Laboratory Study And Numerical Simulation On Sand Control In Unconsolidated Sandstones By Chemical Fluid Injection And Hydraulic Fracturing

The production of sand is a challenge for the drilling,well completion,and production process on poorly or unconsolidated reservoirs,the problems arise when the production of sand accumulates in the production pipes until the erosion of surface equipment,in the worst case can be collapse the borehole,the characteristics of this type of sands,lower elastic modulus,high permeability and porosity,make a complex field for the sand control.Because of that,the choice is the use normally can be Screen and Gravel Pack,Frac&Pack,and use filter or slaves;but sometimes these treatments create mechanical restrictions.In this laboratory study,by consolidation of the sands through the injection of polymers,to create an annular space in the face area near the wellbore was simulated as a treatment for sand control for unconsolidated sandstones reservoirs.Firstly,the small artificial samples were tested after saturated with different proportions of epoxy resin.Showed through UCT improvements in the mechanical properties,and increase in compressive strength.But it was observed a positive skin factor due to the decrease of the permeability,to alleviate this near-wellbore damage,hydraulic fracturing was applied to generate a conductivity bypass with an extensive area of the formation and recover productivity.Then to evaluate well completion open hole by chemical injection,the samples of were prepared with different scales of quartz sand,illite,montmorillonite and water are mixed,according to the depth of typical unconsolidated sandstone reservoirs in the Bohai-China,the size of the samples is 100 mmxmm,while the permeability of the samples is either about 1000 m D.The experimental results showed that the samples without resin were completely saturated by the fracturing fluid and there is not a fracture propagation,and the wall of the wellbore there is not a control for sanding premature,while the best result for the treatment was only successful in samples with a resin injection ratio was 2:3,generating quasi-planar,single wing,and branching fractures,in the radius of consolidation of the core samples,showing to control the orientation of the fractures and a sand control on the wall of the wellbore in a circular area of 14-18 mm.To evaluate the conditions of hydraulic fracturing once the resin injection was applied,results were verified in a model simulated in Plaxis 6.8,to study the elasto-plastic deformation under the Mohr-Coulomb failure criterion and Abaqus CAE,defined traction-separation laws to determine the impact of creation and propagation of fracture in poorly consolidated sands with chemical treatment for sand control.