Study On The Flow Conductivity Of Ultra-light Density Proppant For Polymer Material

The proppant is the key material in fracturing operation of oil and gas wells.The higher the density of proppant,the higher the requirement of suspended sand performance of fracturing fluid,and the more difficult it is to transport.Low density proppant has always been a highly valued research content in the industry.In this paper,an ultra-light density proppant is studied.The main component of the proppant is polystyrene organic polymer.Because of the physical and chemical properties of polymer materials,the properties of polymer proppant are different from those of conventional ceramic proppant.In this paper,Carman-Kozeny formula and Hertz elastic contact theory are used to calculate the stress and deformation of proppant in fracture.A fracture conductivity model for polymer proppant with deformation characteristics is established.The influence of proppant parameters and formation parameters on fracture conductivity is analyzed.The physical properties and flow conductivity of ultra-light density proppant for polymer materials,ceramsite proppant and ultra-hydrophobic coated ceramsite proppant were measured and compared,and the theoretical model of conductivity was verified.The experimental results show that the ultra-light density proppant of polymer materials is under the same conditions.Any increase in particle size,sand concentration,elastic modulus of proppant and elastic modulus of reservoir will result in greater conductivity.The influence of formation and proppant Poisson ratio on fracture conductivity is negligible.The above factors are consistent with the model analysis.When the displacement fluid is water and oil phase,the flow conductivity of ceramsite proppant decreases the most with the increase of closing pressure,compared with that of coated ceramsite proppant and polymer material proppant.When the closing pressure is lower than 38 MPa,the oil phase conductivity of superhydrophobic coated ceramsite is the best,while the water phase is vice versa.The water phase conductivity of polymer proppant is lower than that of oil phase,and the single phase flow conductivity is much larger than that of two phases.When the closing pressure is higher than 65 Mpa,it still has a certain oil phase and water phase flow conductivity.The conductivity of proppant filling layer decreases gradually with the increase of temperature,and the conductivity of polymer proppant changes obviously at high temperature,and the resistance to high temperature is much lower than that of ceramsite proppant.The application results of three wells in the field show that the daily oil production of the test wells with ultra-light density proppant of polymer materials is higher than that of the conventional wells with corresponding horizon.The average dosage of proppant in test well is less than 19.14%,and it has better effect of increasing production.