Research Of The Oil And Gas Accumulation Conditions Of Daheyan Region, Turpan-hami Basin In The Carboniferous-triassic

Daheyan region, which was a blocks with low degree of exploration in Turpan-HamiBasin, was generally believed with poor hydrocarbon conditions in the past. And4drilledexploration wells in this region showed no obvious signs of oil and gas. However, theresearch in the past was concentrated to a large extent in the shallow layers. There waslittle research of the source rocks in the deep layers.This thesis was based on the theoretical methods of petroleum geology, structuralgeology, sequence stratigraphy and combined with methods such as seismic geology andlogging. With the regional context, local structural conditions and reference to the studyof tectonic evolution, the hydrocarbon accumulation conditions of Daheyan Region inTurpan-Hami Basin from Carboniferous to Triassic was analyzed from the aspects ofsource rocks and sandstone distribution.Daheyan Region is located on the intersections of Taibei Depression, Buerjia Riseand Keyayi Depression in Turpan Depression. By the combined effects of tectonicmovement of tectonic units, it has complex structures. First, according to the regionaltectonics and seismic structural characteristics, combined with drilling data in DaheyanRegion and its adjacent areas, by the division of the seismic sequence stratigraphy, thesediment distribution in this area was got. After dividing the seismic stratigraphicsequence, the sequence stratigraphic framework of the typical survey lines wasestablished. Using the drilling data of the Daheyan Region and its adjacent areas, theassociated well profiles were established for the further study of the distribution andchange of formation in this area. On the base of the above studies, using the seismicsections, logging data and referencing the information of the stratigraphic distribution ofnearby areas, the distribution range of the strata and the residue thickness, and lithologicalcharacteristics in Daheyan Region from Carboniferous to Paleogene was clear. Thecontour maps of the main layers were drawn and a brief analysis of the deposition center of each period as well as the migration of the sedimentary center was done. On the baseof stratigraphic studies, combined with the drilling data and outcrop data, the research ofthe source rocks from Carboniferous to Triassic was carried out. At the same time, basedon seismic section, seismic facies profiles of the main targets have been drawn, andaccording to drilling and other data, the seismic facies had been transformed intosedimentary facies. On the base of the distribution of sedimentary facies, the research ofdistribution and reservoir properties of the reservoir in Daheyan Region was applied.Finally, the accumulation conditions of Daheyan Region were summed up and asimple prediction of the exploration potential of this region was proposed.