Comprehensive Evaluation To Clasolite Reservoir In Yingcheng Formation In Shiwu Depression

According to using the theories and techniques of reservoir geology,mineral lithology,logging geology and reservoir evaluation to research thoroughly the feature of lithology,the distribution of sand body ,lithogenesis and the physical property of the clasolite reservoir of the group of Yingcheng in shiwu depression.Drawing triangular diagrams of the reservoir roke types based on the research of lithology feature which is obtained from the hin section analysis and core wafer.From the triangular diagrams,arcose,feldspar lithic sandstone and lithic arkose are the main lithologies,this is beneficial to generate secondary pores.Compositional maturity and texture maturity are both low.The general class of reservoir is middle-fine sandstone. The general shimming materials are carbonatite and mud.From the calculated datum of core physical property,the porosity is generally from 5% to 12%,the permeability is generally from 0.1×10-3μm2 to 10×10-3μm2,so the reservoir is from especially low porosity and especially low permeability to low porosity and especially low permeability.The secondary pores are the main type,the second ones are splits.Inflexible ompation, ementation, uartz overgrowth,metasomasis and dissolution are the main diagenesis types. According to the analysis of diagn field and diagenesis,the diagenetic stage is from A1 subage of the middle diagenetic stage to late diagenetic stage from NE to SW of the reservoir.Forecast the distribution of sand body on the basis of seismic inversion and well drilling datum.The edge of the rift is near the matter source, the continuance of sand body is good.But the inside of the rift is distant from the matter source,so the continuance of sand body gets bad.Around the core datum and log information can use the method of log crossplot to identify sandstones and mudstones.By means of correlation analyse to put the parameter of bore log whose correlation is good and the physical property of core together to establish relationship formula,then to anticipate the porosity and the permeability of the region of interest. Method of weighted mean can be used to evaluate reservoir accumulate ability.According to the five parameteres of porosity,permeability,shale content, cumulative thickness of sandstone and the maximal single layer thickness, the reservoirs can be divided into four types, the chief reservoir is typeⅡ( good) and typeⅢ(middle). TypeⅣ( bad) is developed in the southwest of the eastern slope. The Predication result indicates that every field has satisfactory reservoirs.