Processing method and apparatus for processing spin echo in-phase and quadrature amplitudes from a pulsed nuclear magnetism tool and producing new output data to be recorded on an output record

A nuclear magnetic resonance logging system, comprising:

• a logging tool adapted to be disposed in a wellbore, said logging tool including,
• antenna means for sensing induced voltages representative of a plurality of magnetic moments associated with a plurality of protons precessing in a formation traversed by said wellbore and generating a plurality of spin echo receiver voltage pulses representative of the magnetic moments, amplitude generating means responsive to said plurality of spin echo receiver voltage pulses for generating a plurality (J) of inphase (R.sub.j) amplitudes and a plurality (J) of quadrature (X.sub.j) amplitudes, the plurality of inphase amplitudes and the plurality of quadrature amplitudes totalling 2J amplitudes, and
• first means responsive to the inphase (R.sub.j) and quadrature (X.sub.j) amplitudes for generating a plurality (N.sub.w) of window sums (I.sub.m,m+1), the plurality (N.sub.w) of window sums being less in number than said 2J amplitudes;
• processing means adapted to be disposed at a surface of said wellbore and responsive to said plurality of window sums generated by the first means of said logging tool for generating log outputs and signal distributions;
• and
• output record generating means for recording said log outputs and said signal distributions representing color maps on an output record medium.

A method of transmitting data from a well tool disposed in a wellbore to a processing system disposed at a surface of said wellbore, said well tool including an antenna for sensing information and generating a plurality of inphase amplitudes and a plurality of quadrature amplitudes in response to said information, comprising the steps of:

• in said well tool, estimating a signal phase from the inphase and quadrature amplitudes;
• determining a plurality of values A.sub.j.sup.(+) from the signal phase, the plurality of inphase amplitudes, and the plurality of quadrature amplitudes;
• sub-dividing said plurality of values into groups thereby producing a plurality of groups of said values, where the plurality of groups is less than the plurality of values;
• generating a window sum value for each group of the plurality of groups of said values, thereby producing a plurality of window sums, where the plurality of window sums is equal to the plurality of groups of said values;
• and
• transmitting the plurality of window sums uphole from the well tool disposed in said wellbore to the processing system disposed at the surface of said wellbore.

In a logging system including a well tool adapted to be disposed within a wellbore and a processing system disposed at a surface of said wellbore, a method of generating an output record medium illustrating parameters representative of the quality of a reservoir traversed by said wellbore, comprising the steps of:

• (a) in said well tool, sensing induced voltages representative of a plurality of magnetic moments associated with a plurality of protons precessing in said reservoir traversed by said wellbore and generating a plurality of spin echo receiver voltage pulses representative of the magnetic moments;
• (b) generating a plurality (J) of inphase (R.sub.j) amplitudes and a plurality (J) of quadrature (X.sub.j) amplitudes in response to said plurality of spin echo receiver voltage pulses, the plurality of inphase amplitudes and the plurality of quadrature amplitudes totalling 2J amplitudes, and
• (c) generating a plurality (N.sub.w) of window sums (I.sub.m,m+1) in response to the inphase (R.sub.j) and quadrature (X.sub.j) amplitudes, the plurality (N.sub.w) of window sums being less in number than said 2J amplitudes;
• (d) in said processing system, generating log outputs and signal distributions representing color maps in response to said plurality of window sums;
• and
• (e) recording said log outputs and said signal distributions representing color maps on an output record medium.

A system for receiving induced voltages associated with a material representative of a plurality of magnetic moments associated with a plurality of protons precessing in said material and generating an output record medium for recording information pertaining to a set of characteristics of said material, comprising:

• means responsive to said induced voltages for generating a plurality of spin echo receiver voltage pulses representative of the magnetic moments;
• amplitude generating means responsive to said plurality of spin echo receiver voltage pulses for generating a plurality (J) of inphase (R.sub.j) amplitudes and a plurality (J) of quadrature (X.sub.j) amplitudes, the plurality of inphase amplitudes and the plurality of quadrature amplitudes totalling 2J amplitudes;
• first means responsive to the inphase (R.sub.j) and quadrature (X.sub.j) amplitudes for generating a plurality (N.sub.w) of window sums (I.sub.m,m+1), the plurality (N.sub.w) of window sums being less in number than said 2J amplitudes;
• processing means responsive to said plurality of window sums generated by the first means for generating log outputs and signal distributions;
• and
• output record generating means for recording said log outputs and said signal distributions on said output record medium.