Reasearch And Application Of The Capability Of Liquid Removal And Sand Removal Of Unconsolidated Sandstone Gas Field

The reservoir sandstone of the unconsolidated sandstone gas field in the northwest of china is a set of strata whose development is.affected by geological structure and slightly by lithology.Moreover,the reservoir sandstone is clastic reservoir which have the properties of stable distribution,high mud content,poor diagenesis,fine petrophysics and strong heterogeneity.The strata mainly consist of silt,politic siltstone,a small amount of fine sandstone,high porosity and permeability for the development of the reservoir sandstone is at the stage of early diagenetic.This gas field with loose strata lithology and poor cementation has a multi gas-water system and is surrounded by edge water.Thus,the phenomena of producing water,liquid loading and sanding of gas well is quite common during the development of this consolidated sandstone gas field,especially at the stage of the production of gas well.Through the investigation of the removal model of liquids and sands in gas wells,this paper analyzed and compared the liquid removal model,related theory evidence and scope of application of predecessors for liquid loading in the wellbore of gas well during the development of this unconsolidated sandstone gas field.Furthermore,a new liquid removal model that revised the force analysis in natural gas current with high velocity and the shape factor of droplet is derived on the basis of the force analysis of droplet in gas flow with high velocity and the shape analysis of droplet,combined with the energy balance theory.The validity and applicability are verified through the calculation of more than 6000 field data of liquid loading of the unconsolidated sandstone gas field in the northwest of china.Besides,based on the sanding mechanism of unconsolidated sandstone gas field and combined with the analysis of sanding statistical data of production in gas wells,this paper also investigated the influences of the gas well production,the pressure differential of production and the permeability of the strata on sanding.Thus,a novel method to predict sanding of a gas well is constituted and verified.As this paper focused on the mechanism and regularity of liquid loading and sanding,the obtained models can be applied for the forecast of liquid loading and sanding,which provides fundamental basis for the optimization of production allocation of gas well and the settlement of liquid loading and sanding.