Downhole fluid property measurement tool

An apparatus for trapping a well fluid sample and for measuring a parameter of said well fluid sample while said apparatus remains in a well, comprising:

• an elongated housing having a housing bore defined therein, said housing bore partially defining a sample chamber, and said housing having a sample collection passage defined therein communicating said sample chamber with an exterior of said housing;
• a piston slidably disposed in said housing bore so that a volume of said sample chamber may be expanded and a well fluid sample may be drawn into said sample chamber by movement of said piston in a first direction and so that said volume of said sample chamber may be contracted by movement of said piston in a second direction;
• valve means for closing said sample collection passage and trapping said well fluid sample in said sample chamber after said piston has moved in said first direction past a first position;
• and
• sensor means, communicated with said sample chamber, for sensing a parameter of said well fluid sample.

An apparatus for trapping a well fluid sample and for measuring a parameter of said well fluid sample while said apparatus remains in a well, comprising:

• an elongated housing having a housing bore defined therein, said housing bore partially defining a sample chamber, and said housing having a sample collection passage defined therein communicating said sample chamber with n exterior of said housing;
• a piston slidably disposed in said housing bore so that a volume of said sample chamber may be expanded by movement of said piston in a first direction and so that said volume of said sample chamber may be contracted by movement of said piston in a second direction;
• valve means for closing said sample collection passage and trapping a well fluid sample in said sample chamber after said piston has moved in said first direction past a first position;
• sensor means, communicated with said sample chamber, for sensing a parameter of said well fluid sample;
• and
• piston position control means for moving said piston in said first direction and stopping said piston prior to said piston reaching said first position where said valve means closes, and for then further moving said piston in said first direction in incremental steps while allowing pressure in said sample chamber to stabilize between steps so that said valve means closes trapping said sample and so that a volume of said trapped sample is then incrementally increased.

An apparatus for trapping a well fluid sample and for measuring a parameter of said well fluid sample while said apparatus remains in a well, comprising:

• an elongated housing having a housing bore defined therein, said housing bore partially defining a sample chamber, and said housing having a sample collection passage defined therein communicating said sample chamber with n exterior of said housing;
• a piston slidably disposed in said housing bore so that a volume of said sample chamber may be expanded by movement of said piston in a first direction and so that said volume of said sample chamber may be contracted by movement of said piston in a second direction;
• valve means for closing said sample collection passage and trapping a well fluid sample in said sample chamber after said piston has moved in said first direction past a first position;
• sensor means, communicated with said sample chamber, for sensing a parameter of said well fluid sample;
• spring biasing means for biasing said valve means in said first direction;
• and
• wherein said valve means includes a valve stem which abuts said piston so that said valve stem follows said piston as said piston travels in said first direction until said valve means closes said sample collection passage.