Profile Controlling by Horizontal Well Completion Strings with Inner-located Nozzle

Abstract

AbstractHorizontal well has been used successfully in small block and offshore reservoirs and reservoirs with bottom water for cresting control. Watering-out profile along horizontal well in the reservoir with bottom water can be identified by production logging or by production history matching. The logging information shows that the profile is related to the formation permeability distribution in the well, and the flowing disturbance between high and low permeability interval has been tested from room experiment in a square sand pack model with vertical heterogeneity, it has been shown that start-flowing for displacing fluid though low permeable part in heterogeneous formation depends mainly on the permeability ratio of high to low. The ratio limit is about 3 for light oil reservoir, and little fluids will flow in low permeable part of the perforation interval for commingled injection or producing well. Well completion strings has been designed with concentric tube, filtering cotton coated for outer slotted wall and nozzle located in the inner wall. There may be empty between formation sandface and the well completion strings, and gravel packing and/or packer can be used. Variable mass flow dynamic models have been built based on momentum balance for two channels, and fluids flow transfer between the neighbor channels has been included, flowing relation with watering-out profile character and fluid flowing though gravel packing and/or packer barrier will be coupled in the model. Finite difference scheme has been used to solving the equations and coding procedures, pressure and flow rate distribution in the two channels can be calculated, flowing rate and pressure distribution are not symmetry because of interference of fluids transfer between channels. Different nozzle size and location can be determined for the watering-out profile changing, outer gravel packing and packer spacing can be designed also. The method has been used in the designing for well completion strings in Jidong oil field, and production performance of the well has been shown that the completion strings with inner-located nozzle in horizontal well is successful.