The Analysis Of Maxian Fault Activities And Its Influence On Hydrocarbon Accumulation

This paper is based on the date of drilling, logging, seismic and previousresearch,made the tectonic evolution of the Maxian fault as the main line, theformation comparative as the precondition, analysis the instrinsic link between of thestructure of tectonic and all structure units, and its relationship with regional tectonic.Define the matching relationship between activity time of deformation and theexpulsion time, understand the fault which control the oil source and the traps,finally, noted the favorable direction for the petroleum exploration.Based on the detailed investigation and previous study, the deformation time andcharacteristics of maxian fault are analyzed through stratigraphic correlation betweenthe footwall and hangingwall. The thickness of hangingwall was significantly thinnedcompared to the hangingwall around the Maxian fault, And erosion occurred in theJurassic, Cretaceous and Quaternary, which developed unconformity, and reflect thedeformation time of the maxian fault, which is Jurassic, Cretaceous and Quaternaryperiods respectively.By the analysis of the seismic profile around Maxian Fault and its surroundingarea, it makes it clear that the Maxian fault is the basement involved thrust fault in theNorth of the Qaidam Basin, and it tend to south, it performance as steep at the front,and gentle at the back on the hangingwall of the Maxian fault, which representedclassic fault propagation fold, and a series of sub-level thrust fault developed aroundthe Maxian fault, which all influenced the Mahai uplift with Lingjian fault, then fourkinds of traps developed around the Maxian fault, which are anticline trap, brokennose trap, broken Long trap and fault block type, respectively. According to theanalysis on the thickness between the hangingwall and the footwall strata, Maxianfault act as the characteristics of multiple stage fracture, and act intensely at the lateCenozoic, finally, use the forward method recovery the Maxian fault, reveals theMaxian fault act as an important thrust which role as long term performance at thenorthern margin of the Qaidam Basin.By systematically summed up results of previous studies, there are two source rocks developed around Maxian Fault and its surrounding area, which areXiaomeigou FM and Dameigou FM, which has high TOC, and high thermal maturity,and three types of reservoir, which were sandstone reservoirs, algal limestonereservoir and fracture, respectively, combined with regional cap, Maxian Fault and itssurrounding area has good reservoir, through the study of tectonic subsidence historyand thermal evolution history, the timing of faulting and the timing of jydrocarbongeneration and expulsion play consistency, and Maxian fault as oil and gas migrationchannels. Until late Neogene, the Maxian fault act smaller, and its role play asblocking effect on hydrocarbon accumulation.