Characteristics and controlling over reservoir accumulation of tear fault in foreland thrust belt of Baikouquan area in the northwestern margin of Junggar Basin

Key words:  foreland thrust belt  tear fault  seismic coherency cube  hydrocarbon accumulation

Abstract:

According to theoretical analysis, the features and recognition marks were described combined with the regional tectonic setting. The fault plane of tear fault is nearly vertical，and it usually shows discontinuity of wave group，disorder of seismic event on seismic section. On horizontal time slice, it reveals distortion, variation in width and attitude of seismic event. While for well logs, it results in the increase of interlayer frequency，and enhancement of sawtoothed curve. A certain size of northwest directional tear faults was firstly discovered in the northwestern margin of Junggar Basin. There are eight tear faults in Triassic strata of Baikouquan area, which extended from three to seven kilometers. The tear faults can not only be effective pathways for oil and gas migration and accumulation, but also block off the oil and gas on the side，and it has significant effects on hydrocarbon migration and accumulation.