Application of Nuclear Magnetic Resonance Logging in Evaluation of Reservoir Effectiveness
The complex pore structure and large porosity distribution interval of Al Block in Erlian Oilfield bring great challenges to reservoir evaluation.In order to improve the coincidence rate of logging interpretation,it is urgent to use advanced logging technology to accurately evaluate the validity of reservoirs in this area.NMR logging can measure the transverse relaxation time T2 of hydrogen nuclei,so as to obtain reservoir characteristics with different pore structures,small holes corresponding to short T2,and large holes corresponding to long T2.According to the corresponding relationship between T2 distribution and reservoir pores,multiple pore com-ponents can be obtained by selecting different T2 cutoff values,and then the reservoir effectiveness can be evaluated.Based on Sch-lumberger's CMR NMR log data and production test results,the relationship between movable fluid porosity,capillary bound fluid po-rosity,clay-bound fluid porosity and total porosity and reservoir class was studied in detail.The results show that the parameters re-lated to movable pores are positively correlated with productivity matching,and the higher the proportion of clay-bound pores in the total pores,the lower the natural productivity of the reservoir.When the classification coefficient IB is greater than 0.18,it is classi-fied as class I reservoir,IB between 0.03 and 0.18 is classified as class Ⅱ reservoir,and IB less than 0.03 is classified as class Ⅲreservoir.Based on the established reservoir classification standard,the reservoir of exploration well in Al area was re-classified,and the conformity rate was increased from 82%to 85%according to the oil test results.The research results have important reference value for guiding production,and the classification method can be extended to other oil fields with complex pore structure.
nuclear magnetic resonance loggingreservoir availabilityclassification indexreservoir productivity
万方数据
维普
