The Study Of Diagenetic Sequence And Advantaged Reservoir Of Paleogene System In The BoZhong Depression

Based on the theory of sedimentary , sequence stratigraphy and basin tectonicframework analysis, exerting the analysis method and basic theory of tectonicsequence and diagenetic sequence, this article makes the sediment process anddiagenesis combined from the control action which the structure effects to thedeposition. Through the sequence explanation combined borehole logs and seismicprofile, it analyzes sediment and diagenetic sign in different system tract and probesinto restrict relation between sediment system tract and diagenesis and the influencefor sandstone reserves, modularized by the background environment where reservoircomes in to being and diagenetic environment that is the chemic character of primarypore. In the sequence stratigraphic trellis, diagenesis and its evolvement process areinvestigated , space time distributing rule of high quality storey is forecastedultimately.The research reckons the complexity, activity time and activity intensityotherness in the development of Bozhong depression sunken structure, lead to thefact that there are different configurations in different district with basin, the wholearea mainly forms half fault depression which has the sunken belt, actic region, rampregion three kinds of structure geomorphic units. There is also the difference in thedifferent tectonic element deposition intersertal structure and the deposition type, theactic region mainly grows submarine fan-shaped near bank, the ramp regiongrows delta, the sunken belt mainly becomes the lacustrine facies deposition. Thetectonic movement not only restricts the cracked and sunken basin structure shape, butalso be the main controlling effect in the process of basin sequence stratigraphicdevelopment and deposition filling, all this causes that there are different diagenesisevolvements and diagenesis characteristic in the different sunken structure -landformunit in BoZhong depression。According to the local basin evolution characteristic and tectonic movementcharacteristic, Unifying the dates of seismic profile, drilling cores, well logging,welwitschiopsida and so on in Bozhong depression. Bozhong depression PaleogeneSystem nearly can be divided into a megasequence and three two sequences, on thebases conbin with depression geochemistry the material,the palaeo-climatology, theancient sedimentary environment and the diagenesis, become the crag stage thedivision, initially built on Bozhong depression Paleogene System the diageneticsequence analysis synthesis stick plot, has pointed out the relationship between theorganic carbon that around the surface of lake there are abundant of organic carbonand grundite meanwhile there are abundant of ancudite adjacent to the boundary ofstrata sequence.. The rock and the clay mineral become the crag evolutioncharacteristic according to the fluid chemistry and under the primitive depositionaqueous medium condition, obtains the fluid -rock mutual affects has the gradualcharacteristic in BoZhong depression Paleogene System, and analyzes thedepression actic region, the ramp region diagenesis actiong and diagenesis event.The development of diagenetic facies in actic region feathered with strongcompression diagenetic facies and early stage compacted carbonate-cemented sanddiagenetic facies. The development of diagenetic facies in the sunken belt featheredwith corrosion diagenetic facies and early stage mixed base-sustained corrosiondiagenetic facies. The development of diagenetic facies in ramp region regionfeathered with strong compression diagenetic facies, carbonate-cemented sanddiagenetic facies and calcite lement corrosion diagenetic facies.Unifying the kinds of sedimentary environments and sedimentary facies inBoZhong depression, analyzing reservoir natural controlling factors, it developes thehigh quality deposit " facies control" and "the stratum controls" the research, makesthe final reservoir evaluate and the forecast to BoZhong depression differentsequences ,and proposed two advantaged goal areas according to the sea petroleumreservoir evaluation criteria.