New Experimental Correlations to Predict Proppant Distribution BetweenPerforation Clusters Using Low Viscosity Fluids in a Horizontal Wellbore

摘要

Hydraulic fracturing is a widely applied technology to increase recoverable reserves and accelerateproduction in low permeability reservoirs.In this technique,the hydraulic fractures are generated bypumping a fracturing fluid at a high flow rate and introducing proppant with the fluid to keep the fracturesopen after the pumping is halted.In horizontal well fracturing,one of the most important factors in thismethod is the proppant transport and distribution in the wellbore and among perforation clusters.Unevenproppant distribution between multiple clusters/fractures can cause a drop in the near-wellbore fractureconductivity,which in turn causes a negative impact on the production performance of the hydraulicfractures.This paper presents new experimental correlations that were developed and can be utilized topredict the proppant distribution between subsequent perforation clusters.The experimental correlations were developed using dimensional analysis from appropriate experimentaldata.The experimental data for this study was obtained from a horizontal wellbore apparatus with threeperforation clusters at shot densities of 4 SPF with 90-degree phasing.Several experimental tests wereconducted on 20/40 and 40/70 for white sand(SG of 2.65)and ultra-light weight ceramic(SG of 2.0)usingfreshwater fluids at three flow rates and over a wide range of proppant concentrations.Four types of experimental correlations were developed by experimentally investigating the effect ofeach parameter on the proppant distribution between the three perforation clusters.The first correlationtype developed is based on the proppant concentration,while the second type is based on the flow rateand proppant concentration.The third correlation type includes the particle median diameter as anotherindependent variable,along with the flow rate and proppant concentration.The fourth and final correlationdeveloped consists of the proppant density along with the proppant median diameter,flow rate and proppantconcentration as its independent variables.This fourth and final correlation was validated by comparingthe predicted values to the laboratory values.The results of correlation analysis comparison to lab datashow that the 20/40 and 40/70 ULW ceramic showed the lowest average error values at 2.92% and 1.56%,respectively,while the 20/40 and 40/70 white sand transport predictions were reasonable(average errorrange of 3.67%-11.67%).The low error values indicate the high reliability of the developed correlationsin predicting the proppant distribution between perforation clusters.To the authors'knowledge,the developed correlations are the first of their kind to be based onexperimental data.These correlations can help to determine the optimum flow rate that is required to attaineven distribution of the proppant and provide more insight about the anticipated proppant distribution intoand out of perforation clusters.