Research Of Digital Pore Structure On Remaining Oil Distribution After Polymer Flooding

Recently,the research of digital pore has been a hot topic for science researcher. Through the digital pore which accords with the real pore structure, fluid displacement model can be established. Then,the research of pore structure parameters and the polymer injection parameters on the recovery and the remaining oil distribution can be done quantitatively. Compare to experiment in the lab, the simulation of digital pore does not take too long and will be cheaper. What’s more, the method of digital pore can consider the pore structureparameters, which is difficult to experiment in the lab.Pore throat radius distribution frequency can be obtained by pressing mercury experiment. The coordination number can be measured by CT scan and wettability can also be got by wettability index. Based on the experiment above, considering pore-throat ratio and shape factor, using self-adaption porosity principle, digital pore can be established after fitting of permeability.Using fluid mechanics and seepage mechanics, the saturated oil model and water flooding model will be established.On the basis of polymer flowing characters representation, polymer flooding model will also be established.Through the digital pore, the influence of pore structure parameters and polymer injection parameters on recovery and remaining oil can be studied.The results showed that: When different model water flooding end with same injection PV, polymer flooding recovery will be higher with coordination number increasing and remaining oil will be fewer. When different model water flooding end with same recovery, polymer flooding recovery will be higher with shape factor increasing and the throat with remaining oil will be fewer. When different model water flooding end with same water cut, polymer flooding recovery will be higher with pore-throat ratio decreasing and the pore with remaining oil will be fewer. When different model water flooding end with same water cut, polymer flooding recovery will be higher with the ratio of water-wet throat increasing and remaining oil will be fewer. Increasing the molecular weight or the concentration or relaxation time of polymer, the recovery of polymer flooding will be higher. The areatus remaining oil will increase and single remaining oil will decrease. When the concentrations of polymer fluid are identical and themolecular weightsof polymer fluid are different, polymer flooding recovery will be higher with inaccessible pore volume measured. When the concentrations of polymer fluid are different and themolecular weightsof polymer fluid are identical, polymer flooding recovery will be higher with polymer adsorption measured. When decreasing interfacial tension, polymer flooding recovery will be higher.