Investigation of the influence of gravel stuffing in an open drill on the productive characteristics of the well

Abstract

The negative consequences of sand production from the formation into the wellbore during the operation of wells with unstable rocks are characterized. A highly effective method of preventing sand from entering the well from the formation is the use of gravel packs, which are used in Ukraine and abroad. The types of gravel packs, the conditions for their application, the choice of the diameter of gravel grains for creating gravel pack are given. The types of gravel pack installation are considered depending on the geological and technical conditions of the reservoir. Calculations have been performed using Schlumberger's PipeSim software to assess the effect of gravel pack size and permeability on the performance specification of a gas well. Based on the research results, graphical de-pendences of gas flow rates in the presence of gravel pack on the permeability of the gravel pack at its various thicknesses have been constructed and analyzed. It has been found that the gas flow rate increases with an increase in the thickness of the gravel pack in the considered interval of its variation up to 0.9 m. The effect of the thickness of the gravel pack on the gas flow rate increases with an increase in its permeability. Based on the results of statistical processing of the calculated data using the least-squares method, the optimal values of the gravel pack permeability for various values of its thickness have been determined. The optimal values of the thickness and permeability of the gravel pack have been determined, beyond which the value of the gas flow rate practically does not change. The calculation of the pressure distribution along the bore of a gas well in the presence of gravel pack with certain optimal values of its permeability and thickness is performed. Using the PipeSim software, the influence of the de-gree of relative formation penetration on the productivity of a gas well in the presence of gravel packing has been investigated for determining certain optimal values of permeability and thickness of gravel packing.