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Shahejie Formation Sequence Stratigraphic Framework And Distribution Rules Of Typical Depositional Reservoir Bed And Subtle Hydrocarbon Reservoir, Paleogene, Jiyang Depression

Posted on:2007-06-25Degree:DoctorType:Dissertation
Country:ChinaCandidate:Z P TaoFull Text:PDF
GTID:1100360182980173Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
The main objective of this dissertation is to deepen the sequence correlation scheme ofthe third-order sequence stratigraphy of Shahejie Group, Paleogene, Jiyang depression,Shandong, China and summarize typical depositional, specially beach-bar andunderwater-fan, reservoir distribution and subtle reservoir formation rules withinhigh-resolution sequence framework, studying of typical area and contrasting withregional data.According to sequence stratigraphy, especially high-resolution sequence stratigraphy, allsequence surfaces have two characteristics: cyclic transformation and sedimentarycontinuity, the former characteristic presents consistent within its controlled area and thelatter changes following sedimentary rules. Consequently, these both characteristics canbe used together for regional correlation among the third-order sequences in some astudying area and it is useful to integrate sequence surfaces of these two kinds forconvenient and consistent statement and study. Sequence surfaces, therefore, can beintegrated and classified into 15 kinds of 3 types. This kind of classification method wasrecognized during this study and used for this work conveniently and effectively. Thepractice proved, this classification method was applicable for the third-order sequencecorrelation, all correlation results accorded with stratification data of chosen wellsgenerally, the corresponding cycle transformation characteristics were generallyconsistent in the whole studying area with varying sedimentary surface characteristics andthe corresponding cycles were isochronous, checked and calibrated withage-determination data.Almost all kinds of reservoir beds of continental facies and subtle hydrocarbon reservoirsdeveloped in Shahejie Group, Jiyang depression. Most stratigraphic reservoir distributednear basin margin or (and) third-order sequence surface but lithologic and compoundedreservoirs yielded in the whole basin. At or along central anticline belts, structural,lithologic and compound reservoirs coexisted and prevailed.According to the regional sequence correlation scheme and geological cognition, highfrequency sequence framework was established for Well Gao89 zone, Boxingsub-depression, Dongying, Jiyang and the reservoir bed distribution and subtle reservoirformation rules of beach bar was summarized. Beach bar sedimentation was mainly onthe side of windward lake bank, around the low underwater uplift or isolated island, onthe downthrown side of fault and on the ramp belt regionally, for example in Dongyingsag;in the area like Boxing sub-depression, mainly in the depression along bank, on thefaulted platform, along the sunk side of low uplift and beside two flanks of nose structure;in a well zone like Well Gao89 zone, mainly in the local low depression and along thesunk side of nose structure at regressive stage or mainly on the underwater highlandplatform and beside two flanks of nose structure at transgressive stage. For beach-barhydrocarbon reservoir, the most important control elements are reservoir bed scale,structural shape and paleogeographic situation and some other key elements are the typeand abundance of hydrocarbon resource, the connectivity of transport system, the locationof trap and so on. The beach-bar reservoir mainly developed at the enrichment zone ofsands, higher location of structure and paleogeography and the location between faultsthat control sub-depression and deep sub-depression.High frequency sequence framework was established for the central west zone, Gubeisub-depression, Zhanhua, Jiyang and the reservoir bed distribution and subtle reservoirformation rules of underwater fan was summarized. Underwater fan sediments distributedmainly in the channel, pit, faulted terrace, platform and ramp and near the lowaccommodation transformation surface of high frequency sequence, controlled obviouslyby regional and local sedimentary resource, paleotopography, structure, high frequencysequence, fracture and slope break belt. The dominance reservoir formation zones wereclose to deep depression, centralized and near to local highland of paleotopographyinclined to deep depression and approximately perpendicular to fault strike, controlled bythe facies of underwater fan for instance that all advantageous reservoirs developed inmiddle fan. For these reservoirs, reservoir beds in valley belonging to middle fan andfractures are main transport channels, the overlaid transgressive mud is main seal and thefan root including the transition belt between root fan and middle fan are main lateralplugs.
Keywords/Search Tags:Jiyang depression, regional sequence correlation, beach-bar, underwater fan, subtle hydrocarbon reservoir
PDF Full Text Request
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