New idea for petroleum exploration in Qaidam Basin

Searching for fissure-type oil and gas traps is probably the key of petroleum exploration in Qaidam Basin, where oil seeps and anticlines are abundant but without enough ideal reservoirs. A field research of the Youquanzi anticline shows that there are conjugate kink zones on its northern and southern limbs. The angle between the zones is 110??, and the anticlines in between are of box-shape. The bedding outside the zones is sub-horizontal and the inside bedding is sub-vertical with locally overturned. The zones develop interlayer dilation fractures and small-scale thrusts filled with fiber gypsum and locally with oil, indicating that the zones were once filled with high-pressure fluids. The shoulder of the southern kink zone near the core is the culmination of the structure. Drills should be arranged along the culmination, and then an oblique drill along the main kink zone is expected to obtain fissure-type traps.EI0113-183