This paper demonstrates the practical application of multi-well Pulse Code Testing (PCT) technique for verification of reserves in the vicinity of a horizontal infill well. It also contains an introduction to PCT, where the advantages of this technique over conventional PTA (both single-well and standard multi-well pressure interference testing) are described.
The case study given in this paper deals with the actual implementation of so-called ‘hopper scan’ PCT where a pressure pulse propagates across a row of artificially lifted wells and is then recorded in remote injectors in the next row, thus providing information about a large part of the reservoir without interfering with the production process. The forecast made on the basis of the PCT results was fully confirmed during subsequent hydraulic fracturing operations carried out in the surveyed well, which proved that the PCT information about the reserves was correct.
Three comparatively new technologies have been addressed in this paper:
Pulse code decomposition aimed at minimising production losses;
Automated multi-well matching aimed at improving the accuracy of inter-well parameters evaluation;
‘Hopper scan’ as a means of minimising the need in workovers and tripping operations in artificially lifted wells.