Oil and Gas Industry is focused on accelerating the development of innovative technologies that will allow exploration in deeper and/or harsher environments in an economical manner while reducing risks associated with developing new oil and gas fields. All of the key activities such drilling and completions, subsea and topside facility design and platform/riser design involve solving complex flow and heat transfer problems. Tridiagonal is actively involved in CFD, EFD and Software Development projects across the entire gamut of applications in the oil and gas industry. We work with owners, service companies, process equipment designers and EPC firms.

In drilling and completions segment, Tridiagonal can assist with design evaluation of downhole tools including heat transfer in complex downhole electronics. Cuttings transport and their erosional impacts and pressure drop & shear stress estimation when flowing complex non-Newtonian fluids have also been studied. Inflow Control Devices and Subsurface Control valves have been analyzed for pressure drop and erosion.

Subsea heat transfer studies on manifolds and trees and multiphase flow distribution including sand distribution in complex piping networks and design evaluation of subsea systems are actively conducted at Tridiagonal. On top side, design evaluation of process equipment’s such as separators and gas flotation cells have been conducted. Forces on structures due to sloshing in FPSO have been analyzed for our clients.

Safety studies of offshore structures focus on wind loading studies including identification of turbulence hot spots around helipad and gas dispersion studies to determine gas concentrations around the platform in the event of a leak.

Flow assurance is one of the key problem areas for the oil and gas industry. Tridiagonal is actively pursuing R&D projects in this area. We operate a multiphase flow and erosion testing facility. The erosion facility is unique in that studies can be conducted in 4-inch flow lines for gas velocities up to 50 m/s. Experiments can be conducted in both gas-solid and gas-liquid-solid flows. Using CFD methods to predict erosion has gained traction in the industry. However errors in prediction can be about 100% or more. Tridiagonal is actively involved in validating various published erosion model and improving these models.

In sand producing wells, the sand particles are typically transported by the liquid film. Predicting the velocities at which sand particles begin to roll and eventually lift off the pipe wall requires the liquid film velocities to be predicted accurately. Correlations have been developed to predict the velocities at which sand particles may be transported. However these correlations show a variability of several orders of magnitude. The R&D programs at Tridiagonal are focused on measuring the liquid film velocities and sand velocities and establishing scalable correlations for sand transport.

Accurate estimation of heat transfer rates and overall heat transfer coefficient is very critical during subsea flow line design to determine the possibility for flow assurance challenges. However correlations to estimate heat transfer in partially buried flow lines currently are error prone. Tridiagonal has developed improved correlations to estimate heat transfer coefficients. This is now available as a software tool.

Tridiagonal operates a state of the art test facility to conduct erosion tests in gas-solid and gas-liquid-solid flows. The facility can achieve up to 45 m/s gas velocities in pipe sizes up to 6 inches. An in house developed sand injection system allows controlled injection of sand particles and sand fines for particle sizes ranging from 10 to 450 microns. High precision ultrasonic thickness gauge, also developed in house, is used to reliably measure wall thickness loss. Piping sections mimicking subsea and top side lay outs can be set up and analyzed for erosion. Recent projects have focused on erosion in sand fines, wet gas and undeveloped flows created by chokes or elbows in series.

Case Studies