Seismic sensor housing which naturally couples with well casing when deployed in a deviated production well

摘要

A mandrel or housing 4 which is attached to production tubing 1 houses seismic sensors 7 (eg fibre optic based devices). A tube 5,20 in the mandrel 4 allows flowthrough of production fluids. The outside diameter 21 of the mandrel is slightly smaller than the inside diameter of the well casing 2 which allows the mandrel to naturally couple with the well casing at points of deviation, non-linearity or non-verticality of the well. The sensors 7 fit into a groove 8 in the mandrel and are held in place with clamps 9. Alternatively the sensors 7 are located in a hole formed in the mandrel (see fig 10). The cross section of the mandrel 4 may be round, elliptical (fig 9) or triangular (fig 11), and may include protrusions (fig 12). The mandrel 4 may include channels (fig 6A, 6B) to allow bypass of other fluids such as water or drilling agents.