In recent years, nuclear magnetic resonance （NMR） has been increasingly used for fluid- typing in well-logging because of the improved generations of NMR logging tools. This paper first discusses the applicable cond...In recent years, nuclear magnetic resonance （NMR） has been increasingly used for fluid- typing in well-logging because of the improved generations of NMR logging tools. This paper first discusses the applicable conditions of two one-dimensional NMR methods： the dual TW method and dual TE method. Then, the two-dimensional （T2, D） and （T2, T1） NMR methods are introduced. These different typing methods for hydrocarbon are compared and analyzed by numerical simulation. The results show that the dual TW method is not suitable for identifying a macroporous water layer. The dual TE method is not suitable for typing gas and irreducible water. （T2, T1） method is more effective in typing a gas layer. In an oil-bearing layer of movable water containing big pores, （T2, T1） method can solve the misinterpretation problem in the dual TWmethod between a water layer with big pores and an oil layer. The （T2, T1） method can distinguish irreducible water from oil of a medium viscosity, and the viscosity range of oil becomes wide in contrast with that of the dual TW method. The （T2, D） method is more effective in typing oil and water layers. In a gas layer, when the SNR is higher than a threshold, the （T2, D） method can resolve the overlapping T2 signals of irreducible water and gas that occurs due to the use of the dual TE method. Twodimensional NMR for fluid-typing is an important development of well logging technology.展开更多
The gas saturation in flushed zone of gas layers is low and the observed gas signal is weak because the mud filtrate invasion reduces the native gas saturation.A(T2,T1/T2) two-dimensional nuclear magnetic resonance(NM...The gas saturation in flushed zone of gas layers is low and the observed gas signal is weak because the mud filtrate invasion reduces the native gas saturation.A(T2,T1/T2) two-dimensional nuclear magnetic resonance(NMR) method of typing gas layers was developed.The performance of(T2,T1/T2) method for typing gas at different kinds of reservoirs,signal-to-noise ratios and gas saturations was studied in details through numerical simulation.The results show that(T2,T1/T2) method is especially useful for identifying gas formations.It is suitable for typing lower gas saturation formation where drilling mud filtrate flushes strongly.展开更多
基金support from PetroChina Company Limited Innovation Foundation(Grant No.07-06D-01-04-01-07)State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleum(Beijing)(Grant No.PRPDX2008-02)
文摘In recent years, nuclear magnetic resonance （NMR） has been increasingly used for fluid- typing in well-logging because of the improved generations of NMR logging tools. This paper first discusses the applicable conditions of two one-dimensional NMR methods： the dual TW method and dual TE method. Then, the two-dimensional （T2, D） and （T2, T1） NMR methods are introduced. These different typing methods for hydrocarbon are compared and analyzed by numerical simulation. The results show that the dual TW method is not suitable for identifying a macroporous water layer. The dual TE method is not suitable for typing gas and irreducible water. （T2, T1） method is more effective in typing a gas layer. In an oil-bearing layer of movable water containing big pores, （T2, T1） method can solve the misinterpretation problem in the dual TWmethod between a water layer with big pores and an oil layer. The （T2, T1） method can distinguish irreducible water from oil of a medium viscosity, and the viscosity range of oil becomes wide in contrast with that of the dual TW method. The （T2, D） method is more effective in typing oil and water layers. In a gas layer, when the SNR is higher than a threshold, the （T2, D） method can resolve the overlapping T2 signals of irreducible water and gas that occurs due to the use of the dual TE method. Twodimensional NMR for fluid-typing is an important development of well logging technology.
基金National Natural Science Foundation of China(Grant No.40674075)Petro China Company limited Innovation Foundation(Grant No.07-06D-01-04-01-07)
文摘The gas saturation in flushed zone of gas layers is low and the observed gas signal is weak because the mud filtrate invasion reduces the native gas saturation.A(T2,T1/T2) two-dimensional nuclear magnetic resonance(NMR) method of typing gas layers was developed.The performance of(T2,T1/T2) method for typing gas at different kinds of reservoirs,signal-to-noise ratios and gas saturations was studied in details through numerical simulation.The results show that(T2,T1/T2) method is especially useful for identifying gas formations.It is suitable for typing lower gas saturation formation where drilling mud filtrate flushes strongly.
