Calculation model for moderate sanding production of horizontal wells in unconsolidated sandstone reservoir

To calculate the pressure and output of the horizontal wells in unconsolidated sandstone reservoirs,this paper takes the wellbore from reservoir to the production section of the horizontal well during sand producing as the research subject,builds the analysis model of sanding characteristic parameters by employing the engineering approach.Based on the solution formula for pressure drop of conventional horizontal wellbore,the deduces and establishes the calculation model for pressure drop of horizontal wellbore turning into mass flow during sand producing and the counting model coupled with the inflow performance relationship for horizontal wells.What’s more,computational analysis is conducted by applying these three models and characteristic curves of such important variables as wellbore pressure drop,flow rate and sand density,etc.,are obtained.The heterogeneous regularity of the fluid parameters is indicated as well.It is proposed that the danger sand-settling points be calculated on the basis of the parameters of flow rate and density in real production and evaluation.The research is significant to evaluate the ultimate productivity of the production methods for moderate sand control of the horizontal wells in unconsolidated sandstone reservoir and select parameters for practical application.