Apparatus for Testing Swellable Materials

Abstract

The invention provides an apparatus for use in testing the swell characteristics of swellable components used in downhole exploration or production equipment, such as swellable packers. A method of measuring a test piece using a testing apparatus with a fluid chamber and a transducer is described. Measured data can be compared with data measured from a sample section of a tool to determine a relationship between swell characteristics. The determined relationships can then be used to calculate or predict swelling characteristics of swellable components, for example particular packer designs, in specific fluid samples.

What is claimed is: 
     
         1 . A portable apparatus for testing a swell characteristic of a test piece comprising a swellable material used in a swellable component of downhole hydrocarbon exploration or production equipment, the portable apparatus comprising:
 a fluid chamber configured to receive a triggering fluid and the test piece comprising a swellable material such that the test piece is exposed to the triggering fluid;   a transducer for measuring a swell characteristic of the test piece due to exposure of the test piece to the triggering fluid; and   an output line for outputting measurement data from the transducer.   
     
     
         2 . The portable apparatus of  claim 1 , wherein the transducer is operable to measure a dimension of the test piece. 
     
     
         3 . The portable apparatus of  claim 1 , wherein the transducer is a non-contact transducer which tracks movement of the test piece or a target coupled to the test piece. 
     
     
         4 . The portable apparatus of  claim 3 , wherein the target is configured to move in correspondence with an increase in volume of the swellable material of the test piece. 
     
     
         5 . The portable apparatus of  claim 3 , wherein the transducer is an eddy current transducer and is disposed to measure an eddy current in the test piece or a target coupled to the test piece. 
     
     
         6 . The portable apparatus of  claim 1 , wherein the transducer is a contact transducer. 
     
     
         7 . The portable apparatus of  claim 6 , wherein the transducer is configured to measure a pressure or force exerted by swelling of the test piece. 
     
     
         8 . The portable apparatus of  claim 1 , further comprising a mechanism for adjusting a position of the transducer. 
     
     
         9 . The portable apparatus of  claim 1 , wherein the apparatus is further configured to measure a time series of the swell characteristic of the test piece. 
     
     
         10 . The portable apparatus of  claim 1 , further comprising a temperature control system. 
     
     
         11 . The portable apparatus of  claim 10 , wherein the temperature control system comprises a heating element operable to heat fluid in the fluid chamber. 
     
     
         12 . The portable apparatus of  claim 1 , configured for circulation of fluid in the fluid chamber via an inlet and outlet of the fluid chamber. 
     
     
         13 . The portable apparatus of  claim 1 , further comprising a data logging unit. 
     
     
         14 . The portable apparatus of  claim 1 , further comprising a power supply unit. 
     
     
         15 . The portable apparatus of  claim 1 , further comprising an interface for a portable computer. 
     
     
         16 . The portable apparatus of  claim 1 , wherein the apparatus is configured to measure a test piece swell characteristic which has a known relationship with a swellable component swell characteristic. 
     
     
         17 . The portable apparatus of  claim 1 , wherein the fluid chamber is configured to receive a substantially planar test piece. 
     
     
         18 . The portable apparatus of  claim 17 ,
 wherein the substantially planar test piece comprises a substrate, and   wherein the substrate comprises a disc of metallic material, having a recess formed in one face of the disc.   
     
     
         19 . The portable apparatus of  claim 18 , wherein the disc has a thickness in a range of 1 mm to 5 mm. 
     
     
         20 . A test piece for use in a method of testing a swelling characteristic of a swellable component for downhole exploration or production equipment, the test piece comprising
 a planar substrate having a recess; and   a swellable material selected to increase in volume on exposure at least one triggering fluid moulded into the recess.   
     
     
         21 . The test piece of  claim 20 , wherein the substrate comprises metal. 
     
     
         22 . The test piece of  claim 20 , wherein the substrate comprises a disc, and the recess is formed in one face of the disc. 
     
     
         23 . The test piece of  claim 22 , wherein the disc has a thickness in the range of 1 mm to 5 mm. 
     
     
         24 . The test piece of  claim 20 , wherein the swellable material is bonded to the substrate on the base of the recess. 
     
     
         25 . The test piece of  claim 20 , wherein the swellable material is bonded to the substrate on the side walls of the recess. 
     
     
         26 . The test piece of  claim 20 , wherein the recess has a depth in the range of 0.5 mm to 4 mm. 
     
     
         27 . The test piece of  claim 20 , wherein the recess has a depth of approximately 2 mm. 
     
     
         28 . A method of forming a test piece for a swellable component for downhole exploration or production equipment, the method comprising:
 providing a substantially planar substrate of a non-swellable material; and   bonding a layer of swellable material selected to increase in volume on exposure at least one triggering fluid onto the substrate.   
     
     
         29 . The method of  claim 28 , wherein the swellable material has a thickness in the range of 0.5 mm to 4 mm. 
     
     
         30 . The method of  claim 28 , wherein the swellable material has a thickness of approximately 2 mm. 
     
     
         31 . The method of  claim 28 , wherein the substrate comprises a recess, further comprising:
 moulding the layer of swellable material into the recess.   
     
     
         32 . The method of  claim 31 , wherein bonding a layer of swellable material comprises bonding the swellable material to the substrate on the base of the recess. 
     
     
         33 . The method of  claim 31 , wherein bonding a layer of swellable material comprises bonding the swellable material to the substrate on the side walls of the recess.