Direct push probe assembly for NMR measurements

A direct push probe assembly, comprising:

• a window section constructed of non-conductive, non-magnetic materials for allowing electromagnetic measurements through the window section;
• wherein said window section comprises a non-conductive, non-magnetic cylindrical section of the probe assembly;
• and
• further comprising an NMR sensor positioned within the probe assembly, said NMR sensor having a magnet and coil configuration that uses centered measurements through the window section to create sensitive zone geometries that are sensitive in all azimuthal directions around a center of the probe assembly.

A direct push probe assembly, comprising:

• a window section constructed of non-conductive, non-magnetic materials for allowing electromagnetic measurements through the window section;
• wherein said window section comprises at least one non-conductive, non-magnetic partial cylindrical section of the probe assembly that is not circumferentially continuous;
• and
• further comprising an NMR sensor positioned within the probe assembly, said NMR sensor having a magnet and coil configuration that uses centered measurements through the window section to create sensitive zone geometries that are sensitive in only a portion of the azimuthal directions around a center of the probe assembly.

A direct push probe assembly, comprising:

• a window section constructed of non-conductive, non-magnetic materials for allowing electromagnetic measurements through the window section;
• wherein the window section comprises an inner layer and an outer layer, and wherein both the inner layer and the outer layer are independently attached to an upper metal section of the probe assembly above the window section and a lower metal section of the probe assembly below the window section;
• wherein the inner layer and the outer layer of the window section are both arranged to transfer compressive and tensile forces from the upper metal section to the lower metal section;
• wherein the outer layer of the window section is constructed of a hard material of relatively high elastic modulus;
• and
• wherein the inner layer of the window section is constructed of a material having a lower elastic modulus than the outer layer.

A direct push probe assembly, comprising:

• a window section constructed of non-conductive, non-magnetic materials for allowing electromagnetic measurements through the window section;
• wherein the probe assembly is equipped with a first internal water seal in a bore of the probe assembly above the window section to prevent ingress of water into a cavity of the probe assembly above the window section of the probe assembly in the event that the window section breaks or fails and thus allows ingress of water into the probe assembly;
• and
• wherein the probe assembly is equipped with a second internal water seal in a bore of the probe assembly below the window section to prevent ingress of water into a cavity of the probe assembly below the window section of the probe assembly in the event that the window section breaks or fails and thus allows ingress of water into the probe assembly.

A method of collecting in situ soil measurements, comprising:

• providing a direct push probe assembly having an upper metal housing, a lower metal end piece, and a non-conductive, non-magnetic window section positioned between the upper metal housing and the lower metal end piece;
• pushing the probe assembly into soil;
• and
• performing electromagnetic measurements through the window section as the probe assembly is being pushed into the soil or retracted from the soil;
• wherein said electromagnetic measurements are NMR measurements.

A method for collecting NMR measurements with depth in soil, comprising:

• providing a direct push probe assembly containing an NMR measurement apparatus;
• pushing the probe assembly into the soil using static, vibratory, or percussive forces;
• and
• taking NMR measurements either as the probe assembly is pushed deeper into the soil or as the probe assembly is retracted from depth in the soil or both.