In situ geophysical sensing apparatus method and system

Abstract

An apparatus for in situ geophysical sensing includes a sensor for measuring geophysical data and a liquid absorbent member connected to the sensor that expands in response to contacting a liquid and thereby physically couples the sensor to a local sensing environment. The liquid absorbent member may be formed of beads or pellets or powder that includes a liquid absorbent material. The liquid absorbent member may also include a soluble binding agent for binding the beads or pellets or powder into an integral member such as a casing for containing the sensor. A method and system corresponding to the apparatus are also described herein. The apparatus, method and system described herein may be used to improve borehole sensor data quality without adding significant complexity to the borehole sensor deployment process.

What is claimed is: 
     
         1 . An apparatus for in situ geophysical sensing, the apparatus comprising:
 a sensor for measuring geophysical data; and   a liquid absorbent member proximate to the sensor, the liquid absorbent member including a liquid absorbent material that expands in response to contacting a liquid and thereby physically couples the sensor to a local sensing environment.   
     
     
         2 . The apparatus of  claim 1 , wherein the liquid absorbent member is formed of beads or pellets or powder comprising the liquid absorbent material. 
     
     
         3 . The apparatus of  claim 2 , wherein the liquid absorbent member further comprises a soluble binding agent for binding the beads or pellets or powder into an integral member. 
     
     
         4 . The apparatus of  claim 1 , wherein the liquid absorbent member is coated with a soluble layer for temporary isolation of the liquid absorbent material from the liquid that is adjacent to the liquid absorbent member. 
     
     
         5 . The apparatus of  claim 1 , wherein the liquid absorbent member is a casing configured to fully enclose the sensor. 
     
     
         6 . The apparatus of  claim 5 , wherein the casing comprises a plurality of casing sections that are split along an axial dimension. 
     
     
         7 . The apparatus of  claim 5 , wherein the casing comprises a tip portion having a tip cap for blocking vertical expansion of the liquid absorbent material. 
     
     
         8 . The apparatus of  claim 5 , wherein the casing comprises an end portion having an end cap for blocking vertical expansion of the liquid absorbent material. 
     
     
         9 . The apparatus of  claim 1 , wherein the sensor is connected to a cable. 
     
     
         10 . The apparatus of  claim 9 , wherein the cable facilitates insertion of the sensor into a hole. 
     
     
         11 . The apparatus of  claim 9 , wherein the cable enables uphole communication of the geophysical data provided by the sensor. 
     
     
         12 . The apparatus of  claim 9 , wherein the cable is connected to another sensor. 
     
     
         13 . The apparatus of  claim 9 , wherein the cable is connected to a weight. 
     
     
         14 . The apparatus of  claim 1 , further comprising a plurality of barbs. 
     
     
         15 . A method for in situ geophysical sensing, the method comprising:
 providing an expandable sensor including:
 a sensor for measuring geophysical data, and 
 a liquid absorbent member proximate to the sensor, the liquid absorbent member comprising a liquid absorbent material that expands in response to absorbing a liquid and thereby physically couples the sensor to a local sensing environment; 
   inserting the expandable sensor into a hole and providing a liquid to the expandable sensor;   allowing the liquid absorbent member to expand in response to contacting the liquid and physically couple the sensor to a local sensing environment; and   measuring geophysical data with the expandable sensor.   
     
     
         16 . The method of  claim 15 , further comprising:
 processing the geophysical data to determine an image of a surveyed subsurface.   
     
     
         17 . The method of  claim 15 , further comprising:
 boring a hole for the expandable sensor.   
     
     
         18 . A system for in situ geophysical sensing and processing, the system comprising:
 a plurality of expandable sensors placed into one or more holes and expanded to physically couple to a local sensing environment each expandable sensor including:
 a sensor for measuring geophysical data, and 
 a liquid absorbent member connected to the sensor, the liquid absorbent member comprising a liquid absorbent material that expands in response to absorbing a liquid and thereby physically couples the sensor to a local sensing environment; and 
   data processing equipment for processing the geophysical data.   
     
     
         19 . The system of  claim 18 , further comprising hole-boring equipment for boring the one or more holes. 
     
     
         20 . The system of  claim 18 , wherein the plurality of expandable sensors are attached to each other along a wire and placed in a single well.