut through the lower Jurassic hydrocarbon source rocks of Shuixigou formation. The proposed of this buried giant arc structure system largely change the overall understanding of tectonic framework of Turpan-kumul basin. The opinions of the comparability and symmetry in EW of this huge arc structure belt system are favorable to understand the future exploration domains of Turpan-kumul basin.

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.