Study On Sedimentary Microfacies Of Kongdian2Reservoir Group In Cangdong Seg, Zaoyuan Region

The Zaoyuan region locates in the middle of Kongdian tectonic belt at HuanghuaDepression, including three development zones: Fenghuadian、Zilaitun、Shenjiapu andthe corresponding not producing reserves block. This oilfield multiple oil and gasaccumulation, Development of many sets of oil-bearing series,and Kongdian2reservoirgroup is the major exploration layer. Because this area has complex structure、so muchfaults, it is difficulte to correlate strata; the uplift of Kongdian makes the strataincomplete; the quality of seismic data is low; source system has differences; the divideof subfacies and microfacies has differences.Commence this thesis topics based on the above objectives, select Zaoyuan area ofCangdong depression as the scope of the study, to the Paleogene Kongdian2reservoirgroup, take the sedimentology and sequence stratigraphy, continental theoryfurtherrefined and systematic study of its deposition phase, sedimentary subfacies sedimentarymicro equal characteristics combined with the chronostratigraphic framework, finallyaccording to the analysis of the petrophysical property of this area to predict theadvantaged reservoir.Previous studies indicate that the sedimentary of Zaoyuan region Kongdian2reservoir is mostly black fine sand, through the ancient biological data analysis that inthis period the study area is in warm and humid climate, in sequence this period isdivided into SQ3, theresult has important guiding significance to the study.This research through the study of source location and distributionrange, determinethe sources of sedimentary of each lobe in Zaoyuan area,thus establishing the distributionrange of sedimentary system in this area, and then study the forms of microfacies in eschdepositional system, and obtains the characteristics of advantages microfaciessedimentary and the reservoir differences of each microfacies, according to the range ofsedimentary microfacies, logging constrained inversion, sand distribution and othermeans for judging the reservoir quality in this area, and predict theadvantageous reservoir.Provenance analysis has important guiding significance in determining the distribution of depositional systems. This paper first from the researches of the mineralcomposition framework、seismic attributes,、sand disperse system, with the regionalgravity anomaly and conglomerate content analysis as auxiliary, find the location ofentrances of the provenance, and the spread range of the different sediment in the2reservoir group in Zaoyuan region, Cangdong depression. The conclusion can be madethat, there are7provenance entrances in the area and the sediment mainly from theKongdian uplift in the North, Cangxian uplift in the West and the Xuhei uplift in theEast.Under the study of the geology background of this region and source analysis results,combine with the drilling cores, logging, seismic and test data on the basis of the analysisphase flag, based on the characteristics of rock assemblages, sedimentary structures,profile structure, identify the braided river deltas, lakestype of depositional system, thelocal development of off shore subaqueous fan deposition, and identifies themain sedimentary microfacies types of the sedimentary system and sedimentarycharacteristics. By the laws of sandstone spreads and the features of the seismic facices,the spread of the sedimentary facies in Kongdian2reservoir group of Cangdong Seg，Zaoyuan region can be made, and establish basin margin sedimentary filling pattern inthis region.By analyzing the sandstone spread, characteristics of porosity, the permeabilityrelating to sandstone and sedimentary microfacies, and combining with seismic data, thesand body well comparison, sandstone thickness distributions and other means toanalysis the sandstone trace, evaluates the reservoir of each sedimentary micro facies andthen divided the advantageous reservoir facies; combining with the trap tectoniccharacteristics and advantages sedimentary microfacies reservoir analysis, evaluatesrelationship between characteristics of favorable reservior and characteristic ofstandstone distribution and sedimentary facies zone is clearly. This can provide aguidance, both in theory and practice, for exploration and development in Zaoyuanregion of Dagang oilfield.