Abstract:

In the study of dense sandstone reservoir in the Second Member of Xujiahe Formation in Xinchang area, the reservoir characteristics were analyzed using approved slice and properties data acquired with test methods. Fractures and fluid were identified and predicted using core, logging and seismic methods, to guide the synthetic evaluation of reservoir and the favorable block optimization. It is indicated that secondary pore and micro-fracture develop mostly in target formation, and fractures are mainly low-angle fractures, spreading along fault and fold-belt in structural limbs. The effective reservoir are mainly controlled by sedimentary facies, diagenesis, structure and petroleum accumulation, however, corrosion and crack are the main control factors. The blocks of reservoirⅠ locate in high structural place or nearby faults inTx²₂and Tx⁴₂. It is concluded that the areas of two sides of F3 fault in middle and up sub-segments are the most favorable blocks, while two sides of southern edge of F1 fault in up sub-segment and Xin10-Chuanke1 well area in middle sub-segment are the secondary. The study results are significant in effective development of the Second Member of Xujiahe Formation in Xinchang area.

Key words: Xinchang area, the Second Member of Xujiahe Formation, dense sandstone, fracture, fluids