Optimization Of Horizontal Well Pipe Within The Gravel Pack Completion Parameters

More and more horizontal wells are used to develop unconsolidated sandstone reservoir with the technological development and improvement of horizontal well, extended reach well and multi-branched well. However, we must face sandcontrol of those horizontal wells for developing unconsolidated sandstone reservoir. Horizontal well completion for sandcontrol include open hole gravel pack, inside casing gravel pack and screen or concentric screen. However, inside casing gravel pack completion is the best way of well completion system for sand control. Skin factor general formula and skin factor of inside casing gravel pack were derived. According to Joshi's productivity model, the productivity equation of horizontal well by inside casing gravel pack completed was given and analyzed the single factor and multi-factor.According comprehensive model of perforating horizontal well and the Green's functions and source function solutions, the reservoir pressure response due to the 3D convergence of flow toward perforations were developed, then the reservoir pressure response of inside casing gravel pack was derived by the pressure drop difference of fluid passing the perforation and gravel packing.The mass conservation equation, momentum conservation equation and assistant equation were made up numerical former of describing horizontal well gravel packing, and this model described the sand bed's height and length diversity with packing time increasing. The model also has considered the filtration of carrying fluid to stratum, and optimized the building parameters of inside casing gravel packing by the programmer which composed by those model. According orthogonal tests, the impact trend of packing effectiveness by the mortar delivery volume, carrying fluid viscosity, gravel concentration and washing and screen rate was been found. The optimization of construction parameters can be used to guiding the field practice, and form the builder's effectiveness, single well daily fluid production increased 22.3m~3, the sand content of well mouth test less than 0.01%.