Abstract: An electromagnet model or models are created to generate the static and radio frequency magnetic fields of an NMR downhole logging tool. The magnetic field distributions are then used in spin dynamics (SD) simulations to model the impacts of various effects on NMR logging data, effects that cannot be accurately describe by theoretical formulation alone. The accuracy of the electromagnetic model and the SD simulation may be verified against experimental observations or trial logging runs. Simulation of electronic circuit, molecular diffusion, tool motion can all be incorporated in the SD simulation. The NMR data inversion process can be modified according to echoes obtained from SD simulation to obtain more accurate petrophysical parameters.

Abstract: An electromagnet model or models are created to generate the static and radio frequency magnetic fields of an NMR down-hole logging tool. The magnetic field distributions are then used in spin dynamics (SD) simulations to model the impacts of various effects on NMR logging data, effects that cannot be accurately describe by theoretical formulation alone. The accuracy of the electromagnetic model and the SD simulation may be verified against experimental observations or trial logging runs. Simulation of electronic circuit, molecular diffusion, tool motion can all be incorporated in the SD simulation. The NMR data inversion process can be modified according to echoes obtained from SD simulation to obtain more accurate petrophysical parameters.

Abstract: Methods, devices, and systems for tracking lateral motion of a nuclear magnetic resonance (NMR) tool are disclosed. In some embodiments, a phase shift for one or more spin-echo signals received by the NMR tool is detected during a velocity measurement sequence that corresponds to at least one formation measurement sequence. A lateral velocity of the NMR tool is determined based, at least in part, on the detected phase shift.

Abstract: Methods, devices, and systems for tracking lateral motion of a nuclear magnetic resonance (NMR) tool are disclosed. In some embodiments, a phase shift for one or more spin-echo signals received by the NMR tool is detected during a velocity measurement sequence that corresponds to at least one formation measurement sequence. A lateral velocity of the NMR tool is determined based, at least in part, on the detected phase shift.

Abstract: Various embodiments include a method for configuring and generating a non-adiabatic saturation pulse for use in nuclear magnetic resonance (NMR) logging. One such method configures the pulse by adjusting one or more of pulse amplitude modulation or phase cycling. The modified pulse is transmitted into a fluid such that a substantially uniform nuclear spin saturation or nuclear spin inversion echo response is received from the fluid. A wait time between the pulse transmission and the echo response that indicates that spin equilibrium has been achieved is substantially equal to a T1 time. The wait time is an indication of the characteristics of the fluid.

Abstract: Various embodiments include a method for configuring and generating a non-adiabatic saturation pulse for use in nuclear magnetic resonance (NMR) logging. One such method configures the pulse by adjusting one or more of pulse amplitude modulation or phase cycling. The modified pulse is transmitted into a fluid such that a substantially uniform nuclear spin saturation or nuclear spin inversion echo response is received from the fluid. A wait time between the pulse transmission and the echo response that indicates that spin equilibrium has been achieved is substantially equal to a T1 time. The wait time is an indication of the characteristics of the fluid.