ALS Geochain EHP - Model ASR-1 -Advanced Seismic Receiver

The Geochain^TM EHP array has been designed for use in the most harshest of open and cased holes using standard 7 conductor wireline.  The array is based on the well proven ASR-1 downhole geophone and can be used in wells up to 30,000 psi (2,070 bar) and hole sizes from 3 3⁄4”-22” (95 to 559mm).  The modular nature of the ASR-1 EHP tool allows quick optimisation for various surveys ranging from high temperature deep well check shot to complex high sensitivity microseismic monitoring.

All the satellites locking arms open and close simultaneously and the entire string can lock into a 9 5⁄8” (244mm) well in only 30 seconds.  All satellites have a failsafe arm mechanism for retrieval of the string in the event of power failure.  All Inter-Tool Cables (ITC) use standard 7 conductor wireline.  The cable heads have graduated weak links and composite pressure bulkhead connectors are used throughout.  A rigid ITC option is also available to preserve sensor orientation.

When used in digital operation, the Geochain^TM EHP employs the TAS-2 telemetry adapter section and VRS-1 Voltage regulator section at the top and bottom of the tool string respectively.  The ASR-1 downhole satellites are populated with the distributed electronic modules featuring 24 bit Delta-Sigma converters for maximum dynamic range along with real time data transmission and display. Constant synchronisation of the string allows for very long record lengths.

Our latest unique active cooling system (ACS) allows continuous operation up to 385°F (195°C) within a hermetically sealed environment, and the robust telemetry system will ensure operation in the harshest conditions.

Up to 62 satellites can be used in the array with a maximum tool spacing of >600 feet (200m).

The digital GeochainSlim^TM system is supplied operating current at surface via a Geochain Power Panel (GPP) which features a Wireline Interface Box (WIB) enabling both DC power and AC data to be transmitted over same wireline cable. From 2016 this panel will be replaced by the upgraded Geochain Monitor Panel (GMP).  The entire system is controlled by a Geochain System Panel (GSP-1) which currently operates with a standard digital seismic interface and up to 16 analogue channels.  The panel has a 1.536Mb digital interface with 24 bit delta sigma converters along with a built in firing circuit. The GSP uses standard running ASL Acquisition suite.

Digital Geochain^TM systems can now be combined with a Downhole Formatting Unit (DFU) for passive monitoring operation to double the number of satellites in a string for a given sample rate.  These can record continuously/gapless at the highest sample rate for maximum picking accuracy and recording bandwidth.

The latest user friendly interface for the seismic engineer. The new ‘Bypass’ mode in the software enables data recovery from all active receivers, preventing any individual satellite failures from compromising the survey.  Any down tools can be bypassed, allowing communication and instruction to all tools below.

To help economize and maximize the output of your downhole itinerary, GeochainSlim Recievers (GSR) tools can now be deployed below Geochain ASR tools within the same string.

The modular construction of the standard (analogue) ASR-1 EHP allows it to be easily converted to analogue operation in just minutes.  Replacement of the electronic module with a 200?C rated downhole amplifier (DHA) enables a single or dual level string to be deployed within very hot wells.  The DHA and sensor pack can be upgraded to ASR-1 Extra High Temperature (EHT) to provide 225?C operational temperature.