The Monosandbody Depiction Of The Lower-Section Of Es3 In Block Wei 22

Concerning the current resource and development conditions of the oil field, and the hot nuts to crack arising in the exploitation, this paper subdivided oil layer into different causal monosandbodics and finely comparison contributed to the establishment of high resolution chrono strati graphic sequence framework on the monosandbody level. Fine sedimentary micro face research of the monosandbodies was conducted on the base of face analysis of cored wells and the estiblishment of logging microface mode; Interlayer, inner architecture structure of monosandbodies, and oil and water distribution between them were anlyzed after depicting causal monosandbodies, and then sedimentary model, reservoir structural model, and residual oil distribution model of major potential hydrocarbon monosandbodies in the oil layers were rebuilded in order to lay the solid geological foundation of making clear the connection relationship between individual reservoirs, injection-production relationship, waterlogged characteristics, waterflood, extending border, extending layer effect and keeping the output steady.The Block, since developed, had undergone more than once fracturing, production adjustment in the different development period, which leaded to the abnormally complexity of law of oil and water activity, waterlogging and washing in the reserch block and affected waterflooding effect and constrained the strategy of further tapping potential;Interlayer difference appeared clearly, and the contradiction between layers arised shapely, and there was a serious imbalance of distribution in the producing rate of stratified waterflooding. The low level of understanding of reservoir caused the difficulty of improving the producing rate of waterflooding, and the high level of decline rate in the recent years.Block Wei 22, which was exploited in 1982, had not been studied on the fine characterization and depiction of thin layer and monosandbody, wih the low level of understanding of reservoir.The unconformity of the degree of geological understanding and development demand that the fact that our geological insights were only limited into thin layer couldn’t match the need of fine reservoir tapping potential in the high water-cut development phase, existed indeed. How to relize the stable production of old oil field and tap reservoir residual resource potential would affact the plans of steady producing directly.Impercipience on great lateral change, geometrical morphology, inner structure characteristics and the distribution of interbed and thin interlayer of Es3 Lower-section sandbodies, resulted in the uselessness of the potential of injection-production pattern with sandbody as a unit.The strata of Dongpu Depression consisted of Shahejia Formation of Palaeogene (Sha 4 member, Sha 3 member, Sha 2 member, Sha 1 member), Dongying Formation, which were in angle unconformable contact with lower Tiassic in Mesozoic. After deposition of Paleogene, the area uplift and was denudated, then down-warped settle, and accepted the deposit of Guantao Formation and Minghuazhen Formation of Neogene. Obviously, Paleogene was in the angle unconformable contact with Neogene. The following Pingyuan Formation of Quarternary Covered Neogene in the conformable contact.The paper, on the premise of isochronal stratigraphic framework, based on partition and contrast of sedimentary unit, conducted the depiction of monosandbody in the complex sandbody, concluded the horizonal and vertical identification mark of monosandbodies, fited the quantitative prediction parameter such as ratio of width to thickness, and then finished the depiction according to the spacial contact relationship of single channel sandbody.The development phenomenon could be explained effectly by deviding sediment unit vertically, and causal monosandbodies horizontally, and finally finely depicting the anisotropy of delta reservoir from a macroscopic view, that oil or water well performance data shew that adjacent channel sandbodies had the different response or effectiveness, and that there were different connective quality in the horizonal widespread channel sandbody.So identifying and depicting causal monosandbody correctly and furtherly making sure the connection relationship between different sandbody would play great important guiding role in making the tapping potential adjustment.According to core data and logging curves, we compared the sedimentary characteristics with the former sedimentary facies characteristics using the colors, lithology, sandstone constituent, texture, granularity, and sedimentary structure of, and devidied the faces of the lower-section of Es3 into one face, two subfacies, and nine micro facies with the combination of horizon distribution reserch of sandbody. Generally, given the regional sedimentary background, the lower-section of Es3 of Block 22 could be determined to be shallow water delta deposit, so its facies was delta facies, subfacies could be devidied into delta-front subfacies and prodelta subfacies. As for microfacies, delta-front subfacies could be devidied into underwater distributary channel, underwater distributary channel overflow, mouth bar, distal bar, blanket sand, interdistributary bay microfacies; Prodelta subfacies could be devidied into prodelta mud, blanket sand and turbidite body microfacies.The fine depiction of monosandbodies section distribution shew that in the source direction northwest section major wells controlled by the channel monosandbodies existed the connecting bodies, and most of horizonal sandbodies in the thin layer was continuous and spreaded widely, which existed in the most members. In the vertical source direction wells controlled by channel sandbodies had fewer connecting bodies because of the direction crosscutting source direction, which caused the discontinuity of most of lateral sandbodies in the thin layer, and constrain of connectivity in the lateral range. The major types of horizonal monosandbodies contained monosandbodies of channel overflowing thin sandstone, underwater distributary channel, mouth bar, distal bar, blanket bar, turbidite body. Reservoirs were formed in the delta front sedimentary environment, and the type of channel was distributary channel,whose strike was from northwest to southeast. Single channel had strip and mesh shape.To sum up, the major problem facing to us in the study area was the refining and deepening understanding of the reservoir geology, the key point was fine thin layer devision and contrast, the development condition of thin interlayer and innerbodies in the thick layer, residual oil potential research and fine waterflood tapping potential plan research, because there was of great demand to analyse the architecture of sandbodies of thin layer deeply, and study the control of seepage flow barriers and differences to the remaining oil distribution for the continental reservoir during the later stage of production.