Study On Well Logging Evaluation Of Saturation And Permeability In An Oil Field In The Middle East

With the development of oilfield,carbonate oil and gas reservoirs are widely distributed and have large reserves,but complicated sedimentary and diagenetic process of them,lead to the complicated pore structure.That means the research on its saturation and permeability study exploration is relatively hard.Therefore,the research explore the pore structure of carbonate reservoir,permeability and the saturation logging evaluation studies,is necessary.In the thesis,the lithologic properties,physical properties of the reservoir and pore structure characteristics of the study area are analysed by means of the test data of mercury injection,physical properties,rock electric experiment and logging data of the carbonate reservoir in a Middle East oil field.Since the shape of the capillary pressure curve can be used to describe the pore structure characteristics.By analyzing the shape of capillary pressure curve in the logarithmic coordinate system,the pore structure characteristics of the reservoir were evaluated and described,and the pore distribution function based on Thomeer hyperbola was established.The parameters describing pore structure in Thomeer hyperbolic function were determined,and the core samples collected at the target layer in the study area were classified.The reservoir in the study area is classified according to the results of physical property analysis of the core.It was found that the drainage pressure of the largest type of pore throat in the sample had a good correlation with permeability,and the permeability prediction model was established successively.The parameter m?n in Archie formula model is determined accurately according to the reservoir type,which improves the calculation accuracy of water saturation.Based on the above analysis,we found that in the study area,the pore structure is relatively complex,and more than 42 % of the pores have multi-modal characteristics.In the multi-modal pore system,when the largest type of pores occupies at least 21.6 % of the pore volume,the permeability is only affected by this category,otherwise other pores also contribute to the permeability.Therefore,the permeability prediction model established based on this is reasonable.In the application of the saturation evaluation model based on Archie formula to porous carbonate reservoirs,the accuracy of the calculation mainly depends on the accuracy of Archie parameters.The method is more empirical and needs specific analysis according to the research area.