Reservoir Sedimentology And Modeling Research Of Lower Guantao Formation In The South Area, Chenjiazhuang Oilfield

Sandbodies of fluvial facies always distribute over an area with simple framework of fault and gently attitude of stratum, which show themself as punctates or brachyaxises in the stratigraphic section. Usually the thick channels have distinct strong reflectance signature in the seismic section, so the ordinary wave impedance inversion technology can be well used on sandbody description. But in many area the channel sands are classic thin interbedding sands, and in the seismic response the seismic reflections are always thin interbedded composite reflections in a specified stratum. Under the high frequency interference, the variation in thickness is very difficult to be forecast in the seismic section and custom inversion section. The seismic sections with punctates or brachyaxises reflectance signature are very difficult to be traced in the three-dimensional space, therefore the description and model building of this kind of sand are difficult too. By now we do not have a set of technology of sand identifying and model building to this king of sand. The only method we can adopt in the exploration of this kind of oil reservoir is"wading across the stream by feeling the way". All of these have already seriously effected the cognizance of hydrocarbon accumulation rule of this kind of oil reservoir, and restricted success ratio of exploration wells and designing of development plans. We urgent need to establish a set of suitable technology for the sand identifying and model building of thin interbedding sands.Therefore Chenjiazhuang area was selected as test target area in this thesis to research the identifying of channel sand reservoir and technology of model building in Zhanhua sag. Try to use sequence stratigraphy, reservoir seismology and advanced geophysical method to emphatically research the distributing law of channel sand technical matter of model building in the target area, find the suitable thinking and method of identifying fluvial sand under now available data and technique condition in Zhanhua sag. It has a positive role to make the whole Guantao group sand reservoir alive, to find a great deal of high quality reserves, to enrich and develop surveytechnique of obscure and sutie Traps of Jiyang depression.Be aimed at the research content in this thesis,on the basis of adequately using for reference predecessors'returns,we observed the drilling cores systematically, analyzed the distribution situation of the Guantao group in the regional background of Jiyang depression. On the basis of the research of A.D.Miall(1985),we described the sedimentary facies of down Guantao group systematically by using the theory of fluvial sequence stratigraphy and sedimentology the ten basic architecture elements,and got a reasonable interpretation .This work contribute considerable theoretical basis for stratigraphic correlation and reservoir description of the complex fluvial face reservoir.In this thesis, by mean of sand bodies demarcating and the research of geophysical signature, we analyzed the dominant factors which effect seismic reflectance signature of fluvial facies sand bodies, further analyzed the distributional characteristics of sand bodies with seismic attribute analysis; using statistical analysis of lithology velocity to find the dynamics characters, we researched the sand body identifying with the method of inversion of curve reconfiguration.Aimed at uncertainty of stochastic modeling, we analyzed the stochastic simulation forecast and modeling method of fluvial reservoir, and made the relationship of stochastic simulation forecast, modeling method and it's applicability. The reservoir parameters and oil-bearing factors are controlled by the sedimentary facies. In other words, the distribution of reservoir parameters should be classified to count separately by facies and the reservoir model should be built for each facies. So we adopted the sequential Gaussian simulation method to research the reservoir parameters and oil-bearing factors. By the research of stochastic model building technology, we established a technical proposal of the stochastic simulation forecast using seismic data, that is to say effectively applying seismic attribute to stochastic simulation forecast and model building and evaluaterating uncertainty of the forecast by building relationship of probability correlation between the seismic and lithofacies. This method can instead of the common-used forecast method of deterministic horizontal reservoir forecast in a certain degree.On the basis of above research, thinking of other dominant elements, favorable exploration targets were evaluated confirmed. Combined the application, we established the flow chart of fluvial facies sandstone identifying of now available data status. We forecasted 25 sandbodies, proposed 3 exploration targets, got prognostic reserves of 1.8×10~7 tons.