Change and Characterization Method of Formation Sand from Reservoir to Wellbore

Abstract The factors affecting sand production in weakly consolidated reservoir include formation characteristics, well completion and production parameters, etc. The flow space of oil and sand includes porous media, sand control media and production wellbore, which is continuous in space (reservoir - bottom hole - wellbore). In view of the key problems of sand production management, the concept of integration in the sand control completion project is applied to carry out the research on the sand particle change law in the whole flow area from the reservoir to the wellbore. A fractal dimension of the formation sand particle size which reflects the distribution characteristics is proposed to depict the migration change law of the formation sand from the reservoir to the wellbore production system. CFD-DEM (Computational Fluid Dynamics - Discrete Element Method) simulation method is conducted to study the micro sand blocking process of slot screen and a prediction model for cumulative sand production quality and particle size distribution were established. This article studies the filtration of sand control media and the migration law of sand particles in the wellbore. Considering the influence of sand particle size distribution characteristics on solid-liquid two-phase flow, a horizontal wellbore sand concentration prediction model was established based on single factor analysis method and Buckingham's theorem. The influence of different flow conditions on the sand concentration in the wellbore section was revealed. The innovation of the paper is introducing the fractal dimension of sand particles into the establishment of quantitative sand production prediction models and wellbore sand concentration models.