ABSTRACT
The majority of Putaohua layers structural reservoirs in Daqingzijing oilfield is broken nose and block reservoir of faulted reservoirs, of which the lowest common denominator in the formation updip is fault trap, including the following three types. (1) Broken nose structural reservoirs. Due to the regional squeeze and faulted reverse drag, it formed nose uplift. Nose uplift matched with different direction faults formed broken nose structure. Broken nose structure is a large number of types of traps in this area. The hydrocarbon accumulation in the nose structure traps formed fault nose oil and gas reservoirs. Although there are a lot of fault
1 INTRODUCTION
The Daqingzijing area is located Songnan the best SOURCE depression in-Changling north. The northern part in Changling is Qian’an secondary depression and the southern part is Heidimiao secondary depression. Daqingzijing well structure is in the saddle between the two depressions. The overall pattern is the long axis of the northtrending syncline. The east and west wings of the syncline are asymmetrical with steep west wing and moderate east wing. In the Mesozoic and Cenozoic, the district long-term development is in the basin sediments, sedimentation axis, with a more complete strata development, local magmatic intrusions and volcanic eruptions. The Putaohua oil layer is in the first section of Yaojia group. Songliao basin is in the water withdrawal period between the two largest qn1, n2 transgressive periods which are the period of low water lever with the main branch channel deposits. Late period with transgressive water, the depression center moving towards the south, the river retreating, the early delta sandstone was water influx destruction, forming residual mouth bar, coastal dam. Reservoir sand is longitudinal and misfolding with low lateral connectivity, formation of the longitudinal alternating layers of sandstone and mudstone, and the horizontal sandstone and mudstone at the pattern of connection, thus Putaohua reservoir plane distribution reflects faults-lithologic reservoir at the background of local uplift or nose structure.
