Advanced Computational Simulations for Upstream Oil & Gas Applications

Abstract

The complex downhole tools in upstream oil & gas industry are subjected to internal and external pressure due to variety of fluids ranging from drilling mud to reservoir fluids which dictates downhole tool performance in the well bore. Extensive laboratory testing is needed to quantify the downhole tool performance which can be cost and time intensive process. An alternative approach is to conduct numerical simulations to investigate the real operating scenarios and predict the downhole tool performance including high pressure high temperature (HPHT) conditions which are difficult to set up in laboratory environment. The objective of this work is to underscore importance of advanced simulation technology in evaluating down-hole tool performance. To attest usage of simulations two examples are presented, the first one is utilization of computational fluid dynamic (CFD) simulations to analyze the performance of flow regulation inflow control device (ICD) for challenging multi-phase flow operations to predict onset of cavitation and second is to analyze the hold-down slip indentation dynamic operation using advanced explicit finite element simulation methodology.

The completions ICD tool aids in maintaining uniform inflow of production fluid in horizontal and deviated wellbores by providing pressure drop utilizing nozzles. Advanced flow modeling is critical to understand the flow behavior through ICD and check for onset of phase change/cavitation of the production fluid. Three dimensional CFD simulations are conducted using pressure based algorithm for numerically solving mixture multi-phase model coupled with Reynolds-Averaged Navier-stokes (RANS) equation and k-ε turbulence model to predict onset of cavitation for given operating conditions.

The dynamic hold down slips operation is important to set up a packer and during this step casing gets indented with the carbide buttons. The setting up of slips can cause localized permanent deformation in the casing and estimating the setting force along with hanging load capacity of the slip system is important to avoid permanent damage to the casing. Three dimensional explicit non-linear FEA is conducted to predict the stresses and deformations in the casing.

Multi-phase simulations for ICD are conducted with different nozzle configurations and operating conditions. CFD results highlighted velocities, pressure drop through ICD and also indicated onset of cavitation for provided operating conditions. Advanced modeling results helped in configuring the ICD and operating conditions to avoid cavitation.

FEA conducted for hold-down slip predicted the load needed to cause ~0.030" button indentation on casing and also provided insights in collapse analysis of the casing. A detailed presentation of the stress field helped in identifying the loading limits for this system and also probable failure locations due to loading. Advanced simulations helped in assessing the downhole tool performance for given operating envelopes and provided critical insights that delivered confidence in utilizing these tools for field operations.