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The ASR geophone is a compact three component mechanically operated
downhole geophone. It is designed for use in wells up to 20,000 psi and 200oC and provides a fast arm cycle time with an arm force to weight ratio of 5:1. The arm open and close cycles take approximately 45 seconds.
The standard arm will accommodate boreholes from 5" to 13", the short arm will accommodate boreholes from 3-1/2" to 9" and an extended arm can be used to increase this range to 22". The locking force is constant to within 20% throughout its operating range and will lock into 9 5/8" casing in fifteen seconds when fitted with the standard arm.
The tool is provided with a three component gimballed package as standard using one high sensitivity SM4 high temperature element per axis. The gimbal assembly will faithfully follow any borehole deviation from vertical through to horizontal and slightly beyond.
The tool has been designed so as to require very little servicing. Routine servicing can be performed in a few minutes and even a complete overhaul can be accomplished in less than an hour.
The arm mechanism has a fail safe feature to facilitate recovery of the tool in the event of downhole failure.
The tool can be used in single or dual tool analogue mode. No downhole batteries are required instead surface power is used to ensure infinite shooting time. In dual mode both locking arms open in parallel to further reduce survey times.
