Studies And Applications On The Deep Profile Control Technology Of Functional Polimer Microspheres

It has been investigated that the recent profile control and water shutoff agents, the deep profile control agents and technologies, the filed matched technologies of water shutoff in this paper. Based on the above, we have developed the functional polymer microspheres and applied them to the oil filed, which forms a new deep profile control technology. The functional polymer microspheres consist of a positively charged core and a negatively charged shell. The core-shell functional polymer microspheres swelling in water, as a result, the expansion rate of the shell is bigger than that of the core. Then, the positively charged core will expose and adsorb with the negatively charged parts on the shell and layer. Gradually, it will form a kind of larger-structure substance which can adsorb at the pore throat and cause a reduction of cross section area. This can effectively block off the thief zone and high permeability layer by causing fluid diversion and the subsequent fluid will follow into the other channels.In the theoretical analyses and indoor experiments, we have studied the chemical properties of the functional polymer microspheres, such as the original size, expansion rate, thermal stability, salt resistance properties, the influence of different content of cation and anion, and different core-shell rate. The screening and deep profile control performances of the functional polymer microspheres were conducted by single-core and long-core oil pipe experiments, respectively. Their shunting and enhanced oil recovery abilities were evaluated by two-core oil pipe parallel experiments.After investigating the reservoir geology, development status and injection-production situation of test site, we designed the deep profile control testing program of functional polymer microspheres in the24X516well group at zhonger Block Ng5of Gudao Oil Field. This technology was applied to the oil field in September2006and success was achieved in oil enhancing recovery in the8firsttier wells. Oil production increased from13.2tons per day to18tons per day, water ratio decreased from94.1percent to91.4percent. This test increased the oil production and decreased the water ratio remarkably.